摘要
提出了一种酸催化制备间苯二酚-甲醛/二氧化硅复合气凝胶的方法,产物经碳化后得到碳/二氧化硅复合气凝胶。利用模板限制的镁热反应法,在低温(700℃)下将C/SiO2气凝胶转化为纳米SiC气凝胶,并讨论了SiC的镁热反应机制。利用X射线衍射(XRD)、扫描电子显微镜(SEM)、傅里叶红外光谱(FTIR)、拉曼光谱(Raman)和比表面积分析(BET)等测试技术对样品进行了表征。结果表明,产物由立方相SiC纳米晶组成,保留了与原始气凝胶模板相似的微观形貌,表观密度约为130mg/cm3,比表面积约为230m2/g。这种模板限制反应法适用于多种碳/过渡金属氧化物复合气凝胶向碳化物纳米泡沫材料的低温转化,将有利于激光惯性约束核聚变实验用靶的应用研究。
Time-efficient synthesis of resorcinol-formaldehyde/silica composite（RF/SiO2） aerogels was carried out by using acids as catalysts.RF/SiO2 aerogels were pyrolyzed to C/SiO2 aerogels at high temperature.SiC aerogels were successfully converted from C/SiO2 aerogels by a template-confined magnesiothermic reaction at low temperature（700 ℃）.The samples were characterized by XRD,SEM,Raman,FTIR and BET.The results suggest that the products consist of nanocrystalline silicon carbide,and maintain 3D porous network as similar as that of original templates.They possess a bulk density of 130 mg/cm～3 and a specific surface area of 230 m～2/g.Potentially,the proposed method could be expanded to convert other carbon/metal or semimetal oxide aerogels to carbide aerogels,which could be benefit for investigation of ICF experimental targets.
出处
《原子能科学技术》
EI
CAS
CSCD
北大核心
2012年第7期855-860,共6页
Atomic Energy Science and Technology
基金
教育部新世纪优秀人才支持计划资助项目(NCET-08-0405)
国家自然科学基金资助项目(50802064,51172163)
关键词
碳化硅
气凝胶
模板限制
镁热
低温
silicon carbide； aerogels template-confined； magnesiothermic； low tempera-ture
