The Influence on Proton Conductivity and Methanol Permeability of SiO2/PVA-PAMPS Composite Membrane

2012 ◽  
Vol 503-504 ◽  
pp. 625-628 ◽  
Author(s):  
Chun Hua Yuan ◽  
Gui Bao Guo ◽  
Sheng Li An

Polyvinyl alcohol(PVA) modified by SiO2/poly 2-acrylamido 2-methylpropane sulfonic acid (PAMPS) electrolyte membrane (SiO2/PVA-PAMPS ) was prepared by a Sol-gel synthesis in situ technique for DMFC. The influence of the different ratio of AMPS and SiCl4 on the proton conductivity and methanol permeability of these membranes was studied using an impedance analyzer and a gas chromatograph. The results showed that with increasing of the content of silicon dioxide, the SiO2 was homogeneously distributed in the membrane. As the AMPS content increased, the proton conductivity of the SiO2/PVA-PAMPS membranes also increased. The swelling degree of the SiO2/PVA-PAMPS membrane with 30wt% SiCl4 and 20wt% AMPS was 28.79% at 25°C. The membranes possess a methanol permeability of around 10-7 cm2•S-1, which is about one order of magnitude lower than that of Nafion115. These membranes have high selectivity and are promising for use in direct methanol fuel cells (DMFC).

2012 ◽  
Vol 24 (8) ◽  
pp. 756-764 ◽  
Author(s):  
Rong Zeng ◽  
Shuqin Xiao ◽  
Lie Chen ◽  
Yiwang Chen

Sulfonated polynorbornene (SPNB) and 3-aminopropyltriethoxysilane (KH550) hybrid cross-linked proton exchange membranes doped with different weight ratio of phosphotungstic acid (PWA) were prepared by a simple sol-gel process. The cross-linked structures led to low methanol permeability and good stability of the nanocomposites. Incorporation of PWA has significantly improved the proton conductivity of the hybrid membrane due to an extra provided conductive proton-conduction pathway to facilitate proton transportation. In particular, the conductivity of SPNB/KH550/PWA25 reached the maximum of 0.02 S.cm−1 at 80°C under the 100% relative humidity condition, and this value is on the same order of magnitude as that of Nafion117. Furthermore, SPNB /KH550/PWA20 owns the lowest proton transport activation energy (8.39 kJ.mol−1).


2011 ◽  
Vol 23 (7) ◽  
pp. 555-560 ◽  
Author(s):  
Geng Fei ◽  
Mi-Lim Hwang ◽  
Junhwa Shin

Poly(vinylbenzyl sulfonic acid)-grafted poly(tetrafluoroethylene-co-hexafluoropropylene) (FEP- g-PVBSA) electrolyte membrane was prepared by radiation-induced grafting of vinylbenzyl chloride onto FEP film with subsequent sulfonation processes. An energy dispersive X-ray analysis was used to observe the cross-sectional distribution behaviors of the hydrophilic sulfonic acid groups and hydrophobic fluorine groups. The characteristics of an ion-exchange capacity (IEC), water and methanol uptake, methanol permeability, and proton conductivity as a function of the degree of grafting were studied. The IECs and water uptakes of membranes with different degrees of grafting (36 to 102%) were measured in the range of 0.8 to 1.62 meq g−1 and 10 to 30%, respectively. The proton conductivity was higher than that of a Nafion 212 membrane (6.1 E−02 S cm−1), when the degree of grafting reached 60%. The methanol permeability and uptake of the FEP- g-PVBSA membrane was significantly lower than that of the Nafion 212 membrane, and even the degree of grafting reached 102%.


2021 ◽  
pp. 095400832110394
Author(s):  
Yan Ma ◽  
Kaixu Ren ◽  
Ziqiu Zeng ◽  
Mengna Feng ◽  
Yumin Huang

To improve the performances of sulfonated poly (arylene ether nitrile) (SPEN)–based proton exchange membranes (PEMs) in direct methanol fuel cells (DMFCs), the copper phthalocyanine grafted graphene oxide (CP-GO) was successfully prepared via in situ polymerization and subsequently incorporated into SPEN as filler to fabricate a series of SPEN/CP-GO-X (X represents for the mass ratio of CP-GO) composite membranes. The water absorption, swelling ratio, mechanical properties, proton conductivity, and methanol permeability of the membranes were systematically studied. CP-GO possesses good dispersion and compatibility with SPEN matrix, which is propitious to the formation of strong interfacial interactions with the SPEN, so as to provide more efficient transport channels for proton transfer in the composite membranes and significantly improve the proton conductivity of the membranes. Besides, the strong π–π conjugation interactions between CP-GO and SPEN matrix can make the composite membranes more compact, blocking the methanol transfer in the membranes, and significantly reducing the methanol permeability. Consequently, the SPEN/CP-GO-1 composite membrane displayed outstanding tensile strength (58 MPa at 100% RH and 25°C), excellent proton conductivity (0.178 S cm−1 at 60°C), and superior selectivity (5.552 × 105 S·cm−3·s). This study proposed a new method and strategy for the preparation of high performance PEMs.


2019 ◽  
Vol 961 ◽  
pp. 23-29
Author(s):  
Nur Hidayati ◽  
Muhammad Mujiburohman ◽  
Hamid Abdillah ◽  
Herry Purnama ◽  
Arnaldi Dwilaksita ◽  
...  

The low cost of ABS polymer and natural polymer chitosan offer attractive chemical and physical properties for direct methanol fuel cells (DMFC). In this contribution, investigation of blend membrane made of ABS and chitosan, and their characterization for water uptake, swelling degree and ion exchange capacity (IEC) and methanol crossover are reported. This membrane was also assessed for its intermolecular interactions and thermal stability using FTIR and TGA compared to the pristine membrane. The water absorption and IEC values were affected by membrane network structure. The polymer blend had better thermal stability and a reduction of methanol permeability, this indicated the viability of utilization these materials as polymer electrolyte membrane in DMFC


Nanomaterials ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 1292 ◽  
Author(s):  
Gutru Rambabu ◽  
Santoshkumar D. Bhat ◽  
Filipe M. L. Figueiredo

A membrane electrolyte that restricts the methanol cross-over while retaining proton conductivity is essential for better electrochemical selectivity in direct methanol fuel cells (DMFCs). Extensive research carried out to explore numerous blends and composites for application as polymer electrolyte membranes (PEMs) revealed promising electrochemical selectivity in DMFCs of carbon nanomaterial-based polymer composites. The present review covers important literature on different carbon nanomaterial-based PEMs reported during the last decade. The review emphasises the proton conductivity and methanol permeability of nanocomposite membranes with carbon nanotubes, graphene oxide and fullerene as additives, assessing critically the impact of each type of filler on those properties.


2010 ◽  
Vol 506 (2) ◽  
pp. 698-702 ◽  
Author(s):  
Yousef M. Alyousef ◽  
Moni Kanchan Datta ◽  
Karan Kadakia ◽  
S.C. Yao ◽  
Prashant N. Kumta

2009 ◽  
Vol 81 (12) ◽  
pp. 2309-2316 ◽  
Author(s):  
Yong Fang ◽  
Ruiying Miao ◽  
Tongtao Wang ◽  
Xindong Wang

A series of novel composite membranes was prepared by using poly(vinyl alcohol) (PVA) with polyimide (PI) as base material and 8-trimethoxysilylpropyl glycerine ether-1,3,6-pyrenetrisulfonic acid (TSGEPS) as proton conductor for direct methanol fuel cells (DMFCs). The parameters of membranes, including water sorption, hydrolysis stability, dimensional stability, proton conductivity, and methanol permeability were studied. The proton conductivity of the membranes is in the order of 10–2 S/cm, and the membranes show better resistance to methanol permeability (1.51 × 10–7 cm2 s–1) and better selectivity (20.6 × 104 S cm–3 s) than those of Nafion115 under the same measurement conditions.


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