块状纤维素-SiO2复合气凝胶的常压制备及其表征

摘要

Cellulose-SiO2 composite hydrogel was prepared by combining the NaOH/thiourea/H2O solvent system, and the immersion method with controlling the hydrolysis-fasculation reaction speed of tetraethyl orthosilicate (TEOS). Cellulose-SiO2 composite aerogel was prepared by using the method of solvent displacement with alcohol and immersing with TEOS in the process of drying. When the hydrolysis pH was 3 and the volume of ammonia liquor was 8 mL, the composited efficiency of SiO2 was the highest. After composite of SiO2, the hydrophilicity of cellulose aerogel was reduced. In the structure of composite aerogel, TEOS was composited with cellulose in the shape of SiO2 spherical particle and silica aerogel layer. This work provided a effective and simple preparation method for bulk cellulose-SiO2 composite aerogel.%　　利用 NaOH/硫脲/H2O 体系作为溶剂，通过对正硅酸乙酯(TEOS)水解-缩聚反应速率的调控，采用浸泡法获得了纤维素-SiO2复合水凝胶。在水凝胶的干燥过程中，采用乙醇溶剂替换和 TEOS 溶液浸泡、陈化的方法，制备了纤维素-SiO2复合气凝胶。TEOS 水解 pH=3、缩聚反应氨水用量为8 mL 时，SiO2复合效率最高。在复合气凝胶的结构中，TEOS 以 SiO2球状颗粒及硅凝胶层的形式与纤维素气凝胶复合。研究为块状纤维素-SiO2复合气凝胶提供了一种有效、简单的制备方法。