Nanocomposite proton conducting membranes based on amphiphilic PVDF graft copolymer

Abstract

A novel comb-like amphiphilic graft copolymer of poly(vinylidene fluoride-co-chlorotrifluoroethylene)-graft-poly(4-styrene sulfonic acid-co-trimethoxysilyl propyl methacrylate), i.e. P(VDF-co-CTFE)-g-P(SSA-co-TMSPMA) was synthesized using an atom transfer radical polymerization (ATRP) technique. Successful synthesis and a microphase-separated structure of the copolymer were confirmed by proton nuclear magnetic resonance ( 1 H NMR), FTIR spectroscopy and transmission electron microscopy (TEM). This graft copolymer was combined with tetraethoxysilane (TEOS) under acidic conditions to produce organic-inorganic nanocomposite membranes through an in-situ sol-gel reaction between TEOS and PTMSPMA, as characterized by X-ray diffraction (XRD) and TEM. Upon the introduction of silica, the proton conductivity and water uptake of the membranes decreased slightly but the thermal and mechanical properties of the membranes were enhanced significantly. Various morphologies of the nanocomposite membranes were obtained after controlling the TEOS concentration, which were correlated with the thermal, mechanical and transport properties.

Grafting of Vinyl Pyrrolidone/Styrene onto Ethylene/Chlorotrifluoroethylene Membrane for Proton ExchangeMembrane Fuel Cell

“…Grafting of styrene and vinyl pyrrolidone onto ethylene/ chlorotrifluoro ethylene films were performed using different gamma irradiation doses (10,20,30, and 40 kGy) and different monomers ratios. The membranes were characterized chemically, thermally and morphologically using fourier transformer infra-red spectroscopy (FT-IR), thermal gravimetric analysis (TGA) and scan electron microscope (SEM).…”

“…A VP with different ratios to styrene were added with their suitable solvents (methanol for Sty and water for VP) to the glass ampoules content. The ampoules were subsequently irradiated for different doses (5,10,20,30 and 40 KGy). After the grafting reaction, the film was taken out, rinsed with benzene and soaked therein over night to remove homopolymer.…”

“…Radiation grafted membranes have a major advantage of utilizing preformed commercial polymer membranes.A partially fluorinated polymer electrolyte membrane is an interesting candidate for replacing commercial membranes because of low costs along with electrochemical properties [10]. Previous fuel cell membrane research had examined the styrene gamma irradiation-grafting.…”

BaTiO3/PVDF-g-PSSA composite proton exchange membranes for vanadium redox flow battery

“…However, the present widely used PEM materials, such as Nafion series, are very expensive. Therefore, much work has been devoted to develop new proton exchange membranes, including inorganic-organic composite membranes [3,4], graft membranes [5][6][7], blend composite membranes [8] etc. It is evident that composite membranes have many advantages: reducing ion permeability, increasing mechanical properties, reducing cost.…”

Investigation of proton conductivity of anhydrous proton exchange membranes prepared via grafting vinyltriazole onto alkaline-treated PVDF

“…Quite recently, many researchers have tried to use several techniques to prepare PEMs that are composed of engineering plastics such as poly(vinylidene fluoride) (PVDF), polytetrafluoroethylene (PTFE), poly(tetrafluoroethylene‐ co ‐hexafluoropropylene) (FEP), poly(tetrafluoroethylene‐ co ‐perfluoropropylvinylether) (PFA), and poly(ethylene‐ alt ‐tetrafluoroethylene) (ETFE) films. Among the aforementioned fluoropolymers, PVDF, one of the most important engineering polymers, has attracted continuous interest due to low cost, high chemical resistance, enhanced thermal, and mechanical properties . However, the application of PVDF is limited to some extent because native PVDF contains no reactive functional groups.…”