A drying process for wet silica-gels obtained from
tetramethylorthosilicate (TMOS) has been performed using
a variable frequency microwave oven (VFM). Comparative
analyses have been carried out using conventional, microwave
and critical point drying (CPD) processes to evaluate
the primary differences between these techniques. The
drying process using microwaves was governed by the
applied power and the frequency range. Furthermore,
the silica surface area, pore volume and pore size were
studied by applying the Barrett-Joyner-Halenda (BJH)
method and Scanning Electron Microscopy (SEM). Results
obtained using microwave drying show substantially reduced
processing times and suggest an influence of frequency
on the size, shape and volume of the porosity of the
resulting silica-gel.
