Academic literature on the topic 'Nanoparticle'
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Journal articles on the topic "Nanoparticle"
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Wang, Cheng, Hong Lin, and Yu Yue Chen. "Study on the Preparation of Steady-State Chitosan Nanoparticle as Silk-Fabric Finishing Agent." Advanced Materials Research 175-176 (January 2011): 745–49. http://dx.doi.org/10.4028/www.scientific.net/amr.175-176.745.
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The chitosan nanoparticles can be prepared by ionotropic gelation method in dispersion system. Chitosan nanoparticle has advantages of both the chitosan and the nano particles, and so it has a wide application in the textile finishing field. In this paper, the effects of the concentration of TPP, Span-80, deposited time and pH value on the diameter distribution of the chitosan nanoparticles are discussed in order to obtain the optimized preparation technics of steady state chitosan nanoparticle. The results show that chitosan nanoparticles are successfully prepared by ionotropic gelation method. Under the optimized preparation technics, chitosan nanoparticles disperse homogeneously in the system and have a good steady state. The average diameter of chitosan nanoparticle in the dispersion system is 20.82nm. Compared with the ordinary silk fabric, the B. mori silk fabric treated with chitosan nanoparticle dispersion system has better deepen effect of reactive dyes. The chitosan nanopartilce dispersion system is helpful to improve the dye uptake and dye fixation of silk fabrics.
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Li, Meng, Liqiang Lin, Ruyan Guo, Amar Bhalla, and Xiaowei Zeng. "Numerical investigation of size effects on mechanical behaviors of Fe nanoparticles through an atomistic field theory." Journal of Micromechanics and Molecular Physics 02, no. 03 (September 2017): 1750010. http://dx.doi.org/10.1142/s2424913017500102.
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At nanoscale, the mechanical response of nanoparticles is largely affected by the particle size. To assess the effects of nanoparticle size (e.g., nanoparticle’s volume, cross-sectional area and length) on mechanical behaviors of bcc Fe nanoparticles under compressive loading, an atomistic field theory was introduced in current study. In the theory, atomistic definitions and continuous local density functions of fundamental physical quantities were derived. Through the atomistic potential-based method, the mechanical responses of bcc Fe nanoparticles were analyzed in different sizes. The simulation results reveal that the ultimate stress decreases as Fe nanoparticle’s volume, cross-sectional area or length increases under compressive loading. Nonetheless, the Young’s modulus increases as nanoparticle size increases. In addition, for a fixed finite volume nanoparticle, this study indicates that the ultimate stress will increase as strain rate increases, but Young’s modulus will decrease with increasing strain rate. A loading–unloading study illustrates the energy dissipation due to irreversible structure changes in Fe nanoparticles.
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Karatrantos, Argyrios, Yao Koutsawa, Philippe Dubois, Nigel Clarke, and Martin Kröger. "Miscibility and Nanoparticle Diffusion in Ionic Nanocomposites." Polymers 10, no. 9 (September 10, 2018): 1010. http://dx.doi.org/10.3390/polym10091010.
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We investigate the effect of various spherical nanoparticles in a polymer matrix on dispersion, chain dimensions and entanglements for ionic nanocomposites at dilute and high nanoparticle loading by means of molecular dynamics simulations. The nanoparticle dispersion can be achieved in oligomer matrices due to the presence of electrostatic interactions. We show that the overall configuration of ionic oligomer chains, as characterized by their radii of gyration, can be perturbed at dilute nanoparticle loading by the presence of charged nanoparticles. In addition, the nanoparticle’s diffusivity is reduced due to the electrostatic interactions, in comparison to conventional nanocomposites where the electrostatic interaction is absent. The charged nanoparticles are found to move by a hopping mechanism.
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Ningrum, Wulan Agustin, W. Wirasti, Yulian Wahyu Permadi, and Fida Faiqatul Himmah. "Uji Sediaan Lotion Nanopartikel Ekstrak Terong Belanda Sebagai Antioksidan." Jurnal Ilmiah Kesehatan 14, no. 1 (March 29, 2021): 99. http://dx.doi.org/10.48144/jiks.v14i1.539.
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Abstrak. Nanopartikel adalah suatu teknologi formulasi suatu partikel yang terdispersi pada ukuran nanometer atau skala per seribu mikron. Tujuan penelitian ini adalah membuat sediaan lotion dari nanopartikel ekstrak terong belanda sebagai antioksidan. Teknologi nanopartikel ekstrak terong belanda mempunyai efek yang sangat baik sebagai antioksidan, sehingga dimungkinkan dibuat sediaan sebagai bahan kosmetik Penelitian ini menguji nanopertikel ekstrak terong belanda sebagai antioksidan sediaan lotion. Metode ekstraksi yang digunakan dalam penelitian ini adalah maserasi menggunakan pelarut metanol. Pembuatan teknologi nanopartikel ekstrak terong belanda menggunakan metode nanopertikel berbasis biopolimer. Nanopartikel ekstrak terong belanda diformulasi menjadi sediaan lotion. Uji aktivitas antioksidan dilakukan dengan metode penangkap radikal bebas DPPH. Parameter aktivitas antioksidan yaitu IC50 (Inhibititon Concentration), sedangkan uji sediaan lotion terdiri dari pH, viskositas, stabilitas, organoleptis (warna, aroma, bentuk). Hasil dari penelitian menunjukkan Lotion ekstrak terong belanda yang dihasilkan memenuhi syarat evaluasi fisik sediaan. Nilai IC50 lotion nanopartikel ekstrak terong belanda adalah 62 µg/mL. Ukuran partikel dari ekstrak nanopartikel adalah 182,4 µm. Lotion nanopartikel ekstrak terong belanda mempunyai kestabilan yang baik. Perlu dilakukan pembuatan bentuk sediaan yang lain dengan tujuan sebagai kosmetika.
Kata kunci : Ekstrak terong belanda, nanopartikel, lotion, IC50
Tamarillo Extract Nanoparticle Lotion Preparation Test As Antioxidant
Abstract. Nanoparticles are a technology for the formulation of particles that are dispersed at the nanometer size or scale per thousand microns. The purpose of this study was to make lotion preparations from the nanoparticles of tamarillo extract as an antioxidant. The nanoparticle technology of tamarillo extract has a very good effect as an antioxidant, so it is possible to make a cosmetic ingredient. This study tested the nanoparticle extract of tamarillo as an antioxidant for lotion preparations. The extraction method used in this research is maceration using methanol as a solvent. The manufacture of tamarillo extract nanoparticle technology used a biopolymer-based nanoperticle method. The nanoparticles of tamarillo extract were formulated into lotions. The antioxidant activity test was carried out using the DPPH free radical scavenger method. The parameter of antioxidant activity is IC50 (Inhibititon Concentration), while the lotion preparation test consists of pH, viscosity, stability, organoleptic (color, aroma, shape). The results showed that the tamarillo extract lotion produced met the requirements for the physical evaluation of the preparation. The IC50 value of tamarillo extract nanoparticle lotion was 62 µg / mL. The particle size of the nanoparticle extract was 182.4 µm. Tamarillo extract nanoparticle lotion has good stability. It is necessary to make other dosage forms for the purpose of cosmetics.
Keywords: Tamarillo extract, nanoparticle, lotion, IC50
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Shannahan, Jonathan. "The biocorona: a challenge for the biomedical application of nanoparticles." Nanotechnology Reviews 6, no. 4 (August 28, 2017): 345–53. http://dx.doi.org/10.1515/ntrev-2016-0098.
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AbstractFormation of the biocorona on the surface of nanoparticles is a significant obstacle for the development of safe and effective nanotechnologies, especially for nanoparticles with biomedical applications. Following introduction into a biological environment, nanoparticles are rapidly coated with biomolecules resulting in formation of the nanoparticle-biocorona. The addition of these biomolecules alters the nanoparticle’s physicochemical characteristics, functionality, biodistribution, and toxicity. To synthesize effective nanotherapeutics and to more fully understand possible toxicity following human exposures, it is necessary to elucidate these interactions between the nanoparticle and the biological media resulting in biocorona formation. A thorough understanding of the mechanisms by which the addition of the biocorona governs nanoparticle-cell interactions is also required. Through elucidating the formation and the biological impact of the biocorona, the field of nanotechnology can reach its full potential. This understanding of the biocorona will ultimately allow for more effective laboratory screening of nanoparticles and enhanced biomedical applications. The importance of the nanoparticle-biocorona has been appreciated for a decade; however, there remain numerous future directions for research which are necessary for study. This perspectives article will summarize the unique challenges presented by the nanoparticle-biocorona and avenues of future needed investigation.
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Mohammed, Tawfik Mahmood. "Mathematical modeling of the electronic structure of Titanium dioxide \((TiO_2 )_6\) nanoparticles." University of Aden Journal of Natural and Applied Sciences 24, no. 2 (March 22, 2022): 519–26. http://dx.doi.org/10.47372/uajnas.2020.n2.a19.
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The calculation of the number of atoms of the given dimensional nanoparticle, composed of different type atoms has been researched in this work. The calculations have been carried out for nanoparticles of titanium dioxide. Theoretical visual models have been configured, and quantum – mechanical calculations have been carried out for \((TiO_2 )_6\) nanoparticle. The calculations for titanium dioxide nanoparticle have been carried out on the basis of Gaussian atomic orbitals. Besides, Gaussian functions have been used as atomic orbitals. The numerical values of unknown coefficients of the linear combination of atomic orbitals of the atoms of the titanium nanoparticle have been found from the solution of Hartree–Fock–Roothaan (HFR) equations.The values of orbital energies, ionization potential, and the total electronic energy of titanium dioxide nanoparticles have been determined. The calculations show that ,titanium dioxide nanoparticle is tough, electrophile, and stable dielectric, material. The effective charge of atoms have been calculated, and the theoretical visual mode of titanium dioxide nanopartical have been constructed.
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Wang, Shenqing, Xiliang Yan, Gaoxing Su, and Bing Yan. "Cytotoxicity Induction by the Oxidative Reactivity of Nanoparticles Revealed by a Combinatorial GNP Library with Diverse Redox Properties." Molecules 26, no. 12 (June 14, 2021): 3630. http://dx.doi.org/10.3390/molecules26123630.
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It is crucial to establish relationship between nanoparticle structures (or properties) and nanotoxicity. Previous investigations have shown that a nanoparticle’s size, shape, surface and core materials all impact its toxicity. However, the relationship between the redox property of nanoparticles and their toxicity has not been established when all other nanoparticle properties are identical. Here, by synthesizing an 80-membered combinatorial gold nanoparticle (GNP) library with diverse redox properties, we systematically explored this causal relationship. The compelling results revealed that the oxidative reactivity of GNPs, rather than their other physicochemical properties, directly caused cytotoxicity via induction of cellular oxidative stress. Our results show that the redox diversity of nanoparticles is regulated by GNPs modified with redox reactive ligands.
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Zhang, Yong, Xiao Jing Zhao, Qiang He, Ye Jun, and Qin Po Niu. "Experimental Study of Nanoparticle as Oil Additives." Advanced Materials Research 230-232 (May 2011): 288–92. http://dx.doi.org/10.4028/www.scientific.net/amr.230-232.288.
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Cu nanoparticles as N32 base oil additives were studied in the paper. The structure of Cu nanoparticlcs was characterized by Transmission Electron Microscopy (TEM) and X-ray powder diffraction spectroscope (XRD). The widely used steel-steel friction system was chosen to test the feasibility and practicality of Cu nanoparticles as bearing lubricant additives. The results show that N32 base oil with 0.5% Cu nanoparticle can improve the test sample contact fatigue life than pure N32 base oil.
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Wang, Xijun. "The Magnetic Nanoparticle Movement in Magnetic Fluid Characterized by the Laser Dynamic Speckle Interferometry." Journal of Nanomaterials 2014 (2014): 1–7. http://dx.doi.org/10.1155/2014/287813.
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A dual scanning laser speckle interferometry experiment was designed to observe the dynamic behavior of the magnetic fluid actuated by a magnetic field. In order to improve the spatial resolution of the dynamic speckle measurement, the phase delay scanning was used to compensate the additional phase variation which was caused by the transverse scanning. The correlation coefficients corresponding to the temporal dynamic speckle patterns within the same time interval scattering from the nanoparticles were calculated in the experiment on nanoscale magnetic clusters. In the experiment, the speckle of the magnetic nanoparticle fluid movement has been recorded by the lens unmounted CCD within the interferometry strips, although the speckle led to the distinguished annihilation of the light coherence. The results have showed that the nanoparticle fluid dynamic properties appeared synergistically in the fringe speckles. The analyses of the nanoparticle's relative speed and the speckle pattern moving amount in the fringes have proved the nanoparticle’s movement in a laminar flow in the experiment.
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Bao, Lingling, Chaoyang Zhong, Pengfei Jie, and Yan Hou. "The effect of nanoparticle size and nanoparticle aggregation on the flow characteristics of nanofluids by molecular dynamics simulation." Advances in Mechanical Engineering 11, no. 11 (November 2019): 168781401988948. http://dx.doi.org/10.1177/1687814019889486.
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Molecular dynamics simulation is used to investigate the flow characteristics of Cu–Ar nanofluids considering the influence of nanoparticle size and nanoparticle aggregation. Nanofluids viscosity is calculated by equilibrium molecular dynamics based on Green–Kubo equation. Results demonstrate that the viscosity of nanofluids decreases with the increase of nanoparticle size. In addition, nanoparticle aggregation results in the increase of the nanofluids viscosity. Compared with nanoparticle size, nanoparticle aggregation has a larger impact on viscosity. Nanofluids flowing in parallel-plate nanochannels are simulated. The velocity profiles are studied through three nanoparticle sizes (11.55, 14.55, and 18.33 Å) and four nanoparticle aggregate configurations. Results show that the velocity profile of 14.55 Å nanoparticle size is larger than that of other two nanoparticle sizes. As for four nanoparticles, the nanoparticles clustering as a line leads to the maximum velocity profile, while the nanoparticles clustering as a cube causes the minimum velocity profile. Compared with viscosity, nanoparticle aggregation has a greater effect on the velocity profile. When the nanoparticles are evenly distributed, the influence of viscosity on velocity profiles is dominant. Otherwise, the aggregation, aggregate configuration, and distribution of nanoparticles have a dominant impact on the flow characteristics of nanofluids.
Dissertations / Theses on the topic "Nanoparticle"
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Rousseau, Youri. "Hybridation des technologies de jets de nanoparticules et de PVD pour la réalisation d’architectures nanocomposites fonctionnelles." Thesis, Université Paris-Saclay (ComUE), 2016. http://www.theses.fr/2016SACLS347.
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Les films nanocomposites sont des revêtements composés de nanoparticules enrobées dans une matrice solide d’un matériau différent. L’intérêt de ces matériaux réside dans leur capacité à exploiter les caractéristiques inédites des nano-objets qu’ils contiennent tout en bénéficiant des propriétés de résistance mécanique et chimique de la matrice. Ces composites disposent de propriétés très prometteuses pour un grand nombre d’applications comme le photovoltaïque ou la photocatalyse. Plusieurs procédés de synthèse existants permettent de produire des matériaux nanocomposites par des méthodes physiques ou chimiques (co-pulvérisation, sol-gel,…). Cependant, aucun n’est assez flexible pour envisager la synthèse d’une large gamme de nanocomposites par le même procédé. Ceci est un frein au développement à l’échelle industrielle de ce type de matériaux. Le premier objectif de la thèse est de développer un procédé original de synthèse de films nanocomposites. Ce procédé présente un caractère universel en ce qu’il permet un choix a priori illimité dans la nature des nanoparticules et celle de la matrice. Le procédé développé combine un jet de nanoparticules sous vide formé par une lentille aérodynamique à un dispositif de pulvérisation magnétron qui permet de déposer la matrice. Le jet de nanoparticules permet de coupler toute source de nanoparticules à la pulvérisation. Les nanoparticules peuvent être soit synthétisées in situ en phase gazeuse, soit synthétisées préalablement en voie liquide. Une grande variété de nanoparticules peut donc être utilisée. La pulvérisation magnétron permet par ailleurs de disposer d’une très large gamme de matériaux pour la matrice (métaux, céramique, polymère). Dans le cadre de cette thèse, deux types de sources de nanoparticules ont été utilisés. Le premier est un réacteur de pyrolyse laser et le second un générateur d’aérosol. Le réacteur de pyrolyse laser permet une synthèse in-situ des nanoparticules en phase gazeuse alors que le générateur d’aérosol permet d’utiliser une suspension de nanoparticules préalablement synthétisées. Afin d’éprouver la robustesse du procédé de co-dépôt, deux types de matériaux nanocomposites ont été développés. Le premier matériau étudié est composé de nanoparticules d’or sphériques de 35 nm de diamètre, synthétisées préalablement par voix liquide, dans une matrice de silice. Le but ici est de bénéficier des propriétés optiques uniques des nanoparticules d’or dans un film résistant mécaniquement et chimiquement. Les caractérisations réalisées sur ces matériaux ont permis d’optimiser la concentration en nanoparticules d’or dans les films de manière à garder des propriétés mécaniques et chimiques compatibles avec les applications tout en gardant des propriétés optiques satisfaisantes. Le second type de matériaux étudiés est composé de nanoparticules semi-conductrices synthétisées in situ par pyrolyse laser et d’une matrice métallique. La synthèse de ce matériau permet de démontrer la flexibilité du procédé de co-dépôt à synthétiser une large gamme de films nanocomposites. Enfin, la robustesse du procédé ayant été démontrée, la conception d’un pilote industriel a été entreprise. Le but final étant de disposer d’une machine répondant aux exigences industrielles dans l’optique d’un transfert technologiqueThe nanocomposite films are coatings of nanoparticles embedded in a solid matrix of a different material. The advantage of these materials is their ability to exploit the unique properties of nano-objects while benefiting of the mechanical and chemical resistance properties of the matrix. These composites have very promising properties for many applications such as photovoltaics and photocatalysis. Several existing synthetic methods can produce nanocomposite materials by physical or chemical methods (co-sputtering, sol-gel, ...). However, none is flexible enough to consider the synthesis of a wide range of nanocomposites by the same method. This is an obstacle to the development on an industrial scale of this type of material. The first objective of the thesis is to develop an original synthesis process of nanocomposite films. This method is universal in which it presents no limit in the choice of nanoparticles and matrix. The developed method combines vacuum nanoparticle jets formed by an aerodynamic lens with a magnetron sputtering device for depositing the matrix. The nanoparticle jets can be coupled with any source of nanoparticles. Nanoparticles may be synthesized in situ in the gas phase or beforehand solution synthesis. A wide variety of nanoparticles can be used. Magnetron sputtering also enables to have a very wide range of materials for the matrix (metal, ceramic, polymer). During this thesis, two types of nanoparticles sources were used. The first one is a laser pyrolysis reactor and the second is an aerosol generator. The laser pyrolysis reactor enables in-situ gas phase synthesis of the nanoparticles while the aerosol generator use a suspension of previously synthesized nanoparticles. To test the robustness of the co-deposition process, two types of nanocomposite materials have been developed. The first material is composed of 35 nm spherical gold nanoparticles, chemically synthesized, in a silica matrix. The goal here is to benefit from the unique optical properties of gold nanoparticles in a film mechanically and chemically resistant. The characterizations carried out on these materials have optimized the gold nanoparticle concentration in the films to keep the mechanical and chemical properties compatible with applications while maintaining satisfactory optical properties. The second type of materials studied is composed of semiconductor nanoparticles in situ synthesized by laser pyrolysis and a metal matrix. The synthesis of this material demonstrates the flexibility of the co-deposition method to synthesize a wide variety of nanocomposite films. Finally, the design of an industrial pilot was undertaken. The final goal is to have a pilot-scale setup that meets industry requirements in the context of a technology transfer
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Tang, Lu. "Nanoparticules mimes des propriétés biologiques des GAGs : vers un inhibiteur sélectif de CXCL12." Thesis, Université Paris-Saclay (ComUE), 2015. http://www.theses.fr/2015SACLS072.
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L'Héparane Sulfate (HS), un polysaccharide linéaire, module les activités biologiques de nombreuses protéines. Afin d'élucider les interactions entre l'HS et les protéines, la synthèse chimique d'HS est un outil précieux, mais elle peut être difficile. Notre équipe a montré que des mélanges combinatoires obtenus par auto-assemblage de différentes combinaisons de dérivés disaccharidiques (lactose et lactose persulfaté) sur surfaces planes d'or peuvent reconnaître spécifiquement certaines protéines se liant à l'HS, telles que les isoformes de la chimiokine CXCL12 ou IFNγ. Avec ces dérivés, nous avons réalisé un auto-assemblage sur des nanoparticules d'or. Mais à cause de la toxicité des nanoparticules d'or, nous avons aussi adapté cette méthode à des nanoparticules lipidiques. En utilisant les conditions qui ont déjà été améliorées pendant la synthèse des dérivés lactose et lactose persulfaté, nous avons préparé deux autres dérivés disaccharidiques plus proches de la structure réelle d'HS. Ces nouveaux dérivés sont utilisés pour réaliser des nanoparticules d'or et nanoparticules lipidiques afin de comparer les propriétés avec les lactose et lactose persulfaté. Les tests d'affinité avec différentes protéines sont en cours de réalisationHéparan Sulfate (HS) is a linear polysaccharide that modulates the biological activities of numerous proteins. In order to elucidate the interaction between HS and proteins, the synthesis of HS is an invaluable tool, but the synthesis is sometimes difficult. Our group has demonstrated that the combinatorial mixtures obtained by self-assembly of different combinations of disaccharide derivatives (lactose and persulfated lactose) on gold plan surfaces could recognize specifically some HS binding proteins, such as the isoforms of the chemokine CXCL12 or IFNγ. Because of the toxicity of gold nanoparticles, we have also adapted this method to lipid nanoparticles. Using the conditions that have already improved during the synthesis of lactose and persulfated lactose derivatives, we have synthesized two other disaccharide derivatives, which were closer to the real structure of HS. These new derivatives were used to prepare the gold and lipid nanoparticles at the aim of comparing the properties with lactose and persulfated lactose. The tests of affinities with different proteins are in progress
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Smith, Beverly. "Investigating Thermal Transformations of Ligand-Stabilized Gold Nanoparticles: Influence of the Structural Attributes of the Nanoparticle and Its Environment on Thermal Stability." Thesis, University of Oregon, 2015. http://hdl.handle.net/1794/19259.
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Ligand-stabilized metal nanoparticles (LSNPs) have garnered significant attention for use in applications including sensing, catalysis, and thin film fabrication. Many uses rely on the size-dependent properties of the metal nanoparticle core. Therefore, preservation of nanoparticle core size is of paramount importance. In other uses, the low processing temperatures afforded by metal LSNPs make them attractive as precursors for conductive thin films. In these distinctly different applications, understanding nanoparticle thermal stability is crucial.
A key finding of this research is that nanoparticle sintering is dependent upon both core size and ligand functionality. Multi-technique analysis of four types of gold nanoparticles (AuNPs) with different ligand compositions and core sizes illustrates that more volatile ligands reduce the onset temperature for sintering. Also, AuNPs of larger core size with the same ligand composition exhibit lower sintering onset temperatures. Correlation between measurements reveals that only a small amount of ligand loss is necessary to trigger rapid sintering and that ligands are excluded to the surface of the porous gold films.
AuNPs with ligand shells composed of two alkanethiols of different chain length and volatility indicate that the onset temperature of sintering can be tuned further through incorporation of a small amount of more volatile alkanethiol into a ligand shell of lower volatility. Mixed LSNPs further reveal that AuNP thermal stability depends upon the ligand shell composition and its intermolecular interactions, which can result in markedly different sintering behavior for different ligand compositions. Long-chain alkanethiol AuNPs sinter after only a small amount of ligand loss, whereas short-chain alkanethiol AuNPs sinter following complete ligand loss and the formation of metastable bare AuNPs. Heated AuNP films prepared with mixed-ligand AuNPs exhibit ligand-dependent differences in film morphology.
To probe AuNP thermal stability in 2D-assemblies, self-assembly using larger ‘marker’ nanoparticles enables the study of small 1.5 nm AuNP arrays with successive TEM monitoring throughout ex situ heating. Monitoring images of the same area shows short-range (1-2 nm) nanoparticle migration/coalescence. In contrast to 3D assemblies, AuNP growth occurs at temperatures as low as 60 °C.
This dissertation includes previously published and unpublished co-authored material.10000-01-01
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McQuillan, Jonathan. "Bacterial-nanoparticle interactions." Thesis, University of Exeter, 2010. http://hdl.handle.net/10036/3101.
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Bionanotechnology is an intersection between biology and nanotechnology, a field in which novel applications for very small materials are being realised at an alarming rate. Nanoparticles have 3 dimensions that can be measured in nanometers, their small size conferring upon them different properties from individual atoms or the bulk material. The interactions between these unique materials and microorganisms are often toxic, thus have been exploited for antimicrobial applications. However, there is a considerable paucity of data for the underlying molecular mechanisms. This study has been carried out to investigate the interactions that occur between nanoparticles and bacteria with the objective of identifying these toxicological mechanisms and novel nanoparticle effects, using the model Gram negative organism Escherichia coli K12. This study has identified metal nanoparticles that are a superior vehicle for the delivery of toxic metal ions to E. coli. The nanoparticles associate with the bacterial surface, but do not cross the cell wall. They then dissolve, releasing a concentration of metal ions that accumulate at the bacterial-nanoparticle interface, enhancing the antibacterial efficacy compared to the concentration of metal ions in the bulk solution phase. Measurement of the whole transcriptome response to silver nanoparticles in comparison to the silver ion indicates that the different modes of ion delivery may induce a differential stress response. Moreover, this data identifies molecular mechanisms that are involved in the toxicity of this metal that is now becoming increasingly prevalent in society. The dissolution based toxic effects of zinc oxide nanoparticles are augmented by an interaction with ultra-violet light, offering an alternative mode for nanoparticle toxicity.
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Kang, Minkyung. "Single nanoparticle electrochemistry." Thesis, University of Warwick, 2017. http://wrap.warwick.ac.uk/99424/.
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This thesis presents various pipette-based techniques for resolving the electrochemical activities of single nanoentities (e.g., nanoparticles, NPs) in time and/or space. In particular, the work provides a framework for understanding the (electro)chemistry of single NPs and the development of tools to resolve them temporally and/or spatially. Through the use of the state-of-the-art instrumentation developed by the Warwick Electrochemistry & Interfaces Group (WEIG), electrochemical measurements with a “static” probe (i.e., micro-droplet electrochemical cell) have revealed detailed (temporally-resolved) information on the dynamics of the interaction of colloidal NPs (in solution) with electrode surfaces. Through careful data analysis, and supported by simulations, it has been demonstrated how current-time traces provide information on the physical dynamics of individual NPs on an electrode surface. This regime has been further applied to understand the electrodissolution of individual NPs and has revealed the complexity of the process, through carefully designed experiments and thorough quantitative analysis of large data sets. In addition, through the use of the aforementioned instrumentation, new scanning electrochemical probe microscopy (SEPM) regimes have been developed with a “dynamic” probe, providing spatial resolution. A greatly simplified nanoprobe configuration (i.e., a single channelled probe) has been proposed for simultaneous topography and electrochemical flux mapping at the nanoscale, implemented with a new scanning protocol in scanning ion conductance microscopy (SICM). This was directly applied in tandem with FEM simulations to observe and explain heterogeneities in the ion flux at and around individual catalytic NPs adhered to an inert conductive surface during catalytic turnover conditions with electrochemical activity information on surface heterogeneities at the nanoscale. Finally, to highlight the generalities of the approaches, a new configuration of scanning electrochemical microscopy (SECM) combined with SICM with a double-channelled nanoprobe has been introduced, demonstrating the simultaneous visualisation of topography and uptake rate on a biological entity (cell), which is quantified by finite element method (FEM) simulations. In this configuration the probe is multifunctional, delivering analytes to the cell surface, providing probe positional information and detecting changes in the uptake rate of electroactive molecules across the interface.
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Pranami, Gaurav. "Understanding nanoparticle aggregation." [Ames, Iowa : Iowa State University], 2009. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:3369880.
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Haghighat, Manesh Mohamad Javad Haghighat. "Effects of the Nanoparticle Protein Corona on Nanoparticle-Cell Membrane Interactions." Ohio University / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1597967288027448.
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Louie, Stacey Marie. "Characterization and Modeling of Macromolecules on Nanoparticles and Their Effects on Nanoparticle Aggregation." Research Showcase @ CMU, 2014. http://repository.cmu.edu/dissertations/396.
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The increasing production and usage of engineered nanoparticles has raised concerns about potential ecological and human exposures and the risks these novel materials may pose. Nanoparticles are often manufactured with an organic macromolecular coating, and they will attain further coatings of adsorbed natural organic matter (NOM) in the environment. The overall objective of this thesis is to improve our ability to quantify the effects of adsorbed coatings on nanoparticle fate in the environment. The physicochemical properties of the coating or the adsorbing macromolecule are expected to strongly mediate the surface interactions, and hence the environmental fate, of coated nanoparticles. To this end, this research focuses on assessing a coating characterization method and applying extensive characterization of NOM coatings to enable the development of correlations to predict nanoparticle deposition onto model environmental surfaces and aggregation. The first objective is to assess the applicability of a soft particle electrokinetic modeling approach to characterize adsorbed layer thickness, which contributes to repulsive steric forces that will affect nanoparticle deposition. A statistical analysis determined that high uncertainty in fitted layer thicknesses will limit this approach to thin, low-charged coatings (for which it may be advantageous to typical sizing methods such as dynamic light scattering). Application of this method in experimental studies further confirmed the model limitations in estimating layer thicknesses and the inability of this measurement (and other commonly measured properties) to fully explain nanoparticle deposition behavior. These results demonstrated the need for improved detail and accuracy in coating characterization. The second objective is to correlate the properties of NOM to its effects on gold nanoparticle aggregation, with particular focus on the role of heterogeneity or polydispersity of the NOM molecular weight. Multiple types of NOM collected from representative water bodies and soils were used, both in whole and separated into molecular weight (MW) fractions, and characterized for chemical composition and MW distribution. While average MW of the NOM provided good correlation with aggregation rate, the highest MW components were found to contribute disproportionately in stabilizing nanoparticles against aggregation, highlighting the importance of measuring and accounting for high MW components to explain nanoparticle aggregation. However, an outlier from the MW trend was identified, emphasizing the need for additional characterization (e.g. of reduced sulfur content or the conformation of the adsorbed NOM) to fully explain the effects of NOM on nanoparticle aggregation. Altogether, this research provides novel knowledge that will guide future application of characterization methods to predict attachment processes for coated nanoparticles in the environment.
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D'britto, V. "Synthesis of metal nanoparticles and polymer/metal nanoparticle composites: investigation towards biological applications." Thesis(Ph.D.), CSIR-National Chemical Laboratory, Pune, 2010. http://dspace.ncl.res.in:8080/xmlui/handle/20.500.12252/3716.
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Marchioni, Marianne. "Ecoconception de nouveaux agents biocides à base de nanoparticules d'argent à enrobage bio-inspiré." Thesis, Université Grenoble Alpes (ComUE), 2018. http://www.theses.fr/2018GREAV046/document.
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Les nanoparticules d'argent sont de plus en plus utilisées dans les objets de consommation courante ainsi que dans les dispositifs médicaux pour leur activité biocide, qui est due au relargage d'ions Ag(I) au cours du temps. Le recul sur ces nano-objets et en particulier sur leur innocuité n'est toujours pas suffisant et les études sur leur transformation et leur impact in vivo sont sujets à d’intenses recherches. En effet, le devenir dans l’organisme des macro- et micro-matériaux étudiés classiquement n’est pas le même que celles des nanomatériaux. Les nanoparticules d’argent illustrent bien cette problématique : l’argent soluble injecté par voie intraveineuse est éliminé plus rapidement que la même quantité d’argent injectée sous forme nanoparticulaire. De plus, la concentration en argent retrouvée dans le sang et les organes est dix fois supérieure lorsque les nanoparticules d’argent sont injectées plutôt qu’ingérées. C'est pourquoi le développement de produits implantatoires qui se retrouvent donc en contact direct avec l’organisme, et qui contiennent des nanoparticules d’argent doit prendre en compte les risques associés, ce qui peut se faire par une approche Safer-by-design.Une des composantes principales du développement Safer-by-design concerne la fonctionnalisation des nano-objets. L’affinité des thiolates pour l’ion Ag(I) étant très forte, des ligands thiolés pourraient donc constituer une piste pour la fonctionnalisation des nanoparticules d’argent. Néanmoins, il est connu que les molécules thiolées conduisent à différents comportements allant de la dissolution de la nanoparticule d’argent en ions Ag(I) à la simple passivation de la surface de la nanoparticule ce qui peut entrainer la perte de son activité biocide.Ainsi, l’Ecoconception de Nouveaux Agents Biocides à base de Nanoparticules d’Argent à Enrobage Bio-inspiré avait pour objectif principal de poser les bases conceptuelles du développement d’un agent biocide Safer-by-design constitué de nanoparticules d’argent et de molécules thiolées en se positionnant à l’interface de plusieurs disciplines.Le développement de ce projet a nécessité d’étudier la réactivité de diverses molécules biologiques ou bio-inspirées thiolées avec les nanoparticules d’argent. Ainsi, nous avons mis en évidence l’importance de la pré-organisation architecturale des biomolécules dans la cinétique de dissolution, ainsi que le nombre de thiols libres dans la molécule. Dans le cas de composés induisant la dissolution des nanoparticules, sa cinétique augmente avec le nombre de thiols libres présents sur la molécule, et avec la pré-organisation du site de liaison du métal. Le projet principal de cette thèse a ensuite mené à la preuve de concept recherchée, avec le développement d’un nouvel agent biocide composé de nanoparticules d’argents pontées entre elles par un ligand thiolé tripode symétrique qui est le mime chimique d’un site de liaison d’une métallothionéine. Ces assemblages de nanoparticules se sont montrés actifs contre les bactéries (E. coli) et moins toxiques sur les cellules eucaryotes (HepG2), malgré une entrée dans les cellules similaire. Enfin, un criblage a également été réalisé avec des polyéthylèneglycols possédant un à huit thiols et des longueurs de polymères variables dans le but d’essayer de rationaliser les différences de comportement des nanoparticules d’argent en présence des molécules thiolées. Ce travail, a conduit à l’observation des comportements très variés qui vont permettre d’explorer de nouvelles voies de développements de biocides à base d’assemblages de nanoparticules médiés par des liaisons thiol – Ag(I).L’ensemble de ce travail de thèse a donc permis à la fois un travail très fondamental sur la réactivité des thiols vis-à-vis des atomes d’argent à la surface des nanoparticules et au développement de produits à potentiel applicatif, les assemblages de nanoparticules d’argent qui sont des biocides Safer-by-designSilver nanoparticles are increasingly used in everyday consumer goods as well as in medical devices for their biocidal activity, which is due to the release of Ag(I) ions over time. The hindsight on these nano-objects and, in particular, on their safety is still not sufficient and studies on their transformation and their impact in vivo is currently an intense research field. Indeed, the fate in the body of macro- and micro-materials studied classically is not the same as for nanomaterials. The case of the silver nanoparticles illustrates this problem: the soluble silver injected intravenously is eliminated faster than the same amount of silver injected in nanoparticular form. Moreover, the concentration of silver found in the bloodstream and organs is ten times higher when silver nanoparticles are injected rather than ingested. The development of silver nanoparticle-containing implanted devices, that get in direct contact with the body, must thus take into account the related risks. A Safer-by-design approach could be a way to solve this issue.One of the main components of Safer-by-design development is the functionalization of nano-objects. The affinity of the thiolates for Ag(I) ions is very high, which would make thiolated ligands a good tool for silver nanoparticle functionalization. However, it is known that the thiolated molecules lead to different behaviors, ranging from the dissolution of silver nanoparticles into Ag(I) ions to the simple passivation of the surface of the nanoparticles, which leads to the loss of their biocidal activity.The Ecodesign of New Biocidal Agents based on Silver Nanoparticles and Bio-inspired Coating is therefore at the interface of several research areas and its main objective was to lay the conceptual foundations for the development of a Safer-by-design biocidal agent based on the interaction between silver nanoparticles and thiolated molecules.The development of this project required to study the reactivity of various biological or bio-inspired thiolated molecules with silver nanoparticles. First of all, we have highlighted the importance of the architectural pre-organization of biomolecules in the dissolution kinetics, as well as the role of the number of free thiols in the molecule. In the case of molecules inducing the dissolution of the nanoparticles, its kinetics increases with the number of free thiols present on the molecule and with the pre-organization of the metal binding site. In a second time, the main project of this thesis was the development of a proof of concept of a new biocidal agent composed of silver nanoparticles bridged together via a thiolated ligand, which is the chemical mimic of one binding site of a metallothionein. These nanoparticle assemblies were active against bacteria (E. coli) and less toxic than silver nanoparticles on eukaryote cells (HepG2), despite a similar cellular entry. Finally, a screening was performed with polyethylene glycols having two to eight thiols and varying polymer lengths in an attempt to rationalize the differences in the behavior of silver nanoparticles in the presence of the thiolated molecules. This ongoing work leads to various behaviors that will enable to explore novel ways for the development of biocidal based on nanoparticles assemblies mediated by thiol – Ag(I) bonds.Therefore, this overall PhD work allows performing both very fundamental researches concerning the reactivity of thiols with surface silver atoms of the nanoparticles and the development of products with application potential, silver nanoparticle assemblies that are Safer-by-design biocide
Books on the topic "Nanoparticle"
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Hosokawa, Masuo. Nanoparticle technology handbook. Amsterdam, Netherlands: Elsevier, 2007.
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Vo-Dinh, Tuan, ed. Nanoparticle-Mediated Immunotherapy. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-78338-9.
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Kumar, Ashutosh, and Alok Dhawan, eds. Nanoparticle–Protein Corona. Cambridge: Royal Society of Chemistry, 2019. http://dx.doi.org/10.1039/9781788016308.
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Kalmykov, Stepan N., and Melissa A. Denecke, eds. Actinide Nanoparticle Research. Berlin, Heidelberg: Springer Berlin Heidelberg, 2011. http://dx.doi.org/10.1007/978-3-642-11432-8.
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Alarcon, Emilio I., May Griffith, and Klas I. Udekwu, eds. Silver Nanoparticle Applications. Cham: Springer International Publishing, 2015. http://dx.doi.org/10.1007/978-3-319-11262-6.
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Rahman, Masoud, Sophie Laurent, Nancy Tawil, L'Hocine Yahia, and Morteza Mahmoudi. Protein-Nanoparticle Interactions. Berlin, Heidelberg: Springer Berlin Heidelberg, 2013. http://dx.doi.org/10.1007/978-3-642-37555-2.
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Kalmykov, Stepan N., and Melissa A. Denecke. Actinide nanoparticle research. Berlin: Springer, 2010.
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Granqvist, Claes, Laszlo Kish, and William Marlow, eds. Gas Phase Nanoparticle Synthesis. Dordrecht: Springer Netherlands, 2004. http://dx.doi.org/10.1007/978-1-4020-2444-3.
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Horikoshi, Satoshi, and Nick Serpone, eds. Microwaves in Nanoparticle Synthesis. Weinheim, Germany: Wiley-VCH Verlag GmbH & Co. KGaA, 2013. http://dx.doi.org/10.1002/9783527648122.
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G, Granqvist Claes, Kish Laszlo B, and Marlow W. H, eds. Gas phase nanoparticle synthesis. Dordrecht: Kluwer Academic Publishers, 2004.
Find full textBook chapters on the topic "Nanoparticle"
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Irvine, William M. "Nanoparticle." In Encyclopedia of Astrobiology, 1106. Berlin, Heidelberg: Springer Berlin Heidelberg, 2011. http://dx.doi.org/10.1007/978-3-642-11274-4_1043.
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Irvine, William M. "Nanoparticle." In Encyclopedia of Astrobiology, 1658–59. Berlin, Heidelberg: Springer Berlin Heidelberg, 2015. http://dx.doi.org/10.1007/978-3-662-44185-5_1043.
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Tadros, Tharwat. "Nanoparticle." In Encyclopedia of Colloid and Interface Science, 747–48. Berlin, Heidelberg: Springer Berlin Heidelberg, 2013. http://dx.doi.org/10.1007/978-3-642-20665-8_121.
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Yoda, Minami, Jean-Luc Garden, Olivier Bourgeois, Aeraj Haque, Aloke Kumar, Hans Deyhle, Simone Hieber, et al. "Nanoparticle." In Encyclopedia of Nanotechnology, 1644. Dordrecht: Springer Netherlands, 2012. http://dx.doi.org/10.1007/978-90-481-9751-4_100527.
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Arakha, Manoranjan, and Suman Jha. "Nanoparticle." In Series in BioEngineering, 1–36. Cham: Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-319-73326-5_1.
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Irvine, William M. "Nanoparticle." In Encyclopedia of Astrobiology, 1. Berlin, Heidelberg: Springer Berlin Heidelberg, 2014. http://dx.doi.org/10.1007/978-3-642-27833-4_1043-3.
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Irvine, William M. "Nanoparticle." In Encyclopedia of Astrobiology, 2043. Berlin, Heidelberg: Springer Berlin Heidelberg, 2023. http://dx.doi.org/10.1007/978-3-662-65093-6_1043.
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Lungu, Antoanetta, Mihai Lungu, Adrian Neculae, and Raluca Giugiulan. "Nanoparticle Characterization Using Nanoparticle Tracking Analysis." In Nanoparticles' Promises and Risks, 245–68. Cham: Springer International Publishing, 2014. http://dx.doi.org/10.1007/978-3-319-11728-7_13.
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Mangold, M. A., A. W. Holleitner, J. S. Agustsson, and M. Calame. "Nanoparticle Arrays." In Handbook of Nanoparticles, 565–601. Cham: Springer International Publishing, 2016. http://dx.doi.org/10.1007/978-3-319-15338-4_27.
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Shannahan, Jonathan H. "Nanoparticle–Biocorona." In Encyclopedia of Nanotechnology, 1–4. Dordrecht: Springer Netherlands, 2014. http://dx.doi.org/10.1007/978-94-007-6178-0_100903-1.
Full textConference papers on the topic "Nanoparticle"
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Attaluri, Anilchandra, Robert Ivkov, Ronghui Ma, and Liang Zhu. "Nanoparticle Redistribution During Magnetic Nanoparticle Hyperthermia: Multi-Physics Porous Medium Model Analyses." In ASME 2012 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/imece2012-89486.
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A coupled theoretical framework comprising a suspension of nanoparticles transport in porous media model and a heat transfer model is developed to address nanoparticle redistribution during heating. Nanoparticle redistribution in biological tissues during magnetic nanoparticle hyperthermia is described by a multi-physics model that consists of five major components: (a) a fully saturated porous media model for fluid flow through tissue; (b) nanoparticle convection and diffusion; (c) heat transfer model based on heat generation by local nanoparticle concentration; (d) a model to predict tissue thermal damage and corresponding change to the porous structure; and (e) a nanoparticle redistribution model based on the dynamic porosity and diffusion diffusivity. The integrated model has been used to predict the structural damage in porous tumors and its effect on nanoparticle-induced heating in tumors. Thermal damage in the vicinity of the tumor center that is predicted by the Arrhenius equation increases from 14% with 10 minutes of heating to almost 99% after 20 minutes. It then induces an increased tumor porosity that increases nanoparticle diffusivity by seven-fold. The model predicts thermal damage induced by nanoparticle redistribution increases by 20% in the radius of the spherical tissue region containing nanoparticles. The developed model has demonstrated the feasibility of enhancing nanoparticle dispersion from injection sites using targeted thermal damage.
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Soni, Sanjeev, Himanshu Tyagi, Robert A. Taylor, and Amod Kumar. "Effect of Nanoparticle Concentration on Thermal Damage in Nanoparticle-Assisted Thermal Therapy." In ASME 2016 5th International Conference on Micro/Nanoscale Heat and Mass Transfer. American Society of Mechanical Engineers, 2016. http://dx.doi.org/10.1115/mnhmt2016-6418.
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Photothermal therapy involving nanoparticles is evolving as a promising targeted treatment for cancer. This paper presents the results for the effect of nanoparticle concentration, within a tumor, to control the thermal damage during nanoparticle assisted thermal therapy. A surface tumor embedded with gold nanoparticles (distributed uniformly) is considered. The thermal damage is evaluated for various nanoparticle concentrations (within the tumor) to identify an optimal concentration of the nanoparticles so as to achieve spatial confinement of the damage to the tumor region. Optical interaction is coupled to the biological heat transfer through Pennes’ bioheat model and Beer’s law. Spatiotemporal thermal damage is simulated through the Arrhenius method. The finite difference implicit method is used to solve the coupled phenomenon. Results show that there is a specific value of nanoparticle concentration at which it is possible to confine thermal damage to the tumor within a spatial scale of less than 1 mm. This way the healthy tissues surrounding a tumor are safe. This optimum value of nanoparticle concentration (irrespective of tumor diameters) is 0.00001%. This concentration along with irradiation intensity of 1 W/cm2 for irradiation duration of 110 seconds is sufficient to thermally ablate the considered tumors. Novelty of this study is that it presents a combination of the controlling parameters for achieving a high (<1 mm) spatial confinement of the thermal damage. This finding is very much significant from clinical point of view. Clinically it is always desired to attain the therapeutic efficacy with minimal delivery of external agents (nanoparticles in this case) to a patient.
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Singh, Manpreet, Qimei Gu, Ronghui Ma, and Liang Zhu. "Temperature Distribution and Thermal Dosage Affected by Nanoparticle Distribution in Tumours During Magnetic Nanoparticle Hyperthermia." In ASME 2019 6th International Conference on Micro/Nanoscale Heat and Mass Transfer. American Society of Mechanical Engineers, 2019. http://dx.doi.org/10.1115/mnhmt2019-4233.
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Abstract Recent microCT imaging study has demonstrated that local heating caused a much larger nanoparticle distribution volume in tumors than that in tumors without localized heating, suggesting possible nanoparticle redistribution/migration during heating. In this study, a theoretical simulation is performed to evaluate to what extent the nanoparticle redistribution affects the temperature elevations and thermal dosage required to cause permanent thermal damage to PC3 tumors. Two tumor groups with similar sizes are selected. The control group consists of five PC3 tumors with nanoparticles distribution without heating, while the experimental group consists of another five resected PC3 tumors with nanoparticles distribution obtained after 25 minutes of local heating. Each generated tumor model is attached to a mouse body model by microCT scans. A previously determined relationship between the nanoparticle concentration distribution and the volumetric heat generation rate is implemented in the theoretical simulation of temperature elevations during magnetic nanoparticle hyperthermia. Our simulation results show that the average steady state temperature elevation in the tumors of the control group is higher than that in the experimental group when the nanoparticles are more spreading from the tumor center to tumor periphery (control group: 64.03±3.2°C vs. experimental group: 62.04±3.07°C). Further we assess the thermal dosage needed to cause 100% permanent thermal damage (Arrhenius integral Ω = 4) to the entire tumor, based on the assumption of unchanged nanoparticle distribution during heating. The average heating time based on the experimental setting from our previous studies demonstrates significantly different designs. Specifically, the average heating time for the control group is 24.3 minutes. However, the more spreading of nanoparticles to tumor periphery in the experimental group results in a much longer heating time of 38.1 minutes, 57° longer than that in the control group, to induce permanent thermal damage to the entire tumor. The results from this study suggest that the heating time needed when considering dynamic nanoparticle migration during heating is probably between 24 to 38 minutes. In conclusion, the study demonstrates the importance of including dynamic nanoparticle spreading during heating into theoretical simulation of temperature elevations in tumors to determine accurate thermal dosage needed in magnetic nanoparticle hyperthermia design.
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Zhu, Youyi, Peng Yu, and Jian Fan. "Study on Nanoparticle Stabilized Emulsions for Chemical Flooding Enhanced Oil Recovery." In International Petroleum Technology Conference. IPTC, 2021. http://dx.doi.org/10.2523/iptc-21456-ms.
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Abstract Chemical flooding is one of enhanced oil recovery (EOR) methods. The primary mechanism of EOR of chemical flooding is interfacial tension reduction, mobility ratio improvement and wettability changes. Recent studies showed that enhancing emulsification performance was beneficial to improve oil displacement efficiency. The formation of Pickering emulsion by nanoparticles could greatly improve the emulsifying performance. Using nanoparticles stabilized emulsions for chemical EOR application is a novel method. In this study, six different types of nanoparticles were selected, including hydrophilic nano silica, modified nano silica, carbon nanotubes and bentonite, etc. The nanoparticle combine with petroleum sulfonate could form a stable emulsion. Particle wettability were measured by using contact angle measurement (OCA20). Emulsifying intensity index was measured for different nanoparticle-stabilized emulsions. The mechanisms of nanoparticle-stabilized emulsions and relationship between emulsion stability have been investigated. The influence of dispersant on nanoparticle-stabilized emulsions also has been investigated. Nanoparticles mainly play a role in improving the stability of emulsions while surfactant play a major role in enhancing the emulsifying dispersion. The wettability of solid particles was one of the most important factors that affects the stability of emulsions. Partial hydrophobic nanoparticles were much easier to form stable emulsions than hydrophilic nanoparticles. Nanoparticles could form a three-dimensional network structure, thereby the stability of the emulsion was improved. Use of surfactant to disperse nanoparticles could further improve the emulsion stability. Finally, three nanoparticles stabilized emulsion formulations were developed for chemical flooding EOR. Nanoparticle-stabilized emulsions could improve oil displacement efficiency in chemical combination flooding. This research was used to optimize chemical combination flooding formulation and has a guidance function for application of nanoparticles in chemical flooding EOR.
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Pilch, Iris, Nils Brenning, Ulf Helmersson, and Daniel Söderström. "High Power Pulsed Hollow Cathode for Nanoparticle Synthesis." In 13th International Conference on Plasma Surface Engineering September 10 - 14, 2012, in Garmisch-Partenkirchen, Germany. Linköping University Electronic Press, 2013. http://dx.doi.org/10.3384/wcc2.118-121.
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Copper nanoparticles were synthesized using a novel method based on sputtering material from a hollow cathode using high power pulses. The high power pulses provide a supersaturated vapor with a high degree of ionization from which the nanoparticles are formed in the gas phase. By adjusting the pulse parameters, the plasma environment and thus the nanoparticle growth can be affected. It was found that the nanoparticle size can be influenced by varying, e.g., the pulse frequency or the pulse power. The results using the high power pulsed hollow cathode are compared to nanoparticles synthesized with a dc discharge using the same setup.
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Wu, Xuan, Ranganathan Kumar, and Parveen Sachdeva. "Calculation of Thermal Conductivity in Nanofluids From Atomic-Scale Simulations." In ASME 2005 International Mechanical Engineering Congress and Exposition. ASMEDC, 2005. http://dx.doi.org/10.1115/imece2005-80849.
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Nanofluids that consist of nanometer sized particles and fibers dispersed in base liquids have shown the potential to enhance the heat transfer performance. Although three features of nanofluids including anomalously high thermal conductivities at very low nanoparticle concentrations, strongly temperature dependent thermal conductivity and significant increases in critical heat flux have been studied widely, and layering of liquid molecules at the particle-liquid interface, ballistic nature of heat transport in nanoparticles, and nanoparticle clustering are considered as the possible causations responsible for such kind of heat transfer enhancement, few research work from atomic-scale has been done to verify or explain those fascinating features of nanofluids. In this paper, a molecular dynamic model, which incorporates the atomic interactions for silica by BKS potential with a SPC/E model for water, has been established. To ensure the authenticity of our model, the position of each atom in the nanoparticle is derived by the crystallographic method. The interfacial interactions between the nanoparticle and water are simplified as the sum of interaction between many ions. Due to the electrostatic interaction, the ions on the nanoparticle’s surface can attract a certain number of water molecules, therefore, the effect of interaction between the nanoparticle and water on heat transfer enhancement in nanofluids is studied. By using Green-Kubo equations which set a bridge between thermal conductivity and time autocorrelation function of the heat current, a model which may derive thermal conductivity of dilute nanofluids that consist of silica nanoparticles and pure water is built. Several simulation results have been provided which can reveal the possible mechanism of heat enhancement in nanofluids.
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Rajendran, Silambarasan. "Consequence of Nanoparticle Physiognomies on Heat Transfer Characteristics of Heat Exchanger." In International Conference on Advances in Design, Materials, Manufacturing and Surface Engineering for Mobility. 400 Commonwealth Drive, Warrendale, PA, United States: SAE International, 2020. http://dx.doi.org/10.4271/2020-28-0462.
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<div class="section abstract"><div class="htmlview paragraph">In this paper the heat transfer coefficient and the heat transfer rate of a heat exchanger is scrutinized by using nanofluids. The silicon carbide nanoparticles, milled and sonificated as nanofluids of volume fractions 0.01499(%) and 0.01399(%). The heat transfer characteristics of SiC(P)/water, SiC(M)/water, SiC(P)/EG, SiC(M)/EG are measured in a concentric tube heat exchanger under laminar flow condition. The consequence of nanoparticle physiognomies, Reynolds number, on the heat transfer characteristic is scrutinized. It has been found that the addition of milled nanoparticlein the base fluids enhances the heat transfer characteristics rather than the normal nanoparticle. The experimental results shows that the heat transfer characteristics of SiC(M) is higher than that of SiC(P) in both the case of water and EG. This is because of the structural changes of SiC-M by the deformation caused by the ball milling.</div></div>
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Yuksel, Anil, Michael Cullinan, and Jayathi Murthy. "Thermal Energy Transport Below the Diffraction Limit in Close-Packed Metal Nanoparticles." In ASME 2017 Heat Transfer Summer Conference. American Society of Mechanical Engineers, 2017. http://dx.doi.org/10.1115/ht2017-4968.
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Fabrication of micro and nanoscale electronic components has become increasingly demanding due to device and interconnect scaling combined with advanced packaging and assembly for electronic, aerospace and medical applications. Recent advances in additive manufacturing have made it possible to fabricate microscale, 3D interconnect structures but heat transfer during the fabrication process is one of the most important phenomena influencing the reliable manufacturing of these interconnect structures. In this study, optical absorption and scattering by three-dimensional (3D) nanoparticle packings are investigated to gain insight into micro/nano heat transport within the nanoparticles. Because drying of colloidal solutions creates different configurations of nanoparticles, the plasmonic coupling in three different copper nanoparticle packing configurations were investigated: simple cubic (SC), face-centered cubic (FCC) and hexagonal close packing (HCP). Single-scatter albedo (ω) was analyzed as a function of nanoparticle size, packing density, and configuration to assess effect for thermo-optical properties and plasmonic coupling of the Cu nanoparticles within the nanoparticle packings. This analysis provides insight into plasmonically enhanced absorption in copper nanoparticle particles and its consequences for laser heating of nanoparticle assemblies.
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Kelley, D. F., H. Tu, and K. Mogoyrosi. "Photophysics of GaSe nanoparticles and nanoparticle aggregates." In Optics & Photonics 2005, edited by Clemens Burda and Randy J. Ellingson. SPIE, 2005. http://dx.doi.org/10.1117/12.616960.
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Suman, Alessio, Alessandro Vulpio, Nicola Casari, and Michele Pinelli. "A Stochastic Model for Nanoparticle Deposits Growth." In ASME Turbo Expo 2021: Turbomachinery Technical Conference and Exposition. American Society of Mechanical Engineers, 2021. http://dx.doi.org/10.1115/gt2021-59458.
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Abstract Natural events and human activities are responsible for the generation and transport of large amounts of micro-sized particles, which could contaminate several engineering devices like solar panels, wind turbines, and aero-engines. In industrial processes, systems as heat exchangers, fans, and dust collectors are continuously affected by nanoparticles’ interaction. For several applications, the adhesion of such nanoparticles is detrimental, generating safety and performance issues. Particle-to-particle and particle-to-surface interactions are well known, even if a general explanation of nanoparticle deposit growth is still unknown. In the present paper, an interpretation of deposit growth due to nanoparticle deposition can predict particle adhesion, and layer accretion is proposed. A statistical model and a set of coefficients are used to generalize nanoparticle deposits’ growth by an S-shaped function. In particular, the nanoparticle deposits grow analogously to a typical autonomous population settlement in a virgin area following statistical rule, which includes the initial growth, the successive stable condition (development), and catastrophic events able to destroy the layer. This approach generalizes nanoparticle adhesion/deposition behavior, overpassing the constraints reported in common deposition models, mainly focused on the mechanical aspect of the nanoparticle impact event. The catastrophic events, such as layer detachment, are modeled with a Poisson’s distribution, related to material characteristics and impact conditions. This innovative approach, analogies, and coefficients applied to common engineering applications may be the starting point for improving the prediction capability of nanoparticle deposition.
Reports on the topic "Nanoparticle"
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Havrilla, George Joseph. Nanoparticle standards. Office of Scientific and Technical Information (OSTI), December 2016. http://dx.doi.org/10.2172/1335590.
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Venedicto, Melissa, and Cheng-Yu Lai. Facilitated Release of Doxorubicin from Biodegradable Mesoporous Silica Nanoparticles. Florida International University, October 2021. http://dx.doi.org/10.25148/mmeurs.009774.
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Cervical cancer is one of the most common causes of cancer death for women in the United States. The current treatment with chemotherapy drugs has significant side effects and may cause harm to healthy cells rather than cancer cells. In order to combat the potential side effects, nanoparticles composed of mesoporous silica were created to house the chemotherapy drug doxorubicin (DOX). The silica network contains the drug, and a pH study was conducted to determine the conditions for the nanoparticle to disperse the drug. The introduction of disulfide bonds within the nanoparticle created a framework to efficiently release 97% of DOX in acidic environments and 40% release in neutral environments. The denotation of acidic versus neutral environments was important as cancer cells are typically acidic. The chemistry was proved with the incubation of the loaded nanoparticle into HeLa cells for a cytotoxicity report and confocal imaging. The use of the framework for the anticancer drug was shown to be effective for the killing of cancerous cells.
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Belcher, Angela. Reversible Nanoparticle Electronics. Fort Belvoir, VA: Defense Technical Information Center, September 2005. http://dx.doi.org/10.21236/ada459317.
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Krantz, Kelsie E., Jonathan H. Christian, Kaitlin Coopersmith, Aaron L. Washington, II, and Simona H. Murph. Gold Nanoparticle Microwave Synthesis. Office of Scientific and Technical Information (OSTI), July 2016. http://dx.doi.org/10.2172/1281776.
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Moyers, Aidan, Michael Becker, and Desiderio Kovar. Nanoparticle Impact 2023 Report. Office of Scientific and Technical Information (OSTI), February 2024. http://dx.doi.org/10.2172/2305285.
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Moyers, Aidan, Michael Becker, and Desiderio Kovar. Nanoparticle Impact 2023 Highlights. Office of Scientific and Technical Information (OSTI), February 2024. http://dx.doi.org/10.2172/2315695.
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Russell, Thomas P. Nanoparticle Assemblies at Fluid Interfaces. Office of Scientific and Technical Information (OSTI), March 2015. http://dx.doi.org/10.2172/1172148.
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Tillman, Ameer J., and Novella N. Bridges. Nanoparticle Sensors for Biological Medicine. Office of Scientific and Technical Information (OSTI), August 2005. http://dx.doi.org/10.2172/974517.
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Cheng, Shengfeng, Steven James Plimpton, Jeremy B. Lechman, and Gary Stephen Grest. Drying/self-assembly of nanoparticle suspensions. Office of Scientific and Technical Information (OSTI), October 2010. http://dx.doi.org/10.2172/993324.
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Murph, S. Hunyadi, M. Brown, K. Coopersmith, S. Fulmer, H. Sessions, and M. Ali. Magnetic induced heating of nanoparticle solutions. Office of Scientific and Technical Information (OSTI), December 2016. http://dx.doi.org/10.2172/1335825.
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