SiO_2/纤维素复合气凝胶的制备及性能研究

Preparation of SiO_2/cellulose composite aerogel and exploration of their property

采用纤维素为原料,氢氧化锂(LiOH)/尿素/水(H_2O)体系为溶剂,硅酸钠(Na_2SiO_3)为硅源,在纤维素凝胶骨架中原位合成纳米二氧化硅(SiO_2),制得SiO_2/纤维素复合气凝胶,并考察了SiO_2对其结构和性能的影响。结果表明,SiO_2/纤维素复合气凝胶不仅保持了纯纤维素气凝胶的骨架结构,同时SiO_2显著增加了气凝胶的比表面积,改善了力学性能,在SiO_2用量为47.27%(wt,质量分数)条件下,SiO_2/纤维素复合气凝胶的比表面积高达528m^2/g,压缩模量为6.18MPa。

SiO2/cellulose composite aerogels were prepared by in-situ formation of nano-silica（SiO2）in cellulose gel matrix using cellulose as the raw material,LiOH/urea/H2O system as the solvent and Na2SiO3 as the precursor.The effect of SiO2 on the structure and properties of aerogels were studied.The results showed that composite aerogels not only kept the porous structure of pure cellulose aerogel,but also increased the specific surface area of aerogels and improved their mechanical property.When the dose of SiO2 in composite aerogels was up to 47.27 wt%,the specific surface area was up to 528 m^2/g and the compressive strength was 6.18 MPa.