Nanocomposites and nanomaterials

Synthesis, functionalization and properties of bacterial cellulose
Shegeda M.A.1, Krolenko K.1, Nedilko S.G.1, Yampolskiy A.L.1, Makarenko O.V.1, Scherbatskii V.1, Gomenyuk O.2, Scheludko V.2
1 National Taras Shevchenko University of Kyiv, Ukraine. 
64/13, Volodymyrska str., Kyiv-01601, Ukraine. 
E-mail: smetchik09@gmail.com
2 O. Dovzhenko Hlukhiv National Pedagogical University, Hlukhiv, Ukraine
Biodegradable cellulose polymer are in environment in the form of microfibrils in the cell walls of wood, plant etc. It can be also synthesized by bacteria in the form of nanofiber networks – it is bacterial cellulose or in other words – biocellulose (BC) [1]. This nanocellulose properties can be modified by substitution of its hydroxyl groups with some functional groups, such as specific acids, chlorides, oxides or dyes to enrich some characteristics or to obtain new properties, e.g. luminescent.
Black tee, sugar and Komagataeibacter xylinus were used to grow the BC samples. They were then rinsed under running water and soaked in water for a long time. After the samples were then soaked in a 2% solution of NaOH for 24 hours and washed with acetic acid solution. Finally, the samples were washed with distilled water to neutral pH and then were dried. 
Some of the samples were functionalized with dyes and Rhodamine C was particularly used to give BC new luminescent properties. To prepare such composites, the BC samples were soaked for some time in 5 % water solution of ethanol.
Different characterization techniques have been used to study structural, mechanical and optical properties of elaborated nanostructured biocellulose. The samples were characterized using X-ray powder diffraction (XRD), scanning electron microscopy (SEM), optical reflectance ellipsometry, optical scattering of light, IR, Raman and luminescence spectroscopy. Some mechanical characteristics such as hardness and tensile strength were measured too.
The obtained data were analyzed in terms of finding a correlation between both mechanical and structural characteristics and optical properties. 

1.	Pradhan S., Brooks A.K., Yadavalli V.K. Nature-derived materials for the fabrication of functional biodevices // Materials Today Bio. – June 2020. - https://doi.org/10.1016/j.mtbio.2020.100065.