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通过利用含侧甲基结构聚芳醚砜的溴化和接枝磺化反应,制备得到一系列结构单元中含有4个柔性侧链结构的磺化聚芳醚砜质子交换膜(4SPAES-x)。通过1HNMR表征其化学结构,并利用原子力显微镜对膜材料的相分离形态结构进行分析,证实所制膜材料具有良好的亲水/疏水相分离形态结构。4SPAES-x膜的离子交换容量在1.12~1.74 mmol/g,30 ℃时的吸水率、溶胀率和质子传导率分别在11%~32%、7%~22%和21~86 mS/cm,均随磺化比例的增大而增大。4SPAES-25膜组装的钒流单电池在40 mA/cm2电流密度下最高能量效率为83.3%,高于Nafion 115的81.5%。此外,该单电池的效率还具有良好的循环稳定性。 相似文献
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为了探索影响芳香族聚噁二唑的磺化反应的因素,分别以发烟硫酸和氯磺酸为磺化试剂对几种含醚键聚芳噁二唑(PEODs)进行磺化,研究了以氯磺酸为磺化试剂时磺化反应时间、用量对磺化反应的影响,并分析了PEODs用于质子交换膜的潜在应用.磺化产物的结构与性能通过傅里叶红外(FT-IR)、氢谱(1H-NMR)、离子交换当量、热重分析(TGA)和溶解性等测试进行了表征.结果表明:发烟硫酸磺化产物磺化度不可控制,磺化度较氯磺酸的磺化产物高;采用氯磺酸磺化时,磺化时间对磺化反应没有影响,氯磺酸用量仅对侧苯基双酚A型聚噁二唑有影响;邻叔丁基型聚噁二唑的氯磺酸磺化产物有用于质子交换膜的潜力. 相似文献
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以六氟双酚A(6FBPA),4,4′-二氟二苯酮(DFBP)和3,3′-二磺酸钠基-4,4′-二氟二苯酮(SDFBP)为单体,调整单体DFBP与SDFBP的摩尔投料比,通过缩合共聚反应合成了一系列离子交换容量不同的含氟磺化聚芳醚酮共聚物(SPEK-6Fs)。采用红外(FT-IR)、核磁共振氢谱(1H-NMR)对共聚物的结构进行了表征,同时对所制备的质子交换膜的吸水率、尺寸稳定性、甲醇透过率、质子电导率及抗氧化性能等进行了一个综合的评价。结果表明:所合成的聚合物具有较高的分子量,可通过溶液浇铸成膜法制备成柔韧、透明的膜,所制备的膜具有良好的尺寸稳定性,在同等测试条件下,具有与杜邦公司Nafion 117膜相当的质子电导率,同时,其甲醇渗透率比Nafion 117膜低1~2个数量级。 相似文献
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《化工学报》2009,60(11)
以工业级4,4'-二氟二苯砜(DFDPS)为原料,利用升华方法进行纯化处理后,采用发烟硫酸直接磺化,通过改变反应物计量比、反应温度、反应时间等参数,系统研究了3,3'-二磺化-4,4'-二氟二苯砜二钠盐(SDFDPS)的制备方法.采用HPLC、UV、~1H NMR 及FTIR对磺化产物结构及纯度进行了表征,由此得到最佳的磺化条件为:反应物摩尔比(SO_3∶DFDPS)为3.0∶1,在110℃下反应20 h.在此反应条件下的磺化产物中未发现单磺化产物以及未磺化的原料DFDPS.经过乙醇/水两次重结晶后,总收率达到75%.以合成的SDFDPS为原料合成了磺化度60%的磺化聚芳醚砜聚合物,该聚合物具有较高的相对黏度,同样也表明了SDFDPS的高纯度. 相似文献
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磺化聚醚砜纳滤膜性能研究 总被引:15,自引:4,他引:11
本文主要研究了磺化聚醚砜 (SPES)复合纳滤膜的性能。详细讨论了纳滤膜对不同溶质的分离特性 ;探讨了无机盐浓度 ,操作压力 ,溶液 p H值及磺化聚醚砜的离子交换容量(IEC)与膜性能的关系 ;并对纳滤膜的电性能进行了初步研究。研究结果表明 ,磺化聚醚砜复合纳滤膜为一荷负电性纳滤膜 ,对无机盐有较好的选择分离性能。磺化聚醚砜的离子交换容量 ,无机盐浓度以及操作压力对膜性能影响较大 ,且对于两性溶质 ,膜的脱除性能与溶液 p H值有关 相似文献
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通过改变共聚单体种类,探究主链元素种类对聚合物质子交换膜性能的影响。以3,3'-二磺酸基钠盐-4,4'-二氟二苯砜为磺化单体,4,4'-二氟二苯砜为非磺化单体,4,4'-二羟基二苯醚或4,4'-二巯基二苯硫醚为共聚单体,通过亲核缩聚反应成功可控制备出磺化度分别为30%和50%的磺化聚芳醚砜(SPES)与磺化聚芳硫醚砜(SPTES)。采用流延法制备了两种聚合物的透明坚韧的质子交换膜。研究发现两种聚合物膜均显示出了良好的力学性能以及较为适中的吸水率与溶胀度。两种聚合物质子交换膜的起始分解温度达到250℃,具有良好的热稳定性。随磺化度的升高,两种聚合物膜的吸水率、溶胀率以及质子传导率均升高。由于主链硫较氧原子与苯环的共轭作用更强以及供电子硫原子与吸电子基团的相互作用,SPTES膜较SPES膜表现出更高的玻璃化转变温度(T g)、更低的溶胀率以及更高质子传导率。其中SPES-50与SPTES-50在80℃、100%RH条件下,质子传导率分别为0.136S/cm与0.142S/cm,表明其作为质子交换膜具有潜在的应用前景。 相似文献
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以环氧氯丙烷和1–甲基咪唑为原料制备新型离子液体(IL),以IL为原料对氧化石墨烯(GO)进行表面修饰制备离子液体功能化氧化石墨烯(IL–GO),以IL–GO为添加剂制备基于含氟聚苯并咪唑(FPBI)复合膜。研究了IL–GO的含量对复合膜的热稳定性、力学强度、离子电导率、离子交换容量(IEC)、吸水率、溶胀度和耐碱性等性能的影响。研究结果表明,复合膜的IEC、离子电导率和拉伸性能都随着IL–GO含量的增加而增大,当IL–GO含量为30%时其拉伸应力和拉伸弹性模量分别达到77.5 MPa和1.95 GPa,在80℃下,其最大离子电导率可达72.3 m S/cm,然而复合膜的热稳定性并没随着IL–GO含量的增加而改变。FPBI/IL–GO复合膜具有良好的稳定性,该系列阴离子交换膜有望在碱性阴离子交换膜燃料电池中得到应用。 相似文献
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Sulfonated poly(arylene ether ketone) (SPAEK) possessing the pendant carboxylic acid groups was synthesized. The carboxylic acid groups of SPAEK were reacted with a cross‐linking reagent to prepare a cross‐linked membrane with a high ion exchange capacity (IEC), a high oxidative stability, and an excellent mechanical strength. The cross‐linking hindered the mobility of the polymer chains and thus strongly affected the water uptake and the methanol permeability of the membranes. Also, as the cross‐linker used in this study bore sulfonic acid groups, cross‐linking did not lead to a noticeable loss of the proton conductivity. The cross‐linked SPAEK membrane with 20% cross‐linking density, CSPAEK‐20% membrane, exhibited a high proton conductivity of 0.045 S cm–1 associated with a high IEC value of 1.78 mmol g–1 but a low methanol permeability of 4.3 × 10–7 cm2 s–1. The CSPAEK‐20% membrane also showed excellent cell performance and oxidation resistance. 相似文献
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A series of poly(aryl ether sulfone)s containing triptycene groups PES-x-TPD (x refers to molar percentage of TPD) were firstly synthesized through nucleophilic aromatic substitution polycondensation by using 2,5-triptycenediol (TPD), bis(4-hydroxyphenyl) sulfone (BHPS) and 4,4′-difluorodiphenyl sulfone (DFDPS). The sulfonation of copolymers was conducted at room temperature by using a mild sulfonating reagent (98% H2SO4), and the degree of sulfonation was readily and accurately controlled by adjusting the ratio of TPD and BHPS. The structures of PES-x-TPD and SPES-x-TPD were characterized by IR, 1H NMR and 13C NMR spectra. These ionomers generally showed high thermal stability and mechanical strength at low humidity regardless of high IEC value. Meanwhile, it is noteworthy that these novel SPES-x-TPD membranes with high IEC value achieved high proton conductivity in a wide range of humidity at 80 °C. For example, SPES-60-TPD with the highest IEC value 2.86 mmol/g displays the conductivity of 2.5 × 10−1 S/cm which is much higher than that of the perfluorinated Nafion membrane (1.1 × 10−1 S/cm) at 80 °C and 94% RH. At 80 °C and 34% RH, SPES-60-TPD displays the conductivity of 4.5 × 10−3 S/cm which is also higher than that of the Nafion membrane (3.0 × 10−3 S/cm). Microscopic analyses revealed that well-de?ned phase separated structures and uniform ionic pathway was formed for SPES-45-TPD membrane with the IEC of 2.29 mmol/g. Moreover, a H2/O2 fuel cell using the SPES-55-TPD (IEC = 2.68 mmol/g) also showed better performance than that of Nafion 117 at 40 °C and 30% RH. 相似文献
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介绍IEC61131 3和多语言编程软件在DCS中的特殊要求,分别从编程软件的构架、功能块的设计实现、功能块的报警、功能块冗余的机制及控制程序在线下载、运行库的执行方式和软仿真等几个方面展开论述,建立起符合IEC61131 3的独立于平台的DCS多语言编程软件的设计与实现方案。 相似文献
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A series of sulfonated copolyimides (SPIs) with hydrophilic segment length of 20–60 based on 4,4′‐sulfide‐bis(naphthalic anhydride) (SBNA) have been successfully synthesized to improve hydrolytic stability and proton conductivity. The SPI membranes were cast from their m‐cresol solutions, and they were characterized by determining the water uptake, water swelling ratio, mechanical properties, hydrolytic stability, oxidative stability, and proton conductivity. It was found that the water uptake of SPI membranes was low and decreased as the hydrophilic segment length increased, which led to good dimensional stability. In addition, the SPI membranes with low ion‐exchange capacity (IEC) value displayed excellent hydrolytic stability and retained good mechanical properties even after harsh hydrolysis testing, in which the block SPI with hydrophilic segment length of 40 had the best hydrolytic stability, while those with high IEC value showed an apparent decrease. All of the block SPI membranes show better conductivity than the random ones at the temperature range from 30 to 70°C. Interestingly, the proton conductivities of random SPI membranes were higher than that of corresponding block ones at 90°C. The block SPI with hydrophilic segment length of 40 gave the highest proton conductivity as the temperature increased among the block SPIs. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41501. 相似文献
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Levent Cavas Pelin Gokfiliz Yildiz Paraskevi Mimigianni Andreas Sapalidis Stephanos Nitodas 《Journal of Coatings Technology and Research》2018,15(1):105-120
Poly (dimethyl siloxane) (PDMS) is a model silicon elastomer used as marine fouling-release coating, because it meets the fouling-release zone conditions of the Baier curve. However, weak mechanical properties limit its use. In this aspect, incorporation of carbon nanoparticles into PDMS is a common method for improving its mechanical properties. Since effective dispersion of nanofillers into polymer matrices is a challenge, a major aim of this study was to examine the PDMS mechanical reinforcement by developing different dispersing methods of pristine MWCNTs into PDMS matrix. SEM images of nanocomposites prepared using dispersion methods 1 and 2 revealed the formation of aggregates which subsequently affected the overall mechanical performance of the samples. Also, the effect of p-MWCNTs content and nanoparticle type [carboxyl-functionalized-MWCNTs, graphene oxide (GO)] on the mechanical properties of the nanocomposites was evaluated. Incorporation of p-MWCNTs did not alter drastically the critical surface energy value of neat PDMS, which subsequently influenced antifouling and cleaning performance of nanoreinforced coatings. To evaluate antifouling and cleaning performance of the nanocomposite coatings, seawater immersion tests were conducted. In conclusion, MWCNTs and GO increased the mechanical strength of the matrix, whereas they contributed to a small extent to the improvement in antifouling and cleaning performance of the composites. 相似文献
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Development of alternate materials to Nafion, based on ionically conducting polymers and their blends is important for the wider applications of proton exchange membrane fuel cells. In this work, blends of sulfonated poly(ether ether ketone) (SPEEK) with poly(ether sulfone) (PES) are investigated. SPEEK with various ion exchange capacity (IEC) was prepared and blended with PES, which is nonionic and hydrophobic in nature. A comparative study of the water uptake, proton conductivity, and thermo‐mechanical characteristics of SPEEK and the blend membranes as a function of the IEC is presented. Addition of PES decreases the water uptake and conductivity of SPEEK. Chemical and thermal stability and mechanical properties of the membrane improve with the addition of PES. The effect of water content on the thermo‐mechanical properties of membranes was also studied. The morphology of blend membranes was studied using SEM to understand the microstructure and miscibility of the components. On the basis of the results, a plausible microstructure of the blends is presented, and is shown to be useful in understanding the variation of different properties with blending. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013 相似文献
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Anion exchange membranes (AEMs) are one of the core components of AEM fuel cells. A series of poly(vinyl alcohol)/polyquaternium-10 (PVA/PQ-10) AEMs with semi-interpenetrating networks (s-IPNs) are prepared by a simple solution-casting method using glutaraldehyde (GA) as a cross-linking agent. Subsequently, the prepared PVA/PQ-10 cross-linked membranes are characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, thermogravimetric analysis, mechanical analysis, water uptake and swelling ratio tests, ion exchange capacity (IEC) tests, ionic conductivity measurements, and oxidative/alkaline stability tests. The effects of the mass ratio of PVA and PQ-10 and the amount of cross-linking agent GA on the performance of the PVA/PQ-10 cross-linked membranes are systematically explored. The results show that the cross-linked PVA/PQ-10 AEMs have high IEC and low water uptake and swelling ratio, and its maximum ionic conductivity can reach 79.37 mS cm–1 at 80 °C. In addition, the PVA/PQ-10 cross-linked membrane has good oxidative and alkaline stability under optimal preparation conditions. These results may provide valuable insights toward more effective scheme designs and new, simple preparation methods for AEMs with s-IPN structures. 相似文献