Sulfonated Polyimide Proton Exchange Membranes with Graphene Oxide show Improved Proton Conductivity, Methanol Crossover Impedance, and Mechanical Properties

Abstract

Graphene oxide has been utilized to enhance the proton conductivity and mechanical properties and reduce the methanol permeability of polymer exchange membranes. The membranes exhibit dramatic improvements in proton conductivity (490.3%), methanol permeability (a 508.9% decrease in methanol permeability and a near 25‐fold increase in selectivity of proton conductivity to methanol permeability were achieved at 80 °C) and the mechanical properties (134.4% enhancements in tensile strength at 30 °C) with SPI/GO_0.5 wt%.

Enhanced ion transport in polymer–ionic liquid electrolytes containing ionic liquid-functionalized nanostructured carbon materials

“…Sulfonated polyimide (SPI) was synthesized according to our previously reported procedure (details in Supporting Information) [18,24]. The properties of SPI containing 80% hydrophilic units are the focus of this study.…”

“…Although carbon materials (CMs) are used as fillers for polymers in many applications, only a few studies have used PEs since they are conductive and thus pose a real risk of electrical shorts. The addition of suitably modified CMs has also been attempted to improve both physical and chemical properties of PEs [17][18][19][20][21][22]. Such improvements in performance may result from the nano-fillers 'tuning' the physical geometry of ionic channels in the composite polymer electrolytes (CPEs) to facilitate ion transfer through low-energy pathways along the nano-filler/matrix interface, thereby resulting in high ionic conductivity.…”

Anhydrous proton exchange membranes comprising of chitosan and phosphorylated graphene oxide for elevated temperature fuel cells

“…The added nanofillers could connect the disordered conducting groups in polymer chains using the acid groups, like "bridges", thus shorting the transfer paths and improving the transfer efficiency [22][23][24]. In addition, the nanofillers could enhance the structural stability of polymeric membrane by interfering with the chain motion and packing [25,26]. According to the shape, nanofillers can be classified into spherical filler (0D/3D), tubular filler (1D), and sheet filler (2D).…”

“…In recent studies, sulfonated graphene oxide (SGO) has been developed to intensify the proton conduction of polymeric membranes [33][34][35]. The authors found that SGO worked as continuous pathway for facile proton transport.…”

Review of Chitosan-Based Polymers as Proton Exchange Membranes and Roles of Chitosan-Supported Ionic Liquids

“…GO is a single-atomic-layered material that consists of oxygen-containing groups, including carbonyl, hydroxyl, carboxyl, and epoxy groups. GO is an enticing active nanofiller for PEM due to its particular properties of facile modification given the presence hydrophilic oxygen-containing groups [101][102][103][104], good mechanical stability and water retention capacity, and potential to improve the proton conductivity of membranes [105][106][107][108]. Moreover, GO exhibits a large surface area, and its proton conduction could be improved through the hopping mechanism, because it contains hydrophilic functional groups.…”