Search results for "composite membrane"
showing 10 items of 11 documents
Influence of synthesis conditions on the performance of chitosan–Heteropolyacid complexes as membranes for low temperature H2–O2 fuel cell
2015
Flat, free-standing chitosan/phosphotungstic acid (PTA) polyelectrolyte membranes were prepared by in-situ ionotropic gelation process at room temperature on porous alumina support firstly impregnated by H3PW12O40. Scanning electron microscopy revealed the formation of compact and homogeneous membranes, whose thickness resulted to be dependent on chitosan concentration and reticulation time. X-ray diffraction and Fourier transform infrared spectroscopy (FTIR) evidenced the formation of almost amorphous membrane without appreciable concentration of not protonated NH2 groups and PTA3- ions with preserved Keggin structure. Membranes were tested as proton conductor in low temperature H2-O2 fuel…
Chitosan-phosphotungstic acid complex as membranes for low temperature H2-O2 fuel cell
2015
Abstract Free-standing Chitosan/phosphotungstic acid polyelectrolyte membranes were prepared by an easy and fast in-situ ionotropic gelation process performed at room temperature. Scanning electron microscopy was employed to study their morphological features and their thickness as a function of the chitosan concentration. The membrane was tested as proton conductor in low temperature H 2 –O 2 fuel cell allowing to get peak power densities up to 350 mW cm −2 . Electrochemical impedance measurements allowed to estimate a polyelectrolyte conductivity of 18 mS cm −1 .
Improvement in the performance of low temperature H2-O2 fuel cell with chitosanephosphotungstic acid composite membranes
2016
Abstract Free-standing chitosan/phosphotungstic acid polyelectrolyte membranes, prepared by ionotropic gelation on alumina porous supports, were employed as proton conductor in low temperature H 2 –O 2 fuel cell. A drying step on glass substrate was introduced in the fabrication procedure to reduce shrinkage and consequent corrugation. Membranes were tested with electrodes prepared according to different procedures and with two different Pt loadings, namely 0.5 and 1 mg cm −2 . Both the investigated kinds of electrodes allowed to get very promising power peaks of 550 mW cm −2 in spite of the different Pt content. The polarization curves and the electrochemical impedance spectra suggest that…
Performance of H2-fed fuel cell with chitosan/silicotungstic acid membrane as proton conductor
2020
Composite organic–inorganic proton exchange membranes for H2–O2 fuel cells were fabricated by ionotropic gelation process combining a biopolymer (chitosan) with a heteropolyacid (silicotungstic acid). According to scanning electron microscopy analysis, compact, homogeneous and free-standing thin layers were synthesized. X-ray diffraction proved the crystallinity of the fabricated membranes and showed the presence of Chitosan Form I polymorph soon after the reticulation step and of the Form II polymorph after the functionalization step. Fourier-transform infrared spectroscopy demonstrated that the Keggin structure of the heteropolyacid is maintained inside the membrane even after the fabrica…
Recent Progress in the Development of Composite Membranes Based on Polybenzimidazole for High Temperature Proton Exchange Membrane (PEM) Fuel Cell Ap…
2020
[EN] The rapid increasing of the population in combination with the emergence of new energy-consuming technologies has risen worldwide total energy consumption towards unprecedent values. Furthermore, fossil fuel reserves are running out very quickly and the polluting greenhouse gases emitted during their utilization need to be reduced. In this scenario, a few alternative energy sources have been proposed and, among these, proton exchange membrane (PEM) fuel cells are promising. Recently, polybenzimidazole-based polymers, featuring high chemical and thermal stability, in combination with fillers that can regulate the proton mobility, have attracted tremendous attention for their roles as PE…
Influence of the Molecular Weight on PVA/GO Composite Membranes for Fuel Cell Applications
2020
Composite polymer electrolyte membranes were prepared with poly (vinyl alcohol) (PVA). Two different molecular weight (Mw), 67·103 and 130·103 g·mol−1 were selected, cross-linked with sulfosuccinic acid (SSA) and doped graphene oxide (GO). The effects on the membranes obtained from these polymers were characterized in order to evaluate the fuel cell performance. Electron microscopy showed a proper nanoparticle distribution in the polymer matrix. The chemical structure was evaluated by Fourier transform infrared spectroscopy. The absence of a crystalline structure and the enhancement on the thermal stability with the addition of 1% of GO was demonstrated by thermal characterization. Total tr…
Composite membranes of aromatic-polyamide for desalination: Membrane preparation and characterization.
1987
A new reverse osmosis composite membrane composed of the following aromatic polymer was estudied. Composite membranes were successfully prepared from PTDS by the conventional phase-inversion method. A typical example of the basic membrane performances is as follows; water flux, 440 1/m2 day and salt rejection, 97.7% determined under the pressure of 40 atm., using 0.1% NaCl solution at 25 °C. The PTDS membrane was characterized by its excellent chemical and thermal resistances, especially against acid, alkali and oxidative atmospheres. These features suggest that the PTDS membrane is a promising candidate for water desalination.
Mechanical Properties of Composite SPEEK Polymer Membranes Modified with Ionic Liquids
2015
In this work, the mechanical properties of sulphonated polyetheretherketone (SPEEK) membranes impregnated with 3 different ionic liquids (1-butyl-2,3-dimethyl- imidazolium dimethylphosphate ([BMMIM][Me2PO4])), 1,2,3-trimethylimidazolium dimethylphosphate ([MMMIM][Me2PO4])), 1,3-dimethylimidazolium dimethylphosphate ([MMIM][Me2PO4])) have been investigated. Prepared SPEEK/ionic liquid composite membranes are characterized by mechanical testing both in room and elevated temperatures. It was found that the stiffness and tensile strength of composites decreased by increasing the content of ionic liquid and the length of alkyl radical in ionic liquid as well as by increasing the temperature.
A Study on Acidification and Intercalation of Illite Clay Minerals and their Potential Use as a Filler in SPEEK Composite Membranes
2018
The acidification and intercalation of illite containing clays were studied for potential use as fillers for sulphonated poly (ether ether ketone) (SPEEK) composite membrane preparation and future proton exchange membrane fuel cells application. The acidification and dimethyl sulfoxide (DMSO) intercalation of illite clays have been studied by powder X-ray diffractometry, X-ray fluorescence spectrometry, and thermogravimetric analysis. SPEEK composite membranes were made with 1, 3 and 5% purified, acidified, DMSO intercalated clay fillers. SPEEK/clay composite membranes were characterized by proton conductivity, water uptake, and mechanical strength.
A Study of Osmosis Rate Through Several Proton Conducting Polymer Composite Membranes
2021
Carbon dioxide is typically considered to be a byproduct of various industrial processes that should not be released into the environment due to its nature as a harmful greenhouse gas. One of the more promising ways to dispose of it in an economical and environmentally friendly way is by using it as a raw material in electrochemical synthesis reactors. An important part of such reactors is an ion exchange membrane. In this study the influence of ZrO2 content in SPEEK – ZrO2 composite membranes on rate of osmosis trough them was investigated, with the goal of evaluating ZrO2 as an additive for making ion exchange membranes with fine-tuned osmotic permeability.