无表面活性剂微乳液体系双甲基增强硅气凝胶的制备与性能研究

Preparation and Properties of Bimethyl-Reinforced Silicon Aerogels Based on Surfactant-Free Microemulsions

硅气凝胶是由SiO_(2)粒子相互聚合组成的一种新型多孔功能材料,以水/乙醇/正己烷无表面活性剂微乳液体系为溶剂,采用酸碱两步溶胶-凝胶法在无需溶剂替换和表面改性的前提下制备无表面活性剂微乳液体系双甲基增强硅气凝胶。采用SEM、FT-IR、BET和接触角等手段对所得样品进行表征,确定增强相二甲基二乙氧基硅烷的最适添加量。结果表明:当二甲基二乙氧基硅烷添加量为0.08 mol时,无表面活性剂微乳液体系双甲基增强硅气凝胶的密度为0.157 g/cm^(3),孔隙率为93%,BJH平均孔径3.92 nm,疏水角为152.5°。

Silica aerogel is a new type of porous functional material composed of SiO_(2)particles polymerized with each other,using water/ethanol/n-hexane surfactant-free microemulsion system as solvent,using acid-base two-step sol-gel method to prepare dimethyl-enhanced silicon aerogel without solvent replacement and surface modification.The obtained samples were characterized by SEM,FT-IR,BET and contact angle to determine the optimal dosage of dimethyldiethoxysilane in the enhanced phase.The results showed that when the addition of dimethyldiethoxysilane was 0.08 mol,the density of the dimethyl-enhanced silicon aerogel without surfactant microemulsion was 0.157 g/cm^(3),the porosity was 93%,the average pore size of BJH was 3.92 nm,and the hydrophobic angle was 152.5°.