梯度气凝胶的孔结构

Pore Size of Gradient Aerogels

采用间苯二酚和糠醛作原料,以氢氧化钠为催化剂,通过溶胶-凝胶工艺制备出了梯度气凝胶。利用光学显微镜、扫描电镜、透射电镜及比表面和孔径分析仪等对反应体系的溶胶-凝胶过程及气凝胶的结构进行表征。讨论了不同温度、溶剂、反应物的质量分数等工艺参数对梯度气凝胶孔结构的影响。结果表明,沉降平衡使反应体系的溶胶产生浓度梯度,进而使气凝胶具有梯度结构。通过控制各种工艺参数来改变胶粒的沉降时间及沉降速度,可以使气凝胶的孔径梯度在0.01nm-8.9nm范围内发生改变。

Using NaOH as catalyzer, gradient aeroge/s were prepared via sol-gel polymerization with resorcinol and furfural. The sol-gel process and aerogel structure were investigated by optical microscopy, scanning electron microscope （SEM）, transmission electron microscope （TEM） and surface area and pore size analyzer. The impacts of temperature,solvent,mass content of reactants on pore structure of gradient aerogel were discussed particularly. The results showed that sedimentation equilibrium make sol forming concentration gradient, and the aerogels will have gradient structure. Pore size gradient of aerogel has been changed from 0.01 nm to 8.9 nm by controlling parameters to change sedimentation time and velocity of colloid particles.