A series of novel fluoropolymer anion exchange membranes based on the copolymer of vinylbenzyl chloride, butyl methacrylate, and hexafluorobutyl methacrylate has been prepared. Fourier transform infrared (FT-IR) spectroscopy and elemental analysis techniques are used to study the chemical structure and chemical composition of the membranes. The water uptake, ion-exchange capacity (IEC), conductivity, methanol permeability, and chemical stability of the membranes are also determined. The membranes exhibit high anionic conductivity in deionized water at 65 °C ranging from 3.86×10(-2) S cm(-1) to 4.36×10(-2) S cm(-1). The methanol permeability coefficients of the membranes are in the range of 4.21-5.80×10(-8) cm(2) s(-1) at 65 °C. The novel membranes also show good chemical and thermal stability. An open-circuit voltage of 0.7 V and a maximum power density of 53.2 mW cm(-2) of alkaline direct methanol fuel cell (ADMFC) with the membrane C, 1 M methanol, 1 M NaOH, and humidified oxygen are achieved at 65 °C. Therefore, these membranes have great potential for applications in fuel cell systems.
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http://dx.doi.org/10.1016/j.jcis.2012.05.043 | DOI Listing |
Oper Dent
November 2024
*Akimasa Tsujimoto, DDS, PhD, professor and chair, Department of Operative Dentistry, Aichi Gakuin University School of Dentistry, Nagoya, Aichi, Japan; adjunct associate professor, Department of Operative Dentistry, University of Iowa College of Dentistry, Iowa City, Iowa, USA; visiting associate professor, Department of General Dentistry, Creighton University School of Dentistry, Omaha, NE, USA.
Objective: This case report presents a novel technique for bridge restoration using polytetrafluoroethylene (PTFE) tape and split dam isolation in situations where achieving complete dental dam isolation is challenging.
Clinical Considerations: Achieving high-quality isolation by controlling gingival crevicular fluid and intraoral relative humidity is important during cementation. However, an improved technique during bridge restoration is needed due to the difficulties faced with dental dam isolation.
ACS Appl Bio Mater
October 2024
School of Mechanics and Safety Engineering, Zhengzhou University, Zhengzhou 450001, China.
Expanded polytetrafluoroethylene (ePTFE) failed to achieve clinical application in the field of small-diameter blood vessels due to its lack of elasticity in the circumferential direction and high stiffness. Excellent multidirectional elasticity and dynamic compliance matching with natural blood vessels are important means to solve the problem of acute thrombosis and poor long-term patency. Herein, novel PTFE spinning blood vessels were prepared by the PTFE emulsion electrospinning process, which not only presented good bidirectional elasticity but also promoted the adhesion and proliferation of endothelial cells and induced the contractile expression of SMCs.
View Article and Find Full Text PDFSensors (Basel)
September 2024
School of Electronics and Computer Science, University of Southampton, Highfield, Southampton SO17 1BJ, UK.
The microfluidic measurement of capillary flow can be used to evaluate the response of biological samples to stimulation, where distance and velocity are altered. Melt-extruded multi-bored microfluidic capillaries allow for high-throughput testing with low device cost, but simple devices may limit control over sample flow when compared to the more complex "lab-on-a-chip" devices produced using advanced microfluidic fabrication methods. Previously, we measured the dynamics of global haemostasis stimulated by thrombin by dipping straight vertical microcapillaries into blood, but only the most rapid response could be monitored, as flow slowed significantly within 30 s.
View Article and Find Full Text PDFBiomater Sci
October 2024
Peoples' Friendship University of Russia (RUDN University), Moscow, 117198, Russia.
Artif Organs
January 2025
Center for Devices and Radiological Health, U.S. Food and Drug Administration, Silver Spring, Maryland, USA.
Background: To accommodate a wider range of medical device sizes, a larger in vitro flow loop thrombogenicity test system using 9.5 -mm inner diameter (ID) tubing was developed and evaluated based on our previously established 6.4 -mm ID tubing system.
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