Synthesis of barium fluoride nanoparticles from microemulsion
T1 - Sol-gel synthesis at neutral pH in W/O microemulsion: A method for enzyme nanoencapsulation in silica gel nanoparticles
Synthesis Of Silica Nanoparticles By Sol Gel Method
AB - Inspired by the high accessibility and low diffusion limitations of fibrous silica nanoparticles (KCC-1), fibrous silica ZSM-5 (FZSM-5) was engineered using a microemulsion system. The spherical FZSM-5 with a dendrimeric silica fiber possessed a high surface area (554 m2), a wide pore diameter (2-20 nm), abundant strong acid sites and high catalytic activity towards cumene hydrocracking.
Herein, thesynthesis of N-diazeniumdiolate-modified silica nanoparticles ofvarious physical and chemical properties for biomedical applications ispresented.
Materials | Free Full-Text | Zinc Oxide—From Synthesis …
The research on superparamagnetic iron oxide nanoparticles (SPIONs) has been growing exponentially over the last several years. The field continues to drive in the direction of biomedical applications, especially molecular therapeutics by exploiting the immense qualities of SPIONs . This includes the distinctive controllable properties such as size, shape, magnetism, crystallinity and flexibility in fabricating multifunctional SPIONs with fluorescence, targeting ligands, drugs etc, thanks to the advancements in the syntheses and functionalization techniques developed hitherto. There are some excellent synthetic methods in prior arts on the formation of superparamagnetic magnetite (Fe3O4) and maghemite (γ-Fe2O3) SPIONs, with size control, narrow distribution, water solubility and surface functionalization [-]. The co-precipitation method is a conventional synthetic paradigm where Fe(II) and Fe(III) salts are co-precipitated in a basic solution in the presence of coating materials such as polymer or dextran (or its derivatives). Although the resulted iron oxide nanoparticles (NPs) are larger in size (ca. 100 nm) and partially crystalline, the particles are readily water soluble where their surfaces are directly functionalized. Alternatively, thermal decomposition method using precursors such as Fe(CO)5, Fe(Stearate)2, with high boiling solvents (octadecene, benzyl ether) and surfactants/ligands (oleic acid, oleylamine) can be used to synthesize smaller sized hydrophobic SPIONs (5-10 nm). In order to impart the SPIONs with water solubility for biomedical applications, water-oil microemulsion method can be employed as a reaction medium for coating a hydrophilic ligand (e.g. silica, peptides) on the hydrophobic surface.
Highly monodisperse sodium citrate-coated spherical silver nanoparticles (Ag NPs) with controlled sizes ranging from 10 to 200 nm have been synthesized by following a kinetically controlled seeded-growth approach via the reduction of silver nitrate by the combination of two chemical reducing agents: sodium citrate and tannic acid. The use of traces of tannic acid is fundamental in the synthesis of silver seeds, with an unprecedented (nanometric resolution) narrow size distribution that becomes even narrower, by size focusing, during the growth process. The homogeneous growth of Ag seeds is kinetically controlled by adjusting reaction parameters: concentrations of reducing agents, temperature, silver precursor to seed ratio, and pH. This method produces long-term stable aqueous colloidal dispersions of Ag NPs with narrow size distributions, relatively high concentrations (up to 6 × 1012 NPs/mL), and, more important, readily accessible surfaces. This was proved by studying the catalytic properties of as-synthesized Ag NPs using the reduction of Rhodamine B (RhB) by sodium borohydride as a model reaction system. As a result, we show the ability of citrate-stabilized Ag NPs to act as very efficient catalysts for the degradation of RhB while the coating with a polyvinylpyrrolidone (PVP) layer dramatically decreased the reaction rate.
Surface modification, functionalization and …
Our group has been actively involved in the synthesis of QDs and magnetic QDs (MQDs) [-]. We have successfully demonstrated the magnetic and fluorescent properties of Fe2O3-CdSe MQDs, silica -coated QDs or MQDs and their application in cell labeling (Figure ) . The silanization using aminopropyl triethoxysilane (APS) in a reverse microemulsion produced thin silica coating on bare CdSe QDs or Fe2O3-CdSe MQD with surface NH2 groups. The methoxy groups of APS were hydrolyzed and condensed with another APS, exposing surface amine groups on the silanized QDs (SiO2/QDs) for conjugation with oleyl-O-poly(ethyleneglycol)-succinyl-N-hydroxysuccinimidyl ester, denoted as bio-anchored membrane (BAM). The reaction between the amine group and NHS ester resulted in a covalent amide bond formation, leaving the exposed oleyl group for the effective targeting of cell membrane. The labeling of live cell membranes (HepG2 human liver cancer cells and NIH-3T3 mouse fibroblast cells) using confocal laser scanning microscopy (CLSM) indicated the successful conjugation of silica-coated QDs or MQDs with BAM.
Water-soluble, highly fluorescent double-layered silica nanoparticles(FL-DLSN) have been successfully synthesized through a reverse(water-in-oil) microemulsion method.
Multifunctional Iron Oxide Nanoparticles for …
Jim Yang Lee Group - National University of Singapore
Controlled Size Silver Nanoparticles Synthesis with Water-in-Oil Microemulsion Method: A Topical Review
Publications Archive » DeSimone Research Group
Today the synthesis of silver nanoparticles is very common due to their numerous applications in various fields
A microemulsion preparation of nanoparticles of …
Synthesis of narrowly distributed polystyrene-encapsulated silica nanoparticles via emulsion polymerization
Development of Organic-Dye-Doped Silica Nanoparticles …
Synthesis of noble metallic nanoparticles, in general, and silver nanoparticles (SNPs), in particular, currently are of special interest. In the present paper, an overview of the enhanced properties of SNPs and consequential applications of SNPs are discussed. Common synthesis methods and their comparison with the microemulsion technology, particularly advantages of SNPs formation with microemulsion technology, are discussed. A brief overview of the basics of microemulsion technology for nanoparticles formation is also presented. The complete topical review of microemulsion synthesis technique used to date for the generation of SNPs is discussed comprehensively. Control parameters have been explicated for influencing size, size uniformity, and stability aspects of the SNPs reported in the literature, allowing a tailored synthesis for specific application. Recent modifications made on the synthesis of SNPs to obtain monodisperse, high yield and stability are also discussed. Lastly, some future trends and perspectives in these research areas are outlined.
16.01.2004 · Abstract
Nanostructured silica and silica-iron composite particles were prepared using water-in-oil (w/o) reverse microemulsion. Double microemulsion technique is used for the synthesis of both types of nanostructured particles. X-ray Diffractometry (XRD), scanning electron microscopy (SEM), nitrogen gas adsorption-desorption isotherm technique, and differential scanning calorimetry (DSC) were used to characterize the synthesized particles. The gas adsorption-desorption measurements revealed a mesoporous structure for the silica (SiO2) particles with a surface area of 300.49 m 2/g. Upon the addition of an iron microemulsion to the silica microemulsion, silica-iron nanocomposite (Fe2O3-SiO 2) was achieved which gave a surface area of 69.87 m2/g. This indicated a positive impregnation of the silica mesopores that was further confirmed by energy dispersive spectrometry (EDS). The XRD of bare SiO 2 gave a single broad peak whereas SiO2-Fe 2O3 demonstrated additional peaks confirming α-iron insertion in mesoporous silica. DSC curve with its characteristic peaks also indicated the presence of iron nanoparticles within silica. The product silica-iron nanocomposite has potential catalytic and semiconducting applications.
20.12.2017 · Synthesis of Nanoparticles in ..
Review of the various control parameters, characterization tools used, and particle sizes obtained for the synthesis of silver nanoparticles (SNPs), with microemulsion technique information, is provided (Table 1). This information is available free of charge via the Internet at .
"I have always been impressed by the quick turnaround and your thoroughness. Easily the most professional essay writing service on the web."
"Your assistance and the first class service is much appreciated. My essay reads so well and without your help I'm sure I would have been marked down again on grammar and syntax."
"Thanks again for your excellent work with my assignments. No doubts you're true experts at what you do and very approachable."
"Very professional, cheap and friendly service. Thanks for writing two important essays for me, I wouldn't have written it myself because of the tight deadline."
"Thanks for your cautious eye, attention to detail and overall superb service. Thanks to you, now I am confident that I can submit my term paper on time."
"Thank you for the GREAT work you have done. Just wanted to tell that I'm very happy with my essay and will get back with more assignments soon."