Control of the porous structure and the surface property of resorcinol – Acetaldehyde carbon cryogels

Mesoporous carbon material enables material transfer more easily than that of microporous carbon material such as activated carbon and has a high porosity and effective surface area. The application for the separation material, the absorbent, the catalyst support and the electrode medium of electric double layer capacitor are expected for the mesoporous material. This study attempted to prepare the mesoporous carbon material. Resorcinol (R) as a raw material and acetaldehyde (A) as a cross-linking agent were used to synthesize the RA hydrogels via the sol-gel polycondensation in a slightly basic aqueous solution. The RA hydrogels were freeze-dried and subsequently pyrolyzed at 1073 K for 30 min (at a hearting rate of 10 K/min) to obtain the RA carbon cryogels. This study attempted to control the surface properties of RA carbon cryogels by varying the constituent ratio of precursor solution and pH of RA aqueous solution at the acid treatment to promote the formation of secondary particle of RA hydro gels. The pore structure of RA carbon cryogels depended on the constituent ratio of precursors and pH of RA solution, probably due to the variation of the subsequent gel particle size. The carbon gels prepared in this study were mesoporous materials with a modal diameter of 20 nm.