Виготовлення та дослідження властивостей бактеріальної наноцелюлози

Abstract

Nanocellulose is a biopolymer that due to its attractive physicochemical properties has been intensively studied as a material for use in biomedicine, food industry, electronics etc. Modern chemical methods of nanocellulose production from wood raw materials require the use of acids, alkalis and solvents. This is a disadvantage from both economic and environmental points of view. The biomass that is obtained as a result of microbial processes can be regarded as an alternative source of nanocellulose. This paper deals with the application of the method based on Kombucha membranes for the preparation of bacterial nanocellulose. The structure and optical properties of the obtained films of bacterial nanocellulose have been studied by X-ray diffraction analysis and luminescence spectroscopy. The difference in the sizes of the regions on which X-ray scattering occurs was established from the analysis of diffraction patterns of nanocellulose films obtained by microbial and chemical methods. These regions are much larger in the case of bacterial nanocellulose. The redistribution of the peaks intensity in the diffraction patterns with a change in the manufacturing method reflects, probably, the difference in the ratio between crystalline and amorphous content for cellulose samples of various types. Samples of bacterial cellulose both "pure" and with the addition of the Rhodamine C dye are characterized by intense visible photoluminescence at room temperature. The treatment of samples with a NaOH solution leads to a decrease in the intensity of the red band (with a maximum at 670 nm) of cellulose luminescence, while the addition of a dye enhances the band in the yellow (maximum at 570 nm) spectral range. Thus, the method used in this work to made bacterial nanocellulose makes it possible to create luminescent films which emission spectra can be easily modified with alkalis or dyes treatment.