Electrospinning from a capillary is one of the methods for the production of nanofibers. The specific properties of such fibers result first of all from their large specific surface and the high porosity of the fiber mat. This article presents a process for producing functional nanofibers with antimicrobiological properties by electrospinning from polyacrylonitrile/dimethyl sulphoxide solution containing a bioactive agent based on quaternary ammonium salts (N, N, n, n,-didecyl-N,N-dimethylammonium chloride, Bis-(3-aminopropyl)-dodecylamine) and 2-propanol. The structure of the nanofibers obtained and their antimicrobial activity are investigated. A 5 wt % addition of bioactive preparation to the polymer solution (concentration of active substance in solution about 1.5 wt %) makes it possible to obtain fibers showing good bactericidal properties. After 6 h in contact with these fibers, Escherichia coli are eliminated to a level of 99.84% and Staphylococcus aureus to 99.99%. The IR spectrophotometric measurements do not indicate a residue of solvent in the bioactive nanofibers and show an increase in content of CH and CH 2 groups in relation to the pure nanofibers, which is connected with the presence of the biocide. Their degree of crystallinity determined by the X-ray scattering method is 44.4%. The nanofibers obtained can be designed for medical and filtration applications.

In this paper studies on sound absorption of the thermoplastic composites on the basis of waste natural fibers are presented. Cotton fibers and cellulose ultra-short and ultra-fine fibers obtained from flax fibers following enzymatic and additional mechanical treatment were used as the components of polylactide composites, and their influence on sound absorption behavior was investigated. The composites were obtained from a pressing process of fibrous multilayer structures. The sound absorption properties of three types of composites were compared: composites reinforced by cotton fibers, composites reinforced by cellulose ultra-short and ultra-fine fibers, and composites reinforced by cotton fibers and cellulose ultra-short and ultra-fine fibers. The role of cellulose ultra-short and ultra-fine fibers in changing the sound absorption properties of composites was determined. It has previously been shown that using natural fibers with a thermoplastic polymer results in increased sound absorption. The best improvement of sound absorption can be obtained by combining cotton fibers and cellulose ultra-short and ultra-fine fibers, especially nanofibers, as a reinforcement.

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