Abstract:The physical properties of bacterial cellulose (BC) prepared using different drying methods were investigated. Three different drying methods for bacterial cellulose membrane included (1) drying at elevated temperature (60 ℃) (BC-DHT), (2) frozening at -20 ℃, and then freeze-drying (BC-FDF), and (3) shock frozening with liquid nitrogen and subsequently freeze-drying (BC-FDN). The scanning electron microscope (SEM) showed that BC-FDN had larger pores and empty spaces than BC-DHT and BC-FDF. One gram of dry BC samples could absorb 2.38 g, 6.22 g, and 58.24 g water for BC-DHT, BC-FDF, and BC-FDN, respectively. The water vapour transmission rate were in the order of BC-FDN?BC-FDF?BC-DHT. X-ray diffraction (XRD) indicated that the crystallinity indexes of BC samples were 78.5%, 64.2%, and 47.5% for BC-DHT, BC-FDF, and BC-FDN, respectively. Thermogravimetric analysis showed that the thermal stability of BC-DHT was better than those of BC-FDF and BC-FDN. Thus, the physical properties of bacterial cellulose can be altered by different drying methods.
