Transport properties of polymer blend membranes of sulfonated and nonsulfonated polysulfones for direct methanol fuel cell application

Abstract

The relation between the phase separated morphologies and their transport properties in the polymer blend membrane for direct methanol fuel cell application was studied. In order to enhance the proton conductivity and reduce the methanol crossover, sulfonated poly(arylene ether sulfone) copolymer, with a sulfonation of 60 mol% (sPAES-60), was blended with nonsulfonated poly(ether sulfone) copolymer (RH-2000, Solvay). Various morphologies were obtained by varying the drying condition and the concentration of the casting solution (10, 15, 20 wt%). The transport properties of proton and methanol molecule through the polymer blend membranes were studied according to the absorbed water. AC impedance spectroscopy was used to measure the proton conductivity and a liquid permeability measuring instrument was designed to measure the methanol permeability. The state of water in the blend membranes was confirmed by differential scanning calorimetry and was used to correlate the morphology of the membrane with the membrane transport properties.

Selective coordination of silver ions to poly(styrene-b-(ethylene-co-butylene)-b-styrene) and its influence on morphology and facilitated olefin transport

“…1, 2, 3, 4… for a lamellar structure, , , , ... for a cylindrical structure, and 1, , , , ... for a spherical structure. [23][24][25][26][27] The neat SEBS block copolymer cast from 10 wt% of SEBS in the THF solution showed a lamellar morphology (q 1 :q 2 =1:2), even though the volume concentration of PS (25 vol% PS) might produce hexagonally packed cylinder morphology. The unusual morphology may arise from the differences of relative interaction strength of THF with PS and EB.…”

Compositional effect on the properties of sulfonated and nonsulfonated polymer blend membranes for direct methanol fuel cell

“…15 Previously in our group, three different drying processes (HT, FD1 and FD2) were developed in order to investigate the effect of the rate of phase separation during the membrane fabrication on morphology, transport properties, and sorption properties for DMFC application. 16,17 At three different drying processes, initial concentration of the blend solutions before drying was varied 10, 15 and 20 wt% in DMAc with fixed blend ratio (1:1) of sulfonated and nonsulfonated components. In consequence, various morphologies were obtained but they were able to be grouped in 4 different categories depending on the distinct morphologies and relevant membrane properties.…”

The effect of annealing on sSEBS/polyrotaxanes electrolyte membranes for direct methanol fuel cells

“…[5][6][7][8][9][10][11][12][13][14][15] Research to develop PEMs for DMFCs can be broadly classified into two categories: (i) synthesizing new membranes from polyhydrocarbon materials or perfluorinated materials; 5 and (ii) modifying conventional polymers by making composite membranes [7][8][9][10][11][12] or modifying their surfaces. [13][14][15] Composite membranes have been typically prepared by introducing nano-sized inorganic materials, such as clay 16 or nanoparticles.…”