Ang Micah Belle Marie Yap, Lau Victor Jr, Ji Yan-Li, Huang Shu-Hsien, An Quan-Fu, Caparanga Alvin R, Tsai Hui-An, Hung Wei-Song, Hu Chien-Chieh, Lee Kueir-Rarn, Lai Juin-Yih
R&D Center for Membrane Technology, Department of Chemical Engineering, Chung Yuan University, Taoyuan 32023, Taiwan.
School of Chemical Engineering and Chemistry, Mapúa University, Manila 1002, Philippines.
Polymers (Basel). 2017 Oct 13;9(10):505. doi: 10.3390/polym9100505.
Membrane support properties influence the performance of thin-film composite nanofiltration membranes. We fabricated several polysulfone (PSf) supports. The physicochemical properties of PSf were altered by adding polyethylene glycol (PEG) of varying molecular weights (200⁻35,000 g/mol). This alteration facilitated the formation of a thin polyamide layer on the PSf surface during the interfacial polymerization reaction involving an aqueous solution of piperazine containing 4-aminobenzoic acid and an organic solution of trimesoyl chloride. Attenuated total reflectance-Fourier transform infrared validated the presence of PEG in the membrane support. Scanning electron microscopy and atomic force microscopy illustrated that the thin-film polyamide layer morphology transformed from a rough to a smooth surface. A cross-flow filtration test indicated that a thin-film composite polyamide membrane comprising a PSf support (TFC-PEG20k) with a low surface porosity, small pore size, and suitable hydrophilicity delivered the highest water flux and separation efficiency (J = 81.1 ± 6.4 L·m·h, R = 91.1% ± 1.8%, and R = 35.7% ± 3.1% at 0.60 MPa). This membrane had a molecular weight cutoff of 292 g/mol and also a high rejection for negatively charged dyes. Therefore, a PSf support exhibiting suitable physicochemical properties endowed a thin-film composite polyamide membrane with high performance.
膜支撑体的性能会影响复合纳滤膜的性能。我们制备了几种聚砜（PSf）支撑体。通过添加不同分子量（200⁻35,000 g/mol）的聚乙二醇（PEG）来改变PSf的物理化学性质。这种改变有助于在界面聚合反应过程中，在PSf表面形成一层薄的聚酰胺层，该反应涉及含有4-氨基苯甲酸的哌嗪水溶液和均苯三甲酰氯的有机溶液。衰减全反射傅里叶变换红外光谱验证了膜支撑体中PEG的存在。扫描电子显微镜和原子力显微镜表明，复合聚酰胺薄膜层的形态从粗糙表面转变为光滑表面。错流过滤测试表明，由具有低表面孔隙率、小孔径和合适亲水性的PSf支撑体组成的复合聚酰胺薄膜（TFC-PEG20k）具有最高的水通量和分离效率（在0.60 MPa下，J = 81.1 ± 6.4 L·m·h，R = 91.1% ± 1.8%，R = 35.7% ± 3.1%）。该膜的截留分子量为292 g/mol，对带负电荷的染料也具有高截留率。因此，具有合适物理化学性质的PSf支撑体赋予了复合聚酰胺薄膜高性能。
