Highly Permeable Reverse Osmosis Membranes via Molecular Layer-by-Layer Deposition of Trimesoyl Chloride and 3,5-Diaminobenzoic Acid
William D. Mulhearn, Christopher Stafford
We present a series of highly cross-linked polyamide membranes, synthesized via molecular layer-by- layer (mLbL) deposition of trimesoyl chloride (TMC) and 3,5-diaminobenzoic acid (BA). These membranes exhibit superior sodium chloride rejection compared to previously reported membranes of the same chemistry prepared via interfacial polymerization, with the improved performance of the mLbL films attributable to a higher cross-link density facilitated by the stepwise deposition process in good solvents. These mLbL TMC-BA membranes exhibit thickness-dependent transport properties with respect to water and salt, consistent with gradual tightening of the polyamide network during film growth. Finally, the TMC-BA membranes are systematically compared with membranes synthesized from TMC and m-phenylenediamine (MPD), the more conventional chemistry employed in commercial reverse osmosis membranes. We demonstrate that the mLbL TMC-BA membranes exhibit nearly 50 % greater water permeability than mLbL TMC-MPD membranes when both membranes are prepared at the minimum thickness capable of 90 % NaCl rejection.
and Stafford, C.
Highly Permeable Reverse Osmosis Membranes via Molecular Layer-by-Layer Deposition of Trimesoyl Chloride and 3,5-Diaminobenzoic Acid, ACS Applied Polymer Materials, [online], https://doi.org/10.1021/acsapm.0c01199, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=931032
(Accessed October 19, 2021)