石墨烯/酚醛复合纤维的制备及性能

Preparation and performance of graphene/phenolic composite fibers

石墨烯纤维是新一代柔性器件的潜力电极材料,制备同时具有良好力学性能和电化学性能的石墨烯基复合纤维是研究的重点。以改良的Hummers法制备的氧化石墨烯为基体,酚醛树脂为增强体,冰乙酸为凝固浴,通过非液晶湿法纺丝的方法制备了石墨烯/酚醛复合纤维,并对得到的石墨烯/酚醛复合纤维的表面形貌、力学性能和电化学性能进行了研究。结果表明,酚醛树脂通过氢键与石墨烯片层相结合,从而减少石墨烯片层间的堆叠,使复合纤维的表面褶皱丰富且均匀。通过调控酚醛树脂的含量,可以得到具有不同表面褶皱程度的复合纤维。随着酚醛树脂用量的增加,纺丝液浓度增大,挤出胀大现象明显,复合纤维片层间隙增大,表面沟壑加深,缺陷增加。石墨烯/酚醛复合纤维的拉伸强度随着酚醛树脂用量的增加呈现先增大后减小的趋势,酚醛树脂用量为10%时纤维的拉伸强度和拉伸弹性模量分别为65.53 MPa和672.91 MPa。得益于表面丰富均匀的褶皱,在电流密度为0.2 A/cm^(3)时,氧化石墨烯∶酚醛为100∶10时体积比电容为583.4 F/cm^(3),远高于纯石墨烯纤维。

Graphene fibers have emerged as a potential electrode material for a new generation of flexible devices.It is crucial to prepare graphene-based composite fibers with both good mechanical and electrochemical properties.Herein,graphene oxide was firstly prepared by the modified Hummers method,and then graphene/phenolic composite fibers were prepared by non-liquid crystal wet spinning method using graphene oxide as the matrix,phenolic resin as the reinforcement,glacial acetic acid as the coagulation bath.The surface morphology,mechanical and electrochemical properties of the obtained graphene/phenolic composite fibers were investigated.The results show that the phenolic resin combines with the graphene sheets through hydrogen bonding,which reducing the stacking between the graphene sheets and resulting in fewer defects and rich surface folds.By controlling the phenolic resin content,fiber composites with different surface morphologies can be obtained.With the increase of phenolic resin content,the higher spinning liquid concentration induce an obvious spinning extrusion expansion,then deepen surface grooves and increase defects.The tensile strength of the composite fiber first increases and then decreases with the increase of phenolic resin.The tensile strength and tensile modulus of elasticity of the fiber using 10% phenolic resin are 65.53 MPa and 672.91 MPa respectively.Owing to the abundant winkles on the surface,graphene oxide/phenolic(100/10) composite has an excellent volumetric capacitance of up to 583.4 F/cm^(3) at a current density of 0.2 A/cm^(3),which is much higher than that of pure graphene fibers.