I have a question about membrane distillation. I have read the following from a review paper about membrane distillation: The membrane distillation should be applied for membrane operations having the following characteristics: - The membrane should be porous. - The membrane should not be wetted by the process liquids. In other words, this membrane has to be hydrophobic. However, I don't think the membrane distillation has to be hydrophobic, except for direct contact membrane distillation...A hydrophilic membrane can be applied to air gas MD, sweeping gas MD and vacuum MD, correct? Or there is any reason that hydrophilic membrane won't work.