含笼型倍半硅氧烷星型嵌段共聚物/聚偏二氟乙烯复合质子交换膜的性能

通过共混的方法制备了含倍半硅氧烷(POSS)星型拓扑结构的嵌段共聚物POSS-(PMMA26-b-SPS156)8/聚偏二氟乙烯(PVDF)复合质子交换膜。通过研究复合膜的离子交换容量(IEC)、质子传导率、吸水率、溶胀率及其在低湿度下的自旋-自旋弛豫时间(T2),考察了PVDF含量对复合膜性能的影响。结果表明,随PVDF添加量的增加,质子交换膜的IEC、吸水率和溶胀率降低,在测定温度下复合膜尺寸稳定性提高;PVDF还可以提高共聚物膜在高温下的电导率,降低膜对湿度的依赖性;在湿度30%,温度80℃时,添加PVDF50%的复合膜比纯共聚物膜的质子传导率高约1个数量级;由复合质子交换膜结合水的状态差异剖析了复合膜在低湿度下质子传导率高的原因。     

磺化聚苯醚/聚醚酰亚胺共混质子交换膜的制备与性能

以磺化聚苯醚(SPPO)和聚醚酰亚胺(PEI)为原料,采用溶液共混法制备了SPPO/PEI共混质子交换膜,并经扫描电镜(SEM)、热重分析、拉伸测试等对膜的结构和性能进行了表征。结果表明,共混膜较纯SPPO膜具有更高的热稳定性、力学性能和尺寸稳定性;SPPO与PEI之间的强烈氢键相互作用使两组分之间并未发生明显的相分离。PEI的引入虽使得共混膜的质子传导率有所下降,但对于PEI含量在40%以下的共混膜,其质子传导率仍维持在约10-2S/cm的数量级水平,能满足质子交换膜的要求。     

氧化石墨烯/笼型聚倍半硅氧烷星型嵌段共聚物复合质子交换膜的制备与性能

通过共混的方法制备了含笼型聚倍半硅氧烷(POSS)星型拓扑结构嵌段共聚物的氧化石墨烯(GO)/笼型聚倍半硅氧烷-(聚甲基丙烯酸甲酯-共聚-磺化聚苯乙烯)(POSS-(PMMA₂₆-b-SPS₁₅₆)₈)复合质子交换膜。通过研究复合质子交换膜的离子交换容量(IEC)、质子传导率、吸水率与溶胀率,考察了GO含量对复合质子交换膜性能的影响。研究发现:复合质子交换膜的离子交换容量随GO含量的增加而升高,吸水率和溶胀率随着GO加入而降低,在测定温度范围内复合质子交换膜均表现出较高的尺寸稳定性,GO的添加改善了纯聚合物膜在80℃失水导致传导率下降的问题,提高了质子交换膜的质子传导率,发现在相对湿度为100%、80℃时,GO含量为0.3wt%的复合质子交换膜的质子传导率约为纯聚合物膜的3.2倍。      

SPEEK/P4VP酸碱复合质子交换膜的制备与性能

利用4-乙烯吡啶(4-VP)碱性单体与磺化聚醚醚酮(SPEEK)共混,通过热聚合方法制备了SPEEK/P4VP酸碱复合质子交换膜,并考察了引发剂种类、用量和P4VP添加量对复合膜制备和性能的影响。质量分数为0.2%的偶氮二异丁腈较适宜作为引发剂制备复合膜;P4VP的添加使得复合膜的质子传导率和离子交换容量IEC(IEC=mmol SO3H/g drymembrane)略有下降,但复合膜的吸水率降低,抑制溶胀能力增强,且温度越高,抑制能力越为明显,此外复合膜的阻醇性能和拉伸屈服应力也有所提高,当4-VP的含量在50%(质量分数,下同)时,复合膜的甲醇渗透率与SPEEK和Nafion膜相比分别下降了70%和99%。     

磺化聚芳醚酮砜/PVA复合质子交换膜的制备与性能

为了进一步提高质子交换膜在中高温时的质子导电率,文中以高磺化度的磺化聚芳醚酮砜(SPAEKS)和聚乙烯醇(PVA)为原料,通过溶液共混法制备了PVA不同含量的磺化聚芳醚酮砜/PVA复合膜。通过对复合膜的性能测试发现,PVA的引入提高了膜的热稳定性、吸水率和保水能力。而且SPAEKS/PVA复合膜的质子传导率高于SPAEKS膜,在80℃时,复合膜的质子传导率都在0.07 S/cm以上,能够满足中高温质子交换膜燃料电池的使用要求。     

SPPO/SiO2/PWA复合质子交换膜的制备及性能

利用溶胶-凝胶法制备出了SPPO/SiO2/PWA复合质子交换膜,对膜的离子交换容量(IEC)、平均当量重量(EW)、磺化度(SD)、吸水性、溶胀率、质子电导率、Tg进行了表征,此外,还对膜的结构进行了FT-IR、SEM表征,结果表明,所制得的掺杂2%～5%SiO2和3%PWA的SPPO复合膜在100℃、100%相对湿度时的质子电导率与Nafion-117?膜相近,有望作为质子交换膜使用。     

低温燃料电池用聚(2,5-苯并咪唑)/磺化海泡石复合质子交换膜的制备与性能EI北大核心CSCD

采用原位法制备了一种适用于低温燃料电池的新型聚(2,5-苯并咪唑)/磺化海泡石(ABPBI/S-Sep)复合质子交换膜。对海泡石酸活化和磺化改性前后的化学结构、亲水性和分散性以及复合膜的形貌、吸水率、磷酸掺杂水平与质子传导率等性能进行了表征和测试。结果显示,所制备的S-Sep粒子在ABPBI聚合物基体中分散均匀,并能促进聚合物分子链的规整排布;与纯ABPBI膜相比,S-Sep粒子的添加显著增强了复合膜对水和磷酸的吸收和保留能力,且在相同或相近磷酸掺杂水平下,ABPBI/S-Sep复合膜的质子传导率显著提高。在40～90℃温度范围内,饱和湿度98%RH时复合膜的质子传导率与Nafion 212相当;在低湿度60%RH时,高磷酸掺杂水平的ABPBI/S-Sep复合膜质子传导率略低于98%RH的结果,但显著优于Nafion 212的质子传导性能。不同温湿度环境下的质子传导率结果表明S-Sep改性ABPBI复合膜具备低温环境使用的特点,可替代Nafion类全氟磺酸膜应用于低温质子交换膜燃料电池。     

低温燃料电池用聚(2,5-苯并咪唑)/磺化海泡石复合质子交换膜的制备与性能

采用原位法制备了一种适用于低温燃料电池的新型聚(2,5-苯并咪唑)/磺化海泡石(ABPBI/S-Sep)复合质子交换膜。对海泡石酸活化和磺化改性前后的化学结构、亲水性和分散性以及复合膜的形貌、吸水率、磷酸掺杂水平与质子传导率等性能进行了表征和测试。结果显示,所制备的S-Sep粒子在ABPBI聚合物基体中分散均匀,并能促进聚合物分子链的规整排布;与纯ABPBI膜相比,S-Sep粒子的添加显著增强了复合膜对水和磷酸的吸收和保留能力,且在相同或相近磷酸掺杂水平下,ABPBI/S-Sep复合膜的质子传导率显著提高。在40～90℃温度范围内,饱和湿度98%RH时复合膜的质子传导率与Nafion 212相当;在低湿度60%RH时,高磷酸掺杂水平的ABPBI/S-Sep复合膜质子传导率略低于98%RH的结果,但显著优于Nafion 212的质子传导性能。不同温湿度环境下的质子传导率结果表明S-Sep改性ABPBI复合膜具备低温环境使用的特点,可替代Nafion类全氟磺酸膜应用于低温质子交换膜燃料电池。     

磺化聚芳醚酮砜/TiO2复合质子交换膜的制备与性能

为了满足高温燃料电池对质子交换膜的要求,通过溶胶共混法制备了掺有不同含量TiO2纳米粒子的磺化聚芳醚酮(SPAEKS)/TiO2复合膜。红外光谱证实TiO2被引入到SPAEKS共聚物中。扫描电镜(SEM)照片显示,纳米级的TiO2粒子能够均匀地分散在SPAEKS共聚物基体中。通过对复合膜的性能测试发现TiO2的引入,复合膜的热稳定性、吸水率、保水能力及阻醇性能都有所提高。而且SPAEKS/TiO2复合膜的质子传导率高于SPAEKS膜,并在高温时尤为明显,能够满足高温燃料电池的需要。     

磺化聚酰亚胺/多孔聚四氟乙烯复合膜的制备与性能研究

采用表面活性剂对聚四氟乙烯多孔膜进行了表面亲水处理,然后与一种磺化聚酰亚胺膜进行复合,成功地制得了磺化聚酰亚胺/多孔聚四氟乙烯复合膜。该复合膜比相应的未复合的磺化聚酰亚胺膜具有更高的力学强度。与相同离子交换容量(IEC)的磺化聚酰亚胺共聚物膜相比,该复合膜具有相近的质子电导率,但其溶胀率和吸水率更低,显示出更好的综合性能。     

Synthesis and characterization of sulfonated poly(ether imide) membranes using thermo-analysis and dialysis process

Polyimides have been investigated as alternative materials to commercial membranes, once these polymers present high thermal, chemical, and mechanical performances. This work has modified poly(ether imide), PEI, by sulfonation reaction using acetyl sulfate as sulfonating agent. Sulfonated PEI (SPEI) films were characterized by infrared spectroscopy, ion exchange capacity (IEC), glass transition temperature (Tg), and proton diffusivity. The influence of degree of sulfonation on IEC, Tg, and proton diffusivity can be observed. SPEI membranes have presented proton diffusivity lower than that obtained with a commercial sulfonated membrane (Nafion). This result was related to low degree of sulfonation and low chain mobility of the obtained SPEI.     

一种新型的磺化聚芳醚酮质子交换膜材料

利用先聚合后磺化的方法合成了一种新型磺化聚芳醚酮,FTIR和HNMR结构表征表明,其磺酸基只连在悬挂侧链上.利用浇铸法将该材料制备成膜,对膜的离子交换容量(IEC)、平均当量重量(EW)、磺化度(SD)、吸水性、线性膨胀率及其电导率进行了表征,结果表明这种膜材料具有良好的吸水性和较低的线性溶胀率,所制得的膜在100℃、100%相对湿度时的质子电导率与Nafion-117~(R)膜相近,有望作为质子交换膜使用.     

Ion transport within random-sulfonated and block-sulfonated copolyimides

A series of sulfonated copolyimides was prepared from 4,4-oxydianiline, sulfonated 4,4′-oxydianiline, and 4,4′-(4,4′-isopropylidenediphenoxy) bis(phthalic anhydride). Both random- and block structures were prepared by varying the timing of monomer addition to the polymerization reaction. The polymers were converted to their acid forms and then cast into films. ¹H NMR, FTIR, and non-aqueous titration verified the degree of polymer sulfonation. The block copolymers showed higher water uptake and proton conductivities than random copolymers with similar ion exchange capacity (IEC) values. These differences became pronounced as the IEC value was increased.     

Ionic polymer–metal composite actuators obtained from sulfonated poly(ether ether sulfone) ion-exchange membranes

The cost-effective and high-performance ionic polymer–metal composites (IPMC) were designed and prepared from ion-exchange membranes based on sulfonated poly(ether ether sulfone) (SPEES) with different degrees of sulfonation (DS). The precursor of SPEES, namely PEES, is commercially available and industrial grade. Moreover, the PEES can be transformed easily into ion-conductive SPEES through a simple sulfonation reaction. The ion exchange capacity (IEC) and water uptake (WU) of SPEES membranes increase with increasing their DS, and the proton conductivities of these hydrated SPEES membranes are subsequently enhanced. Compared with the commercial Nafion ion-exchange membrane, the SPEES membranes have higher IEC and WU. The IPMC actuators made of the SPEES membranes show the large bending strain and fast response under electric stimulation. The SPEES membrane with the highest DS (SPEES4) shows the best performance of IPMC actuators. The electromechanical behaviors of these IPMC actuators indicate that the SPEES is a candidate to substitute Nafion.     

Influence of preparation procedure and ferric oxide nanoparticles addition on transport properties of homogeneous cation-exchange SPPO/SPVC membrane

Homogeneous cation-exchange membranes were prepared through evaporation and phase inversion methods using sulfonated poly(2,6-dimethyl-1,4-phenylene oxide) (SPPO) and sulfonated polyvinylchloride as binders. The effect of polymers blend’s ratio and preparation method on structure and electrochemical properties of the prepared membranes were evaluated. The microstructures of the membranes were investigated by scanning electron microscopy (SEM) and the sulfonation of polyvinylchloride was confirmed by elemental analyses. Moreover, the membranes performance was evaluated by ion-exchange capacity (IEC), fixed ion concentration, membrane potential, transport number, permselectivity, areal resistance, ionic permeability, flux of ions, current efficiency, membrane oxidative stability, mechanical properties and water content tests. The results indicated that IEC and water content were affected by the SPPO content and microstructures of the membranes. The results showed increased efficiency and suitable electrochemical properties for membranes prepared by the evaporation method in comparison with others. Also, \(\hbox {Fe}_{2}\hbox {O}_{3}\) nanoparticles were synthesized at room temperature by a simple sonochemical reaction between ferric chloride and NaOH. The results revealed that the addition of different amounts of \(\hbox {Fe}_{2}\hbox {O}_{3}\) nanoparticles to the polymeric matrix could affect the hydrophilicity and transport properties of ion-exchange membranes.     

全钒液流电池用新型全氟磺酸离子交换膜制备及性能研究

通过溶液流延成膜法制备了具有不同离子交换容量(IEC)的全氟磺酸(PFSA)离子交换膜,并测试了其吸水率、电导率、钒离子(Ⅴ(Ⅳ))透过率和选择性系数。研究发现,具有高IEC值的PFSA离子交换膜具有相对较低的Ⅴ(Ⅳ)离子透过率和较高的质子电导率。其中IEC值为1.10mmol/g的PFSA离子交换膜对Ⅴ(Ⅳ)离子具有最高的选择性,其选择性系数为Nafion 117膜的2.97倍。     

Synthesis,characterization of novel silicotungstic acid incorporated SPEEK/PVA-co-ethylene-based composite membranes for fuel cell

Sulfonated polyether ether ketone (SPEEK) is prepared by the sulfonation of polyether ether ketone (PEEK). Five of the composite membranes (PSW1–PSW5) with various percentage compositions of the SPEEK, PVA-co-ethylene, and silicotungstic acid (SWA) were prepared. The prepared composite membranes were characterized using Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), and thermogravimetric analysis (TGA). Surface morphology of the composite membranes was analyzed using scanning electron microscopy (SEM). Other evaluations related to conductivities (ion exchange capacity, IEC), proton conductivity), absorptivity (water and methanol absorption), durability and mechanical properties (tensile strength and percentage elongation) were also evaluated for the composite membranes. Among the five composite membranes, composite membrane with higher SWA content, PSW5 (which has 10% SWA) showed more conductivity compared to other membranes. These composites also showed very good conductivities, mechanical properties, and durabilities. Hence, these composite membranes have the potential to be used in the development of newer proton exchange membrane fuel cells (PEMFCs).