Fabrication of composite nanofiltration membranes by dopamine-assisted poly(ethylene imine) deposition and cross-linking

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• 作者：Pei-bin Zhang ; Cui-jing Liu ; Jian Sun…
• 关键词：Key wordsDopamine (DA) ; Poly(ethylene imine) (PEI) ; Co ; deposition ; Nanofiltration (NF) membranes ; Cross ; linking
• 刊名：Journal of Zhejiang University-SCIENCE A
• 出版年：2017
• 出版时间：February 2017
• 年：2017
• 卷：18
• 期：2
• 页码：138-150
• 全文大小：
• 刊物类别：Engineering
• 刊物主题：Mechanical Engineering; Civil Engineering; Classical and Continuum Physics; Industrial Chemistry/Chemical Engineering;
• 出版者：Zhejiang University Press
• ISSN：1862-1775
• 卷排序：18

文摘

Positively charged composite nanofiltration (NF) membranes with good stability were prepared by dopamine (DA) assisted poly(ethylene imine) (PEI) deposition on a polysulfone ultrafiltration (UF) substrate followed by a cross-linking step. Attenuated total reflectance Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, scanning electronic microscopy, and atom force microscopy were employed to characterize the surface chemistry and morphology of the obtained composite membranes. The DA and PEI co-deposition conditions were optimized based on knowledge of the co-deposition mechanism. The effects of the cross-linker concentration, cross-linking time, and reaction temperature on the permeation and separation properties of the prepared composite membranes were investigated in detail. Under optimized conditions, the MgCl₂ rejection and permeation flux of the composite membrane reached 80.4% and 19.6 L/(m2·h), respectively (the feed was 0.01 mol/L of MgCl₂ solution under a test pressure of 0.4 MPa). The rejection of various salts followed the order MgCl₂≈CaCl₂>MgSO₄>NaCl>Na₂SO₄, suggesting the membranes were positively charged. The composite membranes showed good durability under alkaline aqueous conditions. This study provided new insights into the fabrication of mussel-inspired thin-film composite nanofiltration membranes.