Biological Effects of Metal Nanoparticles by Elena Mikhailovna Egorova Aslan Amirkhanovich Kubatiev & Vitaly Ivanovich Schvets

Author:Elena Mikhailovna Egorova, Aslan Amirkhanovich Kubatiev & Vitaly Ivanovich Schvets
Language: eng
Format: epub
Publisher: Springer International Publishing, Cham

The films prepared from CMC-Ag nanoparticles mixtures demonstrated a high antimicrobial activity against two kinds of pathogenic bacteria, this activity being considerably stronger than that observed for the control films from CMC without the nanoparticles. Method used for the testing of antibacterial activity and the results obtained are presented in Chap. 7.

5.2 Solid Materials with Ag and Cu Nanoparticles

Deposition of nanoparticles on the surface of solid materials was performed by means of adsorption from micellar or water solution; the purpose was to produce various modified materials with special properties for the application in medicine and technics. In these studies, we used the micellar and aqueous solutions of AOT-stabilized silver nanoparticles, as well as micellar solutions of copper nanoparticles. For each type of material, the conditions were selected that provided the high enough adsorption rate and surface density of the nanoparticles and also ensured the stability of the coverage under the supposed operating conditions. Type of solution used for the deposition of nanoparticles depends on the properties of the adsorbent surface. Here, the adsorption process is governed mainly by the regularities known from the theory of adsorption: polar additives from the nonpolar medium are actively adsorbed on hydrophilic surfaces, while nonpolar additives from the polar medium are actively adsorbed on hydrophobic surfaces [330]. From this point of view, a micellar solution with nanoparticles is the nonpolar medium, where nanoparticles in reverse micelles represent a polar component; such solutions were used for the deposition on glass, metals, textiles, metal oxide powders, silica gel, and other materials with polar groups on the surface. Aqueous solution containing nanoparticles is the polar medium where the nanoparticles in AOT micelles can be regarded as nonpolar component. From such solutions, the nanoparticles were well adsorbed on activated carbon, carbon clothes, as well on the other materials with the surface which possessed predominantly hydrophobic properties.

Control of the adsorption rate was performed by spectrophotometric measurements of the changes in intensity of the nanoparticles absorption band in solution used for the deposition on the particular material. The amount of adsorbed nanoparticles was estimated as amount of the deposited metal per unit weight of the material (usually in mg/g) or (if the specific surface area for a sample was known) as amount of the metal per unit surface area (mg/cm2). If the nanoparticles adsorbed from the solution with narrow particle size distribution, the density of coverage was also determined, as the number of nanoparticles per unit surface area of the sample.

Works on the modification of solid materials were performed with silver and copper nanoparticles stabilized by AOT. Until recently, the most required were the materials, modified with silver nanoparticles, because they had good prospects of application in manufacturing of different products for medicine and other areas, where their antimicrobial properties can be applied. Besides, silver nanoparticles deposited on solid carriers are of great interest as efficient catalysts for the chemical industry. With the use of Ag nanoparticles the following modified materials were obtained: (1) activated carbon and polyamide membranes for the

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