【作者】 杨柳；

【导师】 邹小勤；

【作者基本信息】 东北师范大学 ， 无机化学， 2022， 硕士

【摘要】 随着社会和经济的不断发展,蒸馏、结晶、浓缩和净化等分离过程在工业和我们的日常生活中都发挥着不可或缺的作用。然而,这些传统的分离技术通常伴随着高能源消耗的问题,如仅蒸馏就占了2016年世界总能耗的10-15%。因此,开发低能耗的替代性分离技术将减少全球的能源需求,同时对环境保护更加有利。膜分离技术具有能耗低、操作方便、可扩展性好和环境友好等优点,吸引了越来越多的关注,并在工业过程中表现出巨大的潜力。本文主要设计并合成了几种共价有机骨架（COF）膜,并研究其在气体分离和液体分离方面的性能,具体工作内容如下:1.采用超声辅助机械剥离的方法获得了高质量Tp Pa-Py COF纳米片（横纵比为1111）。通过真空抽滤法在尼龙（Nylon）基膜表面将纳米片组装成连续平整的Tp Pa-Py膜。Tp Pa-Py纳米片膜对大分子染料具有较高的截留率（MO:39.6%;RB:72.9%;AF:85.8%;EY:88.8%;MB:94.4%;EB:98.9%）,并且保持了较高的水通量(72.9-91.6 L m^-2 h^-1 bar^-1)。2.通过丝网印刷法成功制备了三种厚度可控且结晶性较好的COF膜:Tp Pa（OH）₂膜、Tp Pa（OH）₂/Tp Pa-Py共混膜和Tp Pa（OH）₂/Tp Pa-Py@双层膜。此外,我们还研究了COF膜的H₂分离性能:三种COF膜中Tp Pa（OH）₂/Tp Pa-Py@双层膜具有更高的H₂/N₂与H₂/CO₂分离性能,分离比分别为5.26和5.21,与基膜Tp Pa（OH）₂膜相比均提高约2倍左右,H₂透过率为1.6×10^-7 mol m^-2 s^-1 Pa^-1。3.通过渗透汽化方法研究了Tp Pa（OH）₂/Tp Pa-Py@双层膜的脱盐性能,结果表明它对盐离子具有较高的截留率(Na⁺、K⁺、Mg²⁺、Ca²⁺截留率分别为88.78%、97.20%、98.53%、97.68%),与Tp Pa（OH）₂膜相比(Na⁺、K⁺、Mg²⁺、Ca²⁺截留率分别为70.58%、76.96%、95.68%、89.79%)截留率有一定程度的提高。制备的Tp Pa（OH）₂/Tp Pa-Py@双层膜在经过近100 h的测试后依然能够保持对Na⁺稳定的截留率,说明它具有较优异的循环稳定性。更多还原

【Abstract】 With the continuous development of society and economy,the separation process（i.e.distillation,crystallization,concentration,purification）plays an indispensable role in the industry and our daily life.However,these traditional separation techniques are usually accompanied by high energy consumptions,for example,only distillation accounts for 10-15%of the world’s total energy consumption in 2016.Therefore,developing low-energy alternative separation techniques can reduce global energy demands,which is more advantageous for environmental protection.Membrane separation technology possessing the advantages of low energy consumption,convenient operation,good scalability and environmental sustainability,has attracted more and more attention and exhibited huge potential in industrial production.We designed and synthesized three kinds of COF membranes,and explored their performances in gas and liquid separation.The specific research content is as follows:1.High-quality nanosheets of Tp Pa-Py COF with aspect ratio 1111 were prepared by ultrasonic-assisted mechanical exfoliation.Tp Pa-Py nanosheets were subsequently assembled on the surface of the nylon substate by vacuum filtration to form a continuous and flat membrane.The Tp Pa-Py nanosheet membrane had high retention rates for macromolecular dyes（MO:39.6%,RB:72.9%,AF:85.8%,EY:88.8%,MB:94.4%,EB:98.9%）and exhibited a high water flux(72.9-91.6 L m^-2 h^-1 bar^-1).2.The screen printing method was used to prepare thickness-controlled COF membranes.Three COF membranes of Tp Pa（OH）₂,blended Tp Pa（OH）₂/Tp Pa-Py and Tp Pa（OH）₂/Tp Pa-Py@bilayer were successfully prepared with high crystallinity.The prepared COF membranes were applied to H₂ separation.The results show that Tp Pa（OH）₂/Tp Pa-Py@bilayer membrane owns the highest H₂/N₂ and H₂/CO₂selectivity among the three COF membranes.The selectivity values of 5.26 and 5.21are both about twice as those of the Tp Pa（OH）₂ membrane.The H₂ permeance is1.6×10^-7 mol m^-2 s^-1 Pa^-1.3.The desalination performance of the Tp Pa（OH）₂/Tp Pa-Py@bilayer membrane was investigated by pervaporation.The results show that this COF membrane has excellent ion rejections(88.78%,97.20%,98.53%and 97.68%for Na⁺,K⁺,Mg²⁺and Ca²⁺respectively),which are higher than those obtained on the Tp Pa（OH）₂ membrane(70.58%,76.96%,95.68%and 89.79%for Na⁺,K⁺,Mg²⁺and Ca²⁺respectively).Moreover,the prepared Tp Pa（OH）₂/Tp Pa-Py@bilayer membrane can maintain high rejection degree for Na⁺after nearly 100 h test,indicating that it has an excellent stability.更多还原