Abstract
Pressure loss in gas flow in three-dimensionally interconnected macropores in silica gel rods was investigated. In the preparation of the silica gel, the continuous macropores are formed by inducing phase separation in a solution containing tetraethoxysilane (TEOS) and poly (ethylene oxide) (PEO), and subsequent freezing of its transitional structures by gelation. Average macropore size of the silica gels was systematically controlled from 25 to 0.6 μm by changing PEO content in the solution without affecting porous morphology. The pressure loss in gas flow in the continuous macropores can be approximated with a simple straight channels model, and well reproduced with the Hargen–Poiseuille’s equation without any correction, in contrast to that in columns packed with micrometer-size particles, which show substantial higher pressure loss than the continuous macropores. The low flow resistance in the macroporous silica rods would be attributed to the absence of necks in flow pathways.
