Entity

Time filter

Source Type


Zhu Y.,Shanghai JiaoTong University | Tang J.,Dongyue Shenzhou New Materials Co. | Zhang Y.,Shanghai JiaoTong University
ECS Transactions | Year: 2012

The copolymeric perfluorosulfonic acid ionomers consisting of both short and long side chain segments (SLSC PFSA) were designed and successfully synthesized. To further enhance the performance of such new ionomers based membranes, SLSC PFSA/PTFE composite membranes were fabricated. On one hand, the membranes kept such advantages of short side chain (SSC) PFSA membranes as high IEC, high crystallinity, and moreover excellent thermal and chemical stability. On the other hand, the long-side chain will affect the membrane microstructures, such as ion cluster size, density, and distribution, thus endowing the new membranes unique and excellent performances. Source


Zhu Y.,Shanghai JiaoTong University | Li H.,Shanghai JiaoTong University | Tang J.,Dongyue Shenzhou New Materials Co. | Wang L.,Dongyue Shenzhou New Materials Co. | And 5 more authors.
RSC Advances | Year: 2014

The stability of perfluorosulfonic acid (PFSA) membranes is one of the most essential issues affecting the performance of fuel cells. The investigation of membrane stability is therefore of significant importance for fuel cell applications. So far, however, the most elaborate research on membrane stability has focused on the commercial Nafion® series, which has a fixed ion exchange capacity (IEC) of 0.91 mmol g-1; there is therefore a lack of systematic studies for membranes with varying IEC values. Recently, our group successfully synthesized a variety of PFSA resins with IEC values ranging from 0.91 to 1.4 mmol g-1, providing an opportunity for us to investigate the effect of factors such as the IEC value, crystallinity and ion-cluster channels, on membrane stability. The proton conductivity and methanol permeability of the membranes are also considered to be crucial parameters which affect fuel cell performance. With these in mind, optimized membranes suitable for fuel cell applications were finally identified. © 2014 The Royal Society of Chemistry. Source


Zhu Y.,Shanghai JiaoTong University | Pei S.,Zhongyuan University of Technology | Tang J.,Dongyue Shenzhou New Materials Co. | Li H.,Shanghai JiaoTong University | And 3 more authors.
Journal of Membrane Science | Year: 2013

Chemical durability of perfluorosulfonic acid (PFSA) membranes is of crucial importance for their applications in proton exchange membrane fuel cells (PEMFCs). Herein, we report an easy method to enhance the chemical durability of PFSA membranes by incorporation of terephthalic acid (TPA) as a hydroxyl radical (OH) scavenger. Recast TPA/PFSA composite membranes were prepared with TPA molecules uniformly dispersed. Fenton acceleration test, an effective method to evaluate the membrane durability, was conducted. PFSA ionomer degradation was characterized by FTIR, XPS, and ion chromatography. It is found that the functional group loss and decomposition ratio of C-F and sulfonic acid groups in TPA/PFSA composite membranes are less than those in PFSA membranes. Proton conductivity, methanol permeability, and mechanical durability investigations testify the remarkably mitigated degradation for TPA/PFSA membranes, owing to the presence of TPA. These results clearly suggest that incorporation of such radical trappers as TPA into PFSA membranes can effectively improve their chemical durability, thus making them promising in fuel cell applications. © 2013 Elsevier B.V. Source


Tang J.,Shanghai JiaoTong University | Yuan W.,Shanghai JiaoTong University | Wang J.,Shanghai JiaoTong University | Tang J.,Dongyue Shenzhou New Materials Co. | And 2 more authors.
Journal of Membrane Science | Year: 2012

Magnetic field treated perfluorosulfonate ionomer (PFSI) membranes (M-PMs) with improved through-plane proton conductivity are facilely fabricated though solvent casting of PFSI/Fe 3O 4 nanocomposite dispersion without any third additive under magnetic field followed by discarding the Fe 3O 4 nanoparticles. In the PFSI/Fe 3O 4 nanocomposite membrane, Fe 3O 4 nanoparticles are clearly uniaxially aligned by magnetic field. Subsequently, M-PMs are obtained by removing Fe 3O 4 from the nanocomposite membranes to eliminate the negative effect of Fe 3O 4 on proton conducting. The effect of magnetic field treatment on M-PMs' performance is investigated by both in- and through-plane proton conductivity. The results demonstrate that the through-plane proton conductivity of the M-PMs prepared from PFSI/Fe 3O 4 nanocomposite membrane with optimized Fe 3O 4 content is enhanced, while the in-plane proton conductivity is reduced compared to the pristine PFSI membrane, which indicate through-plane anisotropic phenomenon of proton conducting in the membranes. Such magnetic field treated PFSI membranes exhibit good appropriateness for using in electrochemical applications, for example fuel cells. © 2012 Elsevier B.V. Source


Zhu Y.,Shanghai JiaoTong University | Mai J.,Beihai Vocational College | Li H.,Shanghai JiaoTong University | Tang J.,Dongyue Shenzhou New Materials Co. | And 2 more authors.
Polymer Degradation and Stability | Year: 2014

Perfluorosulfonic acid (PFSA) membrane is the core component in fuel cell system. However, it is susceptible to degradation due to radical attack on the polymer chains. Thus, improvement of the membrane stability is of significant importance for fuel cell applications. In this work, terephthalic acid (TPA), an effective hydroxyl radical (OH) scavenger, was incorporated into PFSA membranes with varying fractions. The pristine and composite membranes were further treated in supercritical carbon dioxide (Sc-CO2), resulting in membranes with increased crystallinity and thus improved dimensional and physical stability. Fenton acceleration test was conducted to evaluate the chemical durability of the membranes. It is found that Sc-CO2treated membranes show better stability than those without treatment. Moreover, incorporation of appropriate fraction of TPA (0.5-1 wt%) can further mitigate chemical degradation of the membranes owing to its radical trapping capacity. Such combined effect between TPA and Sc-CO2 treatment affords highly stable PFSA membranes, which are promising for fuel cell applications. © 2014 Elsevier Ltd. All rights reserved. Source

Discover hidden collaborations