▎ 摘　　要

The increased demand for durable yet flexible and stretchable membranes has inspired the investigation of polymer nanocomposite films, such as those based on polyvinyl alcohol (PVA). Nanocrystalline cellulose (NCC) and graphene oxide (GO) nanosheets, as well as hybrid nanofillers with different weight NCC/GO ratios were successfully prepared and characterized. Their synergistic effect in enhancing the properties of poly(vinyl alcohol) (PVA) nanocomposites was also investigated. Results show that at an optimal filler content, the UV shielding efficiency exceeds 90%. When used together, NCC and GO enhance the nanocomposite properties to a larger extent than when individually used, which is ascribed to the hydrogen bonding between NCC and GO and the resulting prevention of filler agglomeration in the polymer matrix. Consequently, PVA/NCC/GO films exhibit properties superior to those of PVA/NCC and PVA/GO films Owing to this synergistic property enhancement, the film with the optimal NCC to GO ratio (PVA/3.0%NCC/3.0%GO) has an elongation at break close to that of pure PVA while exhibiting tensile strength and storage modulus exceeding those of pure PVA 2.56- and 2.05-fold, respectively, and featuring higher glass transition and melting temperatures. Thus, at the optimum content of NCC and GO, the synergistic effect between these fillers strongly influences film properties, which can be exploited in the development of multifunctional nanocomposites.