Relevant bibliographies by topics / Anionic Nanoparticles

Academic literature on the topic 'Anionic Nanoparticles'

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Published: 7 September 2023

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Journal articles on the topic "Anionic Nanoparticles"

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Singh, Himanshi, Sugam Kumar, and Vinod K. Aswal. "Interplay of interactions in nanoparticle–surfactant complexes in aqueous salt solution." Journal of Applied Physics 132, no. 22 (December 14, 2022): 224701. http://dx.doi.org/10.1063/5.0118615.

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The evolution of phase behavior and interactions in anionic silica nanoparticles (Ludox HS40), surfactants [non-ionic decaethylene glycol mono-dodecyl ether (C12E10) and anionic sodium dodecyl sulfate (SDS)], and nanoparticle–surfactant solutions in the presence of salt (NaCl) has been studied using small-angle neutron scattering and dynamic light scattering. In an anionic silica nanoparticle solution (1 wt. %), the phase behavior is controlled by salt concentrations (0–1 M) through screening electrostatic interactions. In the case of 1 wt. % surfactant solutions, the anionic SDS surfactant micelles show significant growth upon adding salt, whereas non-ionic surfactant C12E10 micelles remain spherical until a high salt concentration (1 M). In the mixed system of HS40–C12E10, a transition from a highly stable transparent phase to a two-phase turbid system is observed with a small amount of salt addition CS* (∼0.06 M). The single transparent phase of this system corresponds to sterically stabilized micelles-decorated nanoparticles. For the turbid phase, the results are understood in terms of depletion attraction induced by non-adsorption of C12E10 micelles, which explains the appearance of turbidity at a much lower concentration of salt. In the mixed system of similarly charged nanoparticles and micelles (HS40-SDS), the phase behavior is governed by no physical interaction between the components, and salt screens the repulsive interaction among nanoparticles. These results are further utilized to tune multicomponent interactions and phase behavior of nanoparticles with a mixed C12E10-SDS surfactant system in the presence of salt. The mixed surfactants provide tuning of nanoparticle–micelle as well as micelle–micelle interactions to dictate the phase behavior of a nanoparticle–surfactant solution. In these systems, the effective potential can be described by double-Yukawa potential taking account of attractive and repulsive parts at low and intermediate salt concentrations (<CS*). At high salt concentrations (>CS*), the aggregation of nanoparticles is characterized by fractal aggregates.
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Kanapina, A. E. "FEATURES OF THE DECAY OF EXCITED STATES OF IONIC DYES IN THE NEAR FIELD OF METAL NANOPARTICLES." Eurasian Physical Technical Journal 20, no. 2 (44) (June 21, 2023): 106–11. http://dx.doi.org/10.31489/2023no2/106-111.

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The influence factor of silver nanoparticles on the intramolecular processes of deactivation of the electronically excited state of polymethine dyes (PD) of different ionicity has been studied. It has been demonstrated that the optical density forcationic 1 and anionic 2 dyes does not change under the action of the plasmon field of Ag nanoparticles. Whereas an increase in absorbance by almost 18% was observed for neutral dye 3. A decrease in the enhancement in fluorescence intensity in the series of anionic–cationic–neutral dyes was registered upon addition of Ag nanoparticles to their solutions. The fluorescence lifetime practically does not change for all PDs under study.Data processing within the framework of the model of the influence of a plasmonic nanoparticle on radiative transitions in a dye molecule showed that the values of plasmon-enhanced rates of radiative decay of molecules decreases from neutral to cationic and, finally, to anionic dye. The rates of energy transfer from PD to plasmonic nanoparticles decrease in the reverse sequence of dyes, i.e. anionic-cationic-neutral PD. This is expressed in a decrease in the proportion of neutral dye molecules that were deactivated by fluorescence.
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Baig, Mirza Wasif, and Muhammad Siddiq. "Quantum Mechanics of In Situ Synthesis of Metal Nanoparticles within Anionic Microgels." Journal of Theoretical Chemistry 2013 (December 25, 2013): 1–5. http://dx.doi.org/10.1155/2013/410417.

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We discuss the quantum mechanics of many-body systems, that is, hybrid microgel consisting of negatively charged anionic microgels possessing thick sheath of water molecules solvating protruding anionic moieties and nanoparticle captivated within the microgel. Thermodynamic feasibility of synthesis of particular nanoparticle within the microgel is dependent upon the magnitude of interaction between nanoparticle, water molecules, and microgel relative to sum of magnitude of self-interaction between counterions and interaction between counterions and microgel. Nanoparticles synthesized with in the microgels have thick electronic cloud that oscillates under the influence of net interaction potential of charged anionic moieties and solvent water molecules which constitutes the chemical environment of hybrid microgel. Hamiltonian describing energy of oscillating electronic cloud of wrapped around nanoparticle is mathematically derived to be equal to product of integral electron density and product of its position vector overall space and net force acting on the oscillating electronic cloud of nanoparticle is mathematically defined as; ℱ∫ρn{n}n^ dn.
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Rathod, Prakash B., Ashok K. Pandey, Sher Singh Meena, and Anjali A. Athawale. "Quaternary ammonium bearing hyper-crosslinked polymer encapsulation on Fe3O4 nanoparticles." RSC Advances 6, no. 26 (2016): 21317–25. http://dx.doi.org/10.1039/c6ra01543c.

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Rodrigues, João M. M., Andreia S. F. Farinha, Zhi Lin, José A. S. Cavaleiro, Augusto C. Tome, and Joao P. C. Tome. "Phthalocyanine-Functionalized Magnetic Silica Nanoparticles as Anion Chemosensors." Sensors 21, no. 5 (February 26, 2021): 1632. http://dx.doi.org/10.3390/s21051632.

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Anionic species are one of the most common pollutants in residual and freshwaters. The presence of anthropogenic anions in water drastically increases the toxicity to living beings. Here, we report the preparation of a new optical active material based on tri(tosylamino)phthalocyanines grafted to ferromagnetic silica nanoparticles for anion detection and removal. The new unsymmetrical phthalocyanines (Pcs) proved to be excellent chemosensors for several anions (AcO−, Br−, Cl−, CN−, F−, H2PO4−, HSO4−, NO2−, NO3−, and OH−) in dimethyl sulfoxide (DMSO). Furthermore, the Pcs were grafted onto magnetic nanoparticles. The resulting novel hybrid material showed selectivity and sensitivity towards CN−, F−, and OH− anions in DMSO with limit of detection (LoD) of ≈4.0 µM. In water, the new hybrid chemosensor demonstrated selectivity and sensitivity for CN− and OH− anions with LoD of ≈0.2 µM. The new hybrids are easily recovered using a magnet, allowing recyclability and reusability, after acidic treatment, without losing the sensing proprieties.
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Sato, Takumi, and Yoshihiko Murakami. "Temperature-Responsive Polysaccharide Microparticles Containing Nanoparticles: Release of Multiple Cationic/Anionic Compounds." Materials 15, no. 13 (July 5, 2022): 4717. http://dx.doi.org/10.3390/ma15134717.

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Most drug carriers used in pulmonary administration are microparticles with diameters over 1 µm. Only a few examples involving nanoparticles have been reported because such small particles are readily exhaled. Consequently, the development of microparticles capable of encapsulating nanoparticles and a wide range of compounds for pulmonary drug-delivery applications is an important objective. In this study, we investigated the development of polysaccharide microparticles containing nanoparticles for the temperature-responsive and two-step release of inclusions. The prepared microparticles containing nanoparticles can release two differently charged compounds in a stepwise manner. The particles have two different drug release pathways: one is the release of nanoparticle inclusions from the nanoparticles and the other is the release of microparticle inclusions during microparticle collapse. The nanoparticles can be efficiently delivered deep into the lungs and a wide range of compounds are released in a charge-independent manner, owing to the suitable roughness of the microparticle surface. These polysaccharide microparticles containing nanoparticles are expected to be used as temperature-responsive drug carriers, not only for pulmonary administration but also for various administration routes, including transpulmonary, intramuscular, and transdermal routes, that can release multiple drugs in a controlled manner.
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Uchida, Noriyuki, Masayoshi Yanagi, and Hiroki Hamada. "Size-Tunable Paclitaxel Nanoparticles Stabilized by Anionic Phospholipids for Transdermal Delivery Applications." Natural Product Communications 15, no. 3 (March 1, 2020): 1934578X1990068. http://dx.doi.org/10.1177/1934578x19900684.

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Composite nanoparticles composed of an anionic phospholipid of 1,2-dipalmitoyl-sn-glycero-3-phosphorylglycerol (DPPG) and paclitaxel (PTX) were successfully prepared by mixing them in water followed by a subsequent heating/cooling process. The size of DPPG-PTX nanoparticle could be easily tuned by ultrasonic fragmentation. Upon addition of small-sized fluorescently labeled paclitaxel (FLPTX) nanoparticles with DPPG (DPPG-FLPTX) to rat skin tissue, part of the FLPTX molecules permeated to the stratum corneum.
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Xing, Huiping, Jianwei Wang, Ouya Ma, Xiaolian Chao, Yajun Zhou, Yuhu Li, and Zhihui Jia. "Hydroxypropyltrimethyl Ammonium Chloride Chitosan Nanoparticles Coatings for Reinforcement and Concomitant Inhibition of Anionic Water-Sensitive Dyes Migration on Fragile Paper Documents." Polymers 14, no. 18 (September 6, 2022): 3717. http://dx.doi.org/10.3390/polym14183717.

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The fragile paper is treated to improve the stability and appearance of the paper artifact, such as washing, lining, deacidification, and reinforcement. During the above treatments, paper documents inevitably make contact with water directly, leading to the appearance change, stability decrease, and migration or fading of anionic water-sensitive dyes, which are seriously harmful to information security. Herein, Hydroxypropyltrimethyl ammonium chloride chitosan (HACC) nanoparticles were employed for the reinforcement and concomitant inhibition of anionic water-sensitive dye migration on fragile paper. HACC nanoparticles were prepared through physical ball grinding method and characterized via LPSA, SEM, TEM, XRD and FTIR. To evaluate the protective potential of HACC nanoparticles coating, the chemical and mechanical properties of coated and uncoated papers were evaluated after dry heat and hygrothermal accelerated aging. Additionally, good color stability of anionic water-sensitive dyes was observed on the paper coated with HACC nanoparticles after lining technology. Finally, the interaction mechanism between the anionic water-sensitive dyes and HACC nanoparticles was analyzed using an ultraviolet spectrophotometer and FTIR. The as-proposed technique can provide technical support to improve the mechanical properties of fragile paper and enhance the anionic water-sensitive dyes stability in the aqueous phase.
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Foreman-Ortiz, Isabel U., Dongyue Liang, Elizabeth D. Laudadio, Jorge D. Calderin, Meng Wu, Puspam Keshri, Xianzhi Zhang, et al. "Anionic nanoparticle-induced perturbation to phospholipid membranes affects ion channel function." Proceedings of the National Academy of Sciences 117, no. 45 (October 26, 2020): 27854–61. http://dx.doi.org/10.1073/pnas.2004736117.

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Understanding the mechanisms of nanoparticle interaction with cell membranes is essential for designing materials for applications such as bioimaging and drug delivery, as well as for assessing engineered nanomaterial safety. Much attention has focused on nanoparticles that bind strongly to biological membranes or induce membrane damage, leading to adverse impacts on cells. More subtle effects on membrane function mediated via changes in biophysical properties of the phospholipid bilayer have received little study. Here, we combine electrophysiology measurements, infrared spectroscopy, and molecular dynamics simulations to obtain insight into a mode of nanoparticle-mediated modulation of membrane protein function that was previously only hinted at in prior work. Electrophysiology measurements on gramicidin A (gA) ion channels embedded in planar suspended lipid bilayers demonstrate that anionic gold nanoparticles (AuNPs) reduce channel activity and extend channel lifetimes without disrupting membrane integrity, in a manner consistent with changes in membrane mechanical properties. Vibrational spectroscopy indicates that AuNP interaction with the bilayer does not perturb the conformation of membrane-embedded gA. Molecular dynamics simulations reinforce the experimental findings, showing that anionic AuNPs do not directly interact with embedded gA channels but perturb the local properties of lipid bilayers. Our results are most consistent with a mechanism in which anionic AuNPs disrupt ion channel function in an indirect manner by altering the mechanical properties of the surrounding bilayer. Alteration of membrane mechanical properties represents a potentially important mechanism by which nanoparticles induce biological effects, as the function of many embedded membrane proteins depends on phospholipid bilayer biophysical properties.
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Miyamoto, Yoshitaka, Yumie Koshidaka, Katsutoshi Murase, Shoichiro Kanno, Hirofumi Noguchi, Kenji Miyado, Takeshi Ikeya, et al. "Functional Evaluation of 3D Liver Models Labeled with Polysaccharide Functionalized Magnetic Nanoparticles." Materials 15, no. 21 (November 5, 2022): 7823. http://dx.doi.org/10.3390/ma15217823.

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Establishing a rapid in vitro evaluation system for drug screening is essential for the development of new drugs. To reproduce tissues/organs with functions closer to living organisms, in vitro three-dimensional (3D) culture evaluation using microfabrication technology has been reported in recent years. Culture on patterned substrates with controlled hydrophilic and hydrophobic regions (Cell-ableTM) can create 3D liver models (miniature livers) with liver-specific Disse luminal structures and functions. MRI contrast agents are widely used as safe and minimally invasive diagnostic methods. We focused on anionic polysaccharide magnetic iron oxide nanoparticles (Resovist®) and synthesized the four types of nanoparticle derivatives with different properties. Cationic nanoparticles (TMADM) can be used to label target cells in a short time and have been successfully visualized in vivo. In this study, we examined the morphology of various nanoparticles. The morphology of various nanoparticles showed relatively smooth-edged spherical shapes. As 3D liver models, we prepared primary hepatocyte–endothelial cell heterospheroids. The toxicity, CYP3A, and albumin secretory capacity were evaluated in the heterospheroids labeled with various nanoparticles. As the culture period progressed, the heterospheroids labeled with anionic and cationic nanoparticles showed lower liver function than non-labeled heterospheroids. In the future, there is a need to improve the method of creation of artificial 3D liver or to design a low-invasive MRI contrast agent to label the artificial 3D liver.
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Dissertations / Theses on the topic "Anionic Nanoparticles"

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Alhilfi, Tamara. "Utilising anionic branched polymerisation techniques for the synthesis of novel nanoparticles." Thesis, University of Liverpool, 2014. http://livrepository.liverpool.ac.uk/16757/.

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Anionic polymerisation techniques have been optimised to develop a “one-pot”, facile method to produce both linear and branched polystyrenes utilising the “Strathclyde” route to highly branched structures. ATRP was investigated as a possible method but anionic polymerisation was found to give much better control over the size and structure of polystyrenes produced. Using this anionic polymerisation relatively monodisperse linear polystyrenes were synthesised with dispersity values as low as 1.03 for a polystyrene chain with a targeted degree of polymerisation (DPn) of 100 monomer units. A number of different structures of branched polystyrene were synthesised, and their different physical properties examined by viscometry measurements and differential calorimetry scanning experiments. It has been found that very dense, highly branched materials (with approximations of 48 polymer chains branched together) can be synthesised with a targeted primary chain DPn = 10 monomer units. Weight average molecular weight (Mw) values as high as 992,000 gmol-1 for branched polystyrene can be synthesised with a primary chain length of DPn =50 monomer units. Functional polystyrenes were synthesised both by initiation with an amine containing compound and sec-BuLi, resulting in chain end functionalisation, and also post-functionalised by sulphonation of synthesised polystyrenes, resulting in a statistical distribution along the polymer chains pendant groups. The hydrophilicity could be manipulated by the percentage of sulphonation. At over 30% sulphonation of the pendant polystyrene groups, the polymers become water soluble. Polymer nanoparticles have been synthesised by a nanoprecipitation method from functionalised branched polystyrene synthesised by anionic polymerisation techniques. Nanoparticles synthesised from DPn10 branched sulphonated polystyrenes were analysed by dynamic light scattering and found to be approximately 60nm with dispersity values as low as 0.15. They were found to be stable after 6 months ambienmt storage, and some preliminary testing on the encapsulation of Oil red suggests that the nanoparticles may be capable of encapsulating hydrophobic drugs.
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Garces, Cortes Camila. "Anionic Synthesis of Block Copolymers for Photonics Applications." University of Akron / OhioLINK, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=akron1271300539.

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Korichenska, O., and N. Kutsevol. "Silver Colloid Synthesis in Linear and Branched Anionic Polymer Matrices by Using Ascorbic Acid as Reductant." Thesis, Sumy State University, 2013. http://essuir.sumdu.edu.ua/handle/123456789/35143.

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Silver colloids were synthesized in linear and branched anionic polymer matrices at different pH reducing by ascorbic acid. The template role of the host polymers in anionic form was studied at pH = 7 and pH = 12. Linear Polyacrylamide and star-like copolymers Dextran-graft-Polyacrylamide after alkaline hydrolysis were used as matrices. Silver colloids were studied by UV-Vis spectrophotometry just after synthesis and in 3 months. It is shown that branched polymer matrices are more efficient in comparison with linear one for in situ silver nanoparticle synthesis. The pH value affects the process of formation was investigated. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/35143
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BARRANCO, LINA MERCEDES DAZA. "SILICA NANOPARTICLES FUNCTIONALIZED WITH AMMONIUM GROUPS AND ANIONIC POLYMERS FOR STABILIZATION OF PICKERING EMULSIONS CONTAINING INSECT REPELLENT." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2018. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=36257@1.

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PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO
CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO
Atualmente a crescente demanda do uso de repelentes de insetos tem promovido a pesquisa de produtos mais eficazes e com uma maior durabilidade da ação repelente. O objetivo deste trabalho foi a obtenção de novas nanopartículas com propriedades interfaciais modificadas superficialmente com grupos funcionais catiônicos e polímeros aniônicos, com o intuito de melhorar a estabilidade de emulsões Pickering contendo um princípio ativo, N,N -dimetil-m-toluamida (DEET), comumente utilizado nos repelentes comerciais. A obtenção das nanopartículas incluiu a funcionalização inicial da superfície de nanopartículas de sílica comerciais com grupos amino secundários (R-NH2), seguido da introdução de grupos catiônicos de amônio quaternário (R-NR4 positivo) e posterior complexação eletrostática com polímeros aniônicos (poli(ácido acrílico), PAA, e poli(4-estireno sulfonato de sódio), PSS). As nanopartículas modificadas mostraram boa dispersabilidade em meio aquoso, favorecendo a estabilização de emulsões de tipo óleo em água (O/A). Os melhores resultados dos estudos de estabilidade no tempo das emulsões foram obtidos usando as nanopartículas catiônicas (SiNP-A,G) recobertas com PAA e com a mistura de polímeros (PAA mais PSS). As emulsões Pickering obtidas com as nanopartículas de sílica recobertas com PAA mostraram os melhores resultados na retardação da evaporação do DEET, com potencial uso para liberação lenta deste composto.
Currently the increasing demand for insect repellent use has promoted research into more effective products and a longer repellent action. The objective of this work was to obtain new nanoparticles by surface modification with cationic functional groups and anionic polymers, with the aim of improving the stability of Pickering emulsions containing an active ingredient, N,N -diethyl-m-toluamide (DEET) commonly used in commercial repellents. The preparation of the nanoparticles included initial surface functionalization of commercial silica nanoparticles with secondary amino groups (R-NH2), followed by the introduction of cationic quaternary ammonium groups (R-NR4 positive) and subsequent electrostatic complexation with anionic polymers (poly (acrylic acid), PAA, and poly(sodium 4-styrenesulfonate), PSS). The modified nanoparticles showed good dispersibility in aqueous medium, favoring the stabilization of emulsions oil-in-water (O/W). The best results of the emulsion time stability studies were obtained using cationic silica nanoparticles (SiNP-A,G) covered with PAA and with the polymer mixture (PA plus PSS). The Pickering emulsions obtained with the cationic silica nanoparticles coated with PAA showed the best results in retarding DEET evaporation, with potential use for slow release of this compound.
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Marchand, Guillaume. "Synthèse et caractérisations de matériaux photosensibles à partir de lignines - Vers une utilisation en Traitement Photodynamique Antimicrobien appliqué à l'agronomie." Thesis, Limoges, 2018. http://www.theses.fr/2018LIMO0108/document.

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La surexploitation des ressources de la planète est aujourd’hui une problématique de premier ordre, et fait du remplacement des sources non renouvelables, d'énergie et de matières premières, l’un des défis majeurs du XXIe siècle. Dans cet objectif, les lignines, par leur disponibilité et leur biocompatibilité, apparaissent comme l’une des alternatives aux ressources fossiles. C’est dans ce contexte que le Laboratoire PEIRENE a décidé de mener ce travail de thèse portant sur le développement de nouveaux matériaux photosensibles à base de lignines modifiées. Dans ce but, trois lignines d’origines différentes ont été acétylées. Leur étude par spectroscopie RPE a révélé que le blocage de leurs fonctions antioxydantes augmente considérablement la quantité d’espèces réactives de l’oxygène qu’elles sont capables de générer sous irradiation lumineuse, permettant ainsi d’envisager l’utilisation de ce biopolymère modifié dans de nombreux domaines tels que le traitement photodynamique antimicrobien. Afin de les rendre hydrodispersibles et d’élargir ainsi leur champ d’applications, ces matériaux aux propriétés prometteuses ont été mis sous forme de nanoparticules puis, leur comportement photosensible a été lui aussi évalué par spectroscopie RPE. Il a ainsi été démontré qu’une fois dispersées dans l’eau sous la forme de nanoparticules, les lignines acétylées étaient toujours capables de produire de l’oxygène singulet sous irradiation lumineuse. Cette activité, qui n’a pas encore été reportée dans la littérature à notre connaissance, reste cependant assez restreinte et nécessite donc d’être améliorée. Afin d’élargir le domaine du spectre solaire permettant leur activation, un photosensibilisateur a par ailleurs été associé à ces nano-objets par encapsulation et par greffage covalent. L’ensemble des résultats découlant de ces travaux permettent d’envisager le développement de systèmes à base de nanoparticules de lignines acétylées dans de nombreux domaines, notamment pharmaceutique et phytosanitaire
The overexploitation of the planet's resources is nowadays a major problem and makes the replacement of non-renewable sources of energy and raw materials, one of the major challenges of the XXIe century. For this purpose, lignins, by their availability and their biocompatibility, appear as one of the alternatives to fossil resourcesIn this context, the PEIRENE Laboratory decided to carry out this PhD work on the development of new photosensitive materials based on modified lignins. For this purpose, three lignins from different origin were acetylated. Their study by EPR spectroscopy revealed that blocking their antioxidant functions considerably increases the quantity of reactive oxygen species they are able to generate under light irradiation. Thus it is possible to envisage the use of this modified biopolymer in many areas such as antimicrobial photodynamic therapy. In order to make them water-dispersible and thus to widen their field of applications, these materials with promising properties were put in the form of nanoparticles. Their photosensitive behavior has been also valuated by EPR spectroscopy. It has been demonstrated that once dispersed in water in the form of nanoparticles, the acetylated lignins were still capable of producing singlet oxygen under light irradiation. This activity, which has not yet been reported in the literature to our knowledge, however, remains quite limited and therefore needs to be improved. In order to widen the range of the solar spectrum allowing their activation, a photosensitizer has also been associated with these nano-objects by encapsulation and covalent grafting. The results of these studies make possible to envisage the development of systems based on acetylated lignins nanoparticles in in many field, in particular pharmaceutical and phytosanitary
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Goursaud, Matthieu. "Contribution to the development of nano-systems for the recognition of fluoride in water." Doctoral thesis, Universite Libre de Bruxelles, 2013. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/209378.

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The development of molecular receptors for anion recognition has become an important aspect of supramolecular chemistry. In this thesis, we focused our attention to the study of systems for fluoride recognition in water. Fluoride is indeed an anion of interest due to its implication in environmental and health related issues. Furthermore, its small size and high hydration energy make its recognition in water particularly challenging.

Most of the synthetic systems reported for fluoride recognition have been extensively studied in organic solvents (DMSO, acetonitrile) using tetrabutylammonium fluoride (TBAF) as the source of fluoride. In many cases, titra- tion behaviours are observed that cannot be ascribed to a classical 1:1 binding isotherm, deprotonation problems of Brønsted-Lowry acid type of receptors aside. In the first part of our thesis we investigated, using a uranyl-salophen re- ceptor which recognizes fluoride via Lewis Acide/Base interactions, the origin of the unusual titration behaviour. Via UV/vis, 19F and 1H NMR spectroscopies, we have been able to highlight that the equilibrium between the fluoride and the corresponding bihalide ion, HF−2 ,which is inevitably generated along with the hydroxide anion in situ due to trace amounts of water, can be at the ori- gin of this singular behaviour. Our results put to light that when undertaking titrations with fluoride in DMSO, the fluoride–bihalide equilibrium can affect the data and that the latter species can even be the dominating species at low TBAF concentrations. When varying the solvent from DMSO to acetonitrile, the s-shape titration curves observed by UV/vis are no longer observed for the uranyl-salophene receptor that we studied. The fluoride-bifluoride equilibrium is still present but both of the anions generated in this process are recognised by the uranyl-salophene receptor with similar affinity constants above 10^6 M−1.

The second part of our work was devoted to finding ways to solubilize anion receptors that are efficient in organic solvents, into an aqueous environment. Two approaches were investigated: (i) grafting of the receptors onto silica nanoparticles and (ii) the micellar incorporation of the receptors. For the first strategy, we developed two silylated urea-based receptors. These receptors were first studied in organic solvents (DMSO and/or acetonitrile) where they showed selectivity, among halides, towards fluoride. Once grafted on the silica nanoparticles, due to the fact that hydroxyl groups and solvent molecules are present in the silica matrix, fluoride recognition was not possible.

We explored it with different simple H-bond based urea receptors in the second srategy. With the cationic surfactants, cetyl trimethyl ammonium chloride and bromide, the counter-ions of the micelles interfere with the fluoride recognition. With the neutral surfactant triton X-100, the incorporation of the anion receptors proved to be difficult. Moreover, the variations observed in the UV/vis spectra upon titrations were too small to be able to make any conclusions about fluoride recognition.
Doctorat en Sciences de l'ingénieur
info:eu-repo/semantics/nonPublished

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Serpell, Christopher J. "Imidazole-based ligands for anion recognition and catalytic metal nanoparticles." Thesis, University of Oxford, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.533879.

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Filby, Maria ? "Anion binding host systems based on calix[4]arenes and nanoparticles." Thesis, Durham University, 2007. http://etheses.dur.ac.uk/2399/.

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A range of novel host molecules with various degrees of pre-organisation for the supramolecular complexation of anionic guest species have been synthesized. Both organic core and nanoparticle-based derivatives of the ligands have been prepared and the properties of the new host ligands studied with particular reference to their anion binding behaviour. Two types of calix[4]arene derived cationic hosts for anions with, respectively, 1,3-altemate and cone conformations have been prepared. The affinity of the tetrasubstituted calix[4]arene hosts for a variety of anions has been probed with Ή NMR spectroscopic titration. The ԼՅ-alternate system binds dicarboxylate anions in a ditopic manner while the cone compounds have the highest affinity for bromide anion and are deprotonated by carboxylates. The potentially fluorescent 1,3-altemate calix[4]arene that contains a pyridinium functionality coupled via a methylene spacer to a pyrene group undergoes selective chloride-induced conformational change which results in strong increase in both monomer and excimer emission. Gold nanoparticles protected with 5-[l ,2]dithiolan-3yl-pentanoic acid pyridin-3-ylamide remain stable as colloidal solution in methanol and the UV aborption spectra demonstrate the nanoparticles' response to exposure of a variety of anions by red shift with concomitant decrease in intensity. Titration of the colloidal solution with silver tetrafluoroborate results in an increase in absorption indicating possible interaction of silver cations with the pyridyl nitrogen atoms
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Nahle, Sara. "Réponse macrophagique aux nanomatériaux carbonés : effets de leur caractéristiques physiques et chimiques sur le transcriptome Carbon-based nanomaterials induce inflammation and autophagy in rat alveolar macrophages Single wall and multiwall carbon nanotubes induce different toxicological responses in rat alveolar macrophages Gene expression profiling of alveolar macrophages exposed to non-functionalized, anionic or cationic multi-walled carbon nanotubes shows three different mechanisms of toxicity Cytotoxicity and global transcriptional responses induced by zinc oxide nanoparticles NM 110 in PMA-differentiated THP-1 cells Protein and lipid homeostasis altered in rat macrophages after exposure to metallic oxide nanoparticles." Thesis, Université de Lorraine, 2019. http://www.theses.fr/2019LORR0142.

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Les nanomatériaux carbonés (NMC) sont très utilisés dans le monde industriel et leurs applications, nombreuses, sont en plein développement. L’absence de réglementation pour leur préparation et leur emploi fait qu’il est nécessaire comme pour tous les nano-objets, de déterminer le risque qu’une exposition fait courir à l’Homme et d’adapter la législation en conséquence. Une meilleure connaissance de leur potentiel toxique est donc nécessaire. Les difficultés de plus en plus grandes pour utiliser les modèles animaux, rend nécessaire le développement d’études avec des lignées cellulaires au sein desquelles les macrophages ont une place prépondérante. Ces NMC sont très légers et forment facilement des aérosols et les modèles préférés sont les macrophages alvéolaires. Cependant il n’existe pas à l’heure actuelle de lignées de macrophages alvéolaires humains à la différence de cellules de rat. Le sujet de ma thèse porte sur l’étude de la réponse macrophagique aux NMC et la compréhension des effets de leurs caractéristiques physiques et chimiques sur leur transcriptome. Les NMC étudiés sont les nanotubes de carbone (NTC) multi feuillets, les NTC mono feuillets, le noir de carbone et l’oxyde de graphène. Nos résultats montrent que tous les NMC étudiés déclenchent une réaction inflammatoire dans les cellules NR8383 et les cellules THP-1 différenciées, et certains d’entre eux induisent une cytotoxicité importante. La taille, la fonctionnalisation et la forme contrôlent les mécanismes de toxicité induits par les NMC. Des NTC de tailles similaires altèrent des voies de signalisation identiques, une fonctionnalisation par des groupements amines produit un stress des lysosomes tandis que la fonctionnalisation par des groupements carboxyle entraine un stress du réticulum endoplasmique (RE). Les nanotubes induisent une désorganisation du cytosquelette plus importante que les nanoparticules sphériques. Nous avons également mis en évidence une accumulation de lipides chez les cellules NR8383 suite à un stress du RE induit par le Mitsui-7, un NTC multi feuillet. Le même NTC induit aussi une fusion de ces macrophages. La formation de ces cellules spumeuses et des cellules géantes à multi-noyaux sont des évènements clés entrainant la formation de granulomes. Les résultats obtenus présentent un support important pour la compréhension des effets des NMC montrant une certaine toxicité non négligeable de point de vue moléculaire. Cette toxicité est dépendante des caractéristiques physiques et chimiques de ces nanomatériaux. Ainsi, en se basant sur ce type de données, on pourra s’orienter vers une fabrication safe-by-design pour limiter les risques liés à leur exposition
Carbon nanomaterials (CNM) are widely used in the industrial world and they have many applications. The absence of legislation controlling their preparation and uses makes necessary, as for all nano-objects, the study of their toxicity in order to determine the risk of human exposure and to adapt legislation accordingly. Therefore, a better knowledge of their toxic potential is necessary. The increasing difficulties in using animal models make necessary the development of studies using cell lines especially macrophages that play a predominant role. These CNM are very light and form easily aerosols, reason why the preferred models for toxicity studies are alveolar macrophages. However, there are no human alveolar macrophage lines currently but rat cells exist. The subject of my thesis is to study macrophages response to CNM and the understanding of the effect of their physical and chemical characteristics on the transcriptome. The CNM studied are multiwall carbon nanotubes (CNT), single wall CNT, carbon black and graphene oxide. Our results show that all CNM studied trigger an inflammatory reaction in NR8383 and differentiated THP-1 cells, also some of them induce cytotoxicity. Size, functionalization and form control CNM toxicity mechanisms: CNT with similar size alter identical signaling pathways, amino group functionalization produces lysosomal stress, whereas functionalization with carboxyl groups causes reticulum endoplasmic (RE) stress, nanotubes induce cytoskeleton disorganization more than spherical nanoparticles. Otherwise, we identified lipid accumulation in NR8383 cells due to RE stress induced by Mitsui-7, a multiwall CNT. There was also a fusion of these macrophages. The formation of these foam cells and giant multi-nucleus cells are key events leading to granulomas formation. The results obtained are an important support for understanding CNM effects, showing some significant toxicity at molecular level. This toxicity is dependent on the physical and chemical characteristics of these nanomaterials. Thus, based on this type of data, we can move towards a safer manufacture to avoid the risks associated with their exposure
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CALERO, RODRIGUEZ MARÍA PILAR. "Silica nanoparticles as inorganic scaffolds for the preparation of hybrid materials for the optical detection of anions." Doctoral thesis, Universitat Politècnica de València, 2016. http://hdl.handle.net/10251/63459.

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[EN] The PhD Thesis entitled "Silica nanoparticles as inorganic scaffolds for the preparation of hybrid materials for the optical detection of anions" deals with the combination of supramolecular and material chemistry concepts to prepare hybrid sensing materials with the ability to detect selected ions through color and emission changes. The first hybrid material prepared is based in the use of silica nanoparticles as inorganic scaffold functionalized with spirobenzopyrans (signaling unit) and with thiourea moieties (binding unit). In the final nanoparticles the spirobenzopyran signaling unit is in its open polar conformation (red color merocyanine structure). Coordination of long chain carboylates (octanoate, decanoate and dodecanoate) with the thiourea moieties induced the formation of a dense hydrophobic monolayer around the signaling unit. This non-polar monolayer induced a change in the conformation of the spirobenzopyran to the closed spirocyclic form with a subsequent color change. The second part of this PhD Thesis was related with the preparation of silica nanoparticles functionalized with anthracene, as signalling subunit, and two different thioureas, as anion binding sites. Acetonitrile suspensions of the bifunctionalized nanoparticles showed the typical structured emission band of the anthracene fluorophore. Addition of certain anions to acetonitrile suspensions of the nanoparticles induced an enhancement of the emission intensity (Cl-, Br-, H2PO4-, acetate and benzoate) or a marked quenching (F- and CN-). Finally, the last part of this PhD Thesis deals with the preparation of silica nanoparticles functionalized with terpyridine binding sites and sulforhodamine B as signaling subunit. Coordination of transition metal cations (Fe3+, Hg2+, Cu2+, Ni2+ and Pb2+) with the terpyridine bindind sites induced a marked quenching of the emsission intensity (ca. 95%) of the sulforhodamine B fluorophore. The prepared materials were used for the fluorogenic recognition of anions. At this respect, addition of H2PO4-, HSO4-, F-, Cl-, Br-, I- and NO3-anions induced different degrees of cation displacements with the subsequent enhancement of the emission intensity of the fluorophore. Principal component analysis (PCA) allowed the discrimination of all the anions tested. Besides, only H2PO4- anion was able to induce the displacement of Pb2+ cation with the subsequent emission enhancement.
[ES] La presente Tesis Doctoral titulada "Nanopartículas de sílice como soporte inorgánico para la preparación de materiales híbridos para la detección óptica de aniones" se basa en el empleo de conceptos de química supramolecular y de química de materiales para la preparación de sistemas sensores híbridos con capacidad para reconocer iones mediante cambios de color y de fluorescencia. El primer material sensor desarrollado esta basado en nanopartículas de sílice funcionalizadas con espirobenzopiranos (unidad indicadora) y con tioureas (unidad coordinante). En las nanopartículas bifuncionalizadas el espiropirano está en su forma polar abierta (merocianina de color rojo). Cuando coordinan las tioureas con carboxilatos de cadena larga (octanoato, decanoato y dodecanoato) se forma un entorno apolar alrededor de la unidad indicadora que favorece su transformación de la forma abierta a la apolar espirocíclica cerrada con el consiguiente cambio de color. En la segunda parte de la Tesis se han preparado nanoparticulas de sílice funcionalizadas con antraceno, como unidad indicadora, y con dos diferentes tioureas, como unidades coordinantes de aniones. Suspensiones de las nanopartículas bifuncionalizadas en acetonitrilo muestran la típica emisión estructurada del antraceno. Al añadir diferentes aniones a la suspensión de las nanoparticulas se obiene un aumento de fluorescencia (con Cl-, Br-, H2PO4-, acetato y benzoato) o una desactivación de la misma (F- y CN-). Por último se prepararon nanopartículas de sílice funcionalizadas con terpiridinas, como unidad coordinante, y con sulforodamina B, como unidad indicadora. La coordinación de cationes metálicos de transición (Fe3+, Hg2+, Cu2+, Ni2+ y Pb2+) con las terpiridinas dio lugar a una desactivación importante de la emisión de la sulforodamina B anclada (95% de la inicial). En un segundo paso se estudio la capacidad de ciertos aniones (H2PO4-, HSO4-, F-, Cl-, Br-, I- y NO3-) de desplazar al metal coordinado con la subsiguiente regeneración de la emisión de la sulforodamina. Aplicando el análisis de componentes principales (PCA) se consiguió la discriminación de todos los aniones empleados. Además, las nanopartículas tratadas con el catión Pb2+ dieron una respuesta selectiva con el anión H2PO4-.
[CAT] La present Tesi Doctoral titulada "Nanopartícules de sílice com a suport inorganic en la preparació de materials hibrids per a la detecció optica de anions" es basa en l'ús de conceptes de química supramolecular i de química de materials per a la preparació de sistemes sensors híbrids amb capacitat per a reconèixer ions mitjançant canvis de color i de fluorescència. El primer material sensor desenvolupat està basat en nanopartícules de sílice funcionalitzades amb espirobenzopirans (unitat indicadora) i amb tiourees (unitat coordinant). A les nanopartícules bifuncionalitzades l'espiropirà està en la seua forma polar oberta (merocianina de color vermell). Quan coordinen les tiourees amb carboxilats de cadena llarga (octanoat, decanoat i dodecanoat) es forma un entorn apolar al voltant de la unitat indicadora que afavoreix la seua transformació de la forma oberta a l'apolar espirocíclica tancada amb el conseqüent canvi de color. A la segona part de la Tesi s'han preparat nanoparticules de sílice funcionalitzades amb antracè, com a unitat indicadora, i amb dos tiourees diferents, com unitats coordinants d'anions. Suspensions de les nanopartícules bifuncionalitzades en acetonitril mostren la típica emissió estructurada del'antracè. En afegir diferents anions a la suspensió de les nanoparticules s'obté un augment de fluorescència (amb Cl-, Br-, H2PO4-, acetat i benzoat) o una desactivació de la mateixa (F- i CN-). Finalment es prepararen nanopartícules de sílicie funcionalitzades amb terpiridines, com a unitat coordinant, i amb sulforodamina B, com a unitat indicadora. La coordinació de cations metàl¿lics de transició (Fe3+, Hg2+, Cu2+, Ni2+ i Pb2+) amb les terpiridines va donar lloc a una desactivació important de l'emissió de la sulforodamina B unida covalentment al material (95% de la inicial). En un segon pas, es va estudiar la capacitat de certs anions (H2PO4-, HSO4-, F-, Cl-, Br-, I- i NO3-) de desplaçar al metall coordinat amb la subsegüent regeneració de l'emissió de la sulforodamina. Aplicant l'anàlisi de components principals (PCA) es va aconseguir la discriminació de tots els anions estudiats. A més, les nanopartícules tractades amb el catió Pb2+ van donar una resposta selectiva amb l'anió H2PO4-.
Calero Rodriguez, MP. (2016). Silica nanoparticles as inorganic scaffolds for the preparation of hybrid materials for the optical detection of anions [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/63459
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Book chapters on the topic "Anionic Nanoparticles"

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Dong, Hong, and Juan P. Hinestroza. "Conformal Coating of Antimicrobial Silver Nanoparticles on Cationic and Anionic Cellulosic Substrates." In Cellulose Based Composites, 249–60. Weinheim, Germany: Wiley-VCH Verlag GmbH & Co. KGaA, 2014. http://dx.doi.org/10.1002/9783527649440.ch13.

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Fekry, A. M., S. M. Azab, M. Shehata, and M. A. Ameer. "Electrochemical Detection of Nicotine Using Cerium Nanoparticles Modified Carbon Paste Sensor and Anionic Surfactant." In Springer Proceedings in Physics, 229–40. Cham: Springer International Publishing, 2015. http://dx.doi.org/10.1007/978-3-319-16919-4_30.

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Smirnov, Pierre. "Cellular Magnetic Resonance Imaging Using Superparamagnetic Anionic Iron Oxide Nanoparticles: Applications to In Vivo Trafficking of Lymphocytes and Cell-Based Anticancer Therapy." In Methods in Molecular Biology™, 333–53. Totowa, NJ: Humana Press, 2009. http://dx.doi.org/10.1007/978-1-60327-530-9_19.

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Rukhadze, Marina, Matthias Wotocek, Sylvia Kuhn, and Rolf Hempelmann. "Influence of Anions of the Hofmeister Series on the Size of ZnS Nanoparticles Synthesised via Reverse Microemulsion Systems." In UK Colloids 2011, 67–72. Berlin, Heidelberg: Springer Berlin Heidelberg, 2012. http://dx.doi.org/10.1007/978-3-642-28974-3_12.

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Perlova, Olga, Yuliya Dzyazko, Iryna Halutska, Nataliia Perlova, and Alexey Palchik. "Anion Exchange Resin Modified with Nanoparticles of Hydrated Zirconium Dioxide for Sorption of Soluble U(VI) Compounds." In Nanooptics, Nanophotonics, Nanostructures, and Their Applications, 3–15. Cham: Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-319-91083-3_1.

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Nqombolo, Azile, Anele Mpupa, Jianwei Ren, and Philiswa Nosizo Nomngongo. "Nanocomposite membranes for the removal of dyes." In Waste PET-MOF-Cleanwater: Waste PET-Derived Metal-Organic Framework (MOFs) as Cost-Effective Adsorbents for Removal of Hazardous Elements from Polluted Water, 79–91. UJ Press, 2022. http://dx.doi.org/10.36615/9781776419463-06.

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The scarcity of affordable, sustainable, safe, and clean water is one of the major challenges faced by the world. The use of polymeric membranes in wastewater treatment has become a major solution in fighting water scarcity. Some of these membranes (microfiltration, ultrafiltration, and nanofiltration) operate at low pressure when compared to reverse osmosis. However, permeability, selectivity, and fouling limit the application of these polymeric membranes. The incorporation of nanomaterials into the polymeric matrix has resolved such problems in membrane technology. Recent studies show that nanomaterials such as metal organic frameworks (MOFs), graphene oxide (GO), multi-walled carbon nanotubes (MWCNTs), and iron-based nanoparticles are promising nanomaterials for membrane technology with high permeability, selectivity, and antifouling performance. This chapter represents the application of MOF-based nanocomposite membranes for the rejection of anionic and cationic dyes. This chapter reviews various nanocomposite membranes in dye rejection. Conclusions and future perspectives have been drawn and discussed.
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Yonezawa, Tetsu, Shin-ya Onoue, and Toyoki Kunitake. "Three-dimensional assembly of cationic gold nanoparticles and anionic organic components: DNA and a bilayer membrane." In Studies in Surface Science and Catalysis, 623–26. Elsevier, 2001. http://dx.doi.org/10.1016/s0167-2991(01)82168-6.

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Mosebolatan Jabar, Jamiu. "Antimicrobial Functional Textiles." In Textiles for Functional Applications [Working Title]. IntechOpen, 2021. http://dx.doi.org/10.5772/intechopen.97806.

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Most textile materials are potential substrates for microbial growth. In order to make textile materials suitable as functional materials, the microbial growth must be reduced to the barest minimum or quenched due to their undesirable effects; such as offensive odor, discoloration, degradation, mechanical strength reduction etc. Chemical finishing of textile materials (such as application of silver nanoparticles, quaternary ammonium compounds, chitosan, some synthetic and natural dyes to mention a few) is capable of imparting this functional property among others to the textiles. Although, mechanism of antimicrobial activities of treated textiles is yet to be clearly defined, but in most cases, antimicrobial action of treated textiles usually occurs through interaction of cation in antimicrobial agents with anionic charged microbial cell wall. Antimicrobial treated textiles are usually less prone to offensive odor, discoloration, deteriorating mechanical properties and make the consumers free of skin problems. In fact, they can be used as cheap materials for production of hospital gowns, hand gloves and face masks for containing microorganism borne diseases, such as the current Covid-19 pandemic.
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Younis, Heba, Guohua Zhao, and Hassan Abdellatif. "Pectin and Its Applicability in Food Packaging." In A Glance at Food Processing Applications. IntechOpen, 2022. http://dx.doi.org/10.5772/intechopen.101614.

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Food packaging based on plastic films made from nonrenewable resources often causes environmental problems after disposal. Recently, researchers are increasingly focusing on alternative materials to reduce the use of nonbiodegradable and nonrenewable films. Generally, biomaterials are nontoxic, biocompatible, and renewable always presents reasonable film-forming ability. Thus, they are important for food safety, where undesired chemical compounds might migrate from chemicals migrate from the plastic packaging materials into foods. Pectin (PEC), as a natural carbohydrate polymer, belongs to the anionic heteropolysaccharide family and is often extracted from various residues from plant food processing, such as apple and citrus pomaces. The pectin molecules are highly branched with a backbone α-(1–4) linked D galacturonic acid. Among the naturally derived carbohydrate-based biopolymers, pectin was considered a promising substrate in fabricating edible films due to its diverse advantages, such as perfect film-forming ability, evidenced bioactivity, easy availability, and excellent quality biodegradability and biocompatibility, nontoxicity, and low cost. Pectin-based films have excellent oxygen barrier capacity and extend the shelf life for different fruits. The properties of pure pectin films can enhance through combination with other polymers or nanoparticles/fibers.
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Omer, Shivangi. "Heavy Metal Removal by Alginate Based Agriculture and Industrial Waste Nanocomposites." In Properties and Applications of Alginates [Working Title]. IntechOpen, 2021. http://dx.doi.org/10.5772/intechopen.98832.

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The use of biopolymers and nonliving organisms as sorbents is one of the most promising techniques because they contain several functional groups which show different affinities towards various metal ions. Alginate is naturally occurring anionic biopolymer extracted from brown algae. It also contains numerous applications in biomedical science and engineering due to its favorable properties and ease of gelatin. This chapter represents a overview based on alginate based agriculture and industrial waste nanocomposites and found that limited studies are reported for combination of alginate with industrial/agriculture waste in nanoscalic material so far, but this review study enlightening the several studies based on nanocomposite combinations of alginates and biopolymers and these biopolymers can also be derived from various agro/industrial waste by simple chemical and mechanical methods. So, we should work on the formulation of alginates agro/industrial waste nanocomposites. Preparation of alginate nanomaterials with agriculture/industrial waste constituents confirms its effectiveness in water purification. In the environment, we can control its reutilization by desorption studies. Another advantage is that it can be transform from nanoparticles to nano polymeric films and support to batch adsorption process to fixed bed column in form of large-scale application.
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Conference papers on the topic "Anionic Nanoparticles"

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Ray, Debes, Debasish Saha, Vinod K. Aswal, and Joachim Kohlbrecher. "Structure of individual versus mixed cat-anionic surfactants with nanoparticles." In DAE SOLID STATE PHYSICS SYMPOSIUM 2019. AIP Publishing, 2020. http://dx.doi.org/10.1063/5.0016754.

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Mandal, S. K., N. Mazumder, U. K. Ghorai, S. Saha, and K. K. Chattopadhyay. "Emission behavior of anionic chalcogen acceptor states in ZnO nanoparticles." In SOLID STATE PHYSICS: Proceedings of the 58th DAE Solid State Physics Symposium 2013. AIP Publishing LLC, 2014. http://dx.doi.org/10.1063/1.4873003.

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Pereira, Rosa, Tommy Julianto, Kah Yuen, and Abu Abdul Majeed. "Anionic Eudragit nanoparticles as carriers for oral administration of peptidomimetic drugs." In 2006 International Conference on Nanoscience and Nanotechnology. IEEE, 2006. http://dx.doi.org/10.1109/iconn.2006.340611.

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Wang, Wuchao, Xiaohu Dong, Huiqing Liu, Yan Peng, Zhangxin Chen, Yu Li, and Yunfei Guo. "Fly Ash Nanoparticle-Stabilized Emulsions for Improve Mobility Control Application." In SPE EuropEC - Europe Energy Conference featured at the 83rd EAGE Annual Conference & Exhibition. SPE, 2022. http://dx.doi.org/10.2118/209646-ms.

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Abstract Nanoparticles have demonstrated their capacity to increase emulsion stability by forming what is known as a Pickering emulsion, which is predicted to improve EOR processes by improving conformity control. The goal of this work is to develop a novel way of beneficially utilizing the main waste product from coal power-generation plants - fly ash - by generating fly ash nanoparticle-stabilized emulsions for improved mobility control, especially under high-salinity conditions. First, the ball-milling method was used to decrease the grain size of fly ash, which was too big for injection into reservoirs. Second, fly ash nanoparticles were used to measure the synergy between nanoparticles and surfactants in the creation of oil-in-brine emulsions. Third, the emulsion stability was tested using a microscope and a rheometer with three different surfactants (cationic, nonionic, and anionic). Finally, oil replacement experiments were conducted using intra-formation heterogeneous cores to investigate the recovery enhancement effect of in situ injection of fly ash nanoparticles and cationic surfactant (CS). Thermally treated fly ash (TTFA) nanoparticles with an average size of 150 nm were produced using nano-milling and thermal treatment techniques. The use of either a cationic or nonionic surfactant in conjunction with nanoparticles resulted in strong and stable emulsions. The cationic surfactant had the greatest synergy, while the anionic surfactant had the least, indicating that electrostatic interactions with the surfactant and the liquid/liquid interface were key factors. The in-situ emulsion formed by the fly ash nanoparticles and the cationic surfactant (FA-CS) produced an additional 8.5 % of the original oil in place (OOIP) recovery after waterflooding. This indicates that the emulsion has better mobility control performance and higher crude oil recovery. This study not only has the potential to minimize the amount of surfactant used for emulsion-based EOR mobility control of fly ash nanoparticles but also to sequester fly ash in the subsurface strata.
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Munir, Muhammad, Ramis Arbi, Markus Clark Scharber, Yolanda Salinas, Niyazi Serdar Sariciftci, and Ayse Turak. "Anionic exchange route to synthesize highly uniform, stable and luminescent MAPBr nanoparticles." In Optical Devices and Materials for Solar Energy and Solid-state Lighting. Washington, D.C.: OSA, 2020. http://dx.doi.org/10.1364/pvled.2020.pvtu3g.5.

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Salih, Mohamed, Ramadan Ahmed, and Mahmood Amani. "Stabilization of Drilling Foams Using Nanoparticles." In SPE International Conference on Oilfield Chemistry. SPE, 2023. http://dx.doi.org/10.2118/213839-ms.

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Abstract Foam is the preferred fluid for underbalanced drilling due to its superior hole-cleaning capacity and reduced liquid requirements. However, it must have reasonable stability to function as a drilling fluid under borehole conditions. Unstable foam loses its viscosity and generates drained liquid that causes slugging flow, resulting in temporary overbalance that can damage the formation. This study aims to improve foam stability of aqueous foam using nanoparticles with unique surface properties. Due to their small sizing and large specific surface area, nanoparticles exhibit unique properties. In addition, their surfaces can be modified to display the desired properties for a given application. In this study, bare (NS1) and coated silicon oxide nanoparticles (NS2, and NS3) have been utilized to enhance the stability of foams. A foam circulating flow loop with horizontal pipe viscometers and a vertical drainage testing cell was used to create foams and analyze their characteristics. At 1000 psi, foams with different nanoparticle concentrations and foam qualities were generated. Their rheology and stability were then investigated. A sonicator and laboratory blender were used to mix nanoparticles with water and anionic surfactant to prepare the liquid phase of foams. The hydrostatic pressure distribution at different column depths as a function of time was measured after trapping a fully generated foam in a vertical test cell. Initially, baseline foams without nanoparticles were tested. Later, two types of nanoparticles (bare and coated) were tested at different nanoparticle concentrations (1 to 3 wt%). Increasing the baseline foam quality (in-situ gas volumetric concentration) from 40 to 60% resulted in a significant increase in apparent viscosity and a reduction in liquid drainage. Nanoparticles containing foam also showed similar trends of property changes with foam quality. Besides this, experiments demonstrated the impact of nanoparticles on the characteristics of foams. The viscosity and stability of foams increased with the addition of nanoparticles. Also, the drainage of foams noticeably decreased while their half-life improved with the concentration of nanoparticles. The effectiveness of nanoparticles is also influenced by their type. Silica nanoparticles that are coated (functionalized) with an amino group (NS2) provide better foam stability than regular nanoparticles (NS1) and nanoparticles treated (coated) with silane (NS3). This study contributes to the formulation of a new generation of drilling foams that can be used in harsh borehole environments where foam instability becomes a major concern.
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Demchenko, V., S. Riabov, S. Sinelnikov, O. Radchenko, and N. Rybalchenko. "Structure and antimicrobic properties of nanocomposites based on anionic β­cyclodextrin, chitosan and silver nanoparticles." In Chemical technology and engineering. Lviv Polytechnic National University, 2019. http://dx.doi.org/10.23939/cte2019.01.210.

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Paramarta, Valentinus, Ardiansyah Taufik, Lusitra Munisa, and Rosari Saleh. "Sono- and photocatalytic activities of SnO2 nanoparticles for degradation of cationic and anionic dyes." In INTERNATIONAL CONFERENCE ON ENGINEERING, SCIENCE AND NANOTECHNOLOGY 2016 (ICESNANO 2016). Author(s), 2017. http://dx.doi.org/10.1063/1.4968378.

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Salih, A. H., and H. Bilgesu. "Investigation of Rheological and Filtration Properties of Water-Based Drilling Fluids Using Various Anionic Nanoparticles." In SPE Western Regional Meeting. Society of Petroleum Engineers, 2017. http://dx.doi.org/10.2118/185638-ms.

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Maaref, Sepideh, and Apostolos Kantzas. "Nanoparticle Assisted Foam Stability Under SAGD Conditions." In SPE Canadian Energy Technology Conference. SPE, 2022. http://dx.doi.org/10.2118/208877-ms.

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Abstract Thermal oil recovery processes, and more specifically steam assisted gravity drainage (SAGD), is one of the two commercial methods to produce heavy oil. In the later stages of SAGD heat losses increase. One solution to improve heat losses in the steam chamber is to co-inject a foaming solution with non-condensable gases. It is expected that such a scheme will redirect steam towards heating oil and not the overburden. An appropriate foaming agent is required for successful implementation of a steam-foam process. Conventional laboratory techniques have provided some indication of foam stability with different types of surfactants but failed to match the reservoir conditions and time scale. Recently, the use of nanoparticles along with surfactants has gained attention as a method to stabilize foams under thermal operating conditions. The aim of this research is to investigate the thermal stability of foam under steam conditions (temperatures around 200 °C) using mixtures of different surfactants and silica nanoparticles. A series of foam stability tests were conducted at temperature ranges of 170 °C to 212 °C and pressures of 2.78 MPag and 4.22 MPag using two different anionic surfactants and four different bare and coated silica nanoparticles. The foamy solutions were prepared with a combination of different surfactants and nanoparticles, which were co-injected with N2 gas into a sand pack to generate foam at different temperatures and pressures. The generated foam was then transferred to a high pressure and high temperature visual cell and the foam half-life was measured as the indicator of its decay. It was observed that a small deviation from the dew point (decreasing the temperature or increasing the pressure) significantly improved foam stability. Addition of nanoparticles proved to be synergistic as the foam half-life near the steam dew point increased about four-fold compared to surfactant only foams. Among the tested nanoparticles, the use of polyethylene glycol (PEG) coated silica nanoparticles along with an anionic surfactant resulted in the highest foam stability near the steam dew point. To date, most of the foam stability tests have been conducted at temperatures below 200 °C with the focus on using surfactants. This research extended the foam stability tests to temperatures in excess of 200°C using mixtures of surfactants and nanoparticles. Although the foam stability still needs to be improved for reservoir-scale application, our screening methodology presents a realistic process of generating foam in a porous medium with nanoparticles and surfactants under a desired thermodynamic state for subsequent foam thermal stability testing.
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