木质纳米纤维素为基质制备柔性透明导电膜和电极材料的研究

发布时间：2018-05-17 07:25

  本文选题：木材 + 纳米纤维素　； 参考：《东北林业大学》2015年硕士论文

【摘要】：本研究利用废弃木粉资源为原料,通过酸水解法和超声分离法制备出高长径比和高结晶度的纤维素纳米晶须(CNW)和纤维素纳米纤丝(CNF),并探究其作为环境友好型柔性透光电器膜和生物碳复合电极材料的应用潜力。在环境友好型柔性透光电器膜的研究中,将CNW通过抽滤成膜,既而在其表面层层抽滤沉积石墨烯后热压干燥成膜,对所形成的复合膜的结构、热力学性能和光电性能进行测试分析。在生物碳复合电极材料的研究中,以CNF为碳源,乙酸锰为锰源,对二者冷冻干燥形成的复合气凝胶进行碳化,制备出具有三维结构和丰富孔隙的复合电极材料,并对其结构和电化学性能进行测试分析。研究得到以下结论：(1)以CNW作为基底膜,克服了单层或多层石墨烯不能自持的缺点,所形成的复合膜具有良好的透光性、导电性、柔韧性、可折叠性、高模量和耐高温的特点。基于真空抽滤方法的成膜工艺简单,可控性强。通过控制CNW和石墨烯的加入量,可以调节复合膜的厚度、透光性和导电性能。随石墨烯沉积层数的增多,复合膜的电阻值逐渐减小,导电率逐渐升高；而透光率逐渐下降。复合三层石墨烯所形成的复合膜,具有适中的导电性能(2.8 S/cm)和透光性能(53%),杨氏模量为10.2 GPa,断裂功达472.2 KJ/m,并在室温至280℃区间内具有良好的热稳定性。(2)CNF和乙酸锰的溶液均相混合,解决了直接加入MnO2粉末所导致的分散不均、颗粒团聚的问题。通过冷冻干燥及碳化工艺,制备的MnOx/CNF复合体系具有三维孔隙的自支撑结构,其孔隙率可由混合液的浓度控制。高比表面积和丰富的孔隙为电解液的扩散提供连续通道,表面生长的MnOx与电解液接触的接触面积增加,增加了电极材料的浸润性,缩短电解液的扩散路径,可减小电荷转移阻抗和Warburg阻抗,从而达到提高综合电容性能的目的。随着复合体系中锰源含量增加,MnOx/CNF复合体系的比电容增加,且比电容的增加值较为均匀。当锰源含量为40%时,复合体系具有较高的比电容值(在扫描速率为2 mVs-1时,其比电容可达138.4 Fg-1)和倍率特性,表现出优异的综合电化学性能。在电流密度为lAg-1下经过200次充放电后复合材料的比电容量衰减约10%,充放电次数500次时比电容量衰减为17%,其后随着循环次数的增加比电容的降低速度减缓,表明该电极材料具有较好的的循环稳定性。
[Abstract]:In this study, waste wood flour was used as raw material. Cellulose nanocrystalline whiskers with high aspect ratio and high crystallinity were prepared by acid hydrolysis and ultrasonic separation, and their potential applications as environmentally friendly flexible transparent film and biocarbon composite electrode materials were investigated. In the study of environment-friendly flexible transparent electric apparatus membrane, CNW was filtered into film, and then the composite film was formed by hot pressing and drying on the surface of the film. Thermodynamic and photoelectric properties were tested and analyzed. In the study of biological carbon composite electrode materials, the composite aerogels, which were formed by freeze-drying, were carbonized with CNF as carbon source and manganese acetate as manganese source, and the composite electrode materials with three-dimensional structure and rich pores were prepared. The structure and electrochemical performance were tested and analyzed. The following conclusions are obtained: (1) using CNW as the substrate membrane, it overcomes the shortcoming that single or multilayer graphene can not sustain itself, and the composite film has the characteristics of good transmittance, conductivity, flexibility, foldable, high modulus and high temperature resistance. The film forming process based on vacuum filtration method is simple and controllable. The thickness, transmittance and conductivity of the composite film can be adjusted by controlling the amount of CNW and graphene. With the increase of graphene deposition layer, the resistance of the composite film decreases gradually, the conductivity increases and the transmittance decreases. The composite membrane formed by the composite three-layer graphene has moderate electrical conductivity (2.8s / cm) and light transmittance. The Young's modulus is 10.2GPa. the fracture work is 472.2 KJ / m, and it has good thermal stability and homogeneous mixing with manganese acetate solution in the range of room temperature to 280 鈩，

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