Biodegradation of flax fibers in the presence of silver nanoparticles

Biodegradation of flax fibers differing in the chemical composition, structure of cellulose, and content of concomitant natural impurities (pectin compounds, lignin, hemicellulose) was studied. The effect exerted on the biodegradation by silver nanoparticles immobilized in the fiber was evaluated.     

Chlorophyll and Its Derivatives,Chlorins and Porphyrins,as a Promising Class of Environmentally Friendly Dyes

The possibilities of using pheophorbid (a), chlorin e ₆, its copper complex, 6-N-(2-aminoethylamido)chlorin e ₆ dimethyl ester, and its complexes with Cu(II), Ni(II), Co(II), and Zn(II) as dyes for cellulose, acetate, and wool fibers were studied.     

Structural Transformation of Starch Hydrogels Exposed to Strong Mechanical Field

Structural transformations of starch hydrogels during mechanical preparation of starch gelatinous materials with a rotary pulse apparatus were studied. Two concentration regions distinguished by the structural transformations of starch hydrogels under high shearing stress were revealed.     

Silver Nanoparticles: Dependence of the Antimicrobial Activity on the Synthesis Conditions

Russian Journal of General Chemistry - Specific features of the synthesis of stable silver nanoparticles by chemical reduction with agents differing in the reducing ability were studied using...     

Generation of redox systems by fiber materials on the reduction of vat and sulfur dyes: Research and practical implementation

An essential part of the processes of refinement of textile materials from natural cellulose fiber is based on redox reactions of the components of process solutions both with admixtures in the fiber and with cellulose. The reducing agents involved in these processes are used in the alkaline treatment of textile materials as antioxidants whose function is to prevent oxidative destruction of cellulose; reducing agents are also introduced into vat or sulfur dye compositions to convert these insoluble dyes into soluble leuco compounds.     

Synthesis of Copper-Silver Bicomponent Nanoparticles in the Presence of Nitrilotrimethylenephosphonic Acid

Synthesis of stable mixed nanoparticles (SMNs) by chemical co-reduction of copper and silver complexonates with sodium borohydride in an open system with the access of air oxygen was studied for the first time the. Variation of the Cu²⁺ to Ag⁺ molar ratio within 1: (0.05–0.5) enabled targeted formation of differently structured nanoparticles (core-shell type), Cu_coreAg_shell and Ag_coreCu_shell. It was found that, by choosing appropriate synthesis conditions, it is possible to produce oxidation-resistant copper particles protected by a shell of a precious metal or to involve the copper complex of nitrilotrimethylenephosphonic acid in silver reduction. The resulting SMNs may become widely used for obtaining various functional materials.

     

Influence of Surfactants on the State of Starch Hydrogels under High Shear Stresses

Specific influence of high shear loads on starch hydrogels containing oxyethylene-based surfactants was studied. It was found that a number of oxyethylated fatty alcohols can produce a steady thickening effect on starch hydrogels under high-rate shear strains owing to mechanochemically initiated complexing with starch amylose.     

Bio-protected flax nanocomposites as basis for manufacturing of high-tech eco-products

Data on biodegradation of flax fibers of different chemical composition, structure of cellulose, and included natural impurities (pectic compounds, lignin, and hemicelluloses) are presented. The influence of silver nanoparticles immobilized in the fiber on biodegradation of the objects under study is evaluated. It is demonstrated that this effect depends on the concentration and size of nanoparticles in the polymer matrix.     

Structural inhomogeneity in cotton cellulose upon its interaction with water

Comparative analysis of the characteristics of supramolecular structures of dry and swollen cotton fibers makes it possible to differentiate structural regions accessible to water. The revealed features of water desorption from cotton cellulose (exceptionally low rates at the final stages, presence of residual moisture) are related to the removal of water, which is localized in the regions of the crystalline phase disorganized upon drying. The fact of incomplete moisture removal from cotton fibers at < 325 K is interpreted from the stand-point of the frozen molecular mobility in the microsurroundings of sorption sites, which are located at the defects of crystallites, at the final stage of the desorption process. A marked contribution from the recrystallization of disorganized regions in the surface layer of crystallites to the thermal effect of the interaction between water and cotton cellulose at low water content is established.