Ultrafiltration membrane is a microporous membrane with the same pore size and rated pore size in the range of 0.001-0.02 microns. By applying appropriate pressure on one side of the membrane, solute molecules smaller than the pore size can be screened to separate particles with a molecular weight greater than 500 Daltons (atomic mass unit) and a particle size greater than 10 nanometers. Ultrafiltration membrane is one of the earliest developed polymer separation membranes, and the ultrafiltration device was industrialized in the 1960s.
Reverse osmosis membrane is an artificial semi-permeable membrane with certain characteristics made by simulating biological semi-permeable membrane. Generally made of polymer materials. The diameter of the membrane pores is generally between 0.5 and 10 nm, and the permeability is related to the chemical structure of the membrane itself.