Transport of liquid and supercritical CO₂ and selected organic solvents through surface modified mesoporous γ-alumina and titania membranes

The permeation of liquid and supercritical CO₂ and the organic solvents toluene, heptane, and 1-propanol were investigated in unmodified hydrophilic and modified hydrophobic mesoporous γ-alumina and titania tubular ceramic membranes. These ceramic membranes are solvent resistant, thermally stable, and hydrophilic in nature. Viscosity-corrected solvent flux was used to evaluate the applicability of Darcy’s law, which is governed by convective transport. The permeability coefficients were dependent on solvent type due to unique solvent–membrane interactions, which is a deviation from Darcy’s law. Surface chemistry of modified membranes was evaluated using contact angle measurements, Fourier Transform Infrared Spectroscopy, Scanning Electron Microscopy, and Energy Dispersive X-ray Spectroscopy.