Novel Poly(ester amide) Membranes with Tunable Crosslinked Structures for Nanofiltration

Hao Zhang; Fei Xie; Zhang Zhao; Noor Ul Afsar; Fangmeng Sheng; Liang Ge; Xingya Li; Xiwang Zhang; Tongwen Xu

doi:10.1021/acsami.1c21862

Novel Poly(ester amide) Membranes with Tunable Crosslinked Structures for Nanofiltration

ACS Appl Mater Interfaces. 2022 Mar 2;14(8):10782-10792. doi: 10.1021/acsami.1c21862. Epub 2022 Feb 21.

Authors

Hao Zhang^{1

2}, Fei Xie³, Zhang Zhao², Noor Ul Afsar², Fangmeng Sheng², Liang Ge², Xingya Li², Xiwang Zhang^{1

4}, Tongwen Xu²

Affiliations

¹ Department of Chemical Engineering, Monash University, Clayton, Victoria 3800, Australia.
² Anhui Provincial Engineering Laboratory of Functional Membrane Materials and Technology, Department of Applied Chemistry, School of Chemistry and Materials Science, University of Science and Technology of China, Hefei 230026, P. R. China.
³ Shanghai Key Laboratory of Multiphase Materials Chemical Engineering, Membrane Science and Engineering R&D Laboratory, Chemical Engineering Research Center, School of Chemical Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, P. R. China.
⁴ School of Chemical Engineering, The University of Queensland, Brisbane, Queensland 4072, Australia.

PMID: 35188363
DOI: 10.1021/acsami.1c21862

Abstract

Tuning the crosslinking density of interfacial-polymerized nanofiltration (NF) membranes varying from loose to dense structures can make them meet the demand of various applications. The properties (e.g., pore size and porosity) of NF membranes can be tuned by choosing monomers with different structures and reactivities. Herein, tris(hydroxymethyl)aminomethane (THAM), a low-cost and green monomer, is first employed for the preparation of poly(ester amide) (PEA) thin-film composite membranes via interfacial polymerization. The moderate reactivity of THAM enables rational regulation of the crosslinking density of PEA membranes from loose to dense structures by varying the THAM concentration, which can hardly be achieved for traditional polyamide or polyester membranes. The developed PEA membranes with a wide tunability range of crosslinking densities broaden their potential utility in NF. PEA membranes with dense structures show exceptional desalination performance with a water permeance of 11.1 L m^-2 h^-1 bar^-1 and a Na₂SO₄ rejection of 97.1%. However, loose PEA membranes exhibit good dye/salt separation performance with a dye removal rate over 95.0% and negligible NaCl rejection (<7.5%), as well as high water permeance (>45 L m^-2 h^-1 bar^-1). This work implies that PEA membranes with tunable crosslinked structures provide new possibilities for the development of task-specific separation membranes.

Keywords: crosslinking density; desalination; dye/salt separation; interfacial polymerization; nanofiltration; poly(ester amide).