纳米纤维素-氧化石墨烯层状薄膜的制备与性能

Preparation and characterization of nanocellulose-graphene layered composite films

纳米纤维素是具有可再生性、可降解性的天然高分子材料。基于氧化石墨烯优越的物理性能,采用真空抽滤方法制备纳米纤维素-氧化石墨烯高度有序层状结构以提高纳米纤维素薄膜的力学强度和疏水性能。实验结果表明,当石墨烯质量分数为4%时,纳米纤维素-氧化石墨烯层状薄膜的拉伸强度达到最大值204.4 MPa,比原始CNCs薄膜抗拉强度提升58.8%。层状薄膜的弹性模量随氧化石墨烯质量分数的增加呈现先增加后降低的趋势。通过对层状薄膜进行微观形貌分析和动态热机械性能分析验证了力学试验结果的准确性。对纳米纤维素薄膜和纳米纤维素-氧化石墨烯层状薄膜的接触角进行测定,发现由于纳米纤维素的氢键网络与氧化石墨烯表面游离羟基之间的相互作用,层状薄膜的疏水性能显著提升。

Cellulose nanocrystals(CNCs)is a natural polymer material with renewable and degradable properties.In this current study,based on the outstanding physical properties of graphene oxide(GO),CNCs-GO highly ordered layered structures are prepared by vacuum filtration method to improve the mechanical strength and hydrophobic properties of CNCs films.The experimental results show that when the mass fraction of graphene is 4%,the tensile strength of CNCs-GO layered film reaches a maximum of 204.4 MPa,which is 58.8%higher than that of the original CNCs film.The elastic modulus of layered films increases first and then decreases with the increase of GO mass fraction.The accuracy of mechanical test results is verified by analyzing the microstructure and dynamic thermo-mechanical properties of layered films.The contact angles of CNCs films and CNCs-GO layered films are measured,and it is found that the hydrophobic properties of the layered films are significantly improved due to the interaction between the hydrogen bond network of CNCs and the free hydroxyl groups on the GO surface.