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Reports on the production of carbon aerogels from a solution of poly(vinyl chloride) (PVC) through a novel method in which the sol-gel transformation has been carried out based on dehydrochlorination using a strong organic base. Advantages of this method over the classical one are the wider controllable range of porous structure and the shorter preparation period due to the avoidance of the solvent exchange process prior to the supercritical drying; Conversion of the PVC-based organic aerogels into the carbon aerogels without causing large mass loss and fusion; Application of a stabilization treatment prior to carbonization.

Organic aerogels were derived from dimethylformamide solution of poly(vinyl chloride) (PVC) via dehydrochlorination using a strong base, 1,8-diazabicyclo[5,4,0]undec-7-ene, and supercritical drying using carbon dioxide. From these organic aerogels, carbon aerogels were yielded via stabilization and carbonization. Changes in the porous structure of the aerogels during the preparation process and influences of the preparation conditions on the porous structure were investigated. The framework of the aerogels composed the walls of the meso- and macropores. The volume and the size of these pores were reduced during stabilization and carbonization due to the shrinkage of the framework caused by the release of decomposition gases and densification of the material. Simultaneously, the release of decomposition gases produced additional micropores. The extent of dehydrochlorination, the concentration of PVC in the starting solution and the molecular weight of PVC were the factors with which the porous structure of the aerogels could be controlled over a wide range. In addition, the stabilization conditions notably influenced the carbonization behavior of the organic aerogels and the porous structure of the carbon aerogels. The optimum stabilization conditions that minimized the loss of mass and maximized the pore volume of the carbon aerogels were determined. [Copyright &y& Elsevier]