The effect of surfactants on carbon xerogel structure and CO2 capture

Abstract

Porous carbon xerogels were successfully fabricated by carbonization of resorcinol-formaldehyde-phloroglucinol gels in the presence of surfactants. The effect of non-ionic, cationic, anionic and zwitterionic surfactants on the porous structure of carbon xerogels was investigated. Micropore structural carbon xerogels were obtained when a cationic surfactant was used. The result of surface tension test showed the non-ionic surfactant Tween 60 gave the lowest surface tension. Thermal conductivity experiments revealed the carbon xerogels in this work possessed low thermal conductivity and are suitable as thermal insulation materials. The pore size directly determined the thermal conductivity of carbon xerogels, and the thermal conductivity decreased with pore size. Among the obtained samples, the one using hexamethylenetetramine (HTM) exhibited the highest CO2 adsorption capacity (2.89 mmol g−1) and adsorption selectivity as a result of the high microporosity (88.0%). Therefore, HTM-CA was identified as a promising material for CO2 adsorption.