Advantages of microwave-assisted synthesis of silica gels

Abstract The sol-gel process is a commonly used methodology for producing silica gels with tailored textural properties. However, the full conventional procedure involves several steps and is complicated and time-consuming, preventing production on a large scale. In the present study, as a more practical approach, microwave heating was applied via the acid-base synthesis of different precursor mixtures. By evaluating the effect of microwaves at each synthesis step, optimal pathways were established resulting in considerable time-saving. Mesoporous gels with porosities of around 70 per cent were obtained with a reduction in time consumption of more than 90 per cent compared to conventional methods. Strict control of the production stages has led to a much better understanding of the contribution of each stage to the overall process, making it possible to much more accurately evaluate the effects of applying microwave technology on the final properties of the materials with a view to optimizing their production.