PVA/BC Bionancomposite Films with Particle Size Effect

The use of conventional carbon-based nanofillers such as carbon nanotubes (CNTs) and graphene sheets can be hindered to a certain extent when considering a high level of nanotoxicity via human inhalation and less cost-effectiveness for CNTs while the agglomeration of graphene sheets in polymer matrices. As such, bamboo charcoals (BCs) are suggested as alternative ecofriendly and sustainable carbon-based particles with good affinity to polyvinyl alcohol (PVA) as one of most popular water-soluble biopolymers in order to prepare PVA/BC bionanocomposites with superior material properties. In this chapter, two different types of BC particles, namely microdiameter bamboo charcoals (MBCs) and nanodiameter bamboo charcoals (NBCs), were successfully fabricated using a solution casting method. Nanofiller reinforcement effect was investigated with respect to BC particle size and dispersion, morphological structures and interfacial interactions between BCs and PVA matrices in such bionanocomposites. Overall, the addition of NBCs gave rise to much higher mechanical properties of PVA/NBC bionanocomposites as opposed to PVA/MBC counterparts. The maximum increases in tensile moduli of bionanocomposites were achieved up to 123 and 100% with the inclusion of 10 wt% NBCs and MBCs, respectively. Furthermore, corresponding tensile strengths were enhanced by 110 and 72% when incorporated with 3 wt% NBCs and MBCs accordingly, as compared with that of PVA. It is convincing that associated particle dispersion states within PVA matrices, as well as interfacial interaction between BCs and PVA matrices play a leading role in the remarkable property enhancement in PVA/BC bionanocomposites, which can be potentially used in material packaging and biomedical applications.