共查询到19条相似文献,搜索用时 62 毫秒
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聚偏氟乙烯(PVDF)因含氟乙烯基单体,拥有良好的化学稳定性、热学稳定性和机械性能,与其他高分子膜材料相比更容易提高离子交换膜的性能。本实验采用热压法制备PVDF聚乙烯阴离子交换膜,探讨了PVDF含量对膜性能的影响,如膜电阻、离子交换容量、耐破度、含水率和选择透过性。利用红外光谱仪及扫描电子显微镜表征手段对PVDF膜表面性质和结构进行了分析。结果表明,当PVDF含量增加时,膜面电阻、耐破度升高。离子交换容量、含水率,反离子选择透过性降低。虽然PVDF的添加导致含水率、交换容量等膜性能的下降,但耐破度的升高表明膜稳定性和机械性能得到了提升,这赋予PVDF聚乙烯膜一定的使用价值。 相似文献
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为了进一步提升掺混了聚偏氟乙烯(PVDF)的聚乙烯阴离子交换膜的综合性能,采用低温等离子体接枝改性的方式,将聚苯乙烯磺酸钠(PSS)接枝到膜上,并考察接枝单体浓度及等离子体辉光放电处理时间对离子交换容量和选择透过性能的影响。利用扫描电子显微镜和红外光谱仪对制备出复合膜的膜面形态及结构组成进行了表征和分析。结果表明,使用低温等离子体放电的方式能够成功地将PSS接枝到膜上,制备出PSS-聚乙烯PVDF阴离子交换膜。实验表明,通过合理的控制接枝过程参数,复合膜的离子交换容量以及选择透过性能得到了有效的提升,PSS浓度为1.5 g/L且放电时间为4 min时接枝效果最好,此时膜的性能达到最优。 相似文献
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聚偏氟乙烯膜的亲水性改性研究进展 总被引:11,自引:0,他引:11
疏水性聚合物膜的亲水性改性是当前分离膜研究的热点之一。从膜表面亲水改性和膜材料亲水性改性的角度出发,综述了聚偏氟乙烯(PVDF)分离膜的各种改性方法的特点及改性效果,分析了其亲水改性机理,指出膜材料共混改性是今后发展的主要方向。 相似文献
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通过两步无皂乳液聚合法,改变第二步对苯乙烯磺酸钠的加入量,制备表面携带磺酸根基团量不同的纳米粒子(PSS),并将其应用于正渗透(FO)膜的制备。采用红外光谱仪(FTIR)和光电子能谱仪(XPS)表征粒子组成,通过扫描电子显微镜(SEM)表征膜的表面和断面形貌,测定膜孔隙率和亲水性,考察表面磺酸根量不同的聚合物粒子对膜结构性能的影响。结果表明,PSS的引入能提高膜的孔隙率,改善膜的亲水性,且随着粒子表面携带的磺酸根基团量增多,膜的孔隙率与亲水性也随之提高。这是因为PSS粒子可以支撑内部孔道,且表面携带的亲水基团-SO3Na可以提高膜的亲水性,影响活性层的形成。所制备的FO膜性能也得到相应改善,水通量达到了61.1L/(m2·h),为纯聚砜膜的2.8倍,盐截留率达到93.2%,Js/Jv值仅为0.31g/L,性能得到极大提升。 相似文献
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A cation‐exchange membrane based on a styrene/hydroxyethyl acrylate/lauryl methacrylate (Sty/HEA/LMA) terpolymer was prepared via a postsulfonation reaction for various sulfonation times. Sulfonic groups were introduced into the membrane structure with sulfuric acid as the sulfonating agent and silver sulfate as an initiator in a nitrogen atmosphere. Sulfonated Sty/HEA/LMA terpolymer membranes were characterized by Fourier transform infrared (FTIR) spectrometry and nuclear magnetic resonance as well as by determining the degree of sulfonation (DS), ion‐exchange capacity (IEC), water uptake (WU), and electrical property of the membranes. The presence of sulfonic groups in the sulfonated Sty/HEA/LMA terpolymer was confirmed by FTIR, and the resulting membrane showed an IEC of 1.29 meq/g and an electrical resistance of 0.1 Ω cm2. The WU of the prepared membranes increased with the DS at the reaction time. The surface morphology obtained by atomic force microscopy clearly showed an increase of roughness with reaction time. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011 相似文献
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A mixture of sodium polystyrene sulfonate (NaPSS) and anionic surfactant, sodium dodecyl sulfate (SDS), was used as the emulsifier in the emulsion polymerization of styrene at 60 °C. The latexes prepared were stable, bearing the better resistance to the addition of electrolyte, and have the larger values in particle size and the higher polymerization rates than those counterparts prepared using SDS only. The NaPSS was prepared by a series of process: a concentrated cyclohexane solution of an anionically polymerized polystyrene (PS) was sulfonated with sulfuric acid at 80 °C, and then neutralized and purified through dialysis. The data of average polymer number per particle (np) were found useful in investigating the surfactant content effect on the entry of radicals into particles, where the latex particle size plays an important role. 相似文献
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含氟磺酸型质子交换膜是一类具有高热稳定性、化学稳定性及良好力学性能的离子交换膜,具有极其广阔的应用前景。采用60Co辐照接枝技术,在聚偏氟乙烯(PVDF)基膜上产生自由基聚合位点,进而接枝对苯乙烯磺酰氯单体,经过一定条件酸碱处理得到一种新型偏氟磺酸型质子交换膜。并对其进行红外分析,结果显示PVDF膜上成功接枝上了对苯乙烯磺酰氯单体;定量研究了在相同辐照总剂量、不同剂量率条件下,所得质子交换膜的质子传导率、吸水率及离子交换容量与接枝率的关系,结果表明:当剂量率为40 Gy·min-1时,所得质子交换膜接枝率为52.7%,吸水率为36.85%,80℃时质子传导率达到136 mS·cm-1,离子交换容量为1.274 mmol·g-1。 相似文献
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以1-甲基咪唑(N-MI)为季铵化试剂一步法对聚氯乙烯(PVC)功能化改性,并制备了均相PVC阴离子交换膜,避免了传统阴离子交换膜制备过程中的氯甲基化步骤。通过对比研究,优化后的PVC-N-MI-5表现出较好的综合性能。离子交换容量和迁移数分别高达2.89 mmol·g–1和98.4%;吸水率和溶胀率分别为4.24%和0.21%,低于商业JAM-5阴离子交换膜(4.87%和3.33%);脱盐率、电流效率以及能耗分别为98.38%、55.8%和5.1 kW·h·(kg NaCl)–1,可与商业JAM-5(93.0%、55.2%和4.6 kW·h·(kg NaCl)–1)相比较。低廉的原料与简便的制备过程以及相对良好的电渗析应用性能,表明所制备的PVC-N-MI-5具有一定的应用前景。 相似文献
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多孔碳酸钙微球是一种良好的新型缓释载体,在药物缓释、农药控释、涂层防护、橡胶抗老化等领域有广阔的应用前景,合成具有丰富纳米孔道的碳酸钙微球是实现缓释的关键。以氯化钙和碳酸钠为反应原料,选用聚丙烯酸(PAA)为表面活性剂、聚苯乙烯磺酸钠(PSS)为晶型调控剂,通过复分解法制备出球霰石型多孔碳酸钙微球。采用扫描电子显微镜、透射电子显微镜、红外光谱仪、粒度分析仪、比表面及孔隙度分析仪、热重分析仪等手段对获得产物进行表征分析,并研究PAA、PSS浓度对碳酸钙微球形貌和晶型的影响。结果表明,在反应温度为80℃、搅拌速率为600 r/min、PAA和PSS的质量浓度分别为3.0 g/L和3.6 g/L时,可制备出粒径均一、形貌良好、孔隙率较大的多孔碳酸钙微球。 相似文献
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以六氟丙烯三聚体和对羟基苯磺酸钠为主要原料,合成了对全氟壬烯氧基苯磺酸钠。考察了反应温度、催化剂和投料方式对对全氟壬烯氧基苯磺酸钠收率的影响。通过正交实验确定了最佳工艺条件:反应温度66℃、反应时间4 h、催化剂三乙胺,投料方式为待对羟基苯磺酸钠在N,N-二甲基甲酰胺(DMF)中完全溶解后加入催化剂,再滴加六氟丙烯三聚体,产物收率达80.15%。经FTIR和19FNMR确证了产物结构,TG测出它的热分解温度为350~360℃;表面活性测定结果表明,产物临界胶束浓度为9.26×10-4mol/L,γCMC为18.95 mN/m(20℃)。橡胶脱模应用实验发现,当脱模剂中对全氟壬烯氧基苯磺酸钠的质量分数为4%时,脱模次数达43次。 相似文献
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Identification of optimum synthesis conditions for a novel anion exchange membrane by response surface methodology 下载免费PDF全文
The Response Surface Methodology (RSM) was employed for the optimization of the synthesis conditions of an anion exchange membrane. A novel chlorinated‐polypropylene heterogeneous anion exchange membrane was made via phase inversion. A nonionic surfactant was incorporated into the composition as an additive to enhance the membrane properties. The membrane performance was measured in terms of ion exchange capacity (IEC) and permselectivity. An experimental design was used to quantify the effects of variables including the ratio of resin/polymer, the ratio of additive/total solid, and the ratio of solvent/polymer, on IEC and permselectivity. For each function, a quadratic model was developed to correlate the relationship between variables and the response. The results demonstrated the accuracy of the two models. The anion exchange membrane with the best combination of a high IEC and high permselectivity was synthesized with a solvent/polymer ratio of 18.63 (v/w), resin/polymer ratio of 1 (w/w), and additive/total solid ratio of 0.02 (w/w). © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 39888. 相似文献
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The polystyrene‐DVB/PVDF alloy particles were prepared by pulverizing the polymerization product of styrene/DVB/PVDF in DMF, and then sulfonated with concentrated sulfuric acid to gain the cation exchange alloy powder, which was directly thermoformed by a hot‐press machine to form the titled cation exchange alloy membranes with the structure of semi‐interpenetrating polymer network. The effects of the polystyrene‐DVB to PVDF mass ratio and the DVB content in the monomers on the physical and electrochemical properties of the prepared alloy membranes were investigated. While the Fourier transform infrared spectroscopy (FTIR) confirms the components of membranes, the scanning electron microscopy (SEM) reveals that the alloy membranes possess a uniform distribution of functional groups, and a more dense structure with the increases of DVB content and PVDF content. The optimal prepared membranes have the area electrical resistance values within 3.0–6.6 Ω·cm2, obviously superior to the commercial heterogeneous cation exchange membrane, as well as the moderate water contents of 35–40% and the desirable permselectivity with a transport number more than 0.95. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 1220‐1227, 2013 相似文献