Bacterial cellulose-poly(vinyl alcohol) nanocomposites prepared by an in-situ process

Bio-nanocomposites were prepared by an in-situ growth process through the direct addition of poly(vinyl alcohol) (PVA) into the Acetobacter xylinum inoculated medium and compared with composites made by impregnation of bacterial cellulose (BC) gels with a PVA solution. Mechanical property tests showed that the presence of PVA in the BC acts as a plasticizer, interrupting hydrogen bonding between cellulose fibrils within the BC network. This resulted in a reduction in Young's modulus and an increase in toughness compared to pure BC sheet, especially for in-situ grown samples. Interestingly, the small amount of added PVA turns the BC sheet into optical transparent nanocomposite films with excellent mechanical properties. (C) 2010 Elsevier B.V. All rights reserved.