Synthesis of monolithic carbon aerogels with high mechanical strength via ambient pressure drying without solvent exchange
来源期刊：JOURNAL OF MATERIALS SCIENCE TECHNOLOG2020年第15期
论文作者：Zhi Yang Jian Li Xiaojing Xu Shengyang Pang Chenglong Hu Penglei Guo Sufang Tang Hui-Ming Cheng
文章页码：66 - 74
摘 要：A simple,fast and cost-effective method for monolithic carbon aerogels（CAs） preparation was proposed through sol-gel polycondensation of resorcinol with fo rmaldehyde in a basic aqueous solution followed by ambient pressure drying without solvent exchange,and carbonization.The microstructure and network strength of CAs were tailored by adju sting the catalyst concentration（[resorcinol]/[sodium carbonate] in the range of 300-2000）,water content（[deionized water]/[resorcinol] equals to 17 and 24,respectively）,and gelation temperature(Tgel in the range of 30-90℃).Resultantly,the CAs with a wide range of density（0.30-1.13 g/cm3）,high specific surface area（465-616 m2/g）,high compressive strength（6.5-147.4 MPa）and low thermal conductivity(0.065-0.120 W·m-1 K-1) were obtained in this work.Moreover,the largesized CAs（100×100×20 mm3） can also be prepared by this method since the formed robust skeleton network can resist shrinkage/collapse of pore structure and prevent cracking during drying.The improved mechanical strength and monolithic forming abilities could be mainly attributed to the uniform arrangement of carbon particles and pores,fine particle size,abundant network structure and enhanced particle neck.
Zhi Yang1,2，Jian Li1，Xiaojing Xu3，Shengyang Pang1，Chenglong Hu1，Penglei Guo1,2，Sufang Tang1，Hui-Ming Cheng1
1. Institute of Metal Research, Chinese Academy of Sciences2. School of Materials Science and Engineering, University of Science and Technology of China3. Aerospace Business Department, China Academy of Launch Vehicle Technology
摘 要：A simple,fast and cost-effective method for monolithic carbon aerogels（CAs） preparation was proposed through sol-gel polycondensation of resorcinol with fo rmaldehyde in a basic aqueous solution followed by ambient pressure drying without solvent exchange,and carbonization.The microstructure and network strength of CAs were tailored by adju sting the catalyst concentration（[resorcinol]/[sodium carbonate] in the range of 300-2000）,water content（[deionized water]/[resorcinol] equals to 17 and 24,respectively）,and gelation temperature(Tgel in the range of 30-90℃).Resultantly,the CAs with a wide range of density（0.30-1.13 g/cm3）,high specific surface area（465-616 m2/g）,high compressive strength（6.5-147.4 MPa）and low thermal conductivity(0.065-0.120 W·m-1 K-1) were obtained in this work.Moreover,the largesized CAs（100×100×20 mm3） can also be prepared by this method since the formed robust skeleton network can resist shrinkage/collapse of pore structure and prevent cracking during drying.The improved mechanical strength and monolithic forming abilities could be mainly attributed to the uniform arrangement of carbon particles and pores,fine particle size,abundant network structure and enhanced particle neck.
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