Influence of nonionic surfactant concentration on physical characteristics of resorcinol-formaldehyde carbon cryogel microspheres

Carbon cryogel microspheres (CC microspheres) are unique porous carbon particles that are synthesized by the inverse emulsion polymerization of a resorcinol-formaldehyde (RF) aqueous solution, followed by freeze-drying and pyrolysis in an inert atmosphere. The effects that the concentration of the nonionic surfactant (SPAN80) used in the inverse emulsion polymerization have on the porous properties of both CC microspheres and their carbon precursors, RF cryogel microspheres (RC microspheres), were studied. The effect of the concentration of SPAN80 on the particle size distributions of the the RC and CC microspheres was also investigated. The mesopore sizes and the mesopore volumes of the RC and CC microspheres increased upon decreasing the concentration of SPAN80. By varying the SPAN80 concentration, the peak radius of the mesopore size distribution of both the RC and CC microspheres can be controlled. The particle sizes of the RC and CC microspberes increased upon increasing the SPAN80 concentration.