聚乳酸基纳米纤维素/石墨烯导电复合膜的制备与表征

利用真空抽滤方法，制备了纳米纤维素/石墨烯导电膜，将其嵌在聚乳酸表面得到聚乳酸基纳米纤维素/石墨烯导电复合膜。傅里叶红外（FT-IR）表征结果表明石墨烯与纳米纤维素之间存在一定的相互作用；当纳米纤维素与石墨烯质量比为1：2时，导电复合膜的电导率为12 S·cm^-1，抗张强度达到13.62 MPa，水接触角为80.6°。热重分析（TGA）表征结果表明导电复合膜有良好的热稳定性，300℃时不同质量比的导电复合膜的失重量低于10%，相比纳米纤维素，在相同温度下失重量减少了20%。以聚乳酸材料为基体的导电复合膜，其抗张强度比未被嵌聚乳酸基体的纳米纤维素/石墨烯导电膜提高15～23倍，将聚乳酸基纳米纤维素/石墨烯导电复合膜埋在土壤中5周后，质量损失了3.7%。聚乳酸材料优异的力学性能和可降解性，扩展了纳米纤维素/石墨烯导电复合膜的应用范围。制备的导电复合膜在柔性导电材料领域有潜在的应用前景。

Preparation and characterization of polylactic acid-based cellulose nanofibers/graphene conductive composite membranes

Cellulose nanofibers/graphene conductive membrane (CG) was prepared by vacuum filteration and the as-prepared CG was then coated with polylactic acid (PLA). FT-IR results show that a certain interaction exists between graphene and cellulose nanofibers. The optimal condition is that the composite ratio of cellulose nanofibers to graphene is 1:2, the electrical conductivity is 12 S·cm^-1, the tensile strength reaches 13.62 MPa and its hydrophilic angle is 80.6°. Thermogravimetric analysis (TGA) confirms the mass loss of PLA-based cellulose nanofibers/graphene conductive composite membranes (CGP) at 300℃ are below 10%, which is 20% less than that for pure cellulose nanofibers, suggesting that the introduction of graphene can greatly enhance the thermal stability of cellulose nanofibers. PLA possesses special advantages of mechanical property and degradability. The tensile strength of the CGP increases by 15-23 times as compared with the CG, after being buried in soil for 5 weeks, the mass loss of PLA-based cellulose nanofibers/graphene conductive composite membranes(CGP) was 3.7%. Therefore, CGP has a promising application in the flexible conductive material field.