The Experts below are selected from a list of 18837 Experts worldwide ranked by ideXlab platform
Robert F Savinell - One of the best experts on this subject based on the ideXlab platform.
-
evaluation of a sol gel derived nafion silica hybrid membrane for Proton electrolyte membrane fuel cell applications i Proton Conductivity and water content
Journal of The Electrochemical Society, 2001Co-Authors: Naoto Miyake, Jesse S Wainright, Robert F SavinellAbstract:Sol-gel derived Nafion®/silica hybrid membranes were investigated as a potential polymer electrolyte for fuel cell applications. Membrane Proton Conductivity and water content were measured as a function of temperature, water vapor activity, and silica content. The hybrid membranes have a higher water content at 25 and 120°C, but not at 150 and 170°C. Despite the higher water content, the Proton conductivities in the hybrid membranes are lower than, or equal to, that in unmodified Nafion membranes under all conditions investigated. The Proton Conductivity of the hybrid membrane decreases with increasing silica content under all conditions. © 2001 The Electrochemical Society. All rights reserved.
-
evaluation of a sol gel derived nafion silica hybrid membrane for Proton electrolyte membrane fuel cell applications i Proton Conductivity and water content
Journal of The Electrochemical Society, 2001Co-Authors: Naoto Miyake, Jesse S Wainright, Robert F SavinellAbstract:Sol-gel derived Nafion®/silica hybrid membranes were investigated as a potential polymer electrolyte for fuel cell applications. Membrane Proton Conductivity and water content were measured as a function of temperature, water vapor activity, and silica content. The hybrid membranes have a higher water content at 25 and 120°C, but not at 150 and 170°C. Despite the higher water content, the Proton conductivities in the hybrid membranes are lower than, or equal to, that in unmodified Nation membranes under all conditions investigated. The Proton Conductivity of the hybrid membrane decreases with increasing silica content under all conditions.
Zhongyi Jiang - One of the best experts on this subject based on the ideXlab platform.
-
fabrication of chitosan zwitterion functionalized titania silica hybrid membranes with improved Proton Conductivity
Journal of Membrane Science, 2014Co-Authors: Yongheng Yin, Xiaohui Shen, Zhongyi JiangAbstract:Abstract Based on the discovery that acid–base pairs can construct efficient Proton conduction channels, a binary titania–silica inorganic dopant functionalized with carboxyl groups and amino groups (denoted as TiC–SiN) is introduced into chitosan (CS) to fabricate novel hybrid membranes with Proton-conducting and methanol-rejecting properties. The titania precursor and the silica precursor are prehydrolyzed, and the mixed sol is functionalized with –COOH and –NH 2 groups successively by the facile chelation method to obtain TiC–SiN sol. The hybrid membranes are prepared by mixing the TiC–SiN sol with CS followed by in situ so–gel process. The membranes are characterized in terms of thermal property, water uptake, Proton Conductivity, etc. The results show that incorporation of hygroscopic inorganic phase increases the water uptake ability of the membranes. Moreover, the zwitterionic groups provided by the TiC–SiN dopants construct new Proton pathways, which can enhance the Proton Conductivity of the membranes. Particularly, incorporating 7 wt% TiC–SiN affords the hybrid membrane a Proton Conductivity of 0.0408 S cm −1 at room temperature, which is 4 times higher than that of the pure CS membrane. Overall, the highest selectivity of the hybrid membranes is 4.85×10 4 S s cm −3 , which is nearly 3 times higher than that of the pure CS membrane.
-
zwitterionic microcapsules as water reservoirs and Proton carriers within a nafion membrane to confer high Proton Conductivity under low humidity
ACS Applied Materials & Interfaces, 2014Co-Authors: Xinlin Yang, Zhongyi JiangAbstract:Zwitterionic microcapsules (ZMCs) based on sulfobetaine with tunable hierarchical structures, superior water retention properties, and high Proton conduction capacities are synthesized via precipitation polymerization. The incorporation of ZMCs into a Nafion matrix renders the composite membranes with significantly enhanced Proton Conductivity especially under low humidity. The composite membrane with 15 wt % ZMC-I displayed the highest Proton Conductivity of 5.8 × 10–2 S cm–1 at 40 °C and 20% relative humidity after 90 min of testing, about 21 times higher than that of the Nafion control membrane. The increased Proton Conductivity is primarily attributed to the versatile roles of ZMCs as water reservoirs and Proton conductors for rendering a stable water environment and an additional Proton conduction pathway within the membranes. This study may contribute to the rational design of water-retaining and Proton-conducting materials.
-
enhanced Proton Conductivity under low humidity of sulfonated poly ether ether ketone composite membrane enabled by multifunctional phosphonic acid polymeric submicrocapsules
Journal of Power Sources, 2013Co-Authors: Lingli Nie, Hao Dong, Xi Han, Zhongyi JiangAbstract:Abstract Phosphonic acid polymeric submicrocapsules (PASCs) are synthesized and incorporated into a sulfonated poly(ether ether ketone) (SPEEK) matrix to prepare composite membranes. The microstructure and physicochemical properties of the PASCs and the membranes are characterized by transmission electron microscopy (TEM), energy dispersive X-ray (EDX), field emission scanning electron microscope (FESEM), thermogravimetric analysis (TGA) and Fourier transform infrared spectroscopy (FTIR). Compared with the SPEEK control membrane, the PASC-filled composite membranes exhibit elevated water uptake and Proton Conductivity at 25 °C and 100% relative humidity (RH). The Proton Conductivity depends strongly on water content within the membranes. Under 40 °C and 20% RH, the composite membrane filled with 15 wt.% PASCs (128 nm lumen) shows the highest Proton Conductivity of 0.0142 S cm −1 after 90 min testing, about twelve times higher than that of the SPEEK control membrane (0.0011 S cm −1 ), which is positively correlated with the water retention of the membrane. These results suggest that the PASC-filled composite membranes may find encouraging application as efficient water-retention and Proton-conduction materials in Proton exchange membrane fuel cells (PEMFCs).
-
sulfonated titania submicrospheres doped sulfonated poly ether ether ketone hybrid membranes with enhanced Proton Conductivity and reduced methanol permeability
Journal of Power Sources, 2011Co-Authors: Weiqiang Hou, Jingtao Wang, Xiaohui Shen, Zhongyi JiangAbstract:Abstract Sulfonated titania submicrospheres (TiO2–SO3H) prepared through a facile chelation method are incorporated into sulfonated poly(ether ether ketone) (SPEEK) to fabricate organic–inorganic hybrid membranes with enhanced Proton Conductivity and reduced methanol permeability for potential use in direct methanol fuel cells (DMFCs). The pristine titania submicrospheres (TiO2) with a uniform particle size are synthesized through a modified sol–gel method and sulfonated using 4,5-dihydroxy-1,3-benzenedisulfonic acid disodium salt as the sulfonation reagent. The sulfonation process is confirmed by Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectra (XPS). The hybrid membranes are systematically characterized in terms of thermal property, mechanical property, ionic exchange capacity (IEC), swelling behavior, and microstructural features. The methanol barrier property and the Proton Conductivity of the SPEEK/TiO2–SO3H hybrid membranes are evaluated. The presence of the fillers reduces methanol crossover through the membrane. Compared with the unsulfonated TiO2-doped membranes, the TiO2–SO3H-doped ones exhibit higher Proton Conductivity due to the additional sulfonic acid groups on the surface of TiO2. The hybrid membrane doped with 15 wt.% TiO2–SO3H submicrospheres exhibits an acceptable Proton Conductivity of 0.053 S cm−1 and a reduced methanol permeability of 4.19 × 10−7 cm2 s−1.
Naoto Miyake - One of the best experts on this subject based on the ideXlab platform.
-
evaluation of a sol gel derived nafion silica hybrid membrane for Proton electrolyte membrane fuel cell applications i Proton Conductivity and water content
Journal of The Electrochemical Society, 2001Co-Authors: Naoto Miyake, Jesse S Wainright, Robert F SavinellAbstract:Sol-gel derived Nafion®/silica hybrid membranes were investigated as a potential polymer electrolyte for fuel cell applications. Membrane Proton Conductivity and water content were measured as a function of temperature, water vapor activity, and silica content. The hybrid membranes have a higher water content at 25 and 120°C, but not at 150 and 170°C. Despite the higher water content, the Proton conductivities in the hybrid membranes are lower than, or equal to, that in unmodified Nafion membranes under all conditions investigated. The Proton Conductivity of the hybrid membrane decreases with increasing silica content under all conditions. © 2001 The Electrochemical Society. All rights reserved.
-
evaluation of a sol gel derived nafion silica hybrid membrane for Proton electrolyte membrane fuel cell applications i Proton Conductivity and water content
Journal of The Electrochemical Society, 2001Co-Authors: Naoto Miyake, Jesse S Wainright, Robert F SavinellAbstract:Sol-gel derived Nafion®/silica hybrid membranes were investigated as a potential polymer electrolyte for fuel cell applications. Membrane Proton Conductivity and water content were measured as a function of temperature, water vapor activity, and silica content. The hybrid membranes have a higher water content at 25 and 120°C, but not at 150 and 170°C. Despite the higher water content, the Proton conductivities in the hybrid membranes are lower than, or equal to, that in unmodified Nation membranes under all conditions investigated. The Proton Conductivity of the hybrid membrane decreases with increasing silica content under all conditions.
Jesse S Wainright - One of the best experts on this subject based on the ideXlab platform.
-
evaluation of a sol gel derived nafion silica hybrid membrane for Proton electrolyte membrane fuel cell applications i Proton Conductivity and water content
Journal of The Electrochemical Society, 2001Co-Authors: Naoto Miyake, Jesse S Wainright, Robert F SavinellAbstract:Sol-gel derived Nafion®/silica hybrid membranes were investigated as a potential polymer electrolyte for fuel cell applications. Membrane Proton Conductivity and water content were measured as a function of temperature, water vapor activity, and silica content. The hybrid membranes have a higher water content at 25 and 120°C, but not at 150 and 170°C. Despite the higher water content, the Proton conductivities in the hybrid membranes are lower than, or equal to, that in unmodified Nafion membranes under all conditions investigated. The Proton Conductivity of the hybrid membrane decreases with increasing silica content under all conditions. © 2001 The Electrochemical Society. All rights reserved.
-
evaluation of a sol gel derived nafion silica hybrid membrane for Proton electrolyte membrane fuel cell applications i Proton Conductivity and water content
Journal of The Electrochemical Society, 2001Co-Authors: Naoto Miyake, Jesse S Wainright, Robert F SavinellAbstract:Sol-gel derived Nafion®/silica hybrid membranes were investigated as a potential polymer electrolyte for fuel cell applications. Membrane Proton Conductivity and water content were measured as a function of temperature, water vapor activity, and silica content. The hybrid membranes have a higher water content at 25 and 120°C, but not at 150 and 170°C. Despite the higher water content, the Proton conductivities in the hybrid membranes are lower than, or equal to, that in unmodified Nation membranes under all conditions investigated. The Proton Conductivity of the hybrid membrane decreases with increasing silica content under all conditions.
Zhe Wang - One of the best experts on this subject based on the ideXlab platform.
-
polybenzimidazole ionic liquid functional silica composite membranes with improved Proton Conductivity for high temperature Proton exchange membrane fuel cells
Journal of Membrane Science, 2017Co-Authors: Fengxiang Liu, Shuang Wang, Xue Tian, Xu Wang, Hao Chen, Zhe WangAbstract:Abstract A series of polybenzimidazole containing hydroxyl groups (PBIOH)/ionic-liquid-functional silica (ILS) composite membranes (PBIOH-ILS) have been successfully prepared for the high temperature Proton exchange membrane fuel cells (HT-PEMFCs). These ionic-liquid-functional silica (ILS) nanoparticles, which germinate from the polymer chains by an in situ sol-gel reaction, enhance the performance of polybenzimidazole-based composite membranes. Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy were used to characterize and confirm the Si-O-Si structure in the membranes. The PBIOH-ILS composite membranes have shown excellent thermal stability, oxidative stability and improved mechanical strength. Considering the trade-off of mechanical properties and Proton Conductivity, 5% ILS in weight was demonstrated to be the optimum content in the membranes. The Proton Conductivity was significantly enhanced because the ILS nanoparticles with high specific area in the membranes could absorb more phosphoric acid, which just like stones flooded by the sea after doping with phosphoric acid. The doping level of PBIOH-ILS 5 was as high as 7.54 after doping with phosphoric acid for 48 h and 9.65 after doping with phosphoric acid for 72 h. High doping levels lead to high Proton conductivities. The PBIOH-ILS 5 had a Proton Conductivity of 0.106 S cm −1 at 170 °C, which is higher than some of the known PBI-based membranes measured under similar conditions.
