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A series of polymer/inorganic hybrids based on silica sol and polyacrylamide (SiO2-g-PAAm) with different number and length of PAAm chains was obtained by radical graft polymerization of acrylamide from the surface of SiO2. The main molecular and structural parameters of the hybrids, such as the chemical composition, average radius and charge of SiO2 particles, the number of grafts per one particle and their molecular weight, the average diameter and hydrodynamic volume of hybrid particles, and the thickness of the PAA layer, were determined. For this, elemental analysis, DTGA, static light scattering, viscometry, potentiometric titration, and TEM were used. The functional properties of hybrids as hydrophilic matrices in the in situ synthesis of nickel nanoparticles by borohydride reduction of metal ions from the Ni(NO3)2·6H20 salt in an aqueous medium have been studied. Using the method of UV-Vis spectroscopy and the developed original approach, the kinetics and efficiency of the formation of NiNPs in hybrid solutions were characterized, depending on the structure and concentration of the hybrid matrices and the concentration of the metal salt. An increase in the rate of accumulation and yield of NiNPs in solutions of all hybrids was found with an increase in salt concentration in the range of 0,010-0,078 kg·m-3, as well as a predominant decrease in the reaction rate with an increase in the concentration of hybrid matrices from 0,5 to 2,0 kg·m-3. It was shown that the structure of the hybrid matrices, determined by the number and length of PAAm chains, as well as the permeability of the grafted polymer layer, was one of the key factors affecting the formation rate and yield of NiNPs. It provided greater or lesser accessibility of the active groups of the "corona" and the inorganic "core" for metal ions and reducing agent molecules. Morphological studies of purified reduction products were carried out by TEM. Based on them, the main structural elements of highly dispersed NiNPs/SiO2-g-PAAm nanocomposites were established – swollen hairy particles of hybrids with small amorphous NiNPs (1,7±0,8 nm) included in the polymer "corona".
A series of polymer/inorganic hybrids based on silica sol and polyacrylamide (SiO2-g-PAAm) with different number and length of PAAm chains was obtained by radical graft polymerization of acrylamide from the surface of SiO2. The main molecular and structural parameters of the hybrids, such as the chemical composition, average radius and charge of SiO2 particles, the number of grafts per one particle and their molecular weight, the average diameter and hydrodynamic volume of hybrid particles, and the thickness of the PAA layer, were determined. For this, elemental analysis, DTGA, static light scattering, viscometry, potentiometric titration, and TEM were used. The functional properties of hybrids as hydrophilic matrices in the in situ synthesis of nickel nanoparticles by borohydride reduction of metal ions from the Ni(NO3)2·6H20 salt in an aqueous medium have been studied. Using the method of UV-Vis spectroscopy and the developed original approach, the kinetics and efficiency of the formation of NiNPs in hybrid solutions were characterized, depending on the structure and concentration of the hybrid matrices and the concentration of the metal salt. An increase in the rate of accumulation and yield of NiNPs in solutions of all hybrids was found with an increase in salt concentration in the range of 0,010-0,078 kg·m-3, as well as a predominant decrease in the reaction rate with an increase in the concentration of hybrid matrices from 0,5 to 2,0 kg·m-3. It was shown that the structure of the hybrid matrices, determined by the number and length of PAAm chains, as well as the permeability of the grafted polymer layer, was one of the key factors affecting the formation rate and yield of NiNPs. It provided greater or lesser accessibility of the active groups of the "corona" and the inorganic "core" for metal ions and reducing agent molecules. Morphological studies of purified reduction products were carried out by TEM. Based on them, the main structural elements of highly dispersed NiNPs/SiO2-g-PAAm nanocomposites were established – swollen hairy particles of hybrids with small amorphous NiNPs (1,7±0,8 nm) included in the polymer "corona".
Hydrophilic polymer/inorganic hybrids (PIH) containing silica nanoparticles and polyacrylamide chains proved to be effective matrices for the in situ synthesis of cobalt nanoparticles. PIH sample was synthesized by free-radical polymerization of acrylamide from the unmodified surface of SiO2 nanoparticles and characterized by elemental analysis, dynamic thermogravimetric analysis, static light scattering, potentiometric titration, viscometry and transmission electron microscopy (TEM). The processes of borohydride reduction of cobalt ions from the Co(NO3)2·6H2O solution to nanoparticles in water medium and aqueous solutions of PIH were studied as a function of the concentrations of metal salt and hybrid concentrations using UV-Vis spectroscopy and TEM. A special approach to characterize the kinetics and efficiency of CoNPs formation in water medium and hybrid solutions using UV-Vis spectroscopy was implemented. The kinetic parameters of the CoNPs formation process as well as the yield, size, and morphology of nanoparticles in hybrid solutions and water medium at various concentrations of metal salt and hybrid were determined. The growth of both concentrations of reagents had a positive effect on the rate of formation of metal nanoparticles and their yield, but in all cases, the reduction process developed much slower in hybrid solutions compared to pure water. The morphology of the CoNPs/PIH nanocomposites was mainly represented by separate swollen hybrid particles containing metal nanoparticles with dav~3 nm.
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