微波辅助溶胶-凝胶法制备高比表面积SiO2气凝胶

Synthesis of high specific area silica aero-gels via microwave assist Sol-Gel method

摘要:

以四甲氧基硅烷(TMOS)为原料，三甲基氯硅烷(TMCS)为疏水改性剂，通过微波辅助溶胶-凝胶法制备SiO2气凝胶，用FTIR、SEM、XRD、BET以及TG-DSC对其结构进行表征。结果表明：微波辅助溶胶-凝胶法制得的SiO2气凝胶比表面积达1096 m2?g-1，SiO2气凝胶颗粒呈均匀分布，孔径主要分布在2～10nm之间；与水的接触角为141?，表现出良好疏水性；在空气中的耐温点达543℃，具有良好的热稳定性。

Abstract:

Using TMOS as silica sources, silica aero-gels were synthesized via microwave assist Sol-Gel method and were synthesized into hydrophobic silica aero-gels by the surface chemical modification of TMCS followed by ambient pressure drying technique. The structure, surface morphology, and chemical composition of the produced samples in the experiments were characterized by test methods, such as FTIR, SEM, XRD, BET and TG-DSC. The results showed that the produced samples are hydrophobic silica aero-gels with homogeneous distribution. The specific surface areas of the synthesized silica aero-gels via microwave assist Sol-Gel method is 1096m2?g-1, whose pore diameters mainly range from 2 to10 nm. The contact angle with water is 141?, which shows the super hydrophobic. The resistance temperature of the silica aero-gels are 543℃.The silica aero-gels has good thermal stability.