Hydrophilicity-controlled carbon aerogels with high mesoporosity.

Highly mesoporous carbon aerogels with hydrophilicity-controlled pore walls were synthesized using a unique approach that combines CO(2) supercritical drying and colloidal silica nanocasting. The samples were characterized using nitrogen adsorption at 77 K, water adsorption at 303 K, field-emission scanning electron microscopy (FE-SEM), thermogravimetric analysis, X-ray photoelectron spectroscopy, and Raman spectroscopy. The nitrogen adsorption revealed the presence of micropores and mesopores with narrow pore size distributions. The water adsorption suggested that the hydrophilicity of carbon aerogels can be controlled by the residual silica in their pore walls. The FE-SEM observation confirmed the presence of hierarchical mesostructures and the high mesoporosity. The high surface area, large nanopore volume, and hydrophilicity-controlled pore walls make these aerogels well-suited for many applications.