Photopolymerizable sulfonated poly(ethylene glycol) proton exchange membranes for microfluidic and fuel cell applications

► Photopolymerizable polymer membranes from PEGDA derivatives are characterized. ► Membranes are functionalized by chemical sulfonation to enhance proton conductivity. ► Varying polymer composition allows for tunable membrane properties. ► Membranes can be selectively photopolymerized for use in microfluidic applications. In this study we fabricate and characterize the properties of photopolymerizable proton exchange membranes, formed from composite blends of poly(ethylene glycol) diacrylate (PEGDA) and sulfonated poly(ethylene glycol) phenyl ether acrylate (sPEGPEA). PEGDA–sPEGPEA blends were produced through free radical photopolymerization and were shown to be easily processed into thin membranes using techniques which are compatible with the fabrication of microfluidic fuel cell devices. Membrane materials were characterized through electrochemical impedance spectroscopy (EIS), Fourier transform infra-red spectroscopy (FTIR), dynamic mechanical analysis (DMA), as well as a host of techniques to measure ion exchange capacity, degree of water absorption, and surface morphology. We show that PEGDA–sPEGPEA membranes possess favourable proton exchange membrane characteristics comparable to those of Nafion ® based systems, and could therefore be of utility in microscaled fuel cell implementations.