A novel environment-friendly route to prepare proton exchange membranes for direct methanol fuel cells

Effect of Sulfonation Degree and PVDF Content on the Structure and Transport Properties of SPEEK/PVDF Blend Membranes

Sulfonated poly (ether ether ketone) (SPEEK) with four different sulfonation degrees (SDs) were prepared, and mixed with polyvinylidene fluoride (PVDF) to prepare four series of SPEEK/PVDF blend membranes. The miscibility between SPEEK and PVDF was investigated by observing the micro-morphologies. The miscible blend membranes were found in the SPEEK/PVDF blend membranes in which either SPEEK had relatively low SD or consisted of low content of one component (either SPEEK or PVDF). The PVDF crystallinity was found to decrease in the SPEEK/PVDF membranes that had better blend miscibility. With the increase of PVDF content, all the blend membranes exhibited the decreased proton conductivity and methanol permeability, and the miscible blend membranes decreased more slowly than the immiscible ones.

Preparation and Characterization of sPDVB/SPPO Composite Proton Exchange Membrane for Fuel Cell

In this study, a series of composite proton exchange membranes are prepared from sulfonated polydivinyl benzene (sPDVB) microspheres and sulfonated polyphenyl ether (SPPO). The PDVB microsphers and PPO are functionalized by direct sulfonation. The synthesis products are characterized by Fourier Transform Infrared Spectroscopy technique (FT-IR), thermogravimetry analysis (TGA), scanning electron microscope (SEM). The incorporation of sPDVB decreases the water uptake and proton exchange capacity, so the proton conductivity is lower than that of blank SPPO membrane. But the composite membranes still have the excellent conductivity range from 4.88×10-2 to 6.99×10-2 Scm-1.