Novel branched sulfonated polyimide membrane with remarkable vanadium permeability resistance and proton selectivity for vanadium redox flow battery application

A series of novel branched sulfonated polyimide (bSPI-x) membranes with 8% branched degree are developed for application in vanadium redox flow battery (VRFB). The sulfonation degrees of bSPI-x membranes are precisely regulated for obtaining excellent comprehensive performance. Among all bSPI-x membranes, the bSPI-50 membrane shows strong vanadium permeability resistance, which is as 8 times as that of commercial Nafion 212 membrane. At the same time, the bSPI-50 membrane has remarkable proton selectivity, which is four times as high as that of Nafion 212 membrane. The bSPI-50 membrane possesses slower self-discharge speed than Nafion 212 membrane. Furthermore, the bSPI-50 membrane achieves stable VRFB efficiencies during 200-time charge-discharge cycles at 120–180 mA cm^?2. Simultaneously, the bSPI-50 membrane exhibits excellent capacity retention compared with Nafion 212 membrane. All results imply that the bSPI-50 membrane possesses good application prospect as a promising alternative separator of VRFB.     

硫酸化SnO2/SPPESK复合质子交换膜的制备及燃料电池性能

非氟聚合物磺化聚芳醚砜酮（SPPESK）具有甲醇渗透率低、化学、热稳定性高等优点，但其高的电导率需通过提高磺化度获得，导致膜因过度溶胀而失去尺寸稳定性。添加无机纳米颗粒可以有效提高膜性能，但因其表面缺少功能化基团，导致颗粒有机相容性差，阻醇性能和质子传导率不易同时提高。硫酸化改性的纳米颗粒因其表面具有酸性位点和硫酸基团，能够有效克服这一问题。本文制备表面硫酸化改性的SnO₂（SSnO₂）纳米颗粒并引入SPPESK基质制备有机无机复合质子交换膜。当SSnO₂含量不大于7.5%时，纳米颗粒具有良好的有机相容性，可均匀分散于聚合物基质。SSnO₂含量为7.5%时，80℃下复合膜吸水率（19.6%）比SPPESK原膜提高19%，接近Nafion115。颗粒诱导膜内离子簇的聚集扩大，降低了质子的传导阻力，质子传导率分别比SPPESK原膜和Nafion115膜提高48%和30%。同时，纳米颗粒增大了甲醇传递空间位阻，甲醇渗透率较SPPESK原膜和Nafion115膜分别降低46%和71%。直接甲醇燃料电池0.5V处功率密度分别比SPPESK原膜和Nafion115膜高205%和50%。     

Preparation and properties of lithium sulfonated polyoxadiazoles electrolyte

以硫酸肼（HS）、对苯二甲酸（TPA）、4，4'-联苯醚二甲酸（DPE）为单体，发烟硫酸做溶剂和脱水剂一步合成了一系列不同TPA和DPE单体配比的磺化聚芳噁二唑（SPOD），再通过氢氧化锂中和得到聚芳噁二唑磺酸锂（Li-SPOD）聚合物电解质，采用浇铸成膜法制得Li-SPOD电解质膜，研究改变TPA和DPE两种单体配比对Li-SPOD结构及性能的影响。结果表明，几种不同单体配比均能实现在聚合过程中一步得到SPOD，磺酸基团接枝在DPE结构的苯环上，并且可以达到理论接枝量；同时Li-SPOD电解质膜的聚集态结构差异很小；热性能的表现均非常优异，初始热分解温度都在450 ℃以上；力学性能随DPE单体含量的增加稍有下降但依然保持在较高的水平；电导率约为10^-5S/cm级别，随DPE含量增加而逐渐降低；Li-SPOD固态电解质电化学稳定性较好，对锂稳定电化学窗口均在4.0 V以上。     

钻井液用阳离子型磺化酚醛树脂降滤失剂的研制

将阳离子结构单体在催化剂作用下引入酚醛树脂结构,再通过多步磺化反应制得阳离子型磺化酚醛树脂。简要描述了合成方法,检测了部分表征性能及作为水基钻井液降滤失剂的性能。在红外谱图中能清楚地看到阳离子结构。该结构样品在黏土颗粒上的饱和吸附量高达33.51 mg/g土,浊点盐度(以Cl-计)≥160g/L,参考石油天然气行业标准SY/T5094-2008将阳离子型磺化酚醛树脂200℃热滚16 h后在180℃,3.5 MPa条件下测试其滤失量,评价结果显示阳离子型磺化酚醛树脂的抗高温高压降滤失性优于现用SMP系列产品。     

煤基离子交换剂的制备及应用

以氧化煤与磺化聚苯乙烯高分子采用溶剂共混法 ,制成复合型功能性材料———煤基离子交换剂 .该材料主要用于对废水中重金属离子Zn2 +、Pb2 +、Cd2 +、Ni2 +的处理 ,吸附效果具有独特性 ,是新型的煤基高分子材料 ,在煤的非能源利用方面开辟了新的途径     

磺化苯酚-甲醛缩聚物型(SPF)高效减水剂合成及分散性能研究

根据分子设计的原则,从构成减水剂的分子结构和引入官能团入手,对磺化苯酚-甲醛缩聚物型(SPF)高效减水剂进行了系统的合成试验,研究了原料的配比和反应条件对产物分散性能的影响,同时比较了不同减水剂对于水泥颗粒的分散效果,研究表明磺化苯酚-甲醛缩聚物型(SPF)高效减水剂具有广阔的使用前景。     

氨基化GO/磺化聚苯胺改性水性环氧防腐涂料的制备与性能

以氯磺酸、苯胺和过硫酸铵为主要原料合成磺化聚苯胺（SPANI）,利用聚乙烯亚胺（PEI）还原GO,合成PG复合材料。利用GO上活性位点,将SPANI与PG结合,制备了SPG复合材料。利用SPG与水性环氧树脂共混制备水性环氧防腐涂料。通过FT-IR、XRD对SPG复合材料结构表征,结果表明,PEI上的氨基成功与GO结合,SPANI成功增加了PG的层间距;通过盐雾、电化学等实验对水性环氧涂层的防腐性能进行测定,并分析了涂层的物理性能。结果表明,当添加2wt%SPG时（添加量以环氧树脂和固化剂总质量为基准,下同）的水性环氧防腐涂层具有最优异的耐腐蚀性,腐蚀效率可达到99.19%,与纯EP相比,腐蚀电流密度从1080 nA?cm-2减小至307 nA?cm-2,腐蚀电压从-0.840mV升高至-0.347mV。     

Vicious cycle during chemical degradation of sulfonated aromatic proton exchange membranes in the fuel cell application

Weak phase separation and vulnerable linking groups between aromatic units are common setbacks of sulfonated aromatic proton exchange membranes (PEMs) from durability point of view. In this study, sulfonated poly(ether ether ketone) (SPEEK) membranes were exposed to Fenton's solution for a specific time, ranging from 10 to 60 minutes. Chemical structure and morphology evolution, decay in mechanical and thermal stability, and H₂ permeability of SPEEK membranes were evaluated during the chemical degradation. Less-entangled polymeric chains with lower average molecular weight of degraded SPEEK samples diminished mechanical rigidity. In addition, reduction of aromatic rings in each repeat unit led to higher thermal decomposition rate. Furthermore, randomly distributed micro-defects in the SPEEK morphology and an increase in water sorption can reduce the fatigue strength of membranes in the wet-dry cycles. Eventually, hydrogen cross-over rate was gradually increased, and henceforth, accelerated destructive radical formation and degradation can be predicted.     

Effects of special nanoparticles on fuel cell properties of sulfonated polyethersulfone membrane

Polyethersulfone was sulfonated by changing the reaction time with sulfuric acid. The degree of sulfonation and ion exchange capacity were determined. Sulfonation of polyethersulfone was confirmed by FT-IR analysis and a new peak at 1025 cm^?1. Inorganic materials such as carbon nanotubes, graphene, and kaolinite nanoparticles were synthesized. The effects of three nanoparticles on thermal stability and water uptake of sulfonated polyethersulfone were investigated. The morphology of membranes were also altered due to the addition of inorganic materials. The proton conductivity of the modified membranes increased with respect to increase in relative humidity.