疏水纳米纤维素气凝胶的制备及保温隔热性能

Preparation and thermal insulation performance of hydrophobic nanocellulose aerogels

针对废旧纯棉织物再利用率较低的问题,以废旧纯棉织物为原料制备纳米纤维素气凝胶,并分别采用甲基三甲氧基硅烷(MTMS)和三甲基氯硅烷(TMCS)为改性剂对气凝胶进行疏水改性。采用扫描电子显微镜红外光谱仪热重分析仪、表面接触角测试仪以及导热系数测试仪研究了疏水改性剂种类和添加量对气凝胶结构和性能的影响。结果显示,采用MTMS为改性剂制备的疏水纳米纤维素气凝胶的结构和性能优于TMCS。综合考虑MTMS添加量对气凝胶结构、疏水性、热稳定性和保温隔热性的影响,得出MTMS与CNF的最佳质量比为2:1,此时疏水气凝胶的结构比较平整均匀,疏水性、热稳定性分别增加了1.22倍和1.43倍,导热系数降低了12.3%。

According to the problem of low reuse rate of waste cotton fabric,nanocellulose aerogels are prepared from waste cotton fabric and hydrophobic modified by using MTMS and TMCS as modifiers respectively.The effect of hydrophobic modifer type and addition amount on the structure and properties of aerogels is studied by scanning electron microscope,infrared spectrometer,thermogravimetric analyzer,surface contact angle tester and thermal conductivity tester.The results show that the structure and properties of the hydrophobic nanocellulose aerogels prepared by using MTMS as modifer are better than those of TMCS.Considering the effects of the amount of MTMS on aerogel structure,hydrophobicity,thermal stability and thermal insulation,the optimum mass ratio of MTMS to CNF is 2:1.The hydrophobic and thermal stability of the corresponding hydrophobic aerogelsincrease by 1.22 and 1.43 times respectively,and the thermal conductivity decreases by 12.3%.