目的 以纳米纤维素为基材， 氧化石墨烯为增强相， 制备氧化石墨烯/纳米纤维素复合薄膜。 方法 分别采用酸碱直接处理法和酸碱交替处理法制备纳米纤维素， 采用一步氧化法和循环氧化膨胀法制备氧化石墨烯， 观测其形貌， 得出最佳制备工艺。 测试由最优工艺制备的纯纤维素薄膜和复合薄膜的拉伸和润湿性能。 结果 酸碱交替处理法制备的纳米纤维素薄膜表面结构清晰， 且纤维直径可达50 nm， 循环氧化-膨胀法制备的氧化石墨烯片层厚度在纳米级别 。 当纳米纤维素与氧化石墨烯的质量比为 20∶1 时，氧化石墨烯/纳米纤维素复合薄膜的拉伸强度达149.68 MPa，与纯纤维素薄膜相比增加了 19.55%，且复合薄膜的接触角大于纯纤维素薄膜的。 结论 证实了氧化石墨烯能够增强纳米纤维素薄膜，在一定程度上说明氧化石墨烯/纤维素复合薄膜对水分子的阻隔性优于纤维素薄膜。

Objective In order to combine the advantages of nano cellulose and graphene, in this paper, we used nanocellulose as matrix, and graphene oxide as reinforcing phase, to fabricate the graphene oxide/nano cellulose composite film. Methods The cellulose nanofibrils were prepared by acid and alkali direct treatment method and acid and alkali alternate treatment. The graphene oxide was prepared by one-step oxidation method and oxidation-expansion cycle method. Then its morphology was observed, and the best preparation process was found out. The tensile strength and wetting property of graphene oxide/ nano cellulose composite film were tested, which was prepared by the optimal process. Results The results showed that the nano cellulose film prepared by the acid and alkali alternate treatment had clear structure, and the diameter of the fibre was 50 nm. The graphene oxide prepared by the oxidation-expansion cycle method had thickness of nanoscale. When the quality ratio of nanofibre and graphene oxide was 20∶1, the tensile strength of the GO/nano cellulose composite film reached 149.68 MPa, which was increased by 19.55% as compared with the pure cellulose film. The contact angle of composite film was greater than that of the pure cellulose film. Conclusion It was confirmed that graphene oxide could improve the nano cellulose film to a certain extent, and that the barrier property of the composite film to water was superior to cellulose film.