Novel synthesis route of metal doped resorcinol–formaldehyde polymer xerogels with tuned porosity

Abstract

The complex preparation route of resorcinol–formaldehyde (RF) organogels offers several opportunities for developing metal-containing mesoporous carbon gels. Incorporation of the metal during the sol–gel stage, however, is not always trivial because it can inhibit the polycondensation reaction. A new route is proposed to circumvent this difficulty in the case of molybdenum. We show that a long enough pre-polymerization period (PP) (minimum 110min in our case) before adding the metal salt yields a mesoporous polymer monolith. Scanning electron microscopy (SEM), low temperature N2 adsorption and small angle X-ray scattering (SAXS) investigations reveal how changing the PP modifies the structure at various length scales. Adjusting the PP offers a new means of tuning the mesoporosity of the resulting molybdenum-containing RF gels.