Fabrication of Organic-inorganic Composite Nanofiltration Membrane Based on PET Ion Track Membrane

Nanofiltration membranes are playing more and more important roles in the fields of sea water desalination and drinking water purification. The ion track membrane (ITM), as a kind of important separation membrane with uniform pore size, regulable pore density, and free-defect surface, has potential permission in water treatments and precise separation. The thin ITMs with high pore density as substrates have great potential in the preparation of high-performance nanofiltration membranes. Herein, we report a triple-layered organic-inorganic composite membrane with zirconia (ZrO₂) as a selective layer and polyethylene terephthalate ion track membrane (PET ITM) as support. The polydopamine (PDA)-polyethyleneimine (PEI) intermediate coating facilitates inorganic nanoparticles to form an inorganic layer on the membrane surfaces. The composite membrane can achieve partial rejection for various kinds of salts and exhibit a salt retention order of Na₂SO₄>MgSO₄>MgCl₂>NaCl.