High-performance membranes with full pH-stability

Abstract

Following current strong demands from, among others, paper, food and mining industries, a novel type of nanofiltration membrane was developed, which displays excellent performance in terms of selectivity/flux with a unique combination of chemical stability over the full (0–14) pH-range and thermal stability up to 120 °C. The membrane consists of polyvinylidene fluoride grafted with polystyrene sulfonic acid. The optimum membrane showed water permeances of 2.4 L h⁻¹ m⁻² bar⁻¹ while retaining NaCl, MgSO₄ and Rhodamine B (479 Da) for respectively ≈60%, ≈80% and >96%.