乙酰化木聚糖/多壁碳纳米管分散液涂层纸基导电材料的构建及电化学性能

Carbon nanotube dispersion abilities of acetylated xylans and construction of paper-based conductive materials

摘要:

以粉单竹为原材料，经碱提制备粉单竹木聚糖，利用乙酸酐/DMAP/LiCl均相体系乙酰化粉单竹木聚糖制备乙酰化木聚糖（AX），将其作为分散剂配制多壁碳纳米管（MWCNT）分散液涂布至纸张表面制备导电纸。基于1HNMR、GPC、XRD、纳米激光粒度仪、FESEM的表征的测试，考察乙酰基取代度（DSAC）对AX的MWCNT分散性能的影响，通过电化学工作站测试，评价导电纸的循环伏安（CV）、交流阻抗（EIS）、恒电流充放电（GCD）和循环稳定性等的电化学性能。结果表明，当DSAC＝0.296时，经AX4分散的质量浓度1 mg/mL的MWCNT分散液分散效率最高为64.4%，水合粒径最小为348.8 nm ；以AX4为分散剂配制的MWCNT分散液涂布的导电纸电导率最高为17.89 S/cm ，质量比电容为4.37 F/g，循环1000次后的比电容保留率为50%。

Abstract:

Acetylated xylans with degree of substitution (DS) of 0~0.34 were prepared by acetic anhydride/DMAP/LiCl homogeneous system. The acetylated xylans were used as dispersants to disperse multi-walled carbon nanotubes (MWCNT), and the MWCNT dispersions were coated on paper surface to fabricate paper-based conductive materials. The effects of DS on the MWCNT dispersing performance of xylans and the electrochemical performance of paper-based conductive materials were evaluated. The results show that when DS = 0.296, the acetylated xylan has the best performance in dispersing MWCNT, the dispersion efficiency reaches 64.4%, and the particle size is the smallest. When the DS of acetylated xylan is larger or smaller than 0.296, the dispersion efficiency decreases and the particle size of the dispersion increases, which is attributed to the balanced hydrophilic and hydrophobic properties of acetylated xylan with DS = 0.296 to achieve the effective dispersion of MWCNT. The paper-based conductive materials prepared by acetylated xylan/MWCNT dispersion coating have good electrochemical performance, with a conductivity of 17.89 S/m and a capacitance retention of 50% after 1000 cycles. The results of this work show that acetylated xylan has the potential to be used as a green dispersant to efficiently disperse MWCNT for the preparation of functional materials.