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Surface coating of polyamide reverse osmosis membranes with zwitterionic 3‐(3,4‐dihydroxyphenyl)‐ l ‐alanine ( l ‐DOPA) for forward osmosis
Author(s) -
Saki Seda,
Uzal Nigmet
Publication year - 2020
Publication title -
water and environment journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.437
H-Index - 37
eISSN - 1747-6593
pISSN - 1747-6585
DOI - 10.1111/wej.12475
Subject(s) - membrane , polyamide , contact angle , forward osmosis , chemistry , permeability (electromagnetism) , thin film composite membrane , chemical engineering , chromatography , fouling , reverse osmosis , surface modification , nuclear chemistry , polymer chemistry , biochemistry , engineering
To overcome low permeability and fouling problems of membranes used in FO processes, modification is needed to improve the hydrophilicity, permeability and selectivity of membranes. In this work, thin film composite (TFC) commercial polyamide RO membranes (BW30‐LE, SW30‐HR, AG and AC) were functionalized with zwitterionic l ‐DOPA. The effect of l ‐DOPA on the morphology of membranes was determined via SEM, FT‐IR, AFM and contact angle analysis. The l ‐DOPA modified BW30‐LE membrane showed excellent properties with 46° contact angle and 3.8 L/m 2 hbar water permeability and 0.83 L/m 2 h salt permeability. Although, l ‐DOPA modified BW30‐LE membrane had the highest water flux and hydrophilicity, l ‐DOPA modified SW30‐HR membrane showed higher FO flux with 9.38 L/m 2 h than BW 30 membrane with 3.5 L/m 2 h at 50 g/L NaCl draw solution. Introducing hydroxyl and carboxyl ionic groups on the membrane surface with l ‐DOPA coating enhanced the FO performance and water permeability which provide a new insight in FO applications.