Preparation of sulfonated polysulfone/sulfonated titanium dioxide hybrid membranes for DMFC applications

Abstract

Sulfonated titanium dioxide (STiO 2 ) was prepared by the reaction of TiO 2 with 1,3-propanesultone. Novel STiO 2 incorporated sulfonated poly(aryl ether sulfone) (SPAES) nanocomposite proton exchange membranes (PEMs) were made by solution casting. Fourier transform infrared, X-ray photoelectron spectroscopy, and proton nuclear magnetic resonance indicated the successful preparation of STiO 2 and SPAES. The thermogravimetric analysis and oxidative stability testing results implied that SPAES/STiO 2 membranes had better stability than pristine SPAES membrane. Meanwhile, the scanning electron microscopy spectra exhibited that the introduction of sulfonated groups on the surface of TiO 2 significantly improved its dispersibility in SPAES matrix. More specifically, SPAES membrane incorporated with 2%STiO 2 exhibited higher proton conductivity (60 mS cm −1 ), lower methanol permeability (2.1 × 10 −7 cm 2 s −1 ) and better proton selectivity (28.0 × 10 4 S s cm −3 ) than that of pure SPAES and SPAES/1%TiO 2 membrane. The SPAES-1%STiO 2 membrane showed better performance in direct methanol fuel cell (DMFC) test than SPAES and Nafion 117 due to the reduction of methanol crossover. From these results, it is evident that SPAES/STiO 2 nanocomposite PEMs have great potential for applications in DMFCs.

Improved chemical stability and proton selectivity of semi‐interpenetrating polymer network amphoteric membrane for vanadium redox flow battery application

“…Zinc powder (Zn), toluene, potassium carbonate (K 2 CO 3 ), dimethylacetamide (DMAc), and N‐methyl pyrrolidone (NMP) were obtained from Chron Chem Co., Ltd. Nafion 117 membranes were provided from Dupont Co. NMP and DMAc were dehydrated with 4 Å molecular sieves to prior to use. Sulfonated 4,4′‐difluorodiphenyl sulfone (SDFDPS) was prepared as our previous reported 37 …”

Sulfonated poly (arylene ether sulfone)-graft-sulfonated poly (vinyl alcohol) proton exchange membranes: Improved proton selectivity

“…SDFDPS was synthesized as our previous reported. 34 PVA (1788) was obtained from Aladdin. Toluene, N-methyl pyrrolidinone (NMP), isopropyl alcohol (IPA), dimethyl sulfoxide (DMSO), methanol (MeOH), alcohol, concentrated sulfuric acid and potassium carbonate (K 2 CO 3 ) were obtained from Chron Chem Co., Ltd. Deuterium dimethyl sulfoxide (d 6 -DMSO) were provided from Aldrich.…”

“…The physicochemical properties, including ion exchange capacity (IEC), water uptake (WU), swelling ratio (SR), proton conductivity and methanol permeability were evaluated as our previous work. 34 The IEC was measured by the backtitration method. The degree of sulfonation for SPVA could be calculated through IEC:…”

The preparation of novel sulfonated poly(aryl ether ketone sulfone)/TiO2 composite membranes with low methanol permeability for direct methanol fuel cells

“…In our previous work, sulfonate-modified TiO 2 is doped into SPAES to prepare a composite membrane. 27 It is found that the composite membrane exhibits higher proton conductivity and lower methanol permeability than pure SPAES membrane. Especially the methanol permeability of SPAES membrane incorporated with 2% sulfonate-modified TiO 2 is 2.1 × 10 −7 cm 2 s −1 , which is significantly lower than that of neat SPAES membrane (5.2 × 10 −7 cm 2 s −1 ).…”