Fabrication and Characterization of Monovalent Ion Permselec

发布时间：2024-02-28 05:40

　　本文立意于开发经济型、高性能的单价离子选择性分离膜,并将其应用于选择性离子分离过程。目前,现有的膜基技术,如电渗析(ED)、扩散渗析、反渗透、纳滤和超滤等已被许多行业广泛采用,以解决分离过程中遇到的诸多难题。在这些技术中,ED过程由于其能耗较低、操作简单等优点,在特定的工业分离过程中拥有非常突出的优势。尤其当与单价离子选择性分离膜(MIPMs)结合时,可在不发生相变的情况下,对多种离子混合溶液体系中单/多价离子实现有效分离。然而,在离子选择性分离过程中,Fe2+、Mg2+、SO42-等多价离子的存在给实际工艺带来了严重问题,极大地制约了其工艺分离效率的提高。因此,引入新的功能基团,优化膜的结构设计,赋予离子选择性分离膜高的性能和效率以降低运行过程中的成本,对于预期的应用是必不可少的。本文尝试以聚乙烯醇(PVA)、溴甲基化聚(2,6-二甲基-1,4-苯醚)(BPPO)和磺化聚(2,6-二甲基-1,4-苯醚)(SPPO)等廉价商业化聚合物为膜材料,采用新颖的构筑策略制备了一系列经济型、高选择性单价离子选择性分离膜,以期解决实际应用中棘手的分离问题。具体工作如下:在第三章中,通过层层组装(L...

【文章页数】：128 页

【学位级别】：博士

【文章目录】：
Nomenclature
Acknowledgement
摘要
Abstract
Chapter 1 Literature survey
    1.1 Aims and background
    1.2 Membrane science
    1.3 Membranes materials and filtration processes classification
        1.3.1 Ion exchange membranes
            1.3.1.1 Anion Exchange Membranes (AEMs)
            1.3.1.2 Cation exchange membranes (CEMs)
            1.3.1.3 Monovalent ion perms-selective membranes
            1.3.1.4 Mixed matrix membranes (MMMs)
    1.4 Applications
        1.4.1 Selective electrodialysis (SED)
    1.5 Thesis Outlines
Chapter 2 Characterization of membranes
    2.1 Introduction
    2.2 Physiochemical properties
        2.2.1 Cation exchange capacity (CEC)
        2.2.2 Anion exchange capacity (AEC)
        2.2.3 Transport number (tCl-
) and membrane resistance (R_M)
        2.2.4 Current-Voltage (Ⅰ-Ⅴ) curve
        2.2.5 SEM, TGA, DMA, and ATR-FTIR analysis
        2.2.6 Electrochemical impedance spectroscopy (EIS)
        2.2.7 Electrodialysis (ED)
Chapter 3 CEMs integrated with cationic and anionic layers for selective cationseparation
    3.1 Introduction
    3.2 Experimental section
        3.2.1 Materials
        3.2.2 Synthesis of P-COOH membrane
        3.2.3 Synthesis of QPPO
        3.2.4 Surface modification of P-COOH membrane
    3.3 Results and discussion
        3.3.1 CEC and WU

        3.3.2 ¹H HMR and ATR-FTIR analysis
        3.3.3 Thermal stability
        3.3.4 Morphology of membranes
        3.3.5 Electrochemical impedance spectroscopy (EIS)
        3.3.6 Current-Voltage (Ⅰ-Ⅴ) curve
        3.3.7 Ion flux and perm-selectivity
    3.4 Summary
Chapter 4 SPPO-based CEMs with a positively charged layer for selective cationseparation
    4.1 Introduction
    4.2 Experimental section
        4.2.1 Materials
        4.2.2 Preparation of the SPVA based CEM
        4.2.3 Surface modification of SPVA membrane
    4.3 Results and discussion
        4.3.1 ATR-FTIR analysis
        4.3.2 Morphology of membranes
        4.3.3 Physiochemical characteristics
        4.3.4 Thermal and Mechanical stability
        4.3.5 Current-Voltage (Ⅰ-Ⅴ) curves
        4.3.6 Ion flux and perm-selectivity
        4.3.7 Operational stability
    4.4 Summary
Chapter 5 Zwitterionic membranes for selective cations separation
    5.1 Introduction
    5.2 Experimental section
        5.2.1 Materials
        5.2.2 Synthesis of zwitterion membrane
    5.3 Results and discussion
        5.3.1 Physiochemical characteristics
        5.3.2 ATR-FTIR analysis
        5.3.3 Morphology of membrane
        5.3.4 Current-Voltage (Ⅰ-Ⅴ) curves
        5.3.5 Ion flux and perm-selectivity
        5.3.6 Contrast experiment
    5.4 Summary
Chapter 6 In-suit interfacial polymerization endows surface enrichment of-COOHgroups on AEMs for efficient Cl^-/SO4
2- separation
    6.1 Introduction
    6.2 Experimental section
        6.2.1 Materials
        6.2.2 Preparation of the TMQ membranes
    6.3 Results and discussion
        6.3.1 XPS analysis
        6.3.2 SEM and AFM analysis
        6.3.3 ζ-zeta potential analysis
        6.3.4 W_U,IEC,R_M,and tCl^{-
of membranes
        6.3.5 Current-Voltage (Ⅰ-Ⅴ) curve
        6.3.6 Ions flux and perm-selectivity (Cl-/SO_4
2-} system)
        6.3.7 Operational stability
    6.4 Summary
Chapter 7 Comparative analysis and prospective plans
References
List of publications



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