Rheological Changes and Kinetics of Water Uptake by Poly(ionic liquid)-Based Thin Films

Langmuir ◽  
2013 ◽  
Vol 29 (50) ◽  
pp. 15589-15595 ◽  
Author(s):  
Tânia M. Benedetti ◽  
Roberto M. Torresi
Author(s):  
Ramchandra Gawas ◽  
Rui Sun ◽  
Yawei Li ◽  
Kenneth C. Neyerlin ◽  
Yossef Elabd ◽  
...  

Abstract Ionic liquid (IL) additives to both traditional and advanced oxygen reduction reaction (ORR) electrocatalysts have yielded remarkable improvements in catalyst performance and durability. However, incorporating ILs or IL-modified catalysts into the electrodes of a proton exchange membrane fuel cell (PEMFC) membrane electrode assembly (MEA) has proven to be challenging. Sulfonated poly(ionic liquid) block copolymers (S-PILBCP) present an opportunity to incorporate IL functionality directly into the ionomer, orthogonal to protonic conductivity. Here, we use a rotating disc electrode (RDE) to characterize the interface between a S-PILBCP and Pt catalyst in comparison to Nafion. Catalyst thin films prepared with S-PILBCP show an 80% improvement in the ORR activity over those containing Nafion. Thin films of S-PILBCP also show a significantly reduced degree of poisoning sulfonate adsorption on a Pt(111) surface in comparison to Nafion. These half-cell results provide useful insights that help to highlight the source of the impact of the S-PILBCP on PEMFC MEA performance.


Author(s):  
Wenxin Wei ◽  
Guifeng Ma ◽  
Hongtao Wang ◽  
Jun Li

Objective: A new poly(ionic liquid)(PIL), poly(p-vinylbenzyltriphenylphosphine hexafluorophosphate) (P[VBTPP][PF6]), was synthesized by quaternization, anion exchange reaction, and free radical polymerization. Then a series of the PIL were synthesized at different conditions. Methods: The specific heat capacity, glass-transition temperature and melting temperature of the synthesized PILs were measured by differential scanning calorimeter. The thermal conductivities of the PILs were measured by the laser flash analysis method. Results: Results showed that, under optimized synthesis conditions, P[VBTPP][PF6] as the thermal insulator had a high glass-transition temperature of 210.1°C, high melting point of 421.6°C, and a low thermal conductivity of 0.0920 W m-1 K-1 at 40.0°C (it was 0.105 W m-1 K-1 even at 180.0°C). The foamed sample exhibited much low thermal conductivity λ=0.0340 W m-1 K-1 at room temperature, which was comparable to a commercial polyurethane thermal insulating material although the latter had a much lower density. Conclusion: In addition, mixing the P[VBTPP][PF6] sample into polypropylene could obviously increase the Oxygen Index, revealing its efficient flame resistance. Therefore, P[VBTPP][PF6] is a potential thermal insulating material.


Author(s):  
Vladimir S. Chirvony ◽  
Isaac Suárez ◽  
Jesús Rodríguez-Romero ◽  
Rubén Vázquez-Cárdenas ◽  
Jesus Sanchez-Diaz ◽  
...  

2021 ◽  
Vol 6 (15) ◽  
pp. 3795-3801
Author(s):  
Radostina Kalinova ◽  
Ivaylo Dimitrov ◽  
Christo Novakov ◽  
Svetlana Veleva ◽  
Antonia Stoyanova

Nanoscale ◽  
2021 ◽  
Author(s):  
Ning Gao ◽  
Kang Zhou ◽  
Kai Feng ◽  
Wanlin Zhang ◽  
Jiecheng Cui ◽  
...  

Micellar and vesicular structures capable of sensing and reporting the chemical environment as well as facilely introducing user-defined functions make a vital contribution to constructing versatile compartmentalized systems. Herein, combing...


2011 ◽  
Vol 13 (37) ◽  
pp. 16530 ◽  
Author(s):  
Anja Wedig ◽  
Rotraut Merkle ◽  
Benjamin Stuhlhofer ◽  
Hanns-Ulrich Habermeier ◽  
Joachim Maier ◽  
...  

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