Method for preparing porous symmetrical polymer membrane by delayed phase inversion method and membrane distillation application thereof

The invention discloses a method for preparing a porous symmetric polymer membrane by a delayed phase inversion method and membrane distillation application thereof, and the method is characterized in that the membrane surface is covered with a non-woven fabric, an interlayer is established to slow down the exchange rate of a solvent and a non-solvent instead of changing the components of the solvent/non-solvent or adding a pore-forming agent, and the membrane distillation efficiency is improved. Therefore, the polymer film has a symmetrical structure of integral spongy pores. The prepared porous symmetrical polymer membrane has high surface porosity and overall pore permeability, and the permeability of the membrane can be greatly improved. 本发明公开了一种延迟相转化法制备多孔对称聚合物膜的方法及其膜蒸馏应用，该方法通过在膜表面覆盖无纺布，建立隔层减缓溶剂与非溶剂的交换速率，而非改变溶剂/非溶剂的组分或添加造孔剂，使聚合物膜具有整体海绵状孔的对称结构。制备的多孔对称聚合物膜具有高表面孔隙率和整体孔通透性，能够大幅度提高膜的渗透性能。