Yutaka Taketani

Reverse osmosis membranes from aromatic polymers

Abstract A new reverse osmosis membrane composed of the following aromatic polymer containing benzimidazolone ring was studied. Lonsdales permeability parameters of PBIL (e.g., P1/P2 = 21.3 × 103 g/cm3) show its excellent potential as permselective membrane material. Asymmetric membranes were successfully prepared from PBIL by the conventional phase-inversion method. A typical example of the basic membrane performances is as follows; water flux, 35 l/m2 h and salt rejection, 99.5% determined under the pressure of 80 kg/cm2 using 1% NaCl solution at 36°C. The PBIL membrane was characterized by its excellent chemical and thermal resistances, especially against acid, alkali and the oxidative atmospheres. These features suggest that the PBIL membrane is a promising candidate for one-stage sea water desalination.