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...
Rheological properties of chitosan solutions containing aqueous and water-alcohol solutions of cobalt acetate and its nanoparticles have been studied. From these solutions, composite chitosan films with cobalt nanoparticles have been prepared. The morphological features of obtained films have been studied with the use of scanning electron microscopy with energy dispersive microanalysis, and their compositions have been determined.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.