Drying of meso- and macroporous gels—Length change and drying dynamics

Ambient pressure drying of meso- and macroporous gels with high porosity and low stiffness of their backbone induces significant shrinkage of the sample that is accompanied by the development of cracks, if the drying rate and conditions are not well adjusted. We investigated the drying behavior of organic gels with a porosity of about 80–85% with a setup that allows in situ monitoring of the linear length change of the sample. The parameters varied were the purge flow rate, pore liquid, pore size of the gel and its aging time at room temperature prior to drying. The dried samples were characterized with respect to their density, specific surface area and Young's modulus.