Fabrication and structure of carbon aerogel spheres prepared by inverse suspension/emulsion polymerization and ambient pressure drying

摘要

Carbon aerogel (CA) spheres were fabricated by inverse suspension polymerization of an emulsified resorcinol-formaldehyde aqueous solution with a basic surfactant used as catalyst, and then drying by gradually heating the resultant sol-gel spheres at ambient pressure. The fabrication conditions, nanostructures of the resultant CA spheres, and their electrochemical properties were investigated. By controlling the time at which stirring started, the stirring speed, and the recipe of the emulsion solution, the diameter of the CA spheres can be controlled from 70 to 1000 pm. The internal carbon nanoparticles of the spheres are of a size ranging from 20 to 40 nm, and are interconnected into a three-dimensional network. The highest surface area and mesopore volume of the spherical CAs thus prepared reach 626 m(2)/g and 0.69 cm(3)/g, respectively. These CAs can be used as an electrode in supercapacitors, and the specific capacitance is as high as 197 F/g. (c) 2007 Wiley Periodicals, Inc.