Abstract:

Meso porous Carbon Materials are prepared by sol-gel polycondensation of resorcinol (R) and formaldehyde (F) catalyzed with different proportions of sodium carbonate followed by drying and carbonizing at N2 atmosphere at 900°C. These Carbon Materials, which are called carbon aerogel, receive high attention because of their high BET Surface Area (SBET), hierarchical pores, and high porosity in the last few years. The pore structure and final properties of these materials can be controlled by the concentration of reactants in initial solution, pyrolysis temperature, and drying method. The primary way for drying these materials is supercritical drying which is expensive and dangerous so in order to decrease the production expenses subcritical drying is favored. In this article, monolithic carbon aerogel is synthesized with different molar ratios of resorcinol to catalyst (R/C) and dried at ambient pressure. In order to minimize the volume shrinkage, solvent exchange was performed at 40°C for 3 days prior to drying. Scanning Electron Microscopy (SEM) combined with N2 adsorption desorption measurements are employed to study the microstructure of pores, surface area, and porosity of samples. Using a molar ratio of resorcinol to catalyst of 500 (R/C=500), monolithic carbon aerogel was synthesized with BET surface area of 750 m2g-1 and mean pore size of 6 nm. It is suggested to use this molar ratio of R/C to try to increase the pore volume of carbon aerogels through different drying methods.  

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