نتایج جستجو برای: proton conductivity

تعداد نتایج: 115521  

Journal: :Journal of the American Chemical Society 2012
Nak Cheon Jeong Bappaditya Samanta Chang Yeon Lee Omar K Farha Joseph T Hupp

HKUST-1, a metal-organic framework (MOF) material containing Cu(II)-paddlewheel-type nodes and 1,3,5-benzenetricarboxylate struts, features accessible Cu(II) sites to which solvent or other desired molecules can be intentionally coordinated. As part of a broader investigation of ionic conductivity in MOFs, we unexpectedly observed substantial proton conductivity with the "as synthesized" versio...

2014
Kyungho Hwang Jun-Hyun Kim Sung-Yul Kim Hongsik Byun

Various polybenzimidazole (PBI)-based ion-exchange films were prepared and thoroughly characterized by Fourier transform infrared (FT-IR) spectroscopy, proton conductivity, and water uptake for possible use as fuel cell membranes. Upon the increase in the flexibility of the PBI-based polymer films (e.g., poly(oxyphenylene benzimidazole) (OPBI) and sulfonated OPBI (s-OPBI)), the membranes exhibi...

2005
Ahmad Telfah Günter Majer Michael Schuster Klaus-Dieter Kreuer Joachim Maier

Polymer-electrolyte-membrane fuel cells (PEM-FCs) are considered as the most promising fuel cell technique for applications like automobiles or stationary power supplies. State-of-the-art separator materials in PEM-FCs are commonly sulfonic acid functionalized polymers, like the perfluorinated polymer Nafion. These materials show the required high proton conductivity only at high degree of hydr...

2016
Beatrice Muriithi Douglas A. Loy

The introduction of sulfonic acid modified silica in Nafion nanocomposite membranes is a good method of improving the Nafion performance at high temperature and low relative humidity. Sulfonic acid-modified silica is bifunctional, with silica phase expected to offer an improvement in membranes hydration while sulfonic groups enhance proton conductivity. However, as discussed in this paper, this...

Journal: :Journal of Chemical Physics 2021

Proton transport is critical for many technologies and a variety of biochemical biophysical processes. transfer between molecules (via structural diffusion) considered to be an efficient mechanism in highly proton conducting materials. Yet, the what controls energy barriers this process remain poorly understood. It was shown that mixing phosphoric acid (PA) with lidocaine leads increase conduct...

Journal: :Physical chemistry chemical physics : PCCP 2011
Jie Zeng Yuhua Zhou Lin Li San Ping Jiang

A novel proton exchange membrane using phosphotungstic acid (HPW) as proton carrier and cubic bicontinuous Ia3d mesoporous silica (meso-silica) as framework material is successfully developed as proton exchange membranes for fuel cells. Meso-silica is functionalized by 80wt% HPW using a vacuum impregnation method. The HPW-functionalized meso-silica (HPW-meso-silica) nanocomposites are character...

2012
Zicheng Zuo Yongzhu Fu

Fuel cells hold great promise for wide applications in portable, residential, and large-scale power supplies. For low temperature fuel cells, such as the proton exchange membrane fuel cells (PEMFCs) and direct methanol fuel cells (DMFCs), proton-exchange membranes (PEMs) are a key component determining the fuel cells performance. PEMs with high proton conductivity under anhydrous conditions can...

2014
Bin Wu Jiefeng Pan Liang Ge Liang Wu Huanting Wang Tongwen Xu

The novel oriented electrospun nanofiber membrane composed of MOFs and SPPESK has been synthesized for proton exchange membrane fuel cell operating at high temperature and anhydrous conditions. It is clear that the oriented nanofiber membrane displays the higher proton conductivity than that of the disordered nanofiber membrane or the membrane prepared by conventional solvent-casting method (wi...

2012
C. W. Lin

This study describes the preparation of a novel proton conducting membranes based on bacterial cellulose (BC) modified by grafting of 2-acrylamido-2-methyl-1 -propanesulfonic acid (AMPS) through UV-induced graft polymerization. These AMPS-g-BC membranes have been characterized by various techniques including FTIR, SEM and TGA, to find their successful grafting of AMPS on BC, surface morphology ...

2009
Dongxia Liu Keith Savino Matthew Z. Yates

A new approach to enhancing proton conductivity of ceramics is demonstrated by aligning proton conductive pathways and eliminating resistive grain boundaries. Hydroxyapatite (HAP) membranes are synthesized by multistage crystallization onto palladium. The synthesis involves three steps: electrochemical deposition of HAP seeds, secondary hydrothermal crystallization onto the seed layer to promot...

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