Smart heating profiles for the synthesis of benzene bridged periodic mesoporous organosilicas

In this study the effects of the heating rate and heating time on the formation of crystal-like benzene bridged periodic mesoporous organosilicas (PMOs) are investigated. The time needed to heat up an autoclave during the hydrothermal treatment has shown to be crucial in the synthesis of PMOs, while the total duration of heating gave rise to only minor differences. By choosing a smart heating profile, superior PMO materials can be obtained in a short time. Different heating profiles in a range from one minute to one hour are adopted by microwave equipment and compared with conventional heating methods. The heating rate has a large influence on the porosity characteristics and the uniformity of the obtained particles. Moreover, two new alternative synthetic strategies to adopt the smart heating profile are presented, in order to give some possible solutions for the expensive microwave equipment.

► The beneficial influence of microwave synthesis on porosity has been studied.
► No effect of microwave radiation, but the heating ramp is the key parameter.
► Heating ramps have also influenced on the morphology.
► Two alternative conventional approaches for high quality PMOs are given.