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11.
《International Journal of Hydrogen Energy》2020,45(57):32856-32864
The electrode ionomer is a key factor that significantly affects the catalyst layer morphology and fuel cell performance. Herein, sulfonated poly(arylene ether sulfone)-based electrode ionomers with polymers of various molecular weights and alcohol/water mixtures were prepared, and those comprising the alcohol/water mixture showed a higher performance than the ones prepared using higher boiling solvents, such as dimethylacetamide; this is owing to the formation of the uniformly dispersed ionomer catalyst layer. The relation between ionomer molecular weight for the same polymer structure and the sulfonation degree was investigated. Because the chain length of polymer varies with molecular weight and chain entanglement degree, its molecular weight affects the electrode morphology. As the ionomer covered the catalyst, the agglomerates formed were of different morphologies according to their molecular weight, which could be deduced indirectly through dynamic light scattering and scanning electron microscopy. Additionally, the fuel cell performance was confirmed in the current-voltage curve. 相似文献
12.
《International Journal of Hydrogen Energy》2020,45(35):17782-17794
Phosphotungstic acid (HPW) has a good potential as nanofillers in nanocomposite proton exchange membrane with the prerequisite of solving the leakage issue. It is immobilized onto mesoporous graphitic carbon nitride (mg-C3N4) nanosheets surface, and then incorporated into sulfonated poly (aryl ether sulfone) (SPAES) membrane. Structures of the HPW/mg-C3N4 nanocomposites and corresponding SPAES/HPW/mg-C3N4 membranes are characterized by spectroscopic techniques. Fundamental properties and fuel cell performance of the fabricated nanocomposite membranes, and the leakage of HPW are investigated. Along with the highly suppressed HPW leakage, the SPAES/HPW/mg-C3N4 membranes show improved dimensional stability, water affinity and physicochemical stability, as well as better proton conductivity and fuel cell performance. At 80 °C and 60–100% RH, the SPAES/HPW/mg–C3N4–1.5 membrane exhibits 2–3.6 times peak power densities (354.9–584.2 mW/cm2) of the pristine SPAES membrane, and proton conductivity of 203 mS/cm, dimensional change less than 7.5% and weight loss of 1.4% in Fenton oxidation test at 80 °C. 相似文献
13.
Zhaoyang Wang Yingshuang Shang Xiaocui Han Qixing Yan Jie Liu Zilong Jiang Haibo Zhang 《大分子材料与工程》2020,305(4)
The production of low dielectric materials that can be used in high temperature environments is the primary aim of this work. A cross‐linked structure is introduced into fluorinated poly(aryl ether) (named as FPAE) with high molecular weight (Mw, 140 000 g mol?1) and linear molecular structure using nucleophilic substitution reaction at the ortho‐position of decafluorobiphenyl monomer units in the FPAE molecular chain. The curing temperature and curing time are optimized and the final conditions for the cross‐linking reaction in this study are determined to be 300 °C for 1 h. Moreover, the dielectric constant and dielectric loss of the C‐FPAE film respectively are 2.67 and 0.006 at 1000 Hz when 1 wt% of crosslinking agent is added, and the cross‐linked fluorinated poly(aryl ether) film shows excellent thermal stability (Td(5%), 495 °C), dimensional stability, hydrophobic properties, and high storage modulus in high temperature environments. Such novel low dielectric material with excellent performances has important application value in the aerospace and the integrated electronics field. 相似文献
14.
《International Journal of Hydrogen Energy》2022,47(19):10736-10746
This study demonstrates the successful development of hybrid mesoporous siliceous phosphotungstic acid (mPTA-Si) and sulfonated poly ether ether ketone (SPEEK) as a proton exchange membrane with a high performance in hydrogen proton exchange membrane fuel cells (PEMFC). SPEEK acts as a polymeric membrane matrix and mPTA-Si acts as the mechanical reinforcer and proton conducting enhancer. Interestingly, incorporating mPTA-Si did not affect the morphological aspect of SPEEK as dense membrane upon loading the amount of mPTA-Si up to 2.5 wt%. The water uptake reduced to 14% from 21.5% when mPTA-Si content increases from 0.5 to 2.5 wt% respectively. Meanwhile, the proton conductivity increased to 0.01 Scm?1 with 1.0 wt% mPTA-Si and maximum power density of 180.87 mWcm?2 which is 200% improvement as compared to pristine SPEEK membrane. The systematic study of hybrid SP-mPTA-Si membrane proved a substantial enhancement in the performance together with further improvement on physicochemical properties of parent SPEEK membrane desirable for the PEMFC application. 相似文献
15.
16.
通过无皂乳液聚合法制备得到聚(三氟氯乙烯-乙烯基异丁基醚-十一烯酸钠)[P(CTFE-IBVE-SUA)]含氟乳液。考察了单体配比对聚合反应的影响,研究了SUA用量对乳液及聚合物性能的影响,并对聚合物的结构及乳胶粒的形貌进行了测定。结果表明:含氟无皂乳液P(CTFE-IBVE-SUA)的稳定性好、粒径分布均匀;改变单体配比中IBVE和CTFE的比例可以得到不同结构的含氟聚合物乳液;SUA用量对乳液的稳定性、乳胶粒的粒径大小及粒径分布、聚合物膜与水的接触角都有很大的影响;制得的乳液具有明显的核壳结构。 相似文献
17.
18.
Liang-Chen Wang Chen-Guo Zhu Hong-Bin Liu Wei-Dong Zhao Yao Che Qiao-Ling Zhang Liang-Bi Wang 《应用聚合物科学杂志》2019,136(19):47470
Polymer scale inhibitors have been widely used to reduce the loss caused by mineral scaling in circulating cooling water systems. In this article, four maleic acid-based copolymers [hydrolyzed polymaleic anhydride (HPMA)-AEO] containing different fatty alcohol polyoxyethylene ether (such as AEO-9, AEO-10, AEO-15, and AEO-20) are prepared by the way of free-radical copolymerization and characterized using Fourier transform infrared (FTIR), 1H NMR, and gel permeation chromatographic (GPC) techniques. The effects of HPMA-AEO on CaCO3 scale are studied in several aspects (such as dose, Ca2+ concentration, temperature, inhibition time, pH, the ratio of EO:carboxyl, and the relative supersaturation of CaCO3 solution) by static experiments. The CaCO3 scaling process with dosing of HPMA-AEO-9 is investigated under dynamic tests. CaCO3 deposits and precipitate in the presence of HPMA-AEO-9 are analyzed using scanning electronic microscope (SEM) and X-ray diffraction (XRD). The results show that the performance of HPMA-AEO against CaCO3 scale highly depends upon the ratio of EO:carboxyl; the introduction of AEO group can significantly improve the performance of HPMA-AEO to tolerate high alkalinity, high hardness, and high temperature; the presence of HPMA-AEO-9 can obviously affect the CaCO3 scaling process on the tube wall through interfering with nucleation process and crystal growth process and significantly alter the surface morphology and crystal form of CaCO3 deposits. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47470 相似文献
19.
In this study, the synthesis, morphology, and thermal properties of new poly(ether imide)/titania nanohybrid films were investigated. The novel diamine containing functional nitrile groups was prepared in two steps by the nucleophilic substitution reaction and it was fully characterized by different techniques. Reaction of this diamine with pyromellitic dianhydride and 4-aminobenzoic acid gave poly(ether imide) with carboxylic acid end groups. This acid functionalized poly(ether imide) was condense with different amount of TiO2 nanoparticles to provide organic-inorganic bonding, and the flexible films of these hybrid were prepared. The obtained materials were characterized by Fourier transform-infrared spectroscopy, thermogravimetry analysis (TGA), differential scanning calorimetry, X-ray powder diffraction, UV–Vis spectroscopy, field emission-scanning electron microscopy, and transmission electron microscopy (TEM) techniques. TEM of the nanohybrid films with 12% of TiO2 contents confirms well dispersion of nanoparticles in the polymer matrix. TGA data indicated that the thermal behavior of the hybrid materials was increased with an increasing the content of TiO2 nanoparticles. The tensile stress–strain of the hybrids was investigated and the resulting nanocomposites showed good mechanical properties. The permeability and selectivity of the PEI/TiO2 membranes as a function of the titania weight percentage were study and the results indicated that the permeabilities of CO2 and N2 increase with increasing the titania content. 相似文献
20.
Mohammad Mahdi Hasani-Sadrabadi Erfan Dashtimoghadam Seyed Nasireddin Saeedi Eslami Ghasem Bahlakeh Mohammad Ali Shokrgozar Karl I. Jacob 《Polymer》2014
This work aims to improve the performance of air-breathing microbial fuel cells (MFCs) through using hydrocarbon polymer based nanocomposite proton exchange membranes. Accordingly, nanocomposite membranes based on sulfonated poly(ether ether ketone) (SPEEK) and montmorillonite (MMT) were investigated for such an application. Although the incorporation of MMT into SPEEK membranes resulted in reduced oxygen permeability as well as proton conductivity, but the overall selectivity was found to be improved. MFC tests revealed that using the optimized nanocomposite membrane (SPEEK-70/MMT-3 wt%) results in a considerably higher open circuit voltage (OCV) compared to the corresponding neat membrane. Moreover, it was found that the SPEEK-70/MMT-3 wt% membrane is able to provide about 40% more power output than Nafion®117. On the account of high proton conductivity, low oxygen permeability, high electrochemical performance, ease of preparation and low cost, hydrocarbon based nanocomposite PEMs could be considered as promising electrolytes to enhance the performance of MFCs. 相似文献