Yunusov Кh. E., Djuraeva Kh., Sarimsakov А. А
The Scientific research centre of Polymer Chemistry and Physics
under National University of Uzbekistan,
Синтез бактерицидных Нано частицы серебра В натрий карбокс и метил целлюлоза
At the present time determines that silver and its compounds are able to inhibit the growth and kill more than 650 kinds of bacteria, viruses and fungi, at the same time keep up microelements an essential part all of living organisms.
The aim of this work is making bactericidal, antifungal composition based on Na – carboxymethylcellulose, contained stabilized silver nanoparticles and the study their structures and properties.
We have studied the conditions and the exchange of sodium cations with silver cations in solutions of Na-CMC.
It was experimentally determined that when Na-CMC with DS – 0,65, 0.69, 0.85 by exchange with 0,35; 0,4 and 0,5 mol % ions of Na+ to ions Ag+ formed Ag+CMC– like stable form of hydrogel which is bad soluble in water, in difference to alkali metal salts of Na-CMC that apparently, explained carboxyl groups of Na-CMC ability to forms complexion with ions silver.
It is known that on the basis of the photographic process halide silver is formation of colloidal silver particles with prolonged irradiation of photons above the bandgap. This electron-stimulated the process formation of colloidal particles has been explained by the Mott-Gurney theory, essence of which is follows. In the process of photochemical reduction optically generated electron migrates and catches in the electron catcher at the line interface and near the surface.
The negative charge attract one of interstitial Ag+ ions, present in thermodynamic equilibrium, which move to trapped electrons. This is the first step in the sequence in which the electrons and interstitial atoms are trapped, thus formed clusters and nanoparticles of silver that working out on basis of latent image. The mechanism of the Mott-Gurney will be as follows:
Thus, the photostimulated formation of silver nanoparticles in the hydrogel Ag+CMC– can be considered as electron-stimulated nuclear process mechanism which may be based on the theory Mott-Gurney with photographic process.
Hydrogel, film and cotton material, contained silver nanoparticles with different size and shape were synthesized.
Based on the results of investigations has chosen following conditions of formation homogeneous silver nanoparticles in size:
Time of UV – irradiation 30 minutes; content of the CMC in hydrogel 0.08 mol; content of AgNO3 in solution 3 • 10-5 mol. Spherical silver nanoparticles with size 2-30 nm were formed in the selected conditions.
Bactericidal and bacteriostatic activities of synthesized hydrogel, film and cotton material, containing silver ions and nanoparticles were investigated on strains Staphylococcus epidermidis and Candida albicans.
High bactericidal activity of CMC hydrogel, containing 2-30 nm spherical silver nanoparticles against of Staphylococcus epidermidis and Candida albicans was found.
High bactericidal activity of film contained 5-70 nm spherical silver nanoparticles compared to silver ions was determined, against of pathogenic test bacterium Staphylococcus epidermidis and Candida albicans.
Also investigations shows that spherical silver nanoparticles with size 5-35 nm and with content of 0,0085 % mass. in cotton fabrics has a high bactericidal activity. Stabilization of silver nanoparticles helps to save the bactericidal and bacteriostatic activity during washing the cotton fabrics and textiles on their basis. Actually, the high bactericidal activity of this samples can be explained by small size of silver nanoparticle, high surface and can entering easily of in nucleus of microbe.
Determined, optimal conditions of formation of hydrogels Ag+CMC–, from water-soluble CMC fractions with different DS and DP. By the photoirradiation hydrogels was define the conditions of formation of silver nanoparticles with different shapes and sizes.
Obtained covering agents contained, silver nanoparticles can be used in medicine as a bactericidal drug to cure the burns and wounds.