磺化聚乙烯中空纤维膜渗透蒸发分离水／乙二醇混合物的研究

采用异相氯磺化的方法，使聚乙烯（ＰＥ）中空纤维膜进行氯磺化反应，并将反应产物进一步水解和离子交换，可获得具有离子交换功能的磺化聚乙烯（ＳＰＥ）中空纤维离子交换膜。应用渗透蒸发膜分离方法，研究磺化聚乙烯中空纤维离子交换膜对水／乙二醇混合物的分离效果。讨论了反离子的种类、渗透蒸发分离温度和水／乙二醇混合液的组成等对磺化聚乙烯中空纤维离子交换膜的分离效果的影响。     

醇/水混合物在磺化聚乙烯中空纤维阴离子交换膜中的渗透汽化

通过对聚乙烯中空纤维光化学氯磺化反应,继而胺化和季胺化,制备了磺化聚乙烯中空纤维阴离子交换膜。以恒沸组成的异丙醇/水和85wt%乙醇/水为料液,测定了不同抗衡离子膜的渗透汽化性能。表明:该膜有极高的选择性,分离系数和渗透通量与抗衡离子密切相关,对卤素离子,α_W/A大小次序为I~->Br~->Cl~-;通量大小次序与之相反。三种抗衡离子膜的平衡吸收实验表明,该阴离子膜的选择渗透性不仅与醇水在膜中的溶解度有关,而且取决于平均扩散系数。     

磺化聚乙烯离子交换膜渗透汽化分离二氧六环／水混合物研究

本文用非均相光化学氯磷化反应制得了亲水的耐有机溶剂耐酸碱的磺化聚乙烯离子交换膜．膜截面离子基因密度与反应程度有关．该膜对近恒沸组成的二氧六环／水混合液显示出很高的渗透汽化分离系数和透过速率．研究了对离子、离子交换容量、料液浓度和温度对分离性能的影响．通过膜内水合离子形成“水通道”模型讨论了渗透机理．膜内离子基团密度估计及水的表观渗透活化能的大小支持“水通道”的存在．     

用聚电解质渗透汽化膜进行乙醇脱水

渗透汽化 (PV)膜过程由于可用于有机 /有机及有机 /水的恒沸或近沸混合物的分离而成为近年来膜技术研究开发的热点[1,2 ] .德国 GFT公司所制的富马酸交联 PVA脱水膜[3] 对温度为 80℃的 80 %Et OH料液 ,其分离因子为 350 ,渗透通量为 2 0 0 g/ (m2 ·h) .优秀的分离膜要求渗透通量大 ,同时具有较高的分离因子和良好的稳定性 .因此 ,提高膜的分离性能是渗透汽化技术开发应用的关键 .周继青等 [4 ]研究了 PVA/ PVP互穿网络膜的渗透汽化性能 ,发现膜的渗透通量虽有明显提高 ,但膜的选择性下降 .聚电解质具有优良的亲水性 ,可制得高水通…     

壳聚糖复合膜及异丙醇／水混合液的渗透汽化分离

用磺化聚乙烯离子膜渗透汽化分离恒沸组成的i-PrOH/H_2O(87.2/12.8W/W),分离系数α高,渗透通量J低(小于300g/m~2·h,40℃),当醇含量高于90％时,膜性能变差;用CA膜、赛璐玢膜[2]、Nation-Na~+膜,J较高,α低(<30)。甲壳素脱乙酰基产物壳聚糖(Chitosan,简称CS),易交联改性,成膜性好。CS膜分离i-PrOH/H_2O,α很高,而J低。经戊二醛交联的CS膜尺寸稳定,增加了醇/水的J值,α虽有所下降,对i-PrOH/H_2O体系仍具有很高的值。为了进一步提高J值,我们研制了以聚丙烯腈(PAN)微孔膜作支撑的CS复合膜,     

聚酰亚胺中空纤维膜用于甲醇/甲基叔丁基醚的分离

甲醇／甲基叔丁基醚混合物的膜法分离，大多采用渗透汽化方法，少有采用蒸汽渗透法。用聚酰亚胺中空纤维膜，对以蒸汽渗透和渗透汽化两种方式分离甲醇／甲基叔丁基醚混合物（甲醇质量分数为0．01－0．30）的效果进行了对比。结果显示，在甲醇质量分数低于0．05时，蒸汽渗透较渗透汽化法的分离性能优越。     

丙烯腈类共聚物膜用于醇水分离的研究 Ⅳ.丙烯腈与丙烯酰胺共聚物膜

渗透蒸发用于热敏物质、恒沸物质和组分间沸点相近的有机液体混合物的分离,可节能和简化操作,如乙醇水混合液的分离。 硅橡胶,聚三甲基硅丙炔等少量聚合物属于透醇性膜,而天然高分子膜,离子交换膜以及含亲水基团的共聚物膜等均为透水性膜,尤其是含亲水基团共聚物膜具有力学性能好,分离指     

渗透汽化优先透醇分离膜

20世纪70年代的能源危机促使了人们对可再生能源-发酵法制备乙醇与节能分离工艺的探求。渗透汽化膜分离技术作为一种新兴的膜分离技术,具有分离效率高、低能耗、易于和发酵装置耦合、易于与其它分离方法联用等显著优点,特别适用于乙醇/水等恒沸混合物体系的分离。本文简要介绍了渗透汽化优先透醇膜的研究背景,总结并分析了用于指导膜材料选择的理论,详细介绍了用于制备优先透醇膜的含硅聚合物、含氟聚合物、有机/无机复合膜材料以及其他聚合物等膜材料的的结构特点、改性方法及膜材料分子结构与渗透汽化性能间的关系,并对不同膜材料对乙醇/水的渗透汽化分离性能进行了总结比较,在此基础上总结了目前渗透汽化乙醇/水分离膜存在的问题,并对其未来的研究方向和发展前景进行了展望。     

NaA膜渗透汽化技术在三聚甲醛脱水中的应用

采用NaA膜对三聚甲醛溶液渗透汽化脱水,对比了不同温度下渗透通量和分离性能的变化,研究了甲醛对混合物脱水分离的影响。结果表明NaA膜可将三聚甲醛和水的二元体系含水量从32 wt%降至0.15 wt%,将三聚甲醛、甲醛和水三元体系的含水量从28 wt%降至1.5 wt%,表现出了良好的分离性能;同时使用NaA膜渗透汽化技术无需添加萃取剂,并解决了三聚甲醛溶液共沸分离的难题。     

膜渗透汽化技术在三聚甲醛脱水中的应用

采用NaA膜对三聚甲醛溶液渗透汽化脱水，对比了不同温度下渗透通量和分离性能的变化，研究了甲醛对混合物脱水分离的影响。结果表明NaA膜可将三聚甲醛和水的二元体系含水量从32 wt%降至0.15 wt%，将三聚甲醛、甲醛和水三元体系的含水量从28wt%降至1.5wt%，表现出了良好的分离性能；同时使用NaA膜渗透汽化技术无需添加萃取剂，并解决了三聚甲醛溶液共沸分离的难题。     

PREPARATION AND CHARACTERIZATION OF ION EXCHANGE MEMBRANES BASED ON POLYVINYLIDENE FLUORIDE

A new ion exchange membrane based on polyvinylidene fluoride (PVDF) and sulfonated poly(styrenedivinylbenzene) was prepared by in-situ polymerization. The incorporation of sulfonic groups into the polyvinylidene fluoride composite membrane was confirmed by infrared spectroscopy (IR), ion exchange capacity (IEC) and energy dispersive X-ray analysis (EDAX). Area resistance, IEC and water uptake of the treated membrane were evaluated. When area resistance in NaCl aqueous solution at 25℃, IEC is as high as 2.43 millimoles per gram of the wet membrane. The hydrophilicity of PVDF membrane is also significantly improved after treatment. When 60% of crosslinked membrane was sulfonated at 80℃ for 6 h, water uptake of the treated membrane can attain 64.7%.     

PREPARATION AND CHARACTERIZATION OF ION EXCHANGE MEMBRANES BASED ON POLYVINYLIDENE FLUORIDE

 A new ion exchange membrane based on polyvinylidene fluoride (PVDF) and sulfonated poly(styrene- divinylbenzene) was prepared by in-situ polymerization. The incorporation of sulfonic groups into the polyvinylidene fluoride composite membrane was confirmed by infrared spectroscopy (IR), ion exchange capacity (IEC) and energy dispersive X-ray analysis (EDAX). Area resistance, IEC and water uptake of the treated membrane were evaluated. When 20% of the crosslinked membrane was sulfonated at 80°C for 22 h, the PVDF ion exchange membrane can attain 0.8 Ω·cm²area resistance in NaCl aqueous solution at 25℃, IEC is as high as 2.43 millimoles per gram of the wet membrane. The hydrophilicity of PVDF membrane is also significantly improved after treatment. When 60% of crosslinked membrane was sulfonated at 80 ℃ for 6 h, water uptake of the treated membrane can attain 64.7%.     

Influence of blend miscibility on the proton conductivity and methanol permeability of polymer electrolyte blends

The influence of miscibility on the transport properties of polymer electrolyte blends composed of a proton conductor and an insulator was investigated. The proton‐conductive component in the blends was sulfonated poly(ether ketone ketone) (SPEKK), while the nonconductive component was either poly(ether imide) (PEI) or poly(ether sulfone) (PES). The phase behavior of PEI‐SPEKK blends was strongly influenced by the sulfonation level of the SPEKK. At low sulfonation levels (ion‐exchange capacity (IEC) = 0.8 meq/g), the blends were miscible, while at a slightly higher level (IEC = 1.1 meq/g), they were only partially miscible and for IEC ≥ 1.4 meq/g they were effectively immiscible over the entire composition range. The PES‐SPEKK blends were miscible over the entire range of SPEKK IEC considered in this study (0.8–2.2 meq/g). At high IEC (2.2 meq/g) and at low mass fractions of SPEKK (<0.5), the miscible blends (PES‐SPEKK) had higher proton conductivities and methanol permeabilities than the immiscible ones (PEI‐SPEKK). The opposite relationship was observed for high mass fractions of SPEKK (>0.5). This behavior was explained by the differences in morphology between these two blend systems. At low IEC of SPEKK (0.8 meq/g), where both PEI‐SPEKK and PES‐SPEKK blend systems exhibited miscibility, the transport properties were not significantly different. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 2253–2266, 2006     

Synthesis of ionic polybenzimidazoles with broad ion exchange capacity range for anion exchange membrane fuel cell application

In this study, new anion exchange membranes (AEM) based on crosslinked polybenzimidazole (m-PBI) with quaternary ammonium groups, crosslinkable allyl groups, and hydrophobic ethyl groups as side chains are synthesized and characterized. The AEMs are crosslinked by thermal thiol-ene reaction using a dithiol crosslinker. The ion exchange capacity (IEC) values and crosslinking density were controlled by the number of quaternary ammonium groups and allyl groups, respectively. The introduction of ethyl groups improved the solubility of ionic PBIs even at very low IEC values by eliminating the hydrogen bonding interaction of imidazole rings. This method allows ionic PBIs with broad IEC values, from 0.75 to 2.55 mmol/g, to be prepared. The broad IEC values were achieved by independently controlling the numbers of quaternary ammonium groups, allyl groups, and hydrophobic ethyl groups during preparation. The crosslinked ionic PBIs revealed hydroxide conductivity from 16 to 86 mS/cm at 80°C. The wet membranes also showed excellent mechanical strength with tensile strength of 12.2 to 20.1 MPa and Young's Modulus of 0.67 to 1.45 GPa. The hydroxide conductivity of a crosslinked membrane (0.40Q0.60Et1.00Pr, IEC = 0.95 mmol/g) decreased only 7.9% after the membranes was immersed in a 1.0 M sodium hydroxide solution at 80°C for 720 h. A single fuel cell based on this membrane showed a maximum peak power density of 136 mW/cm² with a current density of 377 mA /cm² at 60°C.     

聚砜阴离子交换膜的制备及结构与性能研究

以1,4-二氯甲氧基丁烷(BCMB)为氯甲基化试剂,使聚砜(PSF)发生氯甲基化反应,制得了氯甲基化聚砜(CMPSF),考察了主要因素对聚砜氯甲基化反应的影响,并使用FTIR及1H-NMR等法对CMPSF的化学结构进行了表征.采用三乙胺(TEA)、三丙胺(TPA)及三丁胺(TBA)等3种叔胺对CMPSF进行了季铵化反应,并以4,4′-联吡啶为交联剂实施了交联反应,制备了聚砜阴离子交换膜(PSFAEM).测定了交换膜PSFAEM的主要性能,包括离子交换容量(IEC)、含水量(WC)及膜电阻(Rm).实验结果表明,使用BCMB,聚砜的氯甲基化反应可顺利进行,以氯仿为溶剂,以SnCl4为Lewis酸催化剂,可制得氯甲基化程度为1.75mmol/g的CMPSF.交换膜PSFAEM的IEC、WC及Rm与季铵化反应时间及叔胺的种类密切相关.季铵化反应时间相同时,采用烷基中碳原子数少的叔胺TEA所制备的交换膜具有高的IEC与WC,低的Rm;使用同一种叔胺时,随季铵化反应时间的增长,交换膜的IEC与WC增大,Rm减小.     

Sulfonated poly(fluorenyl ether) membranes containing perfluorocyclobutane groups for fuel cell applications

This paper describes the preparation and electrochemical properties of new proton conducting polymer membranes, sulfonated poly(fluorenyl ether) membrane-containing perfluorocyclobutane (PFCB) moieties for fuel cell applications. The sulfonated polymers were prepared via thermal cyclodimerization of 9,9-bis(4-trifluorovinyloxyphenyl)fluorene and subsequent post-sulfonation using chlorosulfonic acid (CSA) as a sulfonating agent. The post-sulfonation reaction was carried out by changing the molar ratio of CSA/repeating unit of the polymer at room temperature for 5 h and the resulting sulfonated polymers showed different degrees of sulfonation (DS) and ion exchange capacities (IEC). With the increment of CSA content, the DS, IEC and water uptake of the sulfonated polymer membranes increased. Their proton conductivity was investigated as a function of temperature. The polymer membrane with an IEC value of 1.86 mmol/g showed a water content of 25% similar to Nafion-115's but showed higher proton conductivity than Nafion-115 over the temperature 25–80 °C. The polymer membrane with lower water uptake and higher IEC showed similar proton conductivity and methanol permeability to Nafion-115. These results confirmed that the sulfonated poly(fluorenyl ether)-containing PFCB groups could be a promising material for fuel cell membranes.     

后磺化法精确可控合成主链型磺化聚苯喹喔啉及其质子交换膜性能研究

以不同摩尔比的4,4′-双(4-(2-苯基乙二酮基)苯氧基联苯、4,4′-双(2-苯基乙二酮基)二苯醚与3,3′,4,4′-四氨基联苯共聚制备聚喹喔啉,经后磺化法得到一系列磺化度可控的磺化聚苯基喹喔啉(SPPQ).模型化合物确认,磺酸基团精确接入电子云密度较高的含醚键的联苯片段的2,2′-位上,证明通过单体分子结构设计与后磺化法结合,可使磺酸基团在温和条件下,按预想接入到聚合物主链上,达到磺化度和磺化位置精确可控的目的. SPPQ的相对黏度均在3.8 dL/g以上.通过溶液涂膜法制备的主链型磺化聚苯基喹喔啉质子交换膜(SPPQ PEM)的吸水率都低于39%,尺寸变化率为2.1%~13%,且随着IEC和温度的提高而线性增加.如,80℃下,IEC高达2.21 meq/g的SPPQ-5的膜面和膜厚方向的尺寸变化率仅为11%和13%,具有良好的形状维持能力.热重分析表明,SPPQ PEM在320℃左右脱去磺酸基团,550℃左右发生聚合物主链降解,具有良好的热稳定性. Fenton试剂测试表明,SPPQ PEM开始破碎的时间随IEC的增加而缩短,在20℃时,IEC较低的SPPQ-1 (1.29 meq/g)破碎时间可达151 h,而IEC较高的SPPQ-5(2.21 meq/g)破碎时间缩短至81 h. PEM的质子传导率随温度和IEC的增加而显著提高,最高可达64 mS/cm,由于磺酸基团和喹喔啉酸碱对的形成以及吸水率偏低的原因,这一数值远低于Nafion.     

Alkaline stability of poly(phenylene)-based anion exchange membranes with various cations

Anion exchange membranes comprised of a poly(phenylene) backbone and one of five different cationic head-groups are prepared, briefly characterized, and tested for stability in 4 M KOH at 90 °C. The two membranes with resonance-stabilized cations (benzyl pentamethylguanidinium and benzyl N-methylimidazolium) show large (>25%) decreases in both conductivity and ion exchange capacity (IEC) after just one day of testing. The membrane with benzyl trimethylammonium cations shows a 33% loss of conductivity (14% decrease in IEC) after 14 days while the membrane with trimethylammonium cations attached by a hexamethylene spacer shows the least degradation: a 5% loss of conductivity over 14 days with no accompanying loss in IEC. A similar membrane which has a six-carbon spacer and a ketone adjacent to the phenyl ring shows much lower stability, suggesting that the ketone takes part in degradation reactions. © 2012 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2013, 51, 1736–1742, 2013     

Synthesis and characterization of sulfonated poly(phthalazinone ether phosphine oxide)s by direct polycondensation for proton exchange membranes

A series of sulfonated poly(phthalazinone ether phosphine oxide)s (sPPEPO) were prepared via aromatic nucleophilic substitution polycondensation of 4‐(4‐hydroxyphenyl) phthalazinone (HPPZ) with sulfonated bis(4‐fluorophenyl)phenyl phosphine oxide (sBFPPO) and bis(4‐fluorophenyl)phenyl phosphine oxide (BFPPO) at various ratios. The properties such as molecular weight, ion exchange capacity (IEC), swelling, thermal stability, proton conductivity, and morphology were investigated. sPPEPO with high IEC exhibited high proton conductivity while they still showed low swelling. Typically, sPPEPO with IEC of 1.54 and 1.69 meq/g exhibited high conductivity of 0.091 and 0.19 S/cm, and low swelling ratios of 14.3% and 19.5% at 80 °C, respectively. The low swelling was attributed to the strong intermolecular interaction including the electrostatic force and hydrogen bond. sPPEPO would be promising candidates used as polyelectrolyte membranes for fuel cells. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 1758–1769, 2008     

Sulfonated poly(ether sulfone)s with binaphthyl units as proton exchange membranes for fuel cell application

Sulfonated poly(ether sulfone)s containing binaphthyl units (BNSHs) were successfully prepared for fuel cell application. BNSHs, which have very simple structures, were easily synthesized by postsulfonation of poly(1,1′‐dinaphthyl ether phenyl sulfone)s and gave tough, flexible, and transparent membranes by solvent casting. The BNSH membranes showed low water uptake compared to a typical sulfonated poly(ether ether sulfone) (BPSH‐40) membrane with a similar ion exchange capacity (IEC) value and water insolubility, even with a high IEC values of 3.19 mequiv/g because of their rigid and bulky structures. The BNSH‐100 membrane (IEC = 3.19 mequiv/g) exhibited excellent proton conductivity, which was comparable to or even higher than that of Nafion 117, over a range of 30–95% relative humidity (RH). The excellent proton conductivity, especially under low RH conditions, suggests that the BNSH‐100 membrane has excellent proton paths because of its high IEC value, and water insolubility due to the high hydrophobicity of the binaphthyl structure. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 5827–5834, 2009