Higa Mitsuru, Kakihana Yuriko, Sugimoto Takehiro, Toyota Kakuya
Graduate School of Sciences and Technology for Innovation, Yamaguchi University, 2-16-1 Tokiwadai, Ube, Yamaguchi 755-8611, Japan.
Blue Energy Center for SGE Technology (BEST), Yamaguchi University, 2-16-1 Tokiwadai, Ube, Yamaguchi 755-8611, Japan.
Membranes (Basel). 2019 Jan 2;9(1):4. doi: 10.3390/membranes9010004.
Hollow fiber type cation-exchange (C-HF) membranes and hollow fiber type anion-exchange (A-HF) membranes were prepared from poly (vinyl alcohol) (PVA)-based copolymer with cation-exchange groups and by blending PVA and polycation, respectively, by a gel fiber spinning method. In order to control the water content of the hollow fiber membranes, the membranes were cross-linked physically by annealing, and then cross-linked chemically by using glutaraldehyde (GA) solutions at various GA concentrations. The outer diameter of C-HF and A-HF membranes were ca. 1000 μm and ca. 1500 μm, respectively, and the thickness of the membranes were ca. 170 μm and 290 μm, respectively. Permeation experiments were carried out in two Donnan dialysis systems, which included mixed 0.1 M NaCl and 0.1 M CaCl₂/C-HF /3 × 10 M CaCl₂ and mixed 0.1 M NaCl and 0.1 M NaNO₃/A-HF/3 × 10 M NaNO₃ to examine ionic perm selectivity of the membranes. In the Donnan dialysis experiments using C-HF membranes, uphill transport of the divalent cations occurred, and, in the case of A-HF membranes, uphill transport of NO₃ ions occurred. C-HF and A-HF membranes had about half of the flux in the uphill transported ions and also about half of the selectivity between the uphill transport ions and driven ions in comparison with those of the commercial flat sheet cation-exchange membrane (Neosepta CMX) and anion-exchange membrane (Neosepta AMX). Yet, of C-HF and A-HF membranes were about one fifth of CMX and less than half of AMX, respectively. Since hollow fiber membrane module will have higher packing density than a flat membrane stack, the hollow fiber type ion-exchange membranes (IEMs) prepared in this study will have a potential application to a Donnan dialysis process.
中空纤维型阳离子交换（C-HF）膜和中空纤维型阴离子交换（A-HF）膜分别通过凝胶纤维纺丝法，由带有阳离子交换基团的基于聚乙烯醇（PVA）的共聚物以及通过将PVA与聚阳离子共混制备而成。为了控制中空纤维膜的含水量，先通过退火进行物理交联，然后使用不同戊二醛（GA）浓度的溶液进行化学交联。C-HF膜和A-HF膜的外径分别约为1000μm和约1500μm，膜的厚度分别约为170μm和290μm。在两个唐南透析系统中进行渗透实验，其中包括混合0.1M NaCl和0.1M CaCl₂/C-HF /3×10⁻³M CaCl₂以及混合0.1M NaCl和0.1M NaNO₃/A-HF/3×10⁻³M NaNO₃，以考察膜的离子渗透选择性。在使用C-HF膜的唐南透析实验中，二价阳离子发生上坡传输，而在A-HF膜的情况下，NO₃⁻离子发生上坡传输。与商用平板阳离子交换膜（Neosepta CMX）和阴离子交换膜（Neosepta AMX）相比，C-HF膜和A-HF膜在上坡传输离子中的通量约为其一半，并且在上坡传输离子与驱动离子之间的选择性也约为其一半。然而，C-HF膜和A-HF膜的通量分别约为CMX的五分之一和小于AMX的一半。由于中空纤维膜组件将具有比平板膜堆更高的填充密度，本研究中制备的中空纤维型离子交换膜（IEMs）在唐南透析过程中具有潜在的应用价值。
