Carbon spheres were synthesized by emulsion polymerization and pyrolysis of polyfurfuryl alcohol. Pluronic F-127 was used as the structure-directing agent to synthesize polymer spheres that after pyrolysis led to carbon spheres with average sizes from 50 nm to few micrometers in diameter depending upon the conditions of polymerization. As-synthesized carbon spheres possess high surface areas of around 480 m2/g with an average mean pore size of 0.5 nm. These spheres can be activated using carbon dioxide to create much higher surface areas (>1500 m2/g). Different compositional regions of the pseudo-ternary phase diagram of surfactant/monomer/solvent were explored in order to determine the effects of changes in the emulsion polymerization variables on the kinds of carbon morphologies that could be derived from polyfurfuryl alcohol after pyrolysis. The diameter of the carbon spheres was found to be sensitive to monomer and surfactant concentrations, acid molarity and solvent composition. In general, the diameter of the spheres grew with increasing furfuryl alcohol concentration and decreasing surfactant concentration, respectively. By varying the acid concentration and solvent composition, a minimum diameter for spheres was found. The formation and size of the spheres are strongly influenced both by micelle growth and the polymerization mechanism.
All Science Journal Classification (ASJC) codes
- Materials Science(all)