Role of Water as a Coporogen in the Synthesis of Mesoporous Poly(divinylbenzenes)

The morphology of mesoporous poly(divinylbenzenes) prepared under so called "hydrothermal" conditions and with the monomers diluted in 10 times as much porogen solvent (tetrahydrofuran with 0-20% water) was studied in both dry and swollen states, with nitrogen adsorption/desorption and inverse steric exclusion chromatography, respectively. It was found that the pore volume in the polymer examined just after preparation corresponded to the volume of the porogen used. Such a high porosity can be explained only on the basis of pore formation through microsyneresis rather than the macrosyneresis mechanism that is common in the synthesis of conventional porous polymer materials. Naturally, drying induces a pore collapse and the addition of water to the porogen influences the ability of the polymer to regain the original pore volume by reswelling in tetrahydrofuran. (C) 2014 Wiley Periodicals, Inc.