Polymer Nanocomposite Membranes of Sulfonated Poly(Styrene‐Isobutylene‐Styrene) With Sulfonated Graphene Oxide for Fuel Cell and Protective Clothing Applications

Abstract

Graphene oxide (GO) and its sulfonated analog (sGO) have been incorporated into sulfonated poly(styrene‐isobutylene‐styrene) (SO3H SIBS) in order to enhance its water retention and proton conductivity, while aiming to block permeant passage through the material. The polymer nanocomposite membranes (PNMs) were tested for two applications: direct methanol fuel cell and chemical and biological protective clothing. The transport properties of the membranes were determined as a function of SIBS sulfonation level (i.e., 37, 61, and 88 mol%), filler type (i.e., GO and sGO) and filler loading (i.e., 1, 3, 5, and 10 wt%). Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA) confirmed the functionalization and incorporation of the fillers into SO3H SIBS. No significant changes were observed in the thermal stability or FTIR spectra of the PNMs after addition of the fillers. Dissimilar behaviors were observed for the ion exchange capacity, water absorption capabilities and transport properties of the membranes after incorporation of the fillers. Atomic force microscopy (AFM) phase images and Fenton's test results indicate that the oxidative stability of the PNMs is associated to the interconnectivity between the hydrophilic domains of the fillers and SO3H SIBS. The PNMs presented low permeability and high proton conductivity and thus, functioned adequately for both applications. POLYM. ENG. SCI., 59:E455–E467, 2019. © 2018 Society of Plastics Engineers

Sulfonated poly(styrene‐isobutylene‐styrene) grafted with hexyl‐ and butyl‐imidazolium chloride ionic liquids

“…The membranes with better performance were SIBS 9‐g‐HexImCl ( α G = 49.8), SIBS‐g‐ButImCl ( α G = 49.4), and SIBS 17‐g‐HexImCl ( α G = 30.7). Comparing these values with previous modifications of SIBS such as grafting of poly(vinyl phosphonic acid) ( α G = 6.98), 33 incorporation of sulfonated carbon nanotubes ( α G = 7.39), 51 and sulfonated graphene oxide (~23) 55 ; it can be observed that there is a notable improvement in membrane selectivity with grafting of ionic liquid moieties, indicating superior potential over the former for CPC.…”

High‐performance blended membranes based on poly(arylene ether sulfone) and sulfonated poly(styrene‐isobutylene‐styrene) for direct methanol fuel cell applications

“…This situation may be like that reported by Ruiz-Col on et al ( 2019), where sulfonated SIBS was functionalized by adding sulfonated graphene oxide at various levels. 52 In their work, methanol permeability was independent of water absorption capabilities and IEC. It was argued that water transport was different from methanol transport.…”

Nanotechnology for High‐Performance Textiles: A Promising Frontier for Innovation

“…To improve the water retention and proton conductivity of sulfonated poly(styrene‐isobutylene styrene) and to prevent permeant passage through the material, graphene oxide (GO) and its sulfonated analog (sGO) have been added. This material is used in chemical and biological protective clothing [260] …”