Nanocellulose is a new class of derivatives of cellulose, which is characterized by high crystallinity, surface area, degree of dispersion, ability to decomposition by microorganisms and etc. There is high attention solving problems of obtaining nanocellulose and its application as high quality filler for polymers, biodegradable materials, additives for papers, clotting dispersion and etc. Obtaining of particles of nanosized nanostructure on the base cellulose, studying of processes of their formation, properties and creation nanotechnology on this basis give the chance to obtain materials with unique properties. In this work nanocellulose was obtained from cotton cellulose by hydrolysis with sulfuric acid, ultrasonic dispersion and microwave irradiation. The properties and structure of nanocellulose are investigated by AFM, IR-spectroscopic, X-ray methods. Nanocellulose has rod-like shape with sizes 50-300 nm in length and 10-40 nm in diameters and spherical shape with sizes 50-300 nm depending on the synthesis conditions of obtaining. Quantum-chemical methods have been used to calculate the electronic characteristics of nanocellulose; the change in the energy difference between HOMO and LUMO is shown, showing the change in reactivity and the manifestation of specific properties.
The interaction of chitosan (ChS) and the Bombyx mori protein on different pH ranges was studied, and the fundamental possibility of obtaining complexes of ChS with the Bombyx mori protein was revealed. The for-mation of a polymolecular complex of protein with ChS in aqueous solutions was confirmed by the results of physico-chemical methods. It is shown that the ChS structure is characterized by a certain rigidity and iono-genicity. The results indicate the complexation of the pupae protein with ChS in 2% acetic acid in the range of pH = 4.8–6.7. The detected changes and shifts of the absorption bands in the IR spectra confirm the occur-rence of the complex formation reaction between the molecules of ChS and protein at pH = 4.8–6.7, which is characterized by absorption bands in the IR spectra at 1641 cm–1, 1538 cm–1 and 1068 cm–1. Quantum-chemical DFT study of ChS complexes with amino acids (AAs) was carried out. The stability of complexes of ChS with AAs (ChS-AA) was shown except for the complex formed with histidine in the gas phase. The calculation results indicate the presence of a strong thermodynamic driving force in the complexation of ChS with AAs.
In recent years, use of chitosan (CS) nanoparticles as nanocarriers received much attention due to their bio-degradability, biocompatibility and non-toxicity. Water-soluble sulfated CS derivatives are widely used as anticoagulant and antiviral drugs. The chitosan sulfates (CSS) containing one-to-three sulfate groups were investigated using the DTF. The energy gap [Formula: see text], electronegativity ([Formula: see text]), electron affinity (EA), chemical potential [Formula: see text], ionization potential (IP), hardness [Formula: see text], softness [Formula: see text], electrophilicity index [Formula: see text], and maximum charge transfer index [Formula: see text] were obtained by the B3LYP/6-31++G(d,p) method. The electronic and thermodynamic properties, Mulliken atomic charges of sulfated chitosan with different contents of sulfate groups were obtained using the B3LYP/6-31++G(d,p) method.
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