Physicochemical studies of cotton cellulose and its derivatives containing silver nanoparticles

Abstract

The shape, number, and size of silver nanoparticles contained in cotton cellulose and its derivatives were studied using x-ray diffraction, atomic absorption spectroscopy, transmission electron microscopy, and elemental analysis. Silver nanoparticles in sodium carboxymethylcellulose were smaller and more numerous and had a more even distribution than those in cotton and microcrystalline cellulose. The size and shape of silver nanoparticles depended on the nature of the polymer matrix.Ultradispersed metals exhibit unusual properties that open new possibilities for their practical application. Silver nanoparticles, which are an antimicrobial agent, are especially interesting. Several methods for producing stable metal nanoparticles, including chemical, biochemical, physical, and others, are known.The synthesis of metal clusters and nanoparticles in polymer solutions and matrices is a vigorously developing area for preparing nanostructured metal-containing systems with an array of unusual physicochemical properties [1].Research in this area indicates that macromolecules not only stabilize dispersed systems but also participate directly in their formation by controlling the size and shape of the growing nanoparticles [2]. The use of natural polymers as the polymer matrices for growing metal nanoparticles is even more attractive because they can undergo biodegradation.Therefore, it seemed promising to study the structures and properties of cotton cellulose derivatives containing silver nanoparticles. We studied previously the ability to prepare silver nanoparticles in matrices of cellulose derivatives and showed that the resulting materials acquired new, in particular bactericidal, properties that were uncharacteristic fon the starting materials [3].The goal of the present work was to study cotton cellulose derivatives (microcrystalline and carboxymethylated cellulose) containing silver nanoparticles using physical and physicochemical methods.X-ray diffraction studies showed ( Fig. 1) that carboxymethylcellulose (CMC) had an amorphous structure and gave a diffuse ring at 2T = 21.6°. CMC containing silver ions also had an amorphous structure with a weaker ring in the same region. Two phases were found in diffraction patterns of polymeric CMC composite with reduced silver nanoparticles. These corresponded to amorphous CMC at diffraction angle 2T = 21.6° and metallic silver. Silver with a cubic crystal lattice and a = 4.086 A° gives reflections at 2T = 38°, 44°, 65°, and 78° from planes (111), (200), and (220) [4].The size of the silver crystallites was calculated from the peak widths. The width of x-ray diffraction peaks is known to depend on the size of the crystallites and their coherent scattering regions. The greater the size of these regions is, the narrower the reflection in the x-ray pattern. The effective crystallite sizes were determined using the Scherrer formula and the width of each line.The effective size of the silver crystals in the CMC matrix was 15 nm according to the calculations. Figure 2 shows high-a...

Physicochemical properties and antimicrobial activity of nanocomposite films based on carboxymethylcellulose and silver nanoparticles

“…Stable nanoparticles synthesized by photochemical methods have a narrow particle size distribution and high stability in aqueous media in comparison with colloidal systems obtained by conventional method 22 . In the course of photochemical reduction, optically generated electrons migrate and combine with electron sinks at the embedded interface and near the surface.…”

Bactericidal Hydrogel Based on Sodium-Carboxymethylcellulose Contained Silver Nanoparticles: Obtaining and Properties

“…Stable nanoparticles synthesized by photochemical method have a narrow distribution in particle sizes and high stability in an aqueous medium (chemical reduction, high-frequency electric discharge, ultrasonic dispersing, and the condensation of metal vapors) being used as matrix ionic polymer solution that simultaneously function as nanoparticle stabilizing agent, in compare to colloidal Open Journal of Polymer Chemistry the management of process in-time and in-site, as distinct from the chemical methods applying thermodynamically and kinetically unstable systems [10].…”

“…Decrease of the carboxymethyl anions relative content caused by lowering of the reaction medium pH calls a dramatic decrease in the efficiency of silver ions binding after their UV-irradiation because of their aggregation with the formation of silver nanorods. It could be explained by the increasing of silver ions concentration in CMC structure with simultaneous restoration of silver ions bound to carboxylate anion of Na-CMC (nanoreactor) [10] and free silver ions. These processes carry out with different speeds and lead to polydispersity of formed nanoparticles.…”

Obtaining and Properties of the Implant Film Made With Carboxymethylcellulose Containing Silver Nanoparticles Used for Treatment of Burn Wounds

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