溶胶凝胶法制备SiO2/活性炭复合材料及其吸波性能研究

以正硅酸乙酯为硅的前驱体、活性炭为基体,通过溶胶凝胶反应制备SiO2/活性炭复合材料;以XRD,SEM,BET以及电磁参数测定等手段,对SiO2/活性炭复合体的孔隙结构、电阻率、以及电磁参数等性质进行表征.实验结果表明,活性炭与正硅酸乙酯混合后,经过溶胶凝胶反应,SiO2与活性炭形成结构均一的复合物,且溶胶凝胶温度较低时,反应速度较慢,生成的SiO2颗粒较小、分布较均匀.通过改变SiO2的质量分数量,可以改变SiO2/活性炭复合材料的电磁参数,进而影响其对电磁波的吸收性能,当SiO2质量分数为12%时,复合材料有最佳吸波性能.

Preparation of Active Carbon/SiO2 Composites in Sol-Gel Method and Its Microwave Absorption

SiO2/AC composites were prepared in sol-gel method with tetraethoxysilane (TEOS) as the precursor and active carbon (AC) as the carbon resource. XRD, SEM, BET and electromagnetism parameter analyses showed that the structures, electrical conductivity and electromagnetism parameter varied with the content of SiO2 in SiO2/AC composites, and the microwave absorption could be improved with SiO2 content. It has been found that the active carbon and TEOS will form a homogeneous mixture formation through sol-gel method, the reaction velocity is slower and the generated SiO2 particles are smaller when the temperature is low. The electromagnetic parameters and electromagnetic wave absorption properties of SiO2/AC composites will change if the content of SiO2 is changed. When the content of SiO2 is 12%, the absorption property is the best.