Articles de revues : « Colloidal Nanomaterisls »

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Wang, Yongsheng, Haiyan Huo, Xueren Qian et Jing Shen. « Colloids, nanostructures, and supramolecular assemblies for papermaking ». BioResources 15, n^o 3 (1 mai 2020) : 4646–49. http://dx.doi.org/10.15376/biores.15.3.4646-4649.

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The dominating role of colloid science in papermaking processes, as exemplified by wet-end chemistry, is now well known. The concept of colloids dates back to about 160 years ago. In certain cases, however, the term “colloids” can have an overlapping meaning with the modern terms “nanomaterials” and “supramolecular assemblies”. The latter terms, and the scientists who have gravitated to those terms, have enriched colloid science, providing new insights into colloidal systems. It is proposed here that reconsidering papermaking in light of these multi-disciplinary sciences has potential to facilitate effective teaching and learning pertaining to universities that have pulp and paper programs. Enhanced integration of basic sciences with papermaking may further our understanding and broaden existing research areas, which is likely to create breakthroughs in basic research, applied research, and product development.

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Zhang, Dongshi, Wonsuk Choi, Jurij Jakobi, Mark-Robert Kalus, Stephan Barcikowski, Sung-Hak Cho et Koji Sugioka. « Spontaneous Shape Alteration and Size Separation of Surfactant-Free Silver Particles Synthesized by Laser Ablation in Acetone during Long-Period Storage ». Nanomaterials 8, n^o 7 (13 juillet 2018) : 529. http://dx.doi.org/10.3390/nano8070529.

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The technique of laser ablation in liquids (LAL) has already demonstrated its flexibility and capability for the synthesis of a large variety of surfactant-free nanomaterials with a high purity. However, high purity can cause trouble for nanomaterial synthesis, because active high-purity particles can spontaneously grow into different nanocrystals, which makes it difficult to accurately tailor the size and shape of the synthesized nanomaterials. Therefore, a series of questions arise with regards to whether particle growth occurs during colloid storage, how large the particle size increases to, and into which shape the particles evolve. To obtain answers to these questions, here, Ag particles that are synthesized by femtosecond (fs) laser ablation of Ag in acetone are used as precursors to witness the spontaneous growth behavior of the LAL-generated surfactant-free Ag dots (2–10 nm) into different polygonal particles (5–50 nm), and the spontaneous size separation phenomenon by the carbon-encapsulation induced precipitation of large particles, after six months of colloid storage. The colloids obtained by LAL at a higher power (600 mW) possess a greater ability and higher efficiency to yield colloids with sizes of <40 nm than the colloids obtained at lower power (300 mW), because of the generation of a larger amount of carbon ‘captors’ by the decomposition of acetone and the stronger particle fragmentation. Both the size increase and the shape alteration lead to a redshift of the surface plasmon resonance (SPR) band of the Ag colloid from 404 nm to 414 nm, after storage. The Fourier transform infrared spectroscopy (FTIR) analysis shows that the Ag particles are conjugated with COO– and OH– groups, both of which may lead to the growth of polygonal particles. The CO and CO2 molecules are adsorbed on the particle surfaces to form Ag(CO)x and Ag(CO2)x complexes. Complementary nanosecond LAL experiments confirmed that the particle growth was inherent to LAL in acetone, and independent of pulse duration, although some differences in the final particle sizes were observed. The nanosecond-LAL yields monomodal colloids, whereas the size-separated, initially bimodal colloids from the fs-LAL provide a higher fraction of very small particles that are <5 nm. The spontaneous growth of the LAL-generated metallic particles presented in this work should arouse the special attention of academia, especially regarding the detailed discussion on how long the colloids can be preserved for particle characterization and applications, without causing a mismatch between the colloid properties and their performance. The spontaneous size separation phenomenon may help researchers to realize a more reproducible synthesis for small metallic colloids, without concern for the generation of large particles.

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Liu, Gang, Chong Zhang, Mingzhi Zhao, Wenbo Guo et Qiang Luo. « Comparison of Nanomaterials with Other Unconventional Materials Used as Additives for Soil Improvement in the Context of Sustainable Development : A Review ». Nanomaterials 11, n^o 1 (23 décembre 2020) : 15. http://dx.doi.org/10.3390/nano11010015.

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Since the concept of sustainable development enjoys popular support in the 21st century, various kinds of unconventional materials were introduced for soil improvement in the past few decades to replace the traditional materials like concrete and lime. This paper compared nanomaterials with other three kinds of representative unconventional materials to demonstrate its superiority in soil treatment. The other three kinds of unconventional materials include microbially induced calcite precipitation (MICP), recycled tire and environmental fiber. Nanomaterial and MICP have a comprehensive effect on soil reinforcement, since they can improve shear strength, adjust permeability, resist liquefaction and purify the environment. Recycled tire and environmental fibers are granular materials that are mostly adopted to reinforce reconstituted soil. The reinforcement mechanisms and effects of these four kinds of unconventional materials are discussed in detail, and their price/performance ratios are calculated to make an evaluation about their market application prospects. It can be seen that nanomaterials have promising prospects. Colloidal silica, bentonite and laponite present a satisfactory effect on liquefaction mitigation for sandy foundation, and carbon nanotube has an aptitude for unconfined compressive strength improvement. Among the investigated nanomaterials, colloidal silica is the closest to scale market application. Despite the advantages of nanomaterials adopted as additives for soil improvement, they are known for unwanted interactions with different biological objects at the cell level. Nevertheless, research on nanomaterials that are adopted for soil improvement are very promising and can intensify the relationship between sustainable development and geotechnical engineering through innovative techniques.

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Taniguchi, Takaaki, Leanddas Nurdiwijayanto, Renzhi Ma et Takayoshi Sasaki. « Chemically exfoliated inorganic nanosheets for nanoelectronics ». Applied Physics Reviews 9, n^o 2 (juin 2022) : 021313. http://dx.doi.org/10.1063/5.0083109.

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Two-dimensional (2D) nanomaterials constitute one of the most advanced research targets in materials science and engineering in this century. Among various methods for the synthesis of 2D nanomaterials, including top-down exfoliation and bottom-up crystal growth, chemical exfoliation has been widely used to yield monolayers of various layered compounds, such as clay minerals, transition metal chalcogenides (TMDCs), and oxides, long before the discovery of graphene. Soft chemical exfoliation is a technique to weaken the layer-to-layer interaction in layered compounds by chemical modification of interlayer galleries, which promotes monolayer exfoliation. The chemical exfoliation process using organic substances, typically amines, has been applied to a range of layered metal oxides and hydroxides for two decades, establishing high-yield exfoliation into their highly crystalline monolayers and colloidal integration processes have been developed to assemble the resultant 2D nanomaterials into well-organized nanoscale devices. Recently, such a strategy was found to be effective for TMDC and MXene nanosheets, expanding the lineup of functionalities of solution-processed 2D nanomaterial devices from dielectrics, optics, magnetics, and semiconductors to superconductors. Throughout this review, we share the historical research flow, recent progress, and prospects in the development of soft-chemical exfoliation, colloidal integration, and thin film applications of oxides, TMDC, and MXene nanosheets.

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Ali, Imran, Sara H. Althakfi, Mohammad Suhail, Marcello Locatelli, Ming-Fa Hsieh, Mosa Alsehli et Ahmed M. Hameed. « Advances in Polymeric Colloids for Cancer Treatment ». Polymers 14, n^o 24 (13 décembre 2022) : 5445. http://dx.doi.org/10.3390/polym14245445.

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Polymer colloids have remarkable features and are gaining importance in many areas of research including medicinal science. Presently, the innovation of cancer drugs is at the top in the world. Polymer colloids have been used as drug delivery and diagnosis agents in cancer treatment. The polymer colloids may be of different types such as micelles, liposomes, emulsions, cationic carriers, and hydrogels. The current article describes the state-of-the-art polymer colloids for the treatment of cancer. The contents of this article are about the role of polymeric nanomaterials with special emphasis on the different types of colloidal materials and their applications in targeted cancer therapy including cancer diagnoses. In addition, attempts are made to discuss future perspectives. This article will be useful for academics, researchers, and regulatory authorities.

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Basina, Georgia, Hafsa Khurshid, Nikolaos Tzitzios, George Hadjipanayis et Vasileios Tzitzios. « Facile Organometallic Synthesis of Fe-Based Nanomaterials by Hot Injection Reaction ». Nanomaterials 11, n^o 5 (28 avril 2021) : 1141. http://dx.doi.org/10.3390/nano11051141.

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Fe-based colloids with a core/shell structure consisting of metallic iron and iron oxide were synthesized by a facile hot injection reaction of iron pentacarbonyl in a multi-surfactant mixture. The size of the colloidal particles was affected by the reaction temperature and the results demonstrated that their stability against complete oxidation related to their size. The crystal structure and the morphology were identified by powder X-ray diffraction and transmission electron microscopy, while the magnetic properties were studied at room temperature with a vibrating sample magnetometer. The injection temperature plays a very crucial role and higher temperatures enhance the stability and the resistance against oxidation. For the case of injection at 315 °C, the nanoparticles had around a 10 nm mean diameter and revealed 132 emu/g. Remarkably, a stable dispersion was created due to the colloids’ surface functionalization in a nonpolar solvent.

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Maillette, Sébastien, Caroline Peyrot, Tapas Purkait, Muhammad Iqbal, Jonathan G. C. Veinot et Kevin J. Wilkinson. « Heteroagglomeration of nanosilver with colloidal SiO2 and clay ». Environmental Chemistry 14, n^o 1 (2017) : 1. http://dx.doi.org/10.1071/en16070.

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Environmental contextThe fate of nanomaterials in the environment is related to their colloidal stability. Although numerous studies have examined their homoagglomeration, their low concentration and the presence of high concentrations of natural particles implies that heteroagglomeration rather than homoagglomeration is likely to occur under natural conditions. In this paper, two state-of-the art analytical techniques were used to identify the conditions under which nanosilver was most likely to form heteroagglomerates in natural waters. AbstractThe environmental risk of nanomaterials will depend on their persistence, mobility, toxicity and bioaccumulation. Each of these parameters is related to their fate (especially dissolution, agglomeration). The goal of this paper was to understand the heteroagglomeration of silver nanoparticles in natural waters. Two small silver nanoparticles (nAg, ~3nm; polyacrylic acid- and citrate-stabilised) were covalently labelled with a fluorescent dye and then mixed with colloidal silicon oxides (SiO2, ~18.5nm) or clays (~550nm SWy-2 montmorillonite). Homo- and heteroagglomeration of the nAg were first studied in controlled synthetic waters that were representative of natural fresh waters (50μg Ag L–1; pH 7.0; ionic strength 10–7 to 10–1 M Ca) by following the sizes of the nAg by fluorescence correlation spectroscopy. The polyacrylic acid-coated nanosilver was extremely stable under all conditions, including in the presence of other colloids and at high ionic strengths. However, the citrate-coated nanosilver formed heteroaggregates in presence of both colloidal SiO2 and clay particles. Nanoparticle surface properties appeared to play a key role in controlling the physicochemical stability of the nAg. For example, the polyacrylic acid stabilized nAg-remained extremely stable in the water column, even under conditions for which surrounding colloidal particles were agglomerating. Finally, enhanced dark-field microscopy was then used to further characterise the heteroagglomeration of a citrate-coated nAg with suspensions of colloidal clay, colloidal SiO2 or natural (river) water.

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Garino, Nadia, Tania Limongi, Bianca Dumontel, Marta Canta, Luisa Racca, Marco Laurenti, Micaela Castellino, Alberto Casu, Andrea Falqui et Valentina Cauda. « A Microwave-Assisted Synthesis of Zinc Oxide Nanocrystals Finely Tuned for Biological Applications ». Nanomaterials 9, n^o 2 (6 février 2019) : 212. http://dx.doi.org/10.3390/nano9020212.

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Herein we report a novel, easy, fast and reliable microwave-assisted synthesis procedure for the preparation of colloidal zinc oxide nanocrystals (ZnO NCs) optimized for biological applications. ZnO NCs are also prepared by a conventional solvo-thermal approach and the properties of the two families of NCs are compared and discussed. All of the NCs are fully characterized in terms of morphological analysis, crystalline structure, chemical composition and optical properties, both as pristine nanomaterials or after amino-propyl group functionalization. Compared to the conventional approach, the novel microwave-derived ZnO NCs demonstrate outstanding colloidal stability in ethanol and water with long shelf-life. Furthermore, together with their more uniform size, shape and chemical surface properties, this long-term colloidal stability also contributes to the highly reproducible data in terms of biocompatibility. Actually, a significantly different biological behavior of the microwave-synthesized ZnO NCs is reported with respect to NCs prepared by the conventional synthesis procedure. In particular, consistent cytotoxicity and highly reproducible cell uptake toward KB cancer cells are measured with the use of microwave-synthesized ZnO NCs, in contrast to the non-reproducible and scattered data obtained with the conventionally-synthesized ones. Thus, we demonstrate how the synthetic route and, as a consequence, the control over all the nanomaterial properties are prominent points to be considered when dealing with the biological world for the achievement of reproducible and reliable results, and how the use of commercially-available and under-characterized nanomaterials should be discouraged in this view.

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Hupfeld, Tim, Frederic Stein, Stephan Barcikowski, Bilal Gökce et Ulf Wiedwald. « Manipulation of the Size and Phase Composition of Yttrium Iron Garnet Nanoparticles by Pulsed Laser Post-Processing in Liquid ». Molecules 25, n^o 8 (17 avril 2020) : 1869. http://dx.doi.org/10.3390/molecules25081869.

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Modification of the size and phase composition of magnetic oxide nanomaterials dispersed in liquids by laser synthesis and processing of colloids has high implications for applications in biomedicine, catalysis and for nanoparticle-polymer composites. Controlling these properties for ternary oxides, however, is challenging with typical additives like salts and ligands and can lead to unwanted byproducts and various phases. In our study, we demonstrate how additive-free pulsed laser post-processing (LPP) of colloidal yttrium iron oxide nanoparticles using high repetition rates and power at 355 nm laser wavelength can be used for phase transformation and phase purification of the garnet structure by variation of the laser fluence as well as the applied energy dose. Furthermore, LPP allows particle size modification between 5 nm (ps laser) and 20 nm (ns laser) and significant increase of the monodispersity. Resulting colloidal nanoparticles are investigated regarding their size, structure and temperature-dependent magnetic properties.

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Romolini, G., M. Gambucci, D. Ricciarelli, L. Tarpani, G. Zampini et L. Latterini. « Photocatalytic activity of silica and silica-silver nanocolloids based on photo-induced formation of reactive oxygen species ». Photochemical & ; Photobiological Sciences 20, n^o 9 (27 août 2021) : 1161–72. http://dx.doi.org/10.1007/s43630-021-00089-9.

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AbstractSemiconductor nanomaterials are often proposed as photocatalysts for wastewater treatment; silica nanomaterials are still largely unexploited because their photocatalytic performances need improvements, especially under visible light. The present study is a proof-of-concept that amorphous silica colloids once submitted to the proper surface modifications change into an efficient photocatalyst even under low-energy illumination source. For this reason, silica-based colloidal nanomaterials, such as bare (SiO2 NPs), aminated (NH2-SiO2 NPs), and Ag NPs-decorated (Ag-SiO2 NPs) silica, are tested as photocatalysts for the degradation of 9-anthracenecarboxylic acid (9ACA), taken as a model aromatic compound. Interestingly, upon irradiation at 313 nm, NH2-SiO2 NPs induce 9ACA degradation, and the effect is even improved when Ag-SiO2 NPs are used. On the other hand, irradiation at 405 nm activates the plasmon of Ag-SiO2 NPs photocatalyst, providing a faster and more efficient photodegradation. The photodegradation experiments are also performed under white light illumination, employing a low-intensity fluorescent lamp, confirming satisfying efficiencies. The catalytic effect of SiO2-based nanoparticles is thought to originate from photo-excitable surface defects and Ag NP plasmons since the catalytic degradation takes place only when the 9ACA is adsorbed on the surface. In addition, the involvement of reactive oxygen species was demonstrated through a scavenger use, obtaining a yield of 17%. In conclusion, this work shows the applicability of silica-based nanoparticles as photocatalysts through the involvement of silica surface defects, confirming that the silica colloids can act as photocatalysts under irradiation with monochromatic and white light. Graphic abstract Silica and Ag-decorated silica colloids photosensitize the formation of Reactive Oxygen Species with 17% efficiencies. ROS are able to oxidase aromatic pollutants chemi-adsorbed on the surface of the colloids. Silica-silver nanocomposites present a photocatalytic activity useful to degrade aromatic compounds.

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Jia, Jun, et Fengyuan Sun. « Application of Polymer Nanocolloid Preparation in Stability Analysis of Motion Mechanics ». Advances in Materials Science and Engineering 2022 (31 août 2022) : 1–11. http://dx.doi.org/10.1155/2022/7260515.

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Nanomaterials are widely used in various fields because of their own advantages. When the particle size of the material is reduced to the nanometer level, it will lead to new characteristics of acoustic, optical, electrical, magnetic, and thermal properties. This will greatly enrich the research content of the material and is expected to get new uses. Therefore, the preparation technology of nanomaterials is one of the current research hotspots and has broad application prospects. At present, the most commonly used preparation techniques are hydrothermal method and sol-gel method, but not all crystals grow in a hydrothermal environment, so this paper adopts the sol-gel method for preparation. However, in the preparation of nanocolloids, agglomeration often occurs between colloidal nanoparticles. In order to avoid the agglomeration between particles, this paper adopts an appropriate method to disperse the particles. In order to further explore the stability of nanocolloids, the colloidal film material prepared by the cadmium sulfide (CdS) sol method was used as the research sample. It also proposes a sol preparation method incorporating ultrasonic waves and further discusses the kinetic characteristics. The research results show that the sedimentation velocity of 1 nm cadmium sulfide nanocolloids in water is 1.3 × 10−12 (m/s) prepared by colloid of cadmium sulfide.

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Liu, Yongming, Chen Shen, Xihui Zhang, Huan Yu, Fujun Wang, Yangyun Wang et Leshuai W. Zhang. « Exposure and nephrotoxicity concern of bismuth with the occurrence of autophagy ». Toxicology and Industrial Health 34, n^o 3 (mars 2018) : 188–99. http://dx.doi.org/10.1177/0748233717746810.

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Metal nanoparticles or metal-based compounds have drawn attention in various fields ranging from industry to medicine because of their unique physicochemical properties. Bismuth (Bi) compounds and nanomaterials have been commonly used in alloys, electronic industry, batteries, and as flame retardants as well as for anti- Helicobacter pylori therapy, while the nanomaterial form has great potential for computed tomography imaging and thermotherapy, both of which will be introduced in this review. Although Bi was used for several decades, there is a lack of detailed information concerning their toxicity and mechanisms on human health. We described the toxicity of Bi on the kidney that seemed to be relatively known by researchers, while the mechanisms remain unclear. Recently, our group has found that Bi compounds, including bismuth nitrate (BN) and Bi nanomaterials, can induce autophagy in kidney cells. We also extended our findings by selecting five Bi compounds, and the results showed that BN, bismuth oxychloride, bismuth citrate, colloidal bismuth subcitrate, and Bi nanomaterials all induced slight cytotoxicity accompanied with autophagy. Although the role of autophagy in Bi-induced cytotoxicity and kidney injury is under investigation by us, autophagy may help with the exploration of the mechanisms of nephrotoxicity by Bi.

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Qian, Zhaoxia, et David S. Ginger. « Reversibly Reconfigurable Colloidal Plasmonic Nanomaterials ». Journal of the American Chemical Society 139, n^o 15 (30 mars 2017) : 5266–76. http://dx.doi.org/10.1021/jacs.7b00711.

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Chen, Linmin, Meihuang Zeng, Jingwen Jin, Qiuhong Yao, Tingxiu Ye, Longjie You, Xi Chen, Xiaomei Chen et Zhiyong Guo. « Nanoenzyme Reactor-Based Oxidation-Induced Reaction for Quantitative SERS Analysis of Food Antiseptics ». Biosensors 12, n^o 11 (8 novembre 2022) : 988. http://dx.doi.org/10.3390/bios12110988.

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Nanoenzyme reactors based on shell-isolated colloidal plasmonic nanomaterials are well-established and widely applied in catalysis and surface-enhanced Raman scattering (SERS) sensing. In this study, a “double wing with one body” strategy was developed to establish a reduced food antiseptic sensing method using shell-isolated colloidal plasmonic nanomaterials. Gold nano particles (Au NPs) were used to synthesize the colloidal plasmonic nanomaterials, which was achieved by attaching ferrous ions (Fe2+), ferric ions (Fe3+), nitroso (NO−) group, cyanogen (CN−) group, and dopamine (DA) via coordinative interactions. The oxidation-induced reaction was utilized to generate •OH following the Fe2+-mediated Fenton reaction with the shell-isolated colloidal plasmonic nanomaterials. The •OH generated in the cascade reactor had a high oxidative capacity toward acid preservatives. Importantly, with the introduction of the signal molecule DA, the cascade reactor exhibited also induced a Raman signal change by reaction with the oxidation product (malondialdehyde) which improved the sensitivity of the analysis. In addition, the stable shell-isolated structure was effective in realizing a reproducible and quantitative SERS analysis method, which overcomes previous limitations and could extend the use of nanoenzymes to various complex sensing applications.

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Teste, Bruno, et Stephanie Descroix. « Colloidal nanomaterial-based immunoassay ». Nanomedicine 7, n^o 6 (juin 2012) : 917–29. http://dx.doi.org/10.2217/nnm.12.58.

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Małaczewska, J. « The in vitro effect of commercially available noble metal nanocolloids on the splenocyte proliferative response and cytokine production in mice ». Polish Journal of Veterinary Sciences 17, n^o 1 (1 mars 2014) : 37–45. http://dx.doi.org/10.2478/pjvs-2014-0005.

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Abstract Noble metal nanoparticles, currently among the most popular types of nanomaterials, are capable of penetrating through biological barriers once they enter a living organism. There, they can permeate into organs possessing the reticuloendothelial system, such as the spleen. The objective of this study was to determine the effect of commercial nanocolloids of noble metals (silver, gold and copper), recommended by the manufacturer as dietary supplements, on the in vitro viability, proliferative activity and production of cytokines (IL-1β, IL-2, IL-6, IL- 10 and TNF-α) by mouse splenocytes. All of the analyzed colloids had some effect on the activity of mouse splenocytes. Silver colloid was characterized by high toxicity - concentrations of 1.25 ppm and above substantially depressed the viability of cells as well as their proliferative activity and ability to synthesize cytokines. The other two colloids were far less toxic than nanosilver, although their non-toxic concentrations had a significant effect on the production of cytokines by mitogen activated splenocytes. The colloid of gold decreased the level of IL-2, and the colloid of copper caused an increase in IL-2, IL6 and Il-10. At the same time, copper colloid alone induced the synthesis of IL-1β in mitogen unstimulated cells. The results indicate that colloids of noble metals are capable of affecting the activity of immunocompetent cells in important peripheral organs of the immune system.

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Bantz, Christoph, Olga Koshkina, Thomas Lang, Hans-Joachim Galla, C. James Kirkpatrick, Roland H. Stauber et Michael Maskos. « The surface properties of nanoparticles determine the agglomeration state and the size of the particles under physiological conditions ». Beilstein Journal of Nanotechnology 5 (15 octobre 2014) : 1774–86. http://dx.doi.org/10.3762/bjnano.5.188.

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Due to the recent widespread application of nanomaterials to biological systems, a careful consideration of their physiological impact is required. This demands an understanding of the complex processes at the bio–nano interface. Therefore, a comprehensive and accurate characterization of the material under physiological conditions is crucial to correlate the observed biological impact with defined colloidal properties. As promising candidates for biomedical applications, two SiO2-based nanomaterial systems were chosen for extensive size characterization to investigate the agglomeration behavior under physiological conditions. To combine the benefits of different characterization techniques and to compensate for their respective drawbacks, transmission electron microscopy, dynamic light scattering and asymmetric flow field-flow fractionation were applied. The investigated particle systems were (i) negatively charged silica particles and (ii) poly(organosiloxane) particles offering variable surface modification opportunities (positively charged, polymer coated). It is shown that the surface properties primarily determine the agglomeration state of the particles and therefore their effective size, especially under physiological conditions. Thus, the biological identity of a nanomaterial is clearly influenced by differentiating surface properties.

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Anastasiadis, Spiros H., Kiriaki Chrissopoulou, Emmanuel Stratakis, Paraskevi Kavatzikidou, Georgia Kaklamani et Anthi Ranella. « How the Physicochemical Properties of Manufactured Nanomaterials Affect Their Performance in Dispersion and Their Applications in Biomedicine : A Review ». Nanomaterials 12, n^o 3 (6 février 2022) : 552. http://dx.doi.org/10.3390/nano12030552.

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The growth in novel synthesis methods and in the range of possible applications has led to the development of a large variety of manufactured nanomaterials (MNMs), which can, in principle, come into close contact with humans and be dispersed in the environment. The nanomaterials interact with the surrounding environment, this being either the proteins and/or cells in a biological medium or the matrix constituent in a dispersion or composite, and an interface is formed whose properties depend on the physicochemical interactions and on colloidal forces. The development of predictive relationships between the characteristics of individual MNMs and their potential practical use critically depends on how the key parameters of MNMs, such as the size, shape, surface chemistry, surface charge, surface coating, etc., affect the behavior in a test medium. This relationship between the biophysicochemical properties of the MNMs and their practical use is defined as their functionality; understanding this relationship is very important for the safe use of these nanomaterials. In this mini review, we attempt to identify the key parameters of nanomaterials and establish a relationship between these and the main MNM functionalities, which would play an important role in the safe design of MNMs; thus, reducing the possible health and environmental risks early on in the innovation process, when the functionality of a nanomaterial and its toxicity/safety will be taken into account in an integrated way. This review aims to contribute to a decision tree strategy for the optimum design of safe nanomaterials, by going beyond the compromise between functionality and safety.

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Jia, Zixian, Jiantao Li, Lin Gao, Dezheng Yang et Andrei Kanaev. « Dynamic Light Scattering : A Powerful Tool for In Situ Nanoparticle Sizing ». Colloids and Interfaces 7, n^o 1 (16 février 2023) : 15. http://dx.doi.org/10.3390/colloids7010015.

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Due to surface effects and quantum size effects, nanomaterials have properties that are vastly different from those of bulk materials due to surface effects. The particle size distribution plays an important role in chemical and physical properties. The measurement and control of this parameter are crucial for nanomaterial synthesis. Dynamic light scattering (DLS) is a fast and non-invasive tool used to measure particle size, size distribution and stability in solutions or suspensions during nanomaterial preparation. In this review, we focus on the in situ sizing of nanomaterial preparation in the form of colloids, especially for metal oxide nanoparticles (MONs). The measuring principle, including an overview of sizing techniques, advantages and limitations and theories of DLS were first discussed. The instrument design was then investigated. Ex-situ and in situ configuration of DLS, sample preparations, measurement conditions and reaction cell design for in situ configuration were studied. The MONs preparation monitored by DLS was presented, taking into consideration both ex situ and in situ configuration.

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Saldanha, Pearl L., Vladimir Lesnyak et Liberato Manna. « Large scale syntheses of colloidal nanomaterials ». Nano Today 12 (février 2017) : 46–63. http://dx.doi.org/10.1016/j.nantod.2016.12.001.

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Porotnikov, Dmitry, Benjamin T. Diroll, Dulanjan Harankahage, Laura Obloy, Mingrui Yang, James Cassidy, Cole Ellison et al. « Low-threshold laser medium utilizing semiconductor nanoshell quantum dots ». Nanoscale 12, n^o 33 (2020) : 17426–36. http://dx.doi.org/10.1039/d0nr03582c.

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Liu, Jing, Chengnan Li, Toon Brans, Aranit Harizaj, Shana Van de Steene, Thomas De Beer, Stefaan De Smedt et al. « Surface Functionalization with Polyethylene Glycol and Polyethyleneimine Improves the Performance of Graphene-Based Materials for Safe and Efficient Intracellular Delivery by Laser-Induced Photoporation ». International Journal of Molecular Sciences 21, n^o 4 (24 février 2020) : 1540. http://dx.doi.org/10.3390/ijms21041540.

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Nanoparticle mediated laser-induced photoporation is a physical cell membrane disruption approach to directly deliver extrinsic molecules into living cells, which is particularly promising in applications for both adherent and suspension cells. In this work, we explored surface modifications of graphene quantum dots (GQD) and reduced graphene oxide (rGO) with polyethylene glycol (PEG) and polyethyleneimine (PEI) to enhance colloidal stability while retaining photoporation functionality. After photoporation with FITC-dextran 10 kDa (FD10), the percentage of positive HeLa cells (81% for GQD-PEG, 74% for rGO-PEG and 90% for rGO-PEI) increased approximately two-fold compared to the bare nanomaterials. While for Jurkat suspension cells, the photoporation efficiency with polymer-modified graphene-based nanomaterial reached as high as 80%. Cell viability was >80% in all these cases. In addition, polymer functionalization proved to be beneficial for the delivery of larger macromolecules (FD70 and FD500) as well. Finally, we show that rGO is suitable for photoporation using a near-infrared laser to reach 80% FD10 positive HeLa cells at 80% cell viability. We conclude that modification of graphene-based nanoparticles with PEG and especially PEI provide better colloidal stability in cell medium, resulting in more uniform transfection and overall increased efficiency.

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Gandhi, Mansi, et Khairunnisa Amreen. « Emerging Trends in Nanomaterial-Based Biomedical Aspects ». Electrochem 4, n^o 3 (4 août 2023) : 365–88. http://dx.doi.org/10.3390/electrochem4030024.

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Comprehending the interfacial interaction of nanomaterials (NMs) and biological systems is a significant research interest. NMs comprise various nanoparticles (NPs) like carbon nanotubes, graphene oxides, carbon dots, graphite nanopowders, etc. These NPs show a variety of interactions with biological interfaces via organic layers, therapeutic molecules, proteins, DNA, and cellular matrices. A number of biophysical and colloidal forces act at the morphological surface to regulate the biological responses of bio-nanoconjugates, imparting distinct physical properties to the NMs. The design of future-generation nano-tools is primarily based on the basic properties of NMs, such as shape, size, compositional, functionality, etc., with studies being carried out extensively. Understanding their properties promotes research in the medical and biological sciences and improves their applicability in the health management sector. In this review article, in-depth and critical analysis of the theoretical and experimental aspects involving nanoscale material, which have inspired various biological systems, is the area of focus. The main analysis involves different self-assembled synthetic materials, bio-functionalized NMs, and their probing techniques. The present review article focuses on recent emerging trends in the synthesis and applications of nanomaterials with respect to various biomedical applications. This article provides value to the literature as it summarizes the state-of-the-art nanomaterials reported, especially within the health sector. It has been observed that nanomaterial applications in drug design, diagnosis, testing, and in the research arena, as well as many fatal disease conditions like cancer and sepsis, have explored alongwith drug therapies and other options for the delivery of nanomaterials. Even the day-to-day life of the synthesis and purification of these materials is changing to provide us with a simplified process. This review article can be useful in the research sector as a single platform wherein all types of nanomaterials for biomedical aspects can be understood in detail.

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Svechkarev, Denis, et Aaron M. Mohs. « Organic Fluorescent Dye-based Nanomaterials : Advances in the Rational Design for Imaging and Sensing Applications ». Current Medicinal Chemistry 26, n^o 21 (19 septembre 2019) : 4042–64. http://dx.doi.org/10.2174/0929867325666180226111716.

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Self-assembled fluorescent nanomaterials based on small-molecule organic dyes are gaining increasing popularity in imaging and sensing applications over the past decade. This is primarily due to their ability to combine spectral properties tunability and biocompatibility of small molecule organic fluorophores with brightness, chemical and colloidal stability of inorganic materials. Such a unique combination of features comes with rich versatility of dye-based nanomaterials: from aggregates of small molecules to sophisticated core-shell nanoarchitectures involving hyperbranched polymers. Along with the ongoing discovery of new materials and better ways of their synthesis, it is very important to continue systematic studies of fundamental factors that regulate the key properties of fluorescent nanomaterials: their size, polydispersity, colloidal stability, chemical stability, absorption and emission maxima, biocompatibility, and interactions with biological interfaces. In this review, we focus on the systematic description of various types of organic fluorescent nanomaterials, approaches to their synthesis, and ways to optimize and control their characteristics. The discussion is built on examples from reports on recent advances in the design and applications of such materials. Conclusions made from this analysis allow a perspective on future development of fluorescent nanomaterials design for biomedical and related applications.

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Zhao, Xixia, Qi Yang et Zewei Quan. « Tin-based nanomaterials : colloidal synthesis and battery applications ». Chemical Communications 55, n^o 60 (2019) : 8683–94. http://dx.doi.org/10.1039/c9cc02811k.

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Abolhasani, Milad, Ali Oskooei, Anna Klinkova, Eugenia Kumacheva et Axel Günther. « Shaken, and stirred : oscillatory segmented flow for controlled size-evolution of colloidal nanomaterials ». Lab Chip 14, n^o 13 (2014) : 2309–18. http://dx.doi.org/10.1039/c4lc00131a.

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Nanayakkara, Sanjini U., Jao van de Lagemaat et Joseph M. Luther. « Scanning Probe Characterization of Heterostructured Colloidal Nanomaterials ». Chemical Reviews 115, n^o 16 (21 juillet 2015) : 8157–81. http://dx.doi.org/10.1021/cr500280t.

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Zhu, Jian, et Mark C. Hersam. « Assembly and Electronic Applications of Colloidal Nanomaterials ». Advanced Materials 29, n^o 4 (15 novembre 2016) : 1603895. http://dx.doi.org/10.1002/adma.201603895.

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Zabara, Mahsa, Linda Hong et Stefan Salentinig. « Design and Characterization of Bio-inspired Antimicrobial Nanomaterials ». CHIMIA International Journal for Chemistry 74, n^o 9 (30 septembre 2020) : 674–80. http://dx.doi.org/10.2533/chimia.2020.674.

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Colloidal structures are crucial components in biological systems and provide a vivid and seemingly infinite source of inspiration for the design of functional bio-inspired materials. They form multi-dimensional confinements and shape living matter, and transport and protect bioactive molecules in harsh biological environments such as the stomach. Recently, colloidal nanostructures based on natural antimicrobial peptides have emerged as promising alternatives to conventional antibiotics. This contribution summarizes the recent progress in the understanding and design of these bio-inspired antimicrobial nanomaterials, and discusses their advances in the form of dispersions and as surface coatings. Their potential for applications in future food and healthcare materials is also highlighted. Further, it discusses challenges in the characterization of structure and dynamics in these materials.

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Zienkiewicz-Strzalka, Malgorzata, et Magdalena Blachnio. « Nitrogenous Bases in Relation to the Colloidal Silver Phase : Adsorption Kinetic, and Morphology Investigation ». Applied Sciences 13, n^o 6 (14 mars 2023) : 3696. http://dx.doi.org/10.3390/app13063696.

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The interaction between inorganic nanoparticles and biological molecules is of great importance in the field of biosystems and nanomaterials. Here, we report the adsorption process of a heterocyclic organic compound (nitrogenous base) on a microporous carbon (C) in the presence of a colloidal silver solution (AgNP solution) as an accompanying substance. Analysis of the potential colloid–biomolecule interaction as well as the subsequent phenomenon of changes in the morphology of the colloidal system in the presence of selected nucleotides was investigated. Adenosine nitrogenous base (Anb) was selected as a model molecule of the building block of DNA and RNA. The adsorption process of nucleotides from one- and two-component systems was monitored by cyclic UV-VIS measurements for obtaining time-dependent profiles and estimating the kinetic characteristics of uptake. We demonstrate the temperature-dependent course of the adsorption process with visible nucleotide-AgNP morphology determinants. The experimental adsorption kinetics were analyzed using selected theoretical models (intraparticle diffusion model, multiexponential equation, and many others). On the other hand, obtained Anb/C and Anb/AgNP/C composites were characterized by various techniques suitable for material surface and morphology characterization: high-resolution transmission electron microscopy (HR-TEM and TEM/EDX), N2 physisorption measurements, and thermal analysis (thermogravimetric analysis (TGA)/differential scanning calorimetry (DSC) experiments).

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Sánchez-Calvo, A., A. Costa-García et M. C. Blanco-López. « Paper-based electrodes modified with cobalt phthalocyanine colloid for the determination of hydrogen peroxide and glucose ». Analyst 145, n^o 7 (2020) : 2716–24. http://dx.doi.org/10.1039/c9an02413a.

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Cobalt(ii) phthalocyanine (CoPc) was suspended in aqueous medium and the colloidal system was used as catalyst for the electrochemical determination of hydrogen peroxide on paper-based electrodes modified with carbon nanomaterials.

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Cao, Yue, Hao Zhou, Ruo-Can Qian, Jingquan Liu, Yi-Lun Ying et Yi-Tao Long. « Analysis of the electron transfer properties of carbon quantum dots on gold nanorod surfaces via plasmonic resonance scattering spectroscopy ». Chemical Communications 53, n^o 42 (2017) : 5729–32. http://dx.doi.org/10.1039/c7cc01464c.

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Colloidal nanocomposites consisting of carbon quantum dots and gold nanorods were fabricated on ITO electrode surfaces via electrostatic interactions. The structural, electrochemical and scattering properties of the hybrid nanomaterials were systematically investigated.

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Hahn, Rebeca V. H., Salvador Rodríguez-Bolívar, Panagiotis Rodosthenous, Erik S. Skibinsky-Gitlin, Marco Califano et Francisco M. Gómez-Campos. « Optical Absorption in N-Dimensional Colloidal Quantum Dot Arrays : Influence of Stoichiometry and Applications in Intermediate Band Solar Cells ». Nanomaterials 12, n^o 19 (27 septembre 2022) : 3387. http://dx.doi.org/10.3390/nano12193387.

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We present a theoretical atomistic study of the optical properties of non-toxic InX (X = P, As, Sb) colloidal quantum dot arrays for application in photovoltaics. We focus on the electronic structure and optical absorption and on their dependence on array dimensionality and surface stoichiometry motivated by the rapid development of experimental techniques to achieve high periodicity and colloidal quantum dot characteristics. The homogeneous response of colloidal quantum dot arrays to different light polarizations is also investigated. Our results shed light on the optical behaviour of these novel multi-dimensional nanomaterials and identify some of them as ideal building blocks for intermediate band solar cells.

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Kim, Jisung, Mohamed A. Abdou Mohamed, Kyryl Zagorovsky et Warren C. W. Chan. « State of diagnosing infectious pathogens using colloidal nanomaterials ». Biomaterials 146 (novembre 2017) : 97–114. http://dx.doi.org/10.1016/j.biomaterials.2017.08.013.

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Ibrahim, Arif, Syahrir Ridha, Asna Amer, Radzi Shahari et Tarek Ganat. « Influence of Degree of Dispersion of Noncovalent Functionalized Graphene Nanoplatelets on Rheological Behaviour of Aqueous Drilling Fluids ». International Journal of Chemical Engineering 2019 (26 février 2019) : 1–11. http://dx.doi.org/10.1155/2019/8107168.

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Application of carbon nanomaterials in oil well drilling fluid has been previously studied and was found to enhance its filtration properties. There is a general consensus that addition of colloids in suspension will alter its rheology, i.e., carbon nanomaterials, in this research work; graphene nanoplatelets are hydrophobic materials, which require functionalisation to improve its dispersion in aqueous solution. However, different degrees of dispersion may vary the rheological properties behaviour of drilling fluid. The objective of this study was to characterize the colloidal dispersion of graphene nanoplatelets (GNP) in aqueous solution and its impact on the rheological properties behaviour of water-based drilling fluid. Dispersion of graphene nanoplatelets was achieved through noncovalent functionalisation by means of surfactant attachment. UV-visible spectroscopy was employed to analyze the dispersion of GNP in aqueous solution. The rheological test was carried out using a simple direct-indicating viscometer at six different speeds. Results revealed that the degree of dispersion of GNP using Triton X-100 was generally higher than both SDS and DTAB. Comparison between the rheological properties behaviour of drilling fluid with GNP dispersed using different surfactants shows little to no difference at low shear rates. At high shear rates, however, greater dispersion of GNP shows higher thinning properties while fluid with a low dispersion of GNP exhibited linear behaviour to thickening properties.

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Lauth, Jannika, Michele Failla, Eugen Klein, Christian Klinke, Sachin Kinge et Laurens D. A. Siebbeles. « Photoexcitation of PbS nanosheets leads to highly mobile charge carriers and stable excitons ». Nanoscale 11, n^o 44 (2019) : 21569–76. http://dx.doi.org/10.1039/c9nr07927k.

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Colloidal two-dimensional (2D) PbS nanosheets exhibit stable excitons and highly mobile charge carriers (500–1000 cm² V⁻¹ s⁻¹) rendering solution-processed nanomaterials suitable for ultrathin optoelectronics.

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Sportelli, Maria Chiara, Rosaria Anna Picca, Margherita Izzi, Gerardo Palazzo, Roberto Gristina, Massimo Innocenti, Luisa Torsi et Nicola Cioffi. « ZnO Nanostructures with Antibacterial Properties Prepared by a Green Electrochemical-Thermal Approach ». Nanomaterials 10, n^o 3 (5 mars 2020) : 473. http://dx.doi.org/10.3390/nano10030473.

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Zinc oxide (ZnO) nanostructures are widely applied materials, and are also capable of antimicrobial action. They can be obtained by several methods, which include physical and chemical approaches. Considering the recent rise of green and low-cost synthetic routes for nanomaterial development, electrochemical techniques represent a valid alternative to biogenic synthesis. Following a hybrid electrochemical-thermal method modified by our group, here we report on the aqueous electrosynthesis of ZnO nanomaterials based on the use of alternative stabilizers. We tested both benzyl-hexadecyl-dimetylammonium chloride (BAC) and poly-diallyl-(dimethylammonium) chloride (PDDA). Transmission electron microscopy images showed the formation of rod-like and flower-like structures with a variable aspect-ratio. The combination of UV–Vis, FTIR and XPS spectroscopies allowed for the univocal assessment of the material composition as a function of different thermal treatments. In fact, the latter guaranteed the complete conversion of the as-prepared colloidal materials into stoichiometric ZnO species without excessive morphological modification. The antimicrobial efficacy of both materials was tested against Bacillus subtilis as a Gram-positive model microorganism.

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Wang, Mengjiao, Matteo Crisci, Matilde Pavan, Zheming Liu, Jaime Gallego et Teresa Gatti. « New Insights into the Surfactant-Assisted Liquid-Phase Exfoliation of Bi2S3 for Electrocatalytic Applications ». Catalysts 13, n^o 3 (9 mars 2023) : 551. http://dx.doi.org/10.3390/catal13030551.

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During water electrolysis, adding an electrocatalyst for the hydrogen evolution reaction (HER) is necessary to reduce the activation barrier and thus enhance the reaction rate. Metal chalcogenide-based 2D nanomaterials have been studied as an alternative to noble metal electrocatalysts because of their interesting electrocatalytic properties and low costs of production. However, the difficulty in improving the catalytic efficiency and industrializing the synthetic methods have become a problem in the potential application of these species in electrocatalysis. Liquid-phase exfoliation (LPE) is a low-cost and scalable technique for lab- and industrial-scale synthesis of 2D-material colloidal inks. In this work, we present, to the best of our knowledge, for the first time a systematic study on the surfactant-assisted LPE of bulk Bi2S3 crystalline powder to produce nanosheets (NSs). Different dispersing agents and LPE conditions have been tested in order to obtain colloidal low-dimensional Bi2S3 NSs in H2O at optimized concentrations. Eventually, colloidally stable layered nano-sized Bi2S3 suspensions can be produced with yields of up to ~12.5%. The thus obtained low-dimensional Bi2S3 is proven to be more active for HER than the bulk starting material, showing an overpotential of only 235 mV and an optimized Tafel slope of 125 mV/dec. Our results provide a facile top-down method to produce nano-sized Bi2S3 through a green approach and demonstrate that this material can have a good potential as electrocatalyst for HER.

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Maas, Michael. « Carbon Nanomaterials as Antibacterial Colloids ». Materials 9, n^o 8 (25 juillet 2016) : 617. http://dx.doi.org/10.3390/ma9080617.

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Harrison, Haley B., et Jeffrey R. Alston. « Sonochemical Functionalization of Boron Nitride Nanomaterials ». MRS Advances 5, n^o 14-15 (27 décembre 2019) : 709–16. http://dx.doi.org/10.1557/adv.2019.487.

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AbstractBoron nitride nanotubes (BNNTs) and hexagonal boron nitride platelets (h-BNs) have received considerable attention for aerospace insulation applications due to their exceptional chemical and thermal stability. Presently, making BN nanomaterials compatible with polymer and composite matrices is challenging. Due to their inert and highly stable structure, h-BN and BNNTs are difficult to covalently functionalize. In this work, we present a novel sonochemical technique that enables covalent attachment of fluoroalkoxy substituents to the surface of BN nanomaterials in a controlled and metered process. Covalent functionalization is confirmed via colloidal stability analysis, FT-IR, and x-ray photoelectron spectroscopy (XPS).

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Louie, Stacey M., Justin M. Gorham, Eric A. McGivney, Jingyu Liu, Kelvin B. Gregory et Vincent A. Hackley. « Photochemical transformations of thiolated polyethylene glycol coatings on gold nanoparticles ». Environmental Science : Nano 3, n^o 5 (2016) : 1090–102. http://dx.doi.org/10.1039/c6en00141f.

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Photochemical reactions can cause significant transformations of manufactured nanomaterials and their surface coatings in sunlit environments. In this study, loss of thiolated polyethylene glycol from gold nanoparticle surfaces by chain scission was observed under UV irradiation and resulted in diminished colloidal stability.

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Sneed, Brian T., Allison P. Young et Chia-Kuang Tsung. « Building up strain in colloidal metal nanoparticle catalysts ». Nanoscale 7, n^o 29 (2015) : 12248–65. http://dx.doi.org/10.1039/c5nr02529j.

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The focus on surface lattice strain in nanostructures as a fundamental research topic has gained momentum in recent years as scientists investigated its significant impact on the surface electronic structure and catalytic properties of nanomaterials.

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Corsaro, Carmelo, Giulia Neri, Angela Maria Mezzasalma et Enza Fazio. « Weibull Modeling of Controlled Drug Release from Ag-PMA Nanosystems ». Polymers 13, n^o 17 (27 août 2021) : 2897. http://dx.doi.org/10.3390/polym13172897.

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Traditional pharmacotherapy suffers from multiple drawbacks that hamper patient treatment such as antibiotic resistances or low drug selectivity and toxicity during systemic applications. Some functional hybrid nanomaterials are designed to handle the drug release process under remote-control. More attention has recently been paid to synthetic polyelectrolytes for their intrinsic properties which allow them to rearrange into compact structures, ideal to be used as drug carriers or probes influencing biochemical processes. The presence of Ag nanoparticles (NPs) in the Poly methyl acrylate (PMA) matrix leads to an enhancement of drug release efficiency, even using a low-power laser whose wavelength is far from the Ag Surface Plasmon Resonance (SPR) peak. Further, compared to the colloids, the nanofiber-based drug delivery system has shown shorter response time and more precise control over the release rate. The efficiency and timing of involved drug release mechanisms has been estimated by the Weibull distribution function, whose parameters indicate that the release mechanism of nanofibers obeys Fick’s first law while a non-Fickian character controlled by diffusion and relaxation of polymer chains occurs in the colloidal phase.

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Mattoussi, Hedi, Liang Du, Neda Arabzadeh Nosratabad et Zhicheng Jin. « (Keynote) N-Heterocyclic Carbene-coated Gold Nanoparticles and Luminescent Quantum Dots ». ECS Meeting Abstracts MA2022-02, n^o 20 (9 octobre 2022) : 904. http://dx.doi.org/10.1149/ma2022-0220904mtgabs.

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N-heterocyclic carbenes (NHCs) have generated much interest for use as versatile metal-coordinating groups, since they were first synthesized by Arduengo and coworkers in 1991. NHC molecules can be considered as L-type ligands, because they share their non-bonding electron pairs with the σ-accepting orbital of transition metals, and this endows them with strong coordination interactions. NHC-appended molecules have recently been actively exploited as potentially effective ligands for the surface passivation of various colloidal nanomaterials. We investigate the coordination interactions between a few representative colloidal nanocrystals, including gold nanoparticles (AuNPs) and luminescent quantum dots (QDs), and a NHC-based polymer ligand. The latter presents multiple NHC groups and several short poly (ethylene glycol) (PEG) chains as solubilizing blocks. We find that our NHC-decorated ligands rapidly coordinate onto both sets of nanocrystals, which we attribute to their soft Lewis base nature. These ideally match the soft Lewis acid character of transition metal colloid surfaces, promoting strong coordination bonding through soft‐soft interaction. We combine NMR spectroscopy, fluorescence spectroscopy, high-resolution transmission electron microscopy supplemented with dynamic light scattering to characterize the nature of the binding interactions. Furthermore, the long-term stability of the NHC-stabilized nanocolloids have been tested after phase transfer to water, a highly challenging chemical venue for such groups, due to the moisture sensitive nature of NHC molecules. Data show that our NHC-polymer-stabilized AuNPs and QDs exhibit long-term colloidal stability in buffer media while preserving their optical and fluorescing properties, with no sign of degradation or aggregation build up for at least one year of storage. We will discuss the ligand design and synthesis, characterization of the polymer-stabilized nanocrystals under various conditions, with a particular focus on the beneficial effects of ligand multi-coordination interactions onto the nanocolloid surfaces.

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Yi, Chenglin, Hong Liu, Shaoyi Zhang, Yiqun Yang, Yan Zhang, Zhongyuan Lu, Eugenia Kumacheva et Zhihong Nie. « Self-limiting directional nanoparticle bonding governed by reaction stoichiometry ». Science 369, n^o 6509 (10 septembre 2020) : 1369–74. http://dx.doi.org/10.1126/science.aba8653.

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Nanoparticle clusters with molecular-like configurations are an emerging class of colloidal materials. Particles decorated with attractive surface patches acting as analogs of functional groups are used to assemble colloidal molecules (CMs); however, high-yield generation of patchy nanoparticles remains a challenge. We show that for nanoparticles capped with complementary reactive polymers, a stoichiometric reaction leads to reorganization of the uniform ligand shell and self-limiting nanoparticle bonding, whereas electrostatic repulsion between colloidal bonds governs CM symmetry. This mechanism enables high-yield CM generation and their programmable organization in hierarchical nanostructures. Our work bridges the gap between covalent bonding taking place at an atomic level and colloidal bonding occurring at the length scale two orders of magnitude larger and broadens the methods for nanomaterial fabrication.

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Liang, Yongqi, Min Xie, Juan Li, Liangliang Liu et Yi Cao. « Influence of 3-Hydroxyflavone on Colloidal Stability and Internationalization of Ag Nanomaterials Into THP-1 Macrophages ». Dose-Response 17, n^o 3 (juillet 2019) : 155932581986571. http://dx.doi.org/10.1177/1559325819865713.

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Polyphenols as typical food components can influence the colloidal properties and internalization of nanomaterials (NMs) into mammalian cells. Recently, we found that 3-hydroxyflavone (H3) promoted intracellular Zn ions in ZnO nanoparticle (NP) exposed Caco-2 and HepG2 cells. However, it is unclear if H3 could affect the internalization of metal-based NMs with different morphologies. This study investigated the influence of H3 on colloidal aspects of Ag NPs and Ag nanoflakes (NFs) as well as the internalization of Ag NMs into THP-1 macrophages. 3-Hydroxyflavone at 50 μM promoted the solubility and altered hydrodynamic size, polydispersity index, and ζ potential of Ag NPs and Ag NFs, which indicated that H3 could affect the colloidal stability of Ag NMs. Only H3 but not Ag NMs significantly decreased mitochondrial activities of THP-1 macrophages. The internalization of Ag NMs was markedly increased due to the presence of H3. 3-Hydroxyflavone also exhibited antioxidative properties as it reduced intracellular reactive oxygen species and promoted the activities of ABC transporters as it reduced retention of Calcein in Ag NM-exposed THP-1 macrophages. We concluded that H3 promoted the internalization of Ag NMs into macrophages probably by altering the colloidal stability of Ag NMs and consequently NM-macrophage interactions.

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Ortelli, Simona, Anna Luisa Costa, Magda Blosi, Andrea Brunelli, Elena Badetti, Alessandro Bonetto, Danail Hristozov et Antonio Marcomini. « Colloidal characterization of CuO nanoparticles in biological and environmental media ». Environmental Science : Nano 4, n^o 6 (2017) : 1264–72. http://dx.doi.org/10.1039/c6en00601a.

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SASAKI, Takayoshi. « Colloidal Oxide Nanosheets as a New Class of Nanomaterials ». Journal of the Japan Society of Colour Material 76, n^o 10 (2003) : 391–96. http://dx.doi.org/10.4011/shikizai1937.76.391.

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Murphy, Catherine J., et Jillian M. Buriak. « Best Practices for the Reporting of Colloidal Inorganic Nanomaterials ». Chemistry of Materials 27, n^o 14 (28 juillet 2015) : 4911–13. http://dx.doi.org/10.1021/acs.chemmater.5b02323.

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Nomura, Yosuke, Ilya V. Anoshkin, Chikaaki Okuda, Motoyuki Iijima, Yoshio Ukyo, Hidehiro Kamiya, Albert G. Nasibulin et Esko I. Kauppinen. « Carbon Nanotube/Nanofibers and Graphite Hybrids for Li-Ion Battery Application ». Journal of Nanomaterials 2014 (2014) : 1–7. http://dx.doi.org/10.1155/2014/586241.

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To improve the electrical conductivity of negative electrodes of lithium ion batteries, we applied a direct CVD synthesis of carbon nanomaterials on the surface of graphite particles. To prepare a catalyst, two alternative approaches were utilized: colloidal nanoparticles (NPs) and metal (Ni and Co) nitrate salt precursors deposited on the graphite surface. Both colloidal and precursor systems allowed us to produce carbon nanofibers (CNFs) on the graphite surface with high coverage under the optimum CVD conditions. Electrical measurements revealed that the resistivity of the actual electrodes fabricated from CNFs coated graphite particles was about 40% lower compared to the original pristine graphite electrodes.

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