Reverse osmosis membrane is the core element to realize reverse osmosis, and it is an artificial semi-permeable membrane with certain characteristics made by simulating biological semi-permeable membrane. Generally made of polymer materials. Such as cellulose acetate film, aromatic polyhydrazide film, aromatic polyamide film. The diameter of the surface micropores is generally between 0.5 and 10 nm, and the permeability is related to the chemical structure of the membrane itself. Some polymer materials have good repellency to salt, but the water penetration rate is not good. The chemical structure of some polymer materials has more hydrophilic groups, so the water permeation rate is relatively fast. Therefore, a satisfactory reverse osmosis membrane should have an appropriate amount of permeation or salt rejection rate.
