Abstract
Solvent transport across a hydrophobic PTFE membrane and the modified PTFE membranes was measured in water under a temperature difference. Moreover, thermoosmosis across the anion-exchange membrane, Neosepta AM-1, was measured for poly (acrylamide) and urea solutions. The direction of thermoosmosis across the PTFE and the modified PTFE membranes was from the hot side to the cold side, whereas that across anion-exchange membrane was from the cold side to the hot side. Thermoosmosis across the modified PTFE membranes decreased with increasing the hydrophilic groups in the membrane. For poly (acrylamide) and urea solutions the absolute values of volume fluxes decreased with increasing the concentration of the external solution, because of the decrease of the entropy difference of water between the membrane and the external solution.
