Nanoparticles Sodium chloride

Some of the reports are as follows. Mizukoshi et al. [31] reported ultrasound assisted reduction processes of Pt(IV) ions in the presence of anionic, cationic and non-ionic surfactant. They found that radicals formed from the reaction of the surfactants with primary radicals sonolysis of water and direct thermal decomposition of surfactants during collapsing of cavities contribute to reduction of metal ions. Fujimoto et al. [32] reported metal and alloy nanoparticles of Au, Pd and ft, and Mn02 prepared by reduction method in presence of surfactant and sonication environment. They found that surfactant shows stabilization of metal particles and has impact on narrow particle size distribution during sonication process. Abbas et al. [33] carried out the effects of different operational parameters in sodium chloride sonocrystallisation, namely temperature, ultrasonic power and concentration sodium. They found that the sonocrystallization is effective method for preparation of small NaCl crystals for pharmaceutical aerosol preparation. The crystal growth then occurs in supersaturated solution. Mersmann et al. (2001) [21] and Guo et al. [34] reported that the relative supersaturation in reactive crystallization is decisive for the crystal size and depends on the following factors. 

To find out the stabilization effect of polyelectrolytes, silver nanoparticles coated with PAH or PEG at concentrations either 1 mg/ml or 5 mg/ml were examined in 0.5 M NaCl, 0.1 M NaCl or 0.01 M NaCl by UV-Vis spectroscopy. For each type of polyelectrolytes prepared at the concentration of 1 mg/ml independently from their molecular weight and sodium chloride concentration the UV-Vis measurement data revealed most broad absorption bandwidth. The narrow absorption bandwidths were related to both PAH (15 kDa) and PEG (8 kDa) at the same concentration 5 mg/ml in 0.01 M NaCl. Silver nanoparticles modified with 5 mg/ml PAH and 5 mg/ml PEG in 0.1 M NaCl presented narrow absorption widths and relatively high absorbance intensity. Furthermore, PEG coated silver nanoparticles revealed better UV-Vis absorption results among mentioned polyelectrolytes. 

Grass, R. N. Stark, W. J. Flame synthesis of calcium-, strontium-, barium fluoride nanoparticles and sodium chloride. Chemical Communications 2005, 41, 1767-1769. 

More recently, a composite aerosol filter media has been prepared by depositing polyvinyl alcohol (PVA) nanofibres with mean diameters of about lOOnm on nonwoven fabric substrates by using needleless electrospinning technique. The filtration performance of the composite filter was evaluated by measuring the filtration of sodium chloride nanoparticles (75 20nm). The results showed that the filtration efficiency of the composite filter media for nanoparticles was increased with the increase in thickness of the nanofibre mats, which was controlled by the deposition time of the electrospinning process. 

The result of such exothermal reaction with significant heat release is an iron powder with a particle size of 10-20 nm. In accordance with Refs. [65,66], the coalescence of as-prepared nanoparticles during the reaction can be prevented using sodium chloride additive. The reduction of cobalt and nickel from chlorides are listed in... 

Sato etal. [238] studied the mechanism of formation of silver halide particles grown from reverse microemulsions. In a typical process, aqueous solutions of either (a) silver nitrate or (b) a sodium salt, i.e. sodium chloride, bromide or iodide was injected into AOT/isooctane reverse micelles. When equal volumes of the two kinds of microemulsion were rapidly mixed at 25°C, particles started forming. The particle diameter was a function of the type of the anion, the w value as also reaction time. For AgBr, the maximum diameter was - 2.7 nm for Agl, it went up to 5.5 nm. Bagwe and Khilar [444] synthesized AgCl nanoparticles from AOT/ alkane (cyclohexane, heptane, decane) systems. The aqueous phases were solutions of silver nitrate or alkali/alkaline earth halides. The number average particle size was in the range of 4-10 nm. 

Y. Chen, Z. Xue, D. Zheng, K. Xia, Y. Zhao, T. Liu, Z. Long and J. Xia, Sodium chloride modified silica nanoparticles as a non-viral vector with a high efficiency of DNA transfer into cells. Curr. Gene. Ther., 3, 273-279 (2003). 

Schindler, RW. (1967) Heterogeneous equilibria involving oxides, hydroxides, carbonates and hydroxide carbonates. Equilibria concepts in natural water systems. Adv. Chem. Sen, 67, 196-221. Schmidt, J. and Vogelsberger, W. (2009) Aqueous long-term solubility of tita-nia nanoparticles and titanium(IV) hydrolysis in a sodium chloride system studied by adsorptive stripping voltammetry. /. Solution Chem., 38, 1267-1282. Schuiling, R.D. and Vink, B.W. (1967)... 

Xylan-based micro- and nanoparticles have been produced by simple coacervation (Garcia et al., 2001). In the study, sodium hydroxide and chloride acid or acetic acid were used as solvent and non-solvent, respectively. Also, xylan and surfactant concentrations and the molar ratio between sodium hydroxide and chloride acid were observed as parameters for the formation of micro- and nanoparticles by the simple coacervation technique (Garcia et al., 2001). Different xylan concentrations allowed the formation of micro- and nanoparticles. More precisely, microparticles were found for higher concentrations of xylan while nanopartides were produced for lower concentrations of the polymer solution. When the molar ratio between sodium hydroxide and chloride acid was greater than 1 1, the partides settled more rapidly at pH=7.0. Regarding the surfactant variations, an optimal concentration was found however, at higher ones a supernatant layer was observed after 30 days (Garda et al., 2001). 

An interesting method to produce water-soluble iridium nanoparticles was proposed by Chaudret and coworkers [13]. Here, aqueous soluble iridium nanoparticles were synthesized by the chemical reduction of iridium trichloride with sodium borohydride in an aqueous solution of the surfactant N,N-dimethyl-N-cetyl-N-(2-hydroxyethyl)ammonium chloride (Scheme 15.2). The precursor reduction was assisted by sonication, while the gradual conversion of Ir(lll) ions to lr(0) nanoparticles was followed using UV spectroscopy. The use of a molar surfactant Ir ratio of 10 proved sufficient to obtain stable aqueous soluble iridium nanoparticles however, if the molar surfactant Ir ratio used was <10 then agglomeration was observed in solution after several days. TEM analysis of the iridium nanoparticles revealed a monodispersed size distribution and a mean diameter of 1.9 0.7nm (Figure 15.2). 

Figure 8.12 Schematic illustration of the layer-by-layer deposition on an Au electrode initially with positively charged poly(diallydimethylammonium) chloride (PDDA) and negatively charged poly(sodium 4-styrenesulfonate). Subsequent depositions entailed (I) PDDA-modified Prussian blue nanoparticles (P-PB), followed by (II) negatively charged glucose oxidase (GOx).55 (Reprinted with permission from W. Zhao et al., Langmuir 2005, 21, 9630-9634. Copyright 2005 American Chemical Society.) (See color insert.)...

Silica nanoparticles are commonly prepared by polymerization of appropriate precursors such as silicates, silicon alkoxides, or chlorides (Fig. 11.2).2 Besides the industrial methods, which rely mainly on condensation of sodium silicate in water induced by sodium removal through ion exchange, three different synthetic methods are currently used in research labs to prepare silica nanoparticles loaded with organic molecules. In the first method, proposed by Kolbe in 1956s and developed by Stober and coworkers in the late 1960s,6 the particles are formed via hydrolysis and... 

In contrast to aqueous methods, the polyol approach resulted in the synthesis of metallic nanoparticles protected by surface-adsorbed glycol, thus minimizing the oxidation problem The use of polyol solvent also reduces the hydrolysis problem of ultrafine metal particles, which often occurs in aqueous systems. Oxide nanoparticles can be prepared, however, with the addition of water, which makes the polyol method act more like a sol—gel reaction (forced hydrolysis). For example, 5.5-nm CoFe204 has been prepared by the reaction of ferric chloride and cobalt acetate in 1,2- propanediol with the addition of water and sodium acetate. 

Metal nanoparticles are unstable with respect to agglomeration to the bulk, van der Waals forces between the particles attract them to such an extent that metal metal bond formation occms. The fact that nanoparticles can be kept in solution is due to either electrostatic or steric stabilization. For instance, the ruby red gold sols, prepared from [AuCLi]" and sodium citrate as reducing agent, are stabilized by an electrical double layer formed by adsorbed citrate and chloride... 

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