Polyarylether membranes for dehydration of ethanol and methanol via pervaporation.

Pervaporation membranes made from polyethersulfone (PESU), polyphenylsulfone (PPSU), polytrimethylphenylethersulfone (T-PESU) and hydrophilic PESU-co-Pluronic (H-PESU) polymers were evaluated for dehydration of ethanol and methanol. Fundamental characteristics of pore structure, free volume, d-spacing, water contact angle, water and ethanol uptakes were investigated and correlated with their dehydration performance. The H-PESU membrane shows the best ethanol dehydration performance due to its synergetic combination of the strengths from both rigid hydrophobic PESU and flexible hydrophilic Pluronic moieties. It has the highest water permeability of 0.322 mg m −1  h −1  kPa −1 which is 2–6 times higher than other three membranes because the hydrophilic Pluronic moiety may form special water transport channels. It also has a comparable mole-based selectivity of 685 due to the rigid hydrophobic PESU moiety that prevents the membrane from uncontrolled swelling. Long-term tests evidence the operating stability of both H-PESU and PESU membranes. In addition, the methanol dehydration performance of these membranes is superior to the other reported polymeric membranes. The water in the permeate can be concentrated to 86.8%. These promising preliminary results suggest that these polyarylether (PAE) membranes have great potential for ethanol and methanol dehydration. [ABSTRACT FROM AUTHOR]