scholarly journals An Investigation of Proton Conductivity of Vinyltriazole-Grafted PVDF Proton Exchange Membranes Prepared via Photoinduced Grafting

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Sinan Sezgin ◽  
Deniz Sinirlioglu ◽  
Ali Ekrem Muftuoglu ◽  
Ayhan Bozkurt

Proton exchange membrane fuel cells (PEMFCs) are considered to be a promising technology for clean and efficient power generation in the twenty-first century. In this study, high performance of poly(vinylidene fluoride) (PVDF) and proton conductivity of poly(1-vinyl-1,2,4-triazole) (PVTri) were combined in a graft copolymer, PVDF-g-PVTri, by the polymerization of 1-vinyl-1,2,4-triazole on a PVDF based matrix under UV light in one step. The polymers were doped with triflic acid (TA) at different stoichiometric ratios with respect to triazole units and the anhydrous polymer electrolyte membranes were prepared. All samples were characterized by FTIR and1H-NMR spectroscopies. Their thermal properties were examined by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). TGA demonstrated that the PVDF-g-PVTri and PVDF-g-PVTri-(TA)x membranes were thermally stable up to 390°C and 330°C, respectively. NMR and energy dispersive X-ray spectroscopy (EDS) results demonstrated that PVDF-g-PVTri was successfully synthesized with a degree of grafting of 21%. PVDF-g-PVTri-(TA)3showed a maximum proton conductivity of6×10-3 Scm−1at 150°C and anhydrous conditions. CV study illustrated that electrochemical stability domain for PVDF-g-PVTri-(TA)3extended over 4.0 V.

Membranes ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 826
Author(s):  
Junyu Chen ◽  
Jiamu Cao ◽  
Rongji Zhang ◽  
Jing Zhou ◽  
Shimin Wang ◽  
...  

Hydrogen-air proton exchange membrane fuel cells (PEMFCs) and direct methanol fuel cells (DMFCs) are excellent fuel cells with high limits of energy density. However, the low carbon monoxide (CO) tolerance of the Pt electrode catalyst in hydrogen-air PEMFCs and methanol permanent in DMFCs greatly hindered their extensive use. Applying polybenzimidazole (PBI) membranes can avoid these problems. The high thermal stability allows PBI membranes to work at elevated temperatures when the CO tolerance can be significantly improved; the excellent methanol resistance also makes it suitable for DMFCs. However, the poor proton conductivity of pristine PBI makes it hard to be directly applied in fuel cells. In the past decades, researchers have made great efforts to promote the proton conductivity of PBI membranes, and various effective modification methods have been proposed. To provide engineers and researchers with a basis to further promote the properties of fuel cells with PBI membranes, this paper reviews critical researches on the modification of PBI membranes in both hydrogen-air PEMFCs and DMFCs aiming at promoting the proton conductivity. The modification methods have been classified and the obtained properties have been included. A guide for designing modifications on PBI membranes for high-performance fuel cells is provided.


2012 ◽  
Vol 512-515 ◽  
pp. 2003-2006
Author(s):  
Yuan Qing ◽  
Gui Bao Guo ◽  
Sheng Li An

A proton exchange membrane, poly (vinylidene fluoride)(PVDF) blended polystyrene sulfonated acid(PSSA) was prepared by Blend polymerization method. Mechanical properties of membranes were investigated by the multi-functional material experiment machine.The influences of the content of the styrene on the proton conductivity and methanol permeability of the membranes were studied by the impedance analyzer and gas chromatography instrument. The results showed that Polystyrene is easily blended into PVDF and mechanical properties were improved, with increasing of the content of styrene, the proton conductivity of PVDF-PSSA membranes was increased, and arrived at maximum as the styrene content was 20%, correspondingly, methanol permeability became large gradually.


2011 ◽  
Vol 311-313 ◽  
pp. 244-247 ◽  
Author(s):  
Yu Sheng Li ◽  
Gui Bao Guo ◽  
Sheng Li An

A proton exchange membrane of poly (vinylidene fluoride) grafted onto poly (2-acrylamido-2-methylpropane sulfonic acid) (PVDF-g-PAMPS) was prepared as follows: acrylamido-2-methylpropane sulfonic acid (AMPS) was first added to a N-Methyl pyrrolidone (NMP) solution containing poly (vinylidene fluoride) (PVDF) that was modified with plain sodium silicate. Ammonium persulfate was then added as an evocating agent and PAMPS was directly grafted onto the PVDF that was modified with plain sodium silicate. The influences of AMPS contents on the proton conductivity and mechanical properties were studied. The results showed that AMPS is easily grafted into PVDF modified by Plain sodium silicate (Na4SiO4) and mechanical properties were improved, with increasing of the content of 2-acrylamido-2-methylpropane sulfonic acid, the proton conductivity of PVDF-g-PAMPS membranes was increased.


2020 ◽  
Vol 30 (6) ◽  
pp. 855-860
Author(s):  
Ruixiang Wang ◽  
Pengyang Zhang ◽  
Yucheng Wang ◽  
Yuesheng Wang ◽  
Karim Zaghib ◽  
...  

Coatings ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 437
Author(s):  
Yi Liu ◽  
Luofu Min ◽  
Wen Zhang ◽  
Yuxin Wang

In this article, we proposed a facile method to electrophoretically deposit a highly conductive and corrosion-resistant graphene layer on metal bipolar plates (BPs) while avoiding the oxidation of the metal substrate during the electrophoretic deposition (EPD). p-Phenylenediamine (PPD) was first grafted onto negatively charged graphene oxide (GO) to obtain modified graphene oxide (MGO) while bearing positive charges. Then, MGO dispersed in ethanol was coated on titanium plates via cathodic EPD under a constant voltage, followed by reducing the deposited MGO with H2 at 400 °C, gaining a titanium plate coated with reduced MGO (RMGO@Ti). Under the simulated environment of proton exchange membrane fuel cells (PEMFCs), RMGO@Ti presents a corrosion current of < 10−6 A·cm−2, approximately two orders of magnitude lower than that of bare titanium. Furthermore, the interfacial contact resistance (ICR) of RMGO@Ti is as low as 4 mΩ·cm2, which is about one-thirtieth that of bare titanium. Therefore, RMGO@Ti appears very promising for use as BP in PEMFCs.


2014 ◽  
Vol 2 (19) ◽  
pp. 7015-7019 ◽  
Author(s):  
He-Yun Du ◽  
Chen-Hao Wang ◽  
Chen-Shuan Yang ◽  
Hsin-Cheng Hsu ◽  
Sun-Tang Chang ◽  
...  

A well-controlled Pt/PBI–CNT electrode provides not only good interfacial continuity but also numerous edge planes, which has strong electrochemical activity in HT-PEMFCs.


2010 ◽  
Vol 152-153 ◽  
pp. 44-50 ◽  
Author(s):  
Gui Bao Guo ◽  
Er Ding Han ◽  
Sheng Li An

A new method based on a solution graft technique was used to prepare poly (vinylidene fluoride) grafted polystyrene sulfonated acid (PVDF-g-PSSA) proton exchange membrane. Polystyrene is grafted into PVDF modified by plain sodium silicate (Na4SiO4). There is a linear relationship between the degree of grafting and the content of Na4SiO4. Fourier transform infrared spectroscopy is used to characterize changes of the membrane's microstructures after grafting and sulfonation. The morphology of the membrane's microstructures after grafting and sulfonation is studied by scanning electrolytic microscope (SEM). The effect of plain sodium silicate (Na4SiO4) concentration and relative humidity on the conductivity of the electrolyte was investigated by the impedance at room temperature. The results show that the styrene has been grafted into PVDF. The conductivity of PVDF-g-PSSA electrolyte doped 10% plain sodium silicate (Na4SiO4) is 0.016 S/cm at room temperature. The conductivity of the electrolyte changes slightly at a relative humidity range of 20%-70%. The weightlessness of PVDF-g-PSSA electrolyte heated to 40°C was less than 2%, which indicated that water capacity was good.


Sign in / Sign up

Export Citation Format

Share Document