Academic literature on the topic 'Nanomateriale'
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Journal articles on the topic "Nanomateriale"
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Lobnik, Aleksandra, Marijana Lakić, Aljoša Košak, Matejka Turel, and Špela Korent Urek. "Introduction to Nanomaterials for Use in Textiles." Tekstilec 56, no. 2 (June 10, 2013): 137–44. http://dx.doi.org/10.14502/tekstilec2013.56.137-144.
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S, Lakshmana Prabu. "Toxicity Interactions of Nanomaterials in Biological System: A Pressing Priority." Bioequivalence & Bioavailability International Journal 6, no. 2 (July 15, 2022): 1–6. http://dx.doi.org/10.23880/beba-16000173.
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Nanomaterials have made a rebellion in biomedical application especially treating several diseases due to its distinctive compositions. However, increased utilization of nanomaterials in biomedical applications has made an initiative to understand the possible interaction between the nanomaterials with the biological systems. These tiny particles enter into the body very easily and affect vulnerable systems which raise the interrogation of their potential effects on the susceptible organs. It is very crucial to comprehend the various exposure pathways, their movement, behavior and ultimate outcome. Specific and unique physicochemical properties, such as particle size and distribution, surface area, charge and coatings, particle shape/ structure, dissolution and aggregation, influence the nanomaterial interactions with cells. Toxicities in biological systems occurs as a result of a result of a variety of reasons including the production of ROS reactive oxygen species, degradation of the integrity of membrane and release of toxic metal ions thus preventing normal cell function. Various researchers have provided promising evidence that nanomaterial’s actively encompass and mediate chemical processes of cell, in addition to their passive interactions with cells. Certainly, it is very much essential to understand the possible toxic interactions of nanomaterial’s with the biological system as Nano toxicology. In this review, we emphasize the toxicological effects on different organs pertaining to nanomaterial-biological system interaction
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Zhang, Yanli, Qiang Zhang, Xiangming He, Li Wang, Jingxin Wang, Liangliang Dong, Yingpeng Xie, and Yongsheng Hao. "A Novel Sugar-Assisted Solvothermal Method for FeF2 Nanomaterial and Its Application in LIBs." Materials 16, no. 4 (February 8, 2023): 1437. http://dx.doi.org/10.3390/ma16041437.
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Due to its quite high theoretical specific-energy density, FeF2 nanomaterial is a good candidate for the cathode material of high-energy lithium-ion batteries. The preparation of FeF2 nanomaterial is very important for its application. At present, the preparation process mostly involves high temperature and an inert atmosphere, which need special or expensive devices. It is very important to seek a low-temperature and mild method, without the need for high temperature and inert atmosphere, for the preparation and following application of FeF2 nanomaterial. This article reports a novel sugar-assisted solvothermal method in which the FeF3∙3H2O precursor is reduced into FeF2 nanomaterial by carbon derived from the dehydration and condensation of sugar. The obtained FeF2 nanomaterials are irregular granules of about 30 nm, with inner pores inside each granule. Electrochemical tests show the FeF2 nanomaterial’s potential as a lithium-ion battery cathode material.
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Gulumian, Mary, and Charlene Andraos. "In Search of a Converging Cellular Mechanism in Nanotoxicology and Nanomedicine in the Treatment of Cancer." Toxicologic Pathology 46, no. 1 (October 15, 2017): 4–13. http://dx.doi.org/10.1177/0192623317735776.
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Multiple applications of nanomaterials have raised concern with regard to their toxicity. With increasing research into nanomaterial safety, mechanisms involved in the toxic effects of nanomaterials have begun to emerge. The importance of nanomaterial-induced lysosomal membrane permeabilization through overloading or direct damage of the lysosomal compartment, resulting in the blockade of autophagosome–lysosome fusion and autophagy dysfunction, as well as inflammasome activation were cited as emerging mechanisms of nanomaterial toxicity. It has recently been proposed that these very mechanisms leading to nanomaterial toxicity may be utilized in nanotherapeutics. This review discusses these nanomaterial-induced mechanisms in detail and how it has been exploited in cancer research. This review also addresses certain considerations that need to be kept in mind when using nanomaterials in therapeutics.
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Card, Jeffrey W., and Bernadene A. Magnuson. "A Method to Assess the Quality of Studies That Examine the Toxicity of Engineered Nanomaterials." International Journal of Toxicology 29, no. 4 (July 2010): 402–10. http://dx.doi.org/10.1177/1091581810370720.
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As reports on the safety of various nanomaterials have yielded conflicting results, assessment of the reliability of each study is required to objectively interpret overall safety of the nanomaterial. A 2-step method to assess the quality of nanotoxicity studies is described. The first step uses a publicly available tool to rank the reliability of the study based on adequacy of design and documentation of methods, materials, and results, providing a “study score.” The second step determines the completeness of physicochemical characterization of the nanomaterial/nanomaterials assessed within the study, providing a “nanomaterial score.” This approach is encouraged to promote the notion that for studies conducted with nanomaterials, the combination of a reliable study and sufficient nanomaterial characterization is of significantly greater value than either of these alone. It is anticipated that the use and evolution of this approach will assist with the design and interpretation of studies assessing nanomaterial toxicity.
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Wang, Jiali, Guo Zhao, Liya Feng, and Shaowen Chen. "Metallic Nanomaterials with Biomedical Applications." Metals 12, no. 12 (December 12, 2022): 2133. http://dx.doi.org/10.3390/met12122133.
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Metallic nanomaterials have attracted extensive attention in various fields due to their photocatalytic, photosensitive, thermal conducting, electrical conducting and semiconducting properties. Among all these fields, metallic nanomaterials are of particular importance in biomedical sensing for the detection of different analytes, such as proteins, toxins, metal ions, nucleotides, anions and saccharides. However, many problems remain to be solved, such as the synthesis method and modification of target metallic nanoparticles, inadequate sensitivity and stability in biomedical sensing and the biological toxicity brought by metallic nanomaterials. Thus, this Special Issue aims to collect research or review articles focused on electrochemical biosensing, such as metallic nanomaterial-based electrochemical sensors and biosensors, metallic oxide-modified electrodes, biological sensing based on metallic nanomaterials, metallic nanomaterial-based biological sensing devices and chemometrics for metallic nanomaterial-based biological sensing. Meanwhile, studies related to the synthesis and characterization of metallic nanomaterials are also welcome, and both experimental and theoretical studies are welcome for contribution as well.
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Kim, Jeongho, and Il Je Yu. "National Survey of Workplaces Handling and Manufacturing Nanomaterials, Exposure to and Health Effects of Nanomaterials, and Evaluation of Nanomaterial Safety Data Sheets." BioMed Research International 2016 (2016): 1–10. http://dx.doi.org/10.1155/2016/8389129.
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A national survey on workplace environment nanomaterial handling and manufacturing was conducted in 2014. Workplaces relevant to nanomaterials were in the order of TiO2(91), SiO2(88), carbon black (84), Ag (35), Al2O3(35), ZnO (34), Pb (33), and CeO2(31). The survey results indicated that the number of workplaces handling or manufacturing nanomaterials was 340 (0.27% of total 126,846) workplaces. The number of nanomaterials used and products was 546 (1.60 per company) and 583 (1.71 per company), respectively. For most workplaces, the results on exposure to hazardous particulate materials, including nanomaterials, were below current OELs, yet a few workplaces were above the action level. As regards the health status of workers, 9 workers were diagnosed with a suspected respiratory occupational disease, where 7 were recommended for regular follow-up health monitoring. 125 safety data sheets (SDSs) were collected from the nanomaterial-relevant workplaces and evaluated for their completeness and reliability. Only 4 CNT SDSs (3.2%) included the term nanomaterial, while most nanomaterial SDSs were not regularly updated and lacked hazard information. When taken together, the current analysis provides valuable national-level information on the exposure and health status of workers that can guide the next policy steps for nanomaterial management in the workplace.
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Ma, Haohua, Xin Qiao, and Lu Han. "Advances of Mussel-Inspired Nanocomposite Hydrogels in Biomedical Applications." Biomimetics 8, no. 1 (March 22, 2023): 128. http://dx.doi.org/10.3390/biomimetics8010128.
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Hydrogels, with 3D hydrophilic polymer networks and excellent biocompatibilities, have emerged as promising biomaterial candidates to mimic the structure and properties of biological tissues. The incorporation of nanomaterials into a hydrogel matrix can tailor the functions of the nanocomposite hydrogels to meet the requirements for different biomedical applications. However, most nanomaterials show poor dispersion in water, which limits their integration into the hydrophilic hydrogel network. Mussel-inspired chemistry provides a mild and biocompatible approach in material surface engineering due to the high reactivity and universal adhesive property of catechol groups. In order to attract more attention to mussel-inspired nanocomposite hydrogels, and to promote the research work on mussel-inspired nanocomposite hydrogels, we have reviewed the recent advances in the preparation of mussel-inspired nanocomposite hydrogels using a variety of nanomaterials with different forms (nanoparticles, nanorods, nanofibers, nanosheets). We give an overview of each nanomaterial modified or hybridized by catechol or polyphenol groups based on mussel-inspired chemistry, and the performances of the nanocomposite hydrogel after the nanomaterial’s incorporation. We also highlight the use of each nanocomposite hydrogel for various biomedical applications, including drug delivery, bioelectronics, wearable/implantable biosensors, tumor therapy, and tissue repair. Finally, the challenges and future research direction in designing mussel-inspired nanocomposite hydrogels are discussed.
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Qu, Juntian, and Xinyu Liu. "Recent Advances on SEM-Based In Situ Multiphysical Characterization of Nanomaterials." Scanning 2021 (June 9, 2021): 1–16. http://dx.doi.org/10.1155/2021/4426254.
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Functional nanomaterials possess exceptional mechanical, electrical, and optical properties which have significantly benefited their diverse applications to a variety of scientific and engineering problems. In order to fully understand their characteristics and further guide their synthesis and device application, the multiphysical properties of these nanomaterials need to be characterized accurately and efficiently. Among various experimental tools for nanomaterial characterization, scanning electron microscopy- (SEM-) based platforms provide merits of high imaging resolution, accuracy and stability, well-controlled testing conditions, and the compatibility with other high-resolution material characterization techniques (e.g., atomic force microscopy), thus, various SEM-enabled techniques have been well developed for characterizing the multiphysical properties of nanomaterials. In this review, we summarize existing SEM-based platforms for nanomaterial multiphysical (mechanical, electrical, and electromechanical) in situ characterization, outline critical experimental challenges for nanomaterial optical characterization in SEM, and discuss potential demands of the SEM-based platforms to characterizing multiphysical properties of the nanomaterials.
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Kladko, Daniil V., Aleksandra S. Falchevskaya, Nikita S. Serov, and Artur Y. Prilepskii. "Nanomaterial Shape Influence on Cell Behavior." International Journal of Molecular Sciences 22, no. 10 (May 17, 2021): 5266. http://dx.doi.org/10.3390/ijms22105266.
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Nanomaterials are proven to affect the biological activity of mammalian and microbial cells profoundly. Despite this fact, only surface chemistry, charge, and area are often linked to these phenomena. Moreover, most attention in this field is directed exclusively at nanomaterial cytotoxicity. At the same time, there is a large body of studies showing the influence of nanomaterials on cellular metabolism, proliferation, differentiation, reprogramming, gene transfer, and many other processes. Furthermore, it has been revealed that in all these cases, the shape of the nanomaterial plays a crucial role. In this paper, the mechanisms of nanomaterials shape control, approaches toward its synthesis, and the influence of nanomaterial shape on various biological activities of mammalian and microbial cells, such as proliferation, differentiation, and metabolism, as well as the prospects of this emerging field, are reviewed.
Dissertations / Theses on the topic "Nanomateriale"
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Souza, Caio Guilherme Secco de. "Nanomateriais luminomagnéticos visando aplicações biológicas: síntese, propriedades, funcionalização e estabilidade coloidal." Universidade de São Paulo, 2015. http://www.teses.usp.br/teses/disponiveis/75/75134/tde-11082015-090833/.
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Neste trabalho, foi realizado um estudo da obtenção de nanomateriais luminomagnéticos visando potenciais aplicações biológicas, a partir de dois diferentes tipos de estruturas, sendo elas: a formação de heteronanoestruturas luminomagnéticas de NPM de FePt/Fe3O4-CdSe recobertas com sílica; e a formação de nanomateriais luminomagnéticos por ligação covalente entre NPM de FePt/Fe3O4-Dopa-PIMA-PEG-NH2 e pontos quânticos de CdSe/ZnS-LA-PEG-COOH. Para o primeiro tipo de nanomaterial citado, foram testadas duas metodologias para obtenção das heteronanoestruturas: a mudança da estabilidade coloidal pela adição de pequenas quantidades de NaCl no meio contendo as NPM e os pontos quânticos previamente sintetizados; e o método de injeção a quente do precursor de selênio em um meio contendo as NPM como sementes, o precursor de cádmio e os agentes de superfície. O método de injeção a quente foi o que apresentou melhores condições para a formação das heteronanoestruturas. Para providenciar estabilidade coloidal em meio aquoso e superfície com biocompatibilidade, foi realizado o recobrimento com sílica na superfície das heteronanoestruturas luminomagnéticas com melhores condições. Para essa amostra, o tamanho médio obtido foi de 25,0 nm, com polidispersividade de 8,4 %, Ms = 11,1 emu.g-1 e comportamento superparamagnético, além de duas bandas de emissão (com excitação de 400 nm) centradas em 452 nm e 472 nm, respectivamente. Já para o segundo tipo de nanomaterial obtido neste trabalho, foram primeiramente obtidas NPM de FePt/Fe3O4 pelo método do poliol modificado acoplado à metodologia do crescimento, e pontos quânticos luminescentes de CdSe/ZnS pelo método de decomposição térmica de precursores organometálicos, sendo que ambas nanoestruturas apresentaram superfície hidrofóbica. Para a troca de ligantes para transferência das nanoestruturas para a fase aquosa e para providenciar biocompatibilidade visando aplicações biológicas, foram previamente preparados ligantes poliméricos de Dopa-PIMA-PEG-NH2 para recobrimento das NPM e de LA-PEG-COOH para recobrimento dos pontos quânticos. A conjugação química entre as nanoestruturas de FePt/Fe3O4-Dopa-PIMA-PEG-NH2 e CdSe/ZnS-LA-PEG-COOH foi realizada pelo método da carbodiimida em solução aquosa para a formação de uma ligação covalente amida entre os grupos amina e carboxilato em cada uma das nanoestruturas. Os nanomateriais luminomagnéticos obtidos apresentaram estabilidade coloidal em meio aquoso, com estreita distribuição de tamanho, apresentando RH de 79,96 nm, Ms de, aproximadamente, 10 emu.g-1 com coercividade e remanência quase nulos e intensa banda de emissão centrada em 580 nm. Espera-se que os nanomateriais obtidos neste trabalho possam ser promissores nanomateriais com propriedades multifuncionais para potenciais aplicações biológicas.Here, luminomagnetic nanomaterials were obtained for potential biological applications. We have studied two different types of luminomagnetic nanomaterials, which are: formation of silica-coated FePt/Fe3O4-CdSe heteronanostructures; and formation of luminomagnetic nanomaterials from covalent bond between FePt/Fe3O4-Dopa-PIMA-PEG-NH2 magnetic nanoparticles and CdSe/ZnS-LA-PEG-COOH luminescent quantum dots. For the first type of luminomagnetic nanomaterials obtained, two methodologies were studied for formation of heteronanostructures, which are: modification of colloidal stability by addition of small amounts of NaCl into a solution with hydrophobic magnetic nanoparticles and luminescent quantum dots; and hot injection method of selenium precursor into a solution with magnetic nanoparticles seeds, cadmium precursors and surface agents. The hot injection method obtained better results than the other method studied for formation of heteronanostructures. To provide colloidal stability in aqueous solution and biocompatibility, the heteronanostructures were coated using silica shell. After silica coating, the heteronanostructures showed average diameter of 25 nm and polidispersivity of 8.4%, with Ms = 11.1 emu.g-1 and superparamagnetic behavior. Moreover, these nanomaterials showed two emission peaks centered at 452 and 472 nm. For the second type of nanomaterials obtained, FePt/Fe3O4 magnetic nanoparticles were synthesized by modified polyol method coupled to seeded-mediated growth, and CdSe/ZnS luminescent quantum dots were obtained by thermal decomposition of organometallic precursors. For the ligand exchange to transfer the nanostructures from organic media to aqueous solution, were used Dopa-PIMA-PEG-NH2 and LA-PEG-COOH polymers to provide colloidal stability and biocompatibility on magnetic nanoparticle surface and quantum dot surface, respectively. The chemical conjugation between FePt/Fe3O4-Dopa-PIMA-PEG-NH2 and CdSe/ZnS-LA-PEG-COOH nanostructures was obtained by EDC coupling in aqueous solution, which linked amine and carboxylate groups in each nanostructure to provide the formation of amide bond. The luminomagnetic nanomaterials obtained showed colloidal stability in aqueous solution, narrow size distribution, with RH equal to 79.96 nm, MS around 10 emu.g-1 with low coercivity and remanent magnetization, and intense emission peak centered at 580 nm. We expect these luminomagnetic nanomaterials be promisor nanomaterials with multifunctional properties for potential biological applications.
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Ahmad, Abo Markeb Ahmad Mohamed. "Environmental applications of engineered nanomaterials: synthesis and characterization." Doctoral thesis, Universitat Autònoma de Barcelona, 2017. http://hdl.handle.net/10803/454768.
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Aquesta tesi es basa en el desenvolupament (síntesi) de diferents nanomaterials per a la seva aplicació com a materials adsorbents per a l'eliminació de contaminants en aigua (anions inorgànics, metalls pesats i pesticides) i per l'adsorció de gas metà. El desenvolupament dels diferents materials s'ha basat en una extensa recerca bibliogràfica de l'estat de l'art dels materials utilitzats actualment per a aquesta aplicació, i s'ha tractat de millorar l'eficiència del procés mitjançant l'ús de nanomaterials. Amb aquest objectiu s’han sintetitzat materials magnètics per diferents mètodes. En alguns casos, aquests han estat funcionalitzats amb grups orgànics per adaptar i/o millorar la seva funció d'adsorció o estabilitzar-los en suports (polímers, zeolites, esponges, etc.) per millorar la seva aplicació a una escala real en un futur. A més, es va desenvolupar un nou mètode per a la formació de nanopartícules core-shell amb un nucli de magnetita. Tots els nanomaterials sintetitzats s'han caracteritzat en profunditat, utilitzant les tècniques més avançades per a la caracterització dels nanomaterials. Tècniques com ara la microscòpia electrònica, difracció de raigs X, entre d'altres, permeten conèixer les característiques i propietats dels materials (mida, dispersió, estructura cristal·lina, etc.) i per tant concloure la seva contribució a l'eficàcia de cada un dels materials adsorbents.
Pel que fa als contaminants en aigua, el treball se centra en el fluorur, el fosfat, el nitrat, els metalls cadmi i níquel i pesticides, destacant l'obtenció de resultats excepcionals per a les nanopartícules de Ce-Ti@Fe3O4.
En el cas de tractament de gas, per una banda s'ha desenvolupat un nou nanomaterial basat en nanopartícules magnètiques estabilitzades en esponges de poliuretà que ha presentat resultats interessants per a l'adsorció de metà. A més, s'ha col·laborat amb la Institut Català de Nanotecnologia per a l'aplicabilitat dels Metal Organic Frameworks en l'oxidació de CO.
Una altra aplicació que s'ha donat a les nanopartícules magnètiques ha estat la seva utilització en la separació de algues procedents de processos de tractament d’aigües, per tal de substituir el procés actual de decantació.
Amb tot això, la tesi ofereix una gamma de nanomaterials per a diferents usos en enginyeria ambiental, amb la possibilitat d'investigar i desenvolupar en la seva aplicabilitat a gran escala. Amb aquesta finalitat, es proporcionen diferents solucions per a la millora del medi ambient.This thesis is based on the development (synthesis) of different nanomaterials for their application as adsorbent materials for the removal of pollutants from water (inorganic anions, heavy metals and pesticides) and for the adsorption of methane gas. The development of the different materials has been based on an extensive bibliographical search of the state of the art of the materials currently used for this application, and it has been tried to improve the efficiency of the process by using nanomaterials. Thus, magnetic (magnetite) nanoparticles are synthesized by different methods. These are functionalized with organic groups to adapt and/or improve their adsorption function or stabilize in supports (polymers, zeolites, sponges, etc.) to improve their application on a real scale. In addition, a new method for the formation of core-shell nanoparticles with a magnetite core is developed. All the synthesized nanomaterials have been characterized in depth, using the most advanced techniques for the characterization of nanomaterials. Techniques such as electron microscopy, X-ray diffraction, among others, allow to know the characteristics and properties of the materials (size, dispersion, crystallinity, structure, etc.) and thus conclude their contribution to the efficiency of their application with adsorbent material. As for the contaminants in water, the work focuses on fluoride, phosphates, nitrates, cadmium, nickel and pesticides, obtaining outstanding results for the nanoparticles of Ce-Ti @Fe3O4. In the case of gas treatment, on the one hand has developed a new nanomaterial based on magnetic nanoparticles stabilized in polyurethane sponges which present interesting results for the adsorption of methane and great applicability on a real scale. In addition, we have collaborated with the Institut Català de Nanotecnologia for the applicability of Metal Organic Frameworks in the oxidation of CO. Another application that has been given to magnetic nanoparticles has been its use to separate algae from wastewater treatment processes, in order to substitute the current sedimentation processes. With all this, the thesis offers a range of nanomaterials for different uses in environmental engineering, with the possibility of investigating and developing on its applicability on a large scale. To this end, different solutions are provided for the improvement of the environment.
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Russo, Lorenzo. "Designing advanced nanomaterials for next generation in vitro diagnostics: development of optical and electrochemical biosensors for determination of viral and bacterial infections based on hollow AuAg nanoparticles." Doctoral thesis, Universitat Autònoma de Barcelona, 2019. http://hdl.handle.net/10803/666751.
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En esta tesis doctoral. El dibujo racional de nanomateriales avanzados con propiedades controladas se aplicó para su empleo en biosensing, y condujo al desarrollo de dos plataformas diagnosticas para la determinación de infecciones virales y bacterianas. Primero, se desarrolló un método sintético altamente reproducible y robusto para la producción de nanoshells de una aleación AuAg monodispersas basado en remplazamiento galvánico. El protocolo descrito permite el controlo preciso sobre la morfología de las partículas, en términos de grosor de la capa externa y de tamaño del vacío interior, la composición relativa y distribución topológica de los metales noble constituyentes, y su rugosidad y porosidad superficial. Esta predictibilidad sintética, testeada sobre un rango de tamaños, se ha conseguido a través de un estudio sistemático de la relación entre de cada reactivo, juntos a una detallada caracterización de la composición y estructura del material con diferentes técnicas. Además, el análisis de las propiedades plasmonicas de las NSs de AuAg durante su transformación estructural, que se extiende por casi todo el espectro visible hasta las longitudes de ondas del Near-Infrared, reveló una dependencia estricta con sus características morfológicas y composicionales. Estos resultados, también confirmados con cálculos basados en la teoría de Mie, proveyeron la base para su aplicación como amplificadores de señal en un immunoensayo basado en SERS. Segundo, por la primera vez el comportamiento electroquímico de las NSs de AuAg fe reportado. Causado por la corrosión controlada de átomos de Ag contenidos en los núcleos residuales de las partículas y las capas finas de aleación, el estudio voltametrico de estos nanocristales vacíos se reveló fuertemente dependiente de su composición elemental relativa y, parcialmente, de su tamaño y morfología. Un efecto electrocatalitico peculiar apareció solamente para NSs de AuAg con un ratio Au/Ag suficiente para permitir la electrodeposición catalítica de Ag+ encima de la superficie de las partículas a potenciales menos negativos que el potencial de redacción estándar de Ag. Este comportamiento no previamente reportado está causado solo por el carácter levemente oxidante del electrolito utilizado, sin la necesidad de ningún otro co-reactivo u oxidante. Estos resultados constituyeron la base racional para desarrollar NSs de AuAg con propiedades desiderables para su aplicación en el ensayo electroquímico descrito. Aventajándose de las propiedades plasmonicas de las NSs de AuAg, el desarrollo de un ensayo immunocromatografico basad ene SERS para la detección sensible y cuantitativa de MxA, un biomarcador comúnmente asociado a infecciones virales, fue realizado. Gracias a las intensidades plasmonicas amplificadas enseñadas por las NSs de AuAg, resultante por el efecto de cavidad plasmonica comúnmente observado in nanoestructuras vacias, su superifices se portan como un continuo hot-spot, amplificando cualquier señal Raman emitido por reporters inmovilizados encima. Además, la posibilidad de ajustar precisamente la longitud máxima de LSPR de las NSs de AuAg de manera de coincidir con el láser NIR durante la mesura SERS permitió de mejorar la performance analítica. Entonces, las NSs de AuAg fueron fácilmente conjugadas con anticuerpos anti-MxA e integrados en un ensayo immunocromatografico para revelar su presencia en muestras de suero. Después de atenta optimización de los parámetros de la plataforma point-of-care, al proteína MxA pudo ser detectada a un limite de detección de pocos ng/mL. En fin, la capacidad de modular precisamente la composición elemental de las NSs de AuAg portó al diseño de un ensayo electroquímico para la detección rápida de dos bacterias modelos, Escherichia coli and Salmonella typhimurium. Las NSs de AuAg se utilizaron como reporters electroquímicos por la facilidad de generar la señal electroquímica, causada solamente por el carácter levemente oxidante de la matriz biológica. Por otro lado, el recubrimiento polimérico de las partículas confirió la interacción non específica basada en afinidad con las células bacterianas en solución, evitando de necesitar anticuerpos caros y frágiles. A través de esta estrategia de bajo coste, E.coli puso ser detectado en PBS a concentraciones de 102 CFU/mL, mientras también se consiguió la discriminación semi-selectiva de los perfiles corriente-concentración de las dos bacterias modelos.In this PhD thesis, the rational design of advanced nanomaterials with controlled properties was applied for their employment in biosensing, leading to the development of two diagnostic platforms for the determination of viral and bacterial infections. Firstly, a highly reproducible and robust synthetic method for the production of monodisperse AuAg alloy NSs based on GRR was developed. The protocol described allows the precise control over the particles’ morphology, in terms of shell thicknesses and void sizes, the relative composition and topological distribution of their constituting noble metals, as well as their surface roughness and porosity. This synthetic predictability, tested over a range of sizes, has been achieved through a systematic study of the convoluted interplay of each co-reagent, together with a detailed characterization of the material’s composition and structure through an array of techniques. Moreover, the analysis of AuAg NSs’ plasmonic properties evolution during their structural transformation, which spanned through almost the whole visible spectrum up to NIR wavelengths, revealed a tight dependence with their morphological and compositional features. These results, also confirmed by calculations based on Mie’s theory, provided the basis for their application as signal enhancers in the SERS-based LFA developed. Secondly, for the first time the electrochemical behavior of AuAg NSs was reported. Triggered by the controlled corrosion of Ag atoms contained in the particles’ residual cores and thin alloy shells, the voltammetric study of these hollow nanocrystals has been found to be strongly dependent on their relative elemental composition and, partially, to their size and morphology. Indeed, a peculiar electrocatalytic effect appeared only for AuAg NSs possessing a high-enough Au/Ag ratio to let the catalytic electrodeposition of Ag+ on the NSs’ surfaces occur at potentials less negative than Ag standard reduction one. Interestingly, this unreported feature was shown to be triggered only by the mild oxidating character of the electrolyte used, without the need of any other co-reagent or oxidizer. These findings constituted the rational basis for developing AuAg NSs with desirable properties to be applied in the electrochemical assay described. Taking advantage of the tunable plasmonic properties of AuAg NSs, the development of a SERS-based LFA for the sensitive and quantitative detection of MxA, a biomarker commonly associated to viral infections, was achieved. Thanks to the enhanced plasmons intensities displayed by AuAg NSs, resulting from the plasmonic cavity effect commonly observed in hollow nanostructures, their surfaces acted as a continuous hot-spot, amplifying any Raman signal emitted by the reporters thereby attached. Moreover, the possibility to precisely adjust AuAg NSs’ LSPR maximum wavelength to match the NIR excitation laser used during SERS measurements allowed to further improve the overall analytical performance. Thus, AuAg NSs were easily conjugated with anti-MxA antibodies and integrated in a LFA in order to reveal its presence in spiked serum samples. After careful optimization of the point-of-care platform parameters, MxA protein could be successfully detected down to the analytically-relevant LOD of few ng/mL. Finally, the capability to precisely modulate AuAg NSs elemental composition lead to the design of a proof-of-concept electrochemical assay for the rapid detection of two model bacterial strains, Escherichia coli and Salmonella typhimurium. AuAg NSs were used as electrochemical reporters because of the ease of generation of the electrochemical signal, triggered by the sole mild oxidating character of the biological sample matrix. Besides, the polymeric coating of the hollow particles provided the non-specific, affinity-based interaction with bacterial cells in solution, avoiding the need for costly and fragile antibodies. With this low-cost strategy, E.coli could be detected in PBS down to 102 CFU/mL, while the semi-selective discrimination of the current-concentration profiles of the two model bacterial strains was also achieved.
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Spångberg, Christian. "En studie om regleringen av nanomaterial : - i The Toxic Substances Control Act (TSCA) och Registration, Evaluation, Authorisation and Restriction of Chemicals (REACH)." Thesis, Uppsala universitet, Juridiska institutionen, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-327381.
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LEPORE, EMILIANO. "An experimental study on adhesive or antiadhesiveand strong bio-inspired nanomaterials." Doctoral thesis, Politecnico di Torino, 2012. http://hdl.handle.net/11583/2498977.
Full textAbstract:
This experimental PhD thesis presents the results of research performed in five different facilities: in the Laboratory of Bio-inspired Nanomechanics “Giuseppe Maria Pugno” at the Politecnico of Torino, the “Nanofacility
Piemonte” at the INRIM Institute in Torino, the Division of Dental Sciences and Biomaterials of the Department of Biomedicine at the University of Trieste, the Physics Department of the Politecnico of Torino, the Toscano-
Buono Veterinary Surgery in Torino and the Department of Human and Animal Biology at the University of Torino.
The adhesive abilities of insects, spiders and reptiles have inspired researchers for a long time. All these organisms present outstanding performance particularly for force, adhesion and climbing abilities, especially considering their size and weight. Scientists have focused attention on the gecko’s adhesive paw system and climbing abilities, and its adhesion mechanism has been an important topic of research for nearly 150 years. However, certain phenomena about geckos are still not completely understood and nowadays these still represent the main challenge of several scientific discussions which aim to better understand the gecko’s adhesive ability.
This thesis deals first with the influence of surface roughness on the gecko’s adhesion on the inverted surface of Poly(methyl meth-acrylate) (PMMA) and glass in Chapter 1, of PMMA with different surface roughness in Chapter 2, while Chapter 3 deals with the gecko’s maximum normal
adhesive force and Chapter 4 looks at the optimal adhesion angle at different hierarchical levels. The gecko’s moult (Appendix 1) is examined in a preliminary way.
The Tokay gecko (Gekko gecko) is the most studied gecko among more than 1050 Gekkonid lizard species in the world, due to its strong adhesive ability. Because this thesis reports clear experimental measurements on two living Tokay geckos, it is comparable to scientific results reported in the literature. It is well known how small insects can carry many times their own weight and can walk quickly, but their most interesting ability is their extremely high adhesion. In recent decades, many scientists have studied a number of insects in order to understand and measure their adhesive abilities.
Biological adhesion can be obtained through different adhesive mechanisms (e.g. claw, clamp, sucker, glue, friction). In particular, this thesis focuses on living specimens of the non-climbing cockroach (Blatta Orientalis Linnaeus) by evaluating its maximum shear safety factor on artificial surfaces using a centrifuge machine, see Chapter 5.
In general, the adhesive structure and mechanism of an animal could be connected to the micro-structured roughness of natural substrata (e.g. plant surfaces), which animals usually find when they move around in the natural
environment.
In nature, plants show an extraordinary variety of morphologies and surface structures. Some plants possess two special properties; superhydrophobicity (or water-repellency) and self-cleaning (or dirt-freedom). These two related phenomena were observed for the first time by Aristotle more than 2,000 years ago but it was only in the 20th century that scientists examined them accurately on some natural leaves, e.g. the lotus (Nelumbo nucifera) on
which “raindrops take a clear, spherical shape without spreading, which probably has to be ascribed to some kind of evaporated essence”, as Goethe described in 1817. Accordingly to scientific literature, a strong influence of
surface roughness on wettability and self-cleaning behaviour clearly emerges. This well-defined problem was of particular interest (for the Indesit Company) since we wanted to find an industrial solution which would leave the internal sides of refrigerators clean from condensed water
or dirt. For this reason, a collaborative project started. Two industrial processes, plasma and thermoforming treatments, were applied to polystyrene surfaces. The Indesit refrigerator box is made of polystyrene. The influence of these industrial treatments on the surface wettability were analysed, see Chapter 6. The focus of the Indesit Company was to understand the role of roughness and to produce a superhydrophobic and self-cleaning surface. Thus, this thesis reports the method which we
developed in order to design an artificial biomimetic superhydrophobic polystyrene surface, copying the natural lotus leaf (Chapter 7). In addition, surface roughness implies a modification of the tribological and frictional
properties, so it assumes a crucial role when designing two contacting surfaces, in particular at nano-scale (Chapter 8).
The nanometer scale characterises this thesis and is involved in everything from gecko spatulae to the waxy nanotubules of the lotus leaf, to the fibroin protein materials which constitute spider silks. In general, spider silks display superior mechanical properties but, only in the last few decades, reserachers have studied various types of silks and have evaluated their very different mechanical properties. The fact that the mechanical behaviour of
spider silks varies accordingly to their type is well-known, since silk properties have been demonstrated to be species-specific and are linked to silk-based peptide fibrils or protein aggregates, with different structural and mechanical properties. The dragline silk (or radial silk) and the flag silk (or circumferential silk) of orb weaving spiders have been characterized in scientific literature while, to our knowledge, few studies have been conducted on bundles, which connect the cocoons of Meta menardi to the ceiling of caves. These were tested to determine their mechanical properties in terms of stress, strain and toughness (Chapter 9).
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Garzón, Manjón Alba. "Synthesis of Metal Oxide Nanoparticles for Superconducting Nanocomposites and Other Applications." Doctoral thesis, Universitat Autònoma de Barcelona, 2016. http://hdl.handle.net/10803/399330.
Full textAbstract:
Los proceso térmicos y por microondas, se utilizan para sintetizar nanopartículas de diferentes óxidos metálicos tales como magnetita (Fe3O4) y óxido de cerio (CeO2). Mediante la modificación de los precursores Fe(R2diket)3 (R = Ph, tBu y CF3), Ce(acac)3 y Ce(OAc)3, y siguiendo la misma ruta de síntesis, es posible controlar el tamaño y la forma de los nanocristales obtenidos. La ruta general se lleva a cabo en trietilenglicol (TREG) o benzylalcohol (BnOH), debido a su alto punto de ebullición y que además puede actuar como estabilizante de las nanopartículas en disolventes polares.
Las nanopartículas se han caracterizado por varias técnicas de laboratorio comunes: Alta Resolución Microscopía Electrónica de Transmisión (HR TEM), espectroscopia infrarroja (IR), Rayos X (XRPD), magnetometría tal como Superconducting Quantum Interference Device (SQUID), Resonancia Magnética Nuclear (RMN), Cromatografía de Gases-Espectroscopía de Masas (GC-MS), Espectroscopia de fotoelectrones emitidos por rayos X (XPS) y Análisis Termogravimétrico (TGA). Con todas estas técnicas, el tamaño final, la forma, la composición, la estructura cristalina, el comportamiento magnético y la interacción del ligando con la superficie de las nanopartículas han sido estudiadas y caracterizadas. Además, se demuestra la alta eficiencia de los das dos metodologías que se han optimizado para sintetizar nanopartículas de diferentes familias.
Las soluciones coloidales estables obtenidas en etanol se han utilizado para generar capas superconductoras de YBa2Cu3O7-δ (YBCO) debido a que la corriente crítica se puede aumentar cuando se incrustan las nanopartículas.
Finalmente, una nueva aplicación como comportamiento antioxidante en células humanas se ha llevado a cabo para el caso de las nanopartículas de CeO2 debido a sus específicas propiedades que las hacen muy interesantes en este nuevo campo.Thermal and microwave methodologies are used to synthesize different metal oxides nanoparticles such as magnetite (Fe3O4), cerium oxide (CeO2). By modifying the precursors (Fe(R2diket)3 (R= Ph, tBu and CF3), Ce(acac)3 and Ce(OAc)3), and following the same synthetic route, it is possible to control the size and shape of the nanocrystals obtained. The general route is carried out in triethylene glycol (TREG) or benzyl alcohol (BnOH) media, due to its high boiling point and, which acts also as a capping ligand of the nanoparticles, stabilizing them in polar solvents. Nanoparticles have been characterized by several common physical laboratory techniques: High Resolution Transmission Electron Microscopy (HR TEM), infrared spectroscopy (IR), X-ray Powder Diffraction (XRPD), magnetometry via Superconducting Quantum Interference Device (SQUID), Nuclear Magnetic Resonance (RMN), Gas Chromatography-Mass Spectroscopy (GC-MS), X-ray Photoelectron Spectroscopy (XPS) and Thermogravimetric Analysis (TGA). With all these techniques, the final size, shape, composition, crystal structure, magnetic behaviour and capping ligand interaction have been studied, showing the high quality crystals generated. In addition, we demonstrate the high efficiency of all two one-pot methodologies that have been optimized to synthesize different families of nanoparticles. The stable colloidal solutions obtained in ethanol have been used to generate ex-situ hybrid YBa2Cu3O7-δ (YBCO) superconducting layers because the critical current can be increased when the nanoparticles are embedded. Finally, a new application as an antioxidant behaviour in human cells is tested for the case of CeO2 nanoparticles due to their specifically properties that make them really interested in this new field.
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Rodrigues, Carolina Martins. "Desenvolvimento de materiais nanoestruturados baseados em oxidos mistos de metais de transição (Ti, Zr)." [s.n.], 2007. http://repositorio.unicamp.br/jspui/handle/REPOSIP/249015.
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Orientador: Oswaldo Luiz AlvesDissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Quimica
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Resumo: Esta dissertação visa à obtenção de nanoestruturas partindo do óxido misto Ti1-xZrxO2. O óxido precursor foi preparado pelo método de precipitação homogênea, via tetracloreto de titânio e oxicloreto de zircônio, usando uréia como reagente precipitante. Esses óxidos foram submetidos ao tratamento hidrotérmico em autoclave, em solução de NaOH, empregando temperatura de 140 e 170°C com intervalo de tempo de 2 a 7 dias. De acordo com as caracterizações físico-químicas feitas foi observado que os produtos obtidos via tratamento hidrotérmico com x < 0,50 apresentaram morfologia de nanotubos, nanoplacas e nanobastões. Entretanto, para x acima de 0,05 mostraram a existência de duas fases cristalinas, titanato de sódio e ZrO2 tetragonal. Para x > 0,50 não apresentaram mudanças morfológicas, tendo como fase formada o ZrO2 tetragonal. Quando o precursor com x = 0,50 (fase ZrTiO4) é observado no produto do tratamento hidrotérmico manutenção da estrutura cristalina e presença de nanotubos. Foi também mostrado, para x = 0,15, que o aumento de volume da solução na autoclave promove aumento da cristalinidade e destruição da organização das partículas. O aumento do tempo e da temperatura de reação proporcionou maior cristalinidade aos produtos hidrotérmicos com x = 0,15 e 0,50; para x = 0 aumento de nanotubos e para x = 0,15 diminuição das nanoplacas e para x = 0,80 e 1 não apresentaram mudanças nem na morfologia, nem na cristalinidade. Foi avaliada a reatividade dos nanotubos (x=0) e nanobastões/nanoplacas (x = 0,15) frente às moléculas orgânicas. Foi observado que os nanotubos interagem melhor com moléculas ácidas, e que tais moléculas promovem a destruição da morfologia e mudança da estrutura cristalina, sendo estas mais drásticas quando com aquecimento. Os nanobastões/nanoplacas interagem mais fortemente com as moléculas ácidas, porém sem perda de morfologia e estrutura cristalina
Abstract: The main of this Dissertation is the preparation of nanostructures from T1-xZrxO2 mixed oxide. The precursor oxide was prepared by the homogeneous precipitation method, from titanium tetrachloride and zirconium oxichloride, using urea as the precipitating agent. The oxides were hydrothermally treated in autoclave, in NaOH solution, at temperatures of 140 and 170 °C, for period of 2 to 7 days. According to the physical-chemical characterizations, it was observed that the products prepared by the hydrohermal treatment with x < 0.50 presented morphologies like nanotubes, nanosheets and nanorods. However, for x > 0.05, it was observed the presence of two crystalline phases, sodium titanate and tetragonal ZrO2. For x > 0.50, it was not observed morphological changes, being tetragonal ZrO2 the obtained phase. Starting from the mixed oxide with x = 0.50, ZrTiO4 phase, it was observed nanotubes with the same crystalline phase. For x = 0.15, it was also observed that the increase of solution volume in the autoclave causes a crystallinity increase and destruction of the particles organization. The increase in time and temperature of reaction caused an increase in the crystallinity of the hydrothermal products for x = 0.15 e 0. 50; for x = 0, it was observed more quantity of nanotubes; and for x = 0.15, fewer nanosheets; for x = 0.80 and 1, it was not observed either morphological neither crystalline changes. The reactivity of the nanotubes (x = 0) and nanorods/nanosheets (x = 0.15) with organic molecules, which promote the morphology destructions and changes in the crystalline structure. These effects were increased with heating. The nanorods/nanosheets strongly interact with acid molecules, without loosing of morphology or the original crystalline structures
Mestrado
Quimica Inorganica
Mestre em Química
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Rodríguez, Rodríguez Jordi. "Síntesis y Caracterización de Óxido de Grafeno Reducido Funcionalizado con Nanopartículas Metálicas. Aplicación en el Desarrollo de Sensores Amperométricos Basados en Materiales Nanoestructurados." Doctoral thesis, Universitat Autònoma de Barcelona, 2021. http://hdl.handle.net/10803/671817.
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El desenvolupament de nous (bio)sensors és un camp en ple desenvolupament dins de les necessitats de la Química Analítica i, en general, de la societat. L’ús de sensors està altament estès en la vida quotidiana de les persones. En el mercat, es troben disponibles diferents tipus de glucòmetre, que poden informar de la concentració de glucosa en sang en temps real del pacient. També es pot observar la necessitat d’avui dia de desenvolupar nous test de diagnosi per a malalties com la provocada pel virus SARS-COVID-19. El grafè s’ha convertit en un material de gran interès entre la comunitat científica, a causa de les propietats elèctriques, tèrmiques i mecàniques úniques que aquest material posseeix respecte a altres materials carbònics i 2D. A causa dels seus excepcionals característiques i propietats l’ús de grafè com a material conductor alternatiu en el desenvolupament de transductors electroquímics s’ha estès àmpliament i convertit en un dels principals recursos. Els nanocompósitos se situen com una alternativa molt interessant en el desenvolupament de sensors amperométricos. Degut, especialment, a la capacitat d’integrar diversos materials amb diferents característiques amb la finalitat d’obtenir un nou material amb propietats físiques, mecàniques i elèctriques molt diferents als materials originals que el constitueixen. L’ús de nanocompósitos presenta una sèrie d’avantatges respecte als conductors purs. Aquests avantatges són, per exemple, versatilitat, durabilitat, facilitat de regeneració de la superfície i la seva capacitat d’integració d’altres modificadors, qualitats que proporcionen un valor afegit als dispositius desenvolupats. Les propietats electroquímiques dels nanocompósitos estan altament influenciades per la naturalesa de les partícules conductores que ho formen, així com la quantitat i la distribució espacial d’aquestes en la matriu del nanocompósito. Una de les característiques més rellevants que posseeixen aquests materials és la similitud en el seu comportament electroquímic respecte a un feix de microelectrodos. La presència de partícules conductores, separades per àrees no conductores o aïllants en la superfície de l’elèctrode, mimetitza la distribució més o menys ordenada de microelectrodos separats entre si per un aïllant elèctric, configurant així un feix de microelectrodos. La resposta electroanalítica d’un feix de microelectrodos depèn fonamentalment de les dimensions i separació entre les partícules conductores. Per aquest motiu, és necessària una optimització de la quantitat de material conductor i de la seva distribució amb l’objectiu d’obtenir la millor eficàcia analítica. Sota aquest context, la primera etapa d’aquesta Tesi és la síntesi d’òxid de grafè reduït (rGO) mitjançant el mètode de Hummers. Aquest mètode permet obtenir rGO utilitzant grafit comercial com a material de partida per a la fabricació d’elèctrodes nanocompósitos basats en rGO i una resina epoxi (EpoTek H77). Posteriorment, s’ha implementat un conjunt de tècniques instrumentals que, aplicades de manera estratègica i sistemàtica, han permès la caracterització i optimització de la composició del material conductor; així com la millora de les propietats electroquímiques dels elèctrodes nanocompósitos desenvolupats amb els diferents materials conductors sintetitzats. Una vegada optimitzades les propietats dels transductors electroquímics es va procedir a la millora de les propietats analítiques d’aquests sensors electroquímics, mitjançant la incorporació de diferents nanopartícules (NPs) metàl·liques, amb l’objectiu d’introduir un efecte electrocatalítico en el dispositiu analític. D’aquesta manera, es va desenvolupar una metodologia sintètica, la qual permet incorporar ad hoc NPs de diferents metalls (e.g Au, Ag, Pd) en la superfície del rGO, d’una manera senzilla i mitjançant química verda. Finalment, s’ha desenvolupat un (bio)sensor utilitzant l’enzim glucosa oxidasa (GOD), basat en un nanocompósito de 2Au/*3Pd-Np@rgo. Estudiant l’efecte catalític que tenen les NPs bimetàl·liques de Au i Pd enfront del H2O2. Per a finalitzar, es va estudiar l’efecte de la presència de l’àcid ascòrbic en les mesures electroanalíticas (una interferència present en moltes mostres biològiques).El desarrollo de nuevos (bio)sensores es un campo en desarrollo dentro de la Química Analítica y, en general, de la sociedad. El uso de sensores está altamente extendido en la vida cotidiana de las personas. En el mercado, se encuentran disponibles distintos tipos de glucómetros, que pueden informar de la concentración de glucosa en sangre en tiempo real del paciente. También existe una demanda de nuevos test de diagnosis para enfermedades como la provocada por el virus SARS-COVID-19. El grafeno se ha convertido en un material de gran interés entre la comunidad científica, debido a las propiedades eléctricas, térmicas y mecánicas únicas que este material posee respecto a otros materiales carbonáceos y 2D. Debido a sus excepcionales características y propiedades el uso de grafeno como material conductor alternativo en el desarrollo de transductores electroquímicos se ha extendido ampliamente y convertido en uno de los principales recursos. Los nanocompósitos se sitúan como una alternativa muy interesante en el desarrollo de sensores amperométricos. Debido a la capacidad de integrar varios materiales con diferentes características con la finalidad de obtener un nuevo material con propiedades físicas, mecánicas y eléctricas muy diferentes a los materiales originales que lo constituyen. El uso de nanocompósitos presenta una serie de ventajas respecto a los conductores puros. Por ejemplo, versatilidad, durabilidad, facilidad de regeneración de la superficie y su capacidad de integración de otros modificadores, cualidades que proporcionan un valor añadido a los dispositivos desarrollados. Las propiedades electroquímicas de los nanocompósitos están altamente influenciadas por la naturaleza de las partículas conductoras que lo forman, así como la cantidad y la distribución espacial de estas en la matriz del nanocompósito. Una de las características más relevantes que poseen estos materiales es la similitud en su comportamiento electroquímico respecto a un haz de microelectrodos. La presencia de partículas conductoras, separadas por áreas no conductoras o aislantes en la superficie del electrodo, mimetiza la distribución más o menos ordenada de microelectrodos separados entre sí por un aislante eléctrico, configurando así un haz de microelectrodos. La respuesta electroanalítica de un haz de microelectrodos depende fundamentalmente de las dimensiones y separación entre las partículas conductoras. Por este motivo, es necesaria una optimización de la cantidad de material conductor y de su distribución con el objetivo de obtener la mejor eficacia analítica. Bajo este contexto, la primera etapa de esta Tesis es la síntesis de óxido de grafeno reducido (rGO) mediante el método de Hummers. Este método permite obtener rGO utilizando grafito comercial como material de partida para la fabricación de electrodos nanocompósitos basados en rGO y una resina epoxi (EpoTek H77). Posteriormente, se ha implementado un conjunto de técnicas instrumentales que, aplicadas de forma estratégica y sistemática, han permitido la caracterización y optimización de la composición del material conductor; así como la mejora de las propiedades electroquímicas de los electrodos nanocompósitos desarrollados con los diferentes materiales conductores sintetizados. Una vez optimizadas las propiedades de los transductores electroquímicos se procedió a la mejora de las propiedades de estos sensores, mediante la incorporación de diferentes nanopartículas (NPs) metálicas, con el objetivo de introducir un efecto electrocatalítico en el dispositivo analítico. Se desarrolló una metodología sintética que permite incorporar ad hoc NPs de diferentes metales (e.g Au, Ag, Pd) en la superficie del rGO, de una manera sencilla y mediante química verde. Finalmente, se ha desarrollado un (bio)sensor utilizando la enzima glucosa oxidasa (GOD), basado en un nanocompósito de 2Au/3Pd-NP@rGO. Estudiando el efecto catalítico que tienen las NPs bimetálicas de Au y Pd frente al H2O2. Para finalizar, se estudió el efecto de la presencia del ácido ascórbico en las medidas electroanalíticas.
The development of new (bio)sensors is a field in full development within the needs of Analytical Chemistry and society in general. The use of sensors is highly extended in people’s daily life. Different types of glucometers are available on the market, which can report the concentration of glucose in the patient’s blood in real time. Also, one can see today’s need to develop new diagnostic tests for diseases, such as that caused by the SARS-COVID-19 virus. Graphene has become a material of great interest among the scientific community, due to the unique electrical, thermal and mechanical properties that this material possesses with respect to other carbonaceous and 2D materials. Due to its exceptional characteristics and properties, the use of graphene as an alternative conductor material in the development of electrochemical transducers has become widespread and one of the main resources. Nanocomposites are a very interesting alternative in the development of amperometric sensors. Due, especially, to the capacity of integrating several materials with different characteristics in order to obtain a new material with very different physical, mechanical and electrical properties from the original materials that constitute it. The use of nanocomposites has a series of advantages over pure conductors. These advantages are, for example, versatility, durability, ease of surface regeneration and its ability to integrate other modifiers, qualities that provide added value to the developed devices. The electrochemical properties of nanocomposites are highly influenced by the nature of the conductive particles that form it as well as their amount and spatial distribution in the matrix of the nanocomposite. One of the most relevant characteristics of these materials is the similarity in their electrochemical behavior with respect to a microelectrode array. The presence of conductive particles, separated by non-conductive or insulating areas on the electrode surface, mimics the more or less ordered distribution of microelectrodes separated by an electrical insulator, forming the equivalent of a microelectrode array. The electro-analytical response of a microelectrode array depends mainly on the dimensions and separation between the conductive particles. For this reason, it is necessary to optimize the quantity of conductive material and its distribution to obtain the best analytical efficiency. In this context, the first stage of this Thesis is the synthesis of reduced graphene oxide (rGO) by Hummers’ method. This method allows obtaining rGO, from commercial graphite as a starting material, for the manufacture of nanocomposite electrodes based on rGO and an epoxy resin (EpoTek H77). Subsequently, a set of instrumental techniques have been implemented, which, applied in a strategic and systematic way, have allowed the characterization and optimization of the composition of the conductive material as well as the improvement of the electrochemical properties of the nanocomposite electrodes developed with different synthesized conductive materials. Once the properties of the electrochemical transducers were optimized, it was time to improve the analytical properties of these electrochemical sensors through the incorporation of different metallic nanoparticles (NPs) with the aim of introducing an electrocatalytic effect into the analytical device. This way a synthetic methodology was developed, allowing the incorporation ad hoc of different metal NPs (e.g. Au, Ag, Pd) on the rGO’s surface in a simple way and by means of green chemistry. Finally, a (bio)sensor has been developed using the enzyme glucose oxidase (GOD), based on a 2Au/3Pd-NP@rGO nanocomposite. Studying the catalytic effect that bimetallic Au and Pd NPs have upon H2O2. Finally, the effect of ascorbic acid’s presence in electroanalytical measurements (an interferent present in many biological samples) was studied.
Universitat Autònoma de Barcelona. Programa de Doctorat en Química
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Molet, Bachs Pau. "Managing light in optoelectronic devices with resonant optical nanostructures." Doctoral thesis, Universitat Autònoma de Barcelona, 2021. http://hdl.handle.net/10803/673260.
Full textAbstract:
Actualment, un dels reptes en l’àmbit de la manipulació de la llum a la nanoescala és la transició del laboratori a aplicacions reals. Tot i el gran potencial demostrat per algunes estructures fotòniques per a incrementar la eficiència de instruments optoelectrònics, la seva implementació de d’aquestes a dispositius de mercat sovint es obstruïda per la necessitat d’usar tècniques de fabricació poc escalables i d’alt cost. Aquesta tesis està dedicada al disseny i implementació de estratègies de manipulació de la llum per a millorar la eficiència en la recol·lecció d’energia de plaques solars i fotodetectors, així com la millora de la emissió en dispositius d’il·luminació, mitjançant mètodes de nanoestructuració escalables com la nano-litografia suau. Aquesta tècnica té la capacitat de produir patrons i estructures amb una resolució de pocs nanòmetres amb gran fidelitat en àrees grans. A més a més, és compatible amb el processament a gran escala mitjançant el sistema de impressió en cadena “roll to roll” (carret-a-carret). També es tracta d’una tecnologia molt versàtil, ja que permet l’ús de diferents tipus de substrats, és poc invasiva i generalment pot ser introduïda en el esquema de fabricació sense haver de modificar cap pas. Amb l’ajuda d’aquesta tècnica de nanofabricació, explorem una varietat de arquitectures fotòniques i les diferents ressonàncies fotòniques que les fan especials. Entre aquestes darreres podem trobar ressonàncies de Mie, modes de Brewster i modes de cristall fotònic, que proveiran al sistema amb una major interacció llum-matèria a la capa activa del dispositiu, podent-ne millorar les seves capacitats òptiques.
Primer, hem desenvolupat una estratègia per aconseguir una absorció optima de banda ample en semiconductors ultra-fins, amb menys de 100 nm de gruix, per a totes les energies per sobre de la seva energia de banda prohibida. La sinèrgia de les fortes ressonàncies d’interferència de capes fines presents i els modes del cristall fotònic de l’estructura (amb un alt índex de refracció) fan que l’estructura assoleixi fins a un 81% d’absorció en una ampli rang de longituds d’ona (de 400 a 1500 nm).
En segon lloc, hem combinat la litografia suau amb la deposició química de vapor (CVD en anglès) per obtenir una matriu de semiesferes de silici sobre de una guia d’ones d’alt índex de refracció. Hem estudiat les ressonàncies de Mie característiques del substrat, com hibriden amb modes quasi-guiats de la guia d’ones i com això afecta al camp proper de la metasuperfície. Hem anat un pas més enllà estudiant la com la modificació dels paràmetres de disseny de l’estructura afecta les ressonàncies esmentades. Finalment, n’hem demostrat una possible aplicació com a substrat per a incrementar la emissió de llum per part de una molècula emissora.
En la tercera part de la tesi, ens hem enfocat en la implementació de estructures de cristall fotònic bidimensional a tres dispositius diferents per a la millora de la seva eficiència. En particular, millorem la eficiència en la recol·lecció de fotons d’infraroig proper en cèl·lules solars de punts quàntics col·loïdals (PbS) i en fotodetectors orgànics (P3HT: PC60BM i PBTTT: PC70BM), i millorem l’emissió de llum de capes de nanofòsfors (nanocristalls de GdVO4:Eu3+). Hem desenvolupat sistemes fotònics adaptats a cada cas i hem fet una caracterització òptica i electrònica de tots els dispositius. La nanoestructuració en forma de cristall fotònic bidimensional proveeix a les capes actives amb propietats de guies d’ona ressonants, millorant les seves propietats de confinament de la llum en les longituds d’ona desitjades, demostrant així la possibilitat d’implementar les arquitectures.Actualmente, uno de los retos en el ámbito de la manipulación de la luz a la nanoescala es la transición del laboratorio a aplicaciones reales. A pesar del gran potencial demostrado por algunas estructuras fotónicas para incrementar la eficiencia de instrumentos optoelectrónicos, su implementación en dispositivos de mercado muchas veces es obstruida por la necesidad de utilizar técnicas de fabricación poco escalables y de alto coste. Esta tesis está dedicada al diseño e implementación de estrategias de manipulación de la luz para mejorar la eficiencia en la recolección de energía de placas solares y fotodetectores, así como la mejora de la emisión en dispositivos de iluminación, mediante métodos de nanoestructuración escalables como la nano-litografía suave. Esta técnica tiene la capacidad de producir patrones y estructures con una resolución de pocos nanómetros con gran fidelidad en áreas grandes. Encima, es compatible con el procesamiento a gran escala mediante el sistema de impresión en cadena “roll-to-roll” (carrete-a-carrete). También se trata de una tecnología muy versátil, puesto que permite el uso de diferentes tipos de sustratos, es poco invasiva y generalmente puede ser introducida en el esquema de fabricación sin tener que modificar ningún paso. Con la ayuda de esta técnica de nanofabricación, exploramos una variedad de arquitecturas fotónicas y las diferentes resonancias fotónicas que las hacen especiales. Entre estas últimas podemos encontrar resonancias de Mie, modos de Brewster y modos de cristal fotónico, que proveerán al sistema con una mayor interacción luz-materia a la capa activa del dispositivo, mejorar sus capacidades ópticas. Primero, hemos desarrollado una estrategia para conseguir una absorción óptima de banda ancha en semiconductores ultra-finos, con menos de 100 nm de grosor, para todas las energías por encima de su energía de banda prohibida. La sinergia de las fuertes resonancias de interferencia de capas finas presentes y los modos del cristal fotónico de la estructura (con un alto índice de refracción) hacen que la estructura logre hasta un 81% de absorción en un amplio rango de longitudes de omda (de 400 a 1500 nm). En segundo lugar, hemos combinado la litografía suave con la deposición química de vapor (CVD en inglés) para obtener una matriz de semiesferas de silicio sobre de una guía de ondas de alto índice de refracción. Hemos estudiado las resonancias de Mie características del sustrato, como hibridan con modos casi-guiados de la guía de olas y como esto afecta en el campo próximo de la metasuperfície. Hemos ido un paso más allá estudiando como la modificación de los parámetros del diseño de la estructura afecta a las resonancias mencionadas. Finalmente, hemos demostrado una posible aplicación como sustrato para incrementar la emisión de luz por parte de una molécula emisora. En la tercera parte de la tesis, nos hemos enfocado en la implementación de estructuras de cristal fotónico bidimensional a tres dispositivos diferentes para la mejora de su eficiencia. En particular, mejoramos la eficiencia en la recolección de fotones de infrarrojo próximo en células solares de puntos cuánticos coloidales (PbS) y en fotodetectores orgánicos (P3HT: PC60BM y PBTTT: PC70BM), y mejoramos la emisión de luz de capas de nanofósforos (nanocristales de GdVO4:Eu3+). Hemos desarrollado sistemas fotónicos adaptados a cada caso y hemos hecho una caracterización óptica y electrónica de todos los dispositivos. La nanoestructuración en forma de cristal fotónico bidimensional provee a las capas activas con propiedades de guías de onda resonantes, mejorando sus propiedades de confinamiento de la luz en las longitudes de onda deseadas, demostrando así la posibilidad de implementar las arquitecturas.
Currently, one of the main challenges in light management at the nanoscale is the transition from the laboratory to real applications. Despite the great potential shown by photonic architectures to optically improve the performance of many devices, transitioning into marketable devices is often hampered by the low-throughput and expensive nanofabrication techniques involved. This thesis is devoted to the design and development of subwavelength light managing strategies to improve the light harvesting or out-coupling in solar cells, photodetectors and light emitters while using a scalable nanostructuration such as soft nanoimprint lithography (NIL). This technique has been proven to achieve resolutions down to few tens of nanometers with high fidelity in large areas, being compatible with roll to roll processing. It is also versatile regarding the materials where it can be used, non-invasive, and can be seamlessly introduced in the devices fabrication scheme. With the aid of this technique, we explore a variety of photonic architectures and the different types of resonances sustained, from Brewster modes to Mie resonances, in order to enhance the light-matter interaction with the active layer of the device. First, we develop a strategy to achieve broadband optimal absorption in ultra-thin semiconductor materials (less than 100 nm thick) for all energies above their bandgap. The interplay of strong interference thin film resonances and photonic crystal modes sustained by a high refractive index nanostructure on a gold film renders the system with a 81% total absorption over a broad spectral range (from 400 to 1500 nm). Second, we combine soft NIL and chemical vapor deposition to obtain an array of silicon hemispheres on top of a high refractive index dielectric waveguide. We study the Mie resonances supported by the substrate, how these hybridize with the guided modes of the waveguide and how their interaction influences the electromagnetic near field of the metasurface. We further explore the tunability of such resonances with the design parameters of the structure and we demonstrate a potential application of it as a substrate for enhanced photoluminescence. In the third part of the thesis, we focus on the implementation of 2D photonic structures within the active layer of three different devices to improve performance. In particular we enhance the near infrared (NIR) photon harvesting efficiency in a colloidal quantum dot solar cell (PbS-CQD) and in organic photodetectors (P3HT: PC60BM and PBTTT: PC70BM) and improve the light out coupling from a nanophosphor layer (GdVO4:Eu3+ nanocrystals). We developed photonic systems tailored for each device and provide the complete optical and electronic characterization for each case. The nanostructuration with a 2D periodic arrangement renders the active layers with resonant waveguide properties enhancing its light trapping properties in the targeted spectral ranges, hence demonstrating the possibility to implement photonic schemes within actual devices.
Universitat Autònoma de Barcelona. Programa de Doctorat en Ciència de Materials
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Ballesteros, Ribera Sandra. "New end-points to assess nanomaterials exposure effects." Doctoral thesis, Universitat Autònoma de Barcelona, 2021. http://hdl.handle.net/10803/673866.
Full textAbstract:
Els nanomaterials (NMs) són considerats contaminants emergents, ja que la seua detecció està creixent en les diferents matrius ambientals, provocant riscos potencials per a la salut humana i per als ecosistemes. En aquest sentit, el principal objectiu d’aquesta Tesi ha estat proporcionar noves aproximacions metodològiques per a l’avaluació del perill dels NMs mitjançant models in vitro i ex vivo avançats, així com nous biomarcadors.
En el nostre primer estudi es va desenvolupar un model nou per comprendre el risc d’exposició dels éssers humans a les nanopartícules de poliestirè (NPPS), com a model de micro-nanoplástics (MNPL). Per aconseguir aquest objectiu, les mostres de sang procedents de 5 donants es van exposar ex vivo a diverses dosis de NPPS i es van avaluar diferents biomarcadors en diversos subconjunts de glòbuls blancs perifèrics. Els resultats van mostrar marcades diferències en la internalització de NPPS, amb una absorció molt limitada en els limfòcits i molt alta en els monòcits. A més, l’avaluació del dany genotòxic de l’ADN va revelar una sensibilitat cel·lular específica, sent les cèl·lules polimorfonuclears i monòcits aquelles cèl·lules amb els nivells més significatius de dany genotòxic. A més, l’exposició a NPPS va desencadenar canvis en el secretoma sanguini, amb un augment significatiu en l’expressió de citoquines relacionades amb la resposta inflamatòria i immunitària, l’estrès i la proliferació cel·lular.
En el segon estudi es va utilitzar el model ex vivo abans esmentat per avaluar l’impacte al secretoma sanguini de tres nanomaterials diferents basats en grafè (NMBG). Amb aquest objectiu, es va analitzar un gran panell de citoquines i els resultats van mostrar importants canvis en la seva expressió, estant la majoria d’ells relacionats amb la resposta immunitària i inflamatòria. Al mateix temps, es va utilitzar l’assaig del soft-agar indirecte per analitzar les conseqüències funcionals d’aquests canvis de citoquines. Els resultats van mostrar que el secretoma alterat per NMBG pot inhibir la capacitat de creixement cel·lular independent d’ancoratge de les cèl·lules HeLa, utilitzades com a model de línia cel·lular.
En el tercer estudi les propietats de transformació cel·lular del nanocerio es van confirmar mitjançant un model in vitro de dosis baixes a llarg termini. Es van analitzar les propietats relacionades amb les cèl·lules mare canceroses, el creixement independent d’ancoratge i les capacitats d’invasió, ja que es consideren característiques oncogèniques importants impulsades per l’exposició als NMs. Així mateix, es van confirmar les seves possibles interaccions amb el condensat de tabac, com a model de contaminant cancerigen ambiental, mostrant una interacció positiva en la inducció de la transformació cel·lular. A més, es va avaluar una bateria de microRNAs relacionats amb l’adquisició del fenotip tumoral, revelant que les nanopartícules de diòxid de ceri i la coexposició produïen una toxicitat potencial al transcriptoma.
Finalment, en el nostre quart estudi es van avaluar les possibles conseqüències epigenètiques de l’exposició a llarg termini a nanopartícules de titani i nanotubs de carboni de múltiples capes, específicament els canvis en l’expressió de microRNAs. La bateria de microRNAs analitzada va revelar un gran impacte en el perfil d’expressió de les cèl·lules exposades als dos nanomaterials. A més, a partir de la nostra bateria inicial, es va seleccionar un petit conjunt de cinc microRNAs com a possibles biomarcadors d’efecte després de l’exposició als NMs. Aquest conjunt va ser provat en les línies cel·lulars BEAS-2B i MEF, prèviament exposades a llarg termini a diferents NMs, mostrant efectes positius en totes les mostres provades, confirmant la idoneïtat d’aquesta bateria.Los nanomateriales (NMs) son considerados contaminantes emergentes cuya detección está creciendo en las diferentes matrices ambientales, provocando riesgos potenciales para la salud humana y para los ecosistemas. En este sentido, el principal objetivo de esta Tesis ha sido proporcionar nuevas aproximaciones metodológicas para la evaluación del peligro de los NMs a través de modelos in vitro y ex vivo avanzados, así como de nuevos biomarcadores. En nuestro primer estudio se desarrolló un modelo novedoso para comprender el riesgo de exposición de los seres humanos a las nanopartículas de poliestireno (NPPS), como modelo de micro-nanoplásticos (MNPL). Para ello, las muestras de sangre procedentes de 5 donantes se expusieron ex vivo a varias dosis de NPPS y se evaluaron diferentes biomarcadores en diversos subconjuntos de glóbulos blancos periféricos. Los resultados mostraron marcadas diferencias en la internalización de NPPS, con una absorción muy limitada en los linfocitos y muy alta en los monocitos. Además, la evaluación del daño genotóxico del ADN reveló una sensibilidad celular específica, siendo las células polimorfonucleares y monocitos aquellas células con los niveles más significativos de daño genotóxico. Además, la exposición a NPPS desencadenó cambios en el secretoma sanguíneo, con un aumento significativo en la expresión de citoquinas relacionadas con la respuesta inflamatoria e inmunitaria, el estrés y la proliferación celular. En el segundo estudio, se utilizó el modelo ex vivo antes mencionado para evaluar el impacto a nivel del secretoma sanguíneo de tres nanomateriales diferentes basados en grafeno (NMBG). Para ello, se analizó un gran panel de citoquinas y los resultados mostraron importantes cambios en su expresión, estando la mayoría de ellos relacionados con la respuesta inmunitaria e inflamatoria. Al mismo tiempo, se utilizó el ensayo de soft-agar indirecto para analizar las consecuencias funcionales de estos cambios de citoquinas. Los resultados mostraron que el secretoma alterado por NMBG puede inhibir la capacidad de crecimiento celular independiente del anclaje de las células HeLa, utilizadas como modelo de línea celular. En el tercer estudio, las propiedades de transformación celular del nanocerio se confirmaron mediante un modelo in vitro de dosis bajas a largo plazo. Se analizaron las propiedades relacionadas con las células madre cancerosas, el crecimiento independiente del anclaje y las capacidades de invasión, ya que se consideran características oncogénicas importantes impulsadas por la exposición a los NMs. Asimismo, se confirmaron sus posibles interacciones con el condensado de tabaco, como modelo de contaminante cancerígeno ambiental, mostrando una interacción positiva en la inducción de la transformación celular. Además, se evaluó una batería de microARNs relacionados con la adquisición del fenotipo tumoral, revelando que las nanopartículas de dióxido de cerio y la co-exposición producían una toxicidad potencial a nivel del transcriptoma. Finalmente, en nuestro cuarto estudio se evaluaron las posibles consecuencias epigenéticas de la exposición a largo plazo a nanopartículas de titanio y nanotubos de carbono de múltiples capas, específicamente los cambios en la expresión de microARNs. La batería de microARNs analizada reveló un gran impacto en el perfil de expresión de las células expuestas a ambos nanomateriales. Además, a partir de nuestra batería inicial, se seleccionó un pequeño conjunto de cinco microARNs como posibles biomarcadores de efecto después de la exposición a los NMs. Este conjunto fue probado en las líneas celulares BEAS-2B y MEF, previamente expuestas a largo plazo a diferentes NMs, mostrando efectos positivos en todas las muestras probadas, confirmando la idoneidad de esta batería.
Nanomaterials (NMs) are considered emerging pollutants that are increasingly detected in different environmental matrices, with potential risks for human health and the ecosystems. In this sense, the focus of this Thesis has been directed to provide new approach methodologies for hazard assessment of NMs via advanced in vitro and ex vivo models, as well as novel biomarkers. From our first study, a novel approach was developed to understand the risk of polystyrene nanoparticles (PSNPs) exposure for humans, as a model of micro-nanoplastics (MNPLs). Thus, ex vivo whole blood samples from 5 donors were exposed to several doses of PSNPLs and different end-points were evaluated in diverse subsets of white peripheral blood cells (WBCs). The results showed sharp differences in PSNPLs internalization with very limited uptake in lymphocytes and high uptake in monocytes. Moreover, the genotoxic DNA damage evaluation revealed a specific cellular sensitivity, being polymorphonuclear cells (PMNs), and monocytes those cells with the most significant levels of genotoxic damage. Additionally, PSNPLs exposure triggered changes in the whole blood secretome, with a significant increase in the expression of cytokines related to the inflammatory, immune, and stress response, as well as cell proliferation. In the second study, the before-mentioned whole blood ex vivo model was used to evaluate the impact of three different graphene-based nanomaterials (GBNMs) at the level of the blood secretome. For that purpose, a large panel of cytokines was analysed, and the results showed important cytokine expression changes, most of them related with the immune and inflammatory response. At the same time, the indirect soft-agar assay, was used to unravel the functional consequences of these cytokine changes. The results showed that the GBNMs-altered secretome can inhibit the anchorage-independent cell growth capacity of HeLa cells, used as a model cell-line. In the third study, the cell-transforming properties of nanoceria were confirmed through a long-term low-dose in vitro model. Stem-like properties, anchorage-independent growth, and invasion abilities were analysed as they are considered important oncogenic features driven by NMs exposure. Also, their potential interactions with cigarette smoke condensate (CSC), as a model of environmental carcinogenic pollutant were confirmed, showing a positive interaction in the induction of cell transformation. Besides, a battery of microRNAs related to the acquisition of the tumoral phenotype was assessed, revealing that cerium dioxide nanoparticles (CeO2NPs) and the co-exposure produced potential toxicity at the transcriptome level. Finally, our fourth study evaluated the potential epigenetic consequences of long-term exposure to titanium nanoparticles (TiO2NPs) and multi-walled carbon nanotubes (MWCNT), specifically the microRNAs expression changes. The analysed microRNA battery revealed a big impact on the expression profiling in cells exposed to both nanomaterials. Moreover, from our initial battery, a small set of five microRNAs were selected as potential biomarkers of effect after NMs’ exposures. This set was tested in BEAS-2B and MEF cells previously long-term exposed to different NMs, showing positive effects in all the tested samples, confirming the suitability of this battery.
Universitat Autònoma de Barcelona. Programa de Doctorat en Genètica
Books on the topic "Nanomateriale"
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Al-Douri, Yarub. Nanomaterials. Singapore: Springer Nature Singapore, 2022. http://dx.doi.org/10.1007/978-981-19-3881-8.
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Deutsche Forschungsgemeinschaft DFG, ed. Nanomaterials. Weinheim, Germany: Wiley-VCH Verlag GmbH & Co. KGaA, 2013. http://dx.doi.org/10.1002/9783527673919.
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Singh, Subhash Chandra, Haibo Zeng, Chunlei Guo, and Weiping Cai, eds. Nanomaterials. Weinheim, Germany: Wiley-VCH Verlag GmbH & Co. KGaA, 2012. http://dx.doi.org/10.1002/9783527646821.
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Ramesh, K. T. Nanomaterials. Boston, MA: Springer US, 2009. http://dx.doi.org/10.1007/978-0-387-09783-1.
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Singh, Dheeraj Kumar, Sanjay Singh, and Prabhakar Singh, eds. Nanomaterials. Singapore: Springer Nature Singapore, 2023. http://dx.doi.org/10.1007/978-981-19-7963-7.
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Jaworska, Lucyna. Nanomaterials. Krakow: Institute of Advanced Manufacturing Technology, 2010.
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Capco, David G., and Yongsheng Chen, eds. Nanomaterial. Dordrecht: Springer Netherlands, 2014. http://dx.doi.org/10.1007/978-94-017-8739-0.
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Altavilla, Claudia, ed. Upconverting Nanomaterials. Boca Raton : Taylor & Francis, 2016. | Series: Nanomaterials and: CRC Press, 2016. http://dx.doi.org/10.1201/9781315371535.
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Gogotsi, Yury, ed. Nanomaterials Handbook. Second edition. | Boca Raton : Taylor & Francis, CRC Press, 2017. | Series: Advanced materials and technologies series: CRC Press, 2017. http://dx.doi.org/10.1201/9781315371795.
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Zhou, Kun, ed. Carbon Nanomaterials. First edition. | Boca Raton, FL : CRC Press/Taylor & Francis Group, [2020]: CRC Press, 2019. http://dx.doi.org/10.1201/9781351123587.
Full textBook chapters on the topic "Nanomateriale"
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Fahlman, Bradley D. "Nanomaterials." In Materials Chemistry, 457–583. Dordrecht: Springer Netherlands, 2011. http://dx.doi.org/10.1007/978-94-007-0693-4_6.
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Mo, Yiqun, Rong Wan, David J. Tollerud, and Qunwei Zhang. "Nanomaterials." In Cancer and Inflammation Mechanisms, 235–48. Hoboken, NJ, USA: John Wiley & Sons, Inc., 2014. http://dx.doi.org/10.1002/9781118826621.ch17.
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Gonçalves, M. Clara. "Nanomaterials." In Materials for Construction and Civil Engineering, 629–77. Cham: Springer International Publishing, 2014. http://dx.doi.org/10.1007/978-3-319-08236-3_14.
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Yoda, Minami, Jean-Luc Garden, Olivier Bourgeois, Aeraj Haque, Aloke Kumar, Hans Deyhle, Simone Hieber, et al. "Nanomaterials." In Encyclopedia of Nanotechnology, 1597. Dordrecht: Springer Netherlands, 2012. http://dx.doi.org/10.1007/978-90-481-9751-4_100512.
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Jain, Vimal Kumar. "Nanomaterials." In Solid State Physics, 467–70. Cham: Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-030-96017-9_15.
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Linkov, Igor, Emily Moberg, Benjamin D. Trump, Boris Yatsalo, and Jeffrey M. Keisler. "Nanomaterials." In Multi-Criteria Decision Analysis, 117–22. Second edition. | Boca Raton : CRC Press, 2020. |: CRC Press, 2020. http://dx.doi.org/10.1201/9780429326448-9.
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Fahlman, Bradley D. "Nanomaterials." In Materials Chemistry, 275–356. Dordrecht: Springer Netherlands, 2007. http://dx.doi.org/10.1007/978-1-4020-6120-2_6.
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Alves, Oswaldo L., Ana Carolina Mazarin de Moraes, Mateus Batista Simões, Leandro Carneiro Fonseca, Rafaella Oliveira do Nascimento, Raphael Dias Holtz, and Andreia Fonseca de Faria. "Nanomaterials." In Nanotoxicology, 1–29. New York, NY: Springer New York, 2013. http://dx.doi.org/10.1007/978-1-4614-8993-1_1.
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Vaseashta, A. "Nanomaterials." In Nanomaterials: Risks and Benefits, 397–407. Dordrecht: Springer Netherlands, 2009. http://dx.doi.org/10.1007/978-1-4020-9491-0_31.
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Ramesh, K. T. "Nanomaterials." In Nanomaterials, 1–20. Boston, MA: Springer US, 2009. http://dx.doi.org/10.1007/978-0-387-09783-1_1.
Full textConference papers on the topic "Nanomateriale"
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Gu, Ning, and Song Zhang. "Magnetic Nanomaterial and Its Applications in Biomedicine." In 2007 First International Conference on Integration and Commercialization of Micro and Nanosystems. ASMEDC, 2007. http://dx.doi.org/10.1115/mnc2007-21599.
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Being one kind of functional nanomaterials of importance, magnetic nanomaterial with various excellent properties could be used in many fields, such as information, mechanics, and biomedicine. The main possible applications of magnetic nanomaterial in biomedicine will be described with the focus on the earlier diagnosis and effective treatment of tumors. Also our recent interrelated results are included.
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Alyami, Noktan Mohammed, Vikrant Wagle, Abdullah Saleh Alyami, and Rajendra Kalgaonkar. "Anionic Nanoparticle Based Formulation to Control and Cure Moderate to Severe Losses." In ADIPEC. SPE, 2022. http://dx.doi.org/10.2118/211493-ms.
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Abstract Moderate to severe losses can be treated using the loss circulation composition involving nanomaterial-based dispersion and a chemical activator. The nanomaterial employed is an environmentally friendly type of nanosilica. The composition facilitates delayed gelling of nanomaterial-based dispersion. One key benefit of this technology is that it can place the composition into the target loss circulation zone before the nanomaterial-based dispersion gels up. This ensures that the treatment fluid does not set prematurely before reaching the target zone. It is possible to effectively use the newly developed system up to 300°F. In this study, experiments have been carried out on three different types of nanomaterials that have varying surface charges and particle sizes. Two of the nanomaterials have negatively charged nanomaterial-based dispersions and particles measuring 5nm and 17nm in size, whilst the remaining nanomaterial has a positively charged nanomaterial-based dispersion and particles that are larger than 17nm. Moreover, two different types of chemical activators have been employed, namely organic and inorganic activators, whilst their impacts on gelling times have also been assessed. The gelling time experiments were carried out at four different temperatures starting from 150 °C to 300 °C with increment of 50 °C in each experiment. This research also examined the impacts of activator concentration and different shear rates on the gelling times of the three nanomaterial-based dispersions, whilst permeability plugging tests were carried out using 2mm slotted disks in order to assess their effectiveness in controlling moderate to severe losses.
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Liang, Hong. "Synthesis, Characterization, and Tribological Applications of Nanomaterials." In STLE/ASME 2008 International Joint Tribology Conference. ASMEDC, 2008. http://dx.doi.org/10.1115/ijtc2008-71057.
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Nanomaterials play important roles in tribolgy and manufacturing. This lecture provides an opportunity for us to review and learn the knowledge and techniques that have been involved in nanomaterials and nanotribology areas. Targeting tribological applications, a brief history of nanoparticulates, dated back more than 2500 years, will be given briefly. The classification and synthesis of nanoparticles will be followed by nanomaterils and nanocomposites, their characterization techniques, and mechanical, tribological, chemical, and physical properties. Discussion ends with summary of applications.
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Jiao, Lihong Heidi, and Nael Barakat. "Incorporation of Hands-On Activities in Learning Nanomaterials." In ASME 2011 International Mechanical Engineering Congress and Exposition. ASMEDC, 2011. http://dx.doi.org/10.1115/imece2011-62598.
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For decades, nanomaterials, especially nanoparticles, have received extensive attention from the research community and have gained increasing importance in many industries. Growing production and utilization of nanomaterials result in a significant need for a relevant and skilled workforce. To meet these growing needs, the course “Fundamentals of Nanotechnology” was developed in the School of Engineering (SOE) at Grand Valley State University (GVSU) as one part of the Nanotechnology curriculum development plan sponsored by the National Science Foundation (NSF). Nanomaterials is one of the main topics covered in this course. Many concepts related to nanomaterials are both theoretical and abstract, which are difficult for students to grasp. This paper describes the hands-on lab activities incorporated to enhance the students’ learning and mastery of the subject. Through these hands-on activities, students learned to synthesize zero-dimensional and two-dimensional nanomaterials and characterized different properties of these nanomaterials. Students explored the physical and optical properties of nanoparticles, particle-to-particle aggregation, and applications of nanoparticles as sensors used in different fields. This paper presents the role of these hands-on activities in enhancing the students’ understanding of the theoretical nanomaterial concepts. These lab activities were assessed and results of this assessment from the first offering of the course are presented.
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Gernand, Jeremy M., and Elizabeth A. Casman. "Selecting Nanoparticle Properties to Mitigate Risks to Workers and the Public: A Machine Learning Modeling Framework to Compare Pulmonary Toxicity Risks of Nanomaterials." In ASME 2013 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/imece2013-62687.
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Due to their size and unique chemical properties, nanomaterials have the potential to interact with living organisms in novel ways, leading to a spectrum of negative consequences. Though a relatively new materials science, already nanomaterial variants in the process of becoming too numerous to be screened for toxicity individually by traditional and expensive animal testing. As with conventional pollutants, the resulting backlog of untested new materials means that interim industry and regulatory risk management measures may be mismatched to the actual risk. The ability to minimize toxicity risk from a nanomaterial during the product or system design phase would simplify the risk assessment process and contribute to increased worker and consumer safety. Some attempts to address this problem have been made, primarily analyzing data from in vitro experiments, which are of limited predictive value for the effects on whole organisms. The existing data on the toxicity of inhaled nanomaterials in animal models is sparse in comparison to the number of potential factors that may contribute to or aggravate nanomaterial toxicity, limiting the power of conventional statistical analysis to detect property/toxicity relationships. This situation is exacerbated by the fact that exhaustive chemical and physical characterization of all nanomaterial attributes in these studies is rare, due to resource or equipment constraints and dissimilar investigator priorities. This paper presents risk assessment models developed through a meta-analysis of in vivo nanomaterial rodent-inhalational toxicity studies. We apply machine learning techniques including regression trees and the related ensemble method, random forests in order to determine the relative contribution of different physical and chemical attributes on observed toxicity. These methods permit the use of data records with missing information without substituting presumed values and can reveal complex data relationships even in nonlinear contexts or conditional situations. Based on this analysis, we present a predictive risk model for the severity of inhaled nanomaterial toxicity based on a given set of nanomaterial attributes. This model reveals the anticipated change in the expected toxic response to choices of nanomaterial design (such as physical dimensions or chemical makeup). This methodology is intended to aid nanomaterial designers in identifying nanomaterial attributes that contribute to toxicity, giving them the opportunity to substitute safer variants while continuing to meet functional objectives. Findings from this analysis indicate that carbon nanotube (CNT) impurities explain at most 30% of the variance pulmonary toxicity as measured by polymorphonuclear neutrophils (PMN) count. Titanium dioxide nanoparticle size and aggregation affected the observed toxic response by less than ±10%. Difference in observed effects for a group of metal oxide nanoparticle associated with differences in Gibbs Free Energy on lactate dehydrogenase (LDH) concentrations amount to only 4% to the total variance. Other chemical descriptors of metal oxides were unimportant.
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Kujawski, Mark P., Leela Rakesh, Stanley Hirschi, Brad D. Falhman, Joana C. Finegan, Ekmagage Don N. Almeida, Nicole M. Bullard, Jason Hiller, Michael P. Lalko, and Jeremy V. Miller. "Steady Shear and Linear Viscoelastic Properties of Melt Mixed and Injection Molded Samples of Polypropylene, Polystyrene, and Polyethylene Nanocomposites With Carbon Black, Vapor Grown Carbon Fibers, and Carbon Nanotubes." In ASME 2006 International Mechanical Engineering Congress and Exposition. ASMEDC, 2006. http://dx.doi.org/10.1115/imece2006-15814.
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Tailoring the rheological properties of polymers is important for practical applications such as the stabilization of polymer emulsions, blends, and foams. Nanomaterial (i.e. Carbon Nanotubes, Carbon Nanofibers, Dendrimers, and Carbon Black) are an excellent way to modify the mechanical, thermal, electrical, and optical properties of materials. This paper presents steady shear and linear viscoelastic oscillation testing of three polymers: Polyethylene (PE); Polypropylene (PP); and Polystyrene (PS). These polymers were studied in bulk form and as composites containing designated volume fractions of nanomaterials over a range of processing temperatures and conditions. The nanomaterials investigated in this study include Carbon Black, Vapor Grown Carbon Nanofibers, Multiwalled Carbon Nanotubes, Single Walled Carbon Nanotubes, and COOH functionalized Single Walled Carbon Nanotubes. The nanocomposite samples used for rheological experimentation were manufactured by melt mixing and injection molding. We will address whether the melt rheological measurements can unequivocally detect the co-continuous composition range in such systems. We will also investigate the melt flow rate through nanomaterial concentration variations, as well as discuss the storage modulus (G'), viscous modulus (G"), and complex viscosity of homogeneous polymer materials versus carbon nanocomposite material at various frequencies.
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Hentges, Nicholas, Gurjap Singh, and Albert Ratner. "Experimental Investigation of the Settling of Carbon-Based Nanoparticles in Renewable Jet Fuel." In ASME 2020 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2020. http://dx.doi.org/10.1115/imece2020-24157.
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Abstract Recent studies have shown that the addition of nanomaterials to fuels can improve combustion characteristics. A downside, however, is that these mixtures are unstable and prone to phase separation. Finding stable nanomaterial-fuel mixtures are required to make these mixtures viable for practical use. Current research studied the stability of Renewable jet fuel combined with multiple nanomaterial additives being acetylene black, graphene nanoparticles, and multiwalled carbon nanotubes, at 1.0% w/w ratio. Results were compared with prior research and it was shown that renewable jet fuel had a similar effect on settling as soy biodiesel and the results indicated that the fuel’s bulk viscosity was not a major factor determining the stability of the nanofuel.
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Luo, Xiao-zhong James. "Nanomaterial Registry: A resource for biological and environmental interactions of nanomaterials." In 2012 IEEE International Conference on Bioinformatics and Biomedicine Workshops (BIBMW). IEEE, 2012. http://dx.doi.org/10.1109/bibmw.2012.6470262.
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Alsadi, Jamal, Ronald M. Hernandez, Sarah Haidar Hasham, Chandra Kumar Dixit, Alok Dubey, and Aziz Unnisa. "Critical Review on Recent Advancement in Nanotechnology for Biomedical Application." In International Conference on Recent Advancements in Biomedical Engineering. Switzerland: Trans Tech Publications Ltd, 2022. http://dx.doi.org/10.4028/p-2rg620.
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The new update in advancement in nanotechnology has engaged to develop a new nanomaterial with a different functional property. The morphology modification of nanoparticles has exhibited excellent physio-chemical properties such as high reactivity and absorption rate, photochemical and magnetic property, and larger surface area. Moreover, biomedical application of nanoparticles are yet a hard tool to use for therapeutic application owing to its limits such as Pitiable target specificity, bio-compatibility, low photostability, toxicity to organically, poor blood retention and cellular absorption. Therefore advancement in nanotechnology is required to overcome these defects. In this background, new nanomaterials are identified with suitable biological, chemical and physical properties, which suits the required demands of the application. In this mini-review, we have covered the recent focuses of nanomaterials for biomedical application.
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Tanguay, Robert L., Lisa Truong, Tatiana Zaikova, and James E. Hutchison. "Rapid In Vivo Assessment of the Nano/Bio Interface." In ASME 2013 2nd Global Congress on NanoEngineering for Medicine and Biology. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/nemb2013-93153.
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Recent advances in nanoscience offer great promise for the nanomedicine sector. These advances in the nanotechnology field will undoubtedly increase both human and environmental exposures to engineered nanomaterials. Whether these exposures pose a significant risk remains uncertain. Despite recent collective progress there remain gaps in our understanding of the nanomaterials physiochemical properties that drive or dictate biological compatibility. The development and implementation of rapid relevant and efficient testing strategies to assess these emerging materials prior to large-scale exposures could help advance this exciting field. I will present a powerful approach that utilizes a dynamic in vivo zebrafish embryonic assay to rapidly define the biological responses to nanomaterial exposures. Early developmental life stages are often uniquely sensitive to environmental insults, due in part to the enormous changes in cellular differentiation, proliferation and migration required to form the required cell types, tissues and organs. Molecular signaling underlies all of these processes. Most toxic responses result from disruption of proper molecular signaling, thus, early developmental life stages are perhaps the ideal life stage to determine if nanomaterials perturb normal biological pathways. Through automation and rapid throughput approaches, a systematic and iterative strategy has been deployed to help elucidate the nanomaterials properties that drive biological responses.
Reports on the topic "Nanomateriale"
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Pietrass, Tanja, David Fredrick Teter, and Karen Elizabeth Kippen. Integrated Nanomaterials. Office of Scientific and Technical Information (OSTI), March 2018. http://dx.doi.org/10.2172/1425778.
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Hellman, Frances. Energetics of Nanomaterials. Office of Scientific and Technical Information (OSTI), December 2004. http://dx.doi.org/10.2172/898911.
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Alexandra Navrotsky, Brian Woodfield, Juliana Boerio-Goates, and Frances Hellman. Energetics of Nanomaterials. Office of Scientific and Technical Information (OSTI), January 2005. http://dx.doi.org/10.2172/888867.
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Navrotsky, Alexandra. "Energetics of Nanomaterials". Office of Scientific and Technical Information (OSTI), January 2005. http://dx.doi.org/10.2172/836441.
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Hermans-Blackburn, Leone, and Richard A. Maresca. Nanomaterials Commercialization Center. Fort Belvoir, VA: Defense Technical Information Center, February 2013. http://dx.doi.org/10.21236/ada586723.
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Doorn, Stephen. Nanophotonics and Optical Nanomaterials. Office of Scientific and Technical Information (OSTI), April 2016. http://dx.doi.org/10.2172/1248576.
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Hutchison, James E., Eric Johnson, Karen Guillemin, John Postlethwait, Mark Lonergan, Andy Berglund, Steve Kevan, Richard Taylor, and Dave Johnson. Safer Nanomaterials and Nanomanufacturing. Fort Belvoir, VA: Defense Technical Information Center, February 2013. http://dx.doi.org/10.21236/ada584768.
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Stauber, Rudolf, and Christina Cecco. Nanomaterials in Automotive Applications. Warrendale, PA: SAE International, May 2005. http://dx.doi.org/10.4271/2005-08-0201.
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Kennedy, Alan, Jonathon Brame, Taylor Rycroft, Matthew Wood, Valerie Zemba, Charles Weiss, Matthew Hull, Cary Hill, Charles Geraci, and Igor Linkov. A definition and categorization system for advanced materials : the foundation for risk-informed environmental health and safety testing. Engineer Research and Development Center (U.S.), September 2021. http://dx.doi.org/10.21079/11681/41803.
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Novel materials with unique or enhanced properties relative to conventional materials are being developed at an increasing rate. These materials are often referred to as advanced materials (AdMs) and they enable technological innovations that can benefit society. Despite their benefits, however, the unique characteristics of many AdMs, including many nanomaterials, are poorly understood and may pose environmental safety and occupational health (ESOH) risks that are not readily determined by traditional risk assessment methods. To assess these risks while keeping up with the pace of development, technology developers and risk assessors frequently employ risk-screening methods that depend on a clear definition for the materials that are to be assessed (e.g., engineered nanomaterial) as well as a method for binning materials into categories for ESOH risk prioritization. In this study, we aim to establish a practitioner-driven definition for AdMs and a practitioner-validated framework for categorizing AdMs into conceptual groupings based on material characteristics. The definition and categorization framework established here serve as a first step in determining if and when there is a need for specific ESOH and regulatory screening for an AdM as well as the type and extent of risk-related information that should be collected or generated for AdMs and AdM-enabled technologies.
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Ahtiainen, Jukka, and Elina Väänänen. Regulatory Safety Assessment of Nanomaterials. Nordic Council of Ministers, September 2012. http://dx.doi.org/10.6027/tn2012-515.
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