Synthesis Of Polymer Electrolyte Membranes Research Articles

Synthesis and characterization of sulfonated chitosan (SCS) / sulfonated polyvinyl alcohol (SPVA) blend membrane for microbial fuel cell application

We have reported the synthesis of newly blended membranes, SPVA/SCS, using the solution-casting and solvent evaporation technique. The selection of appropriate polymers is crucial for the synthesis of polymer electrolyte membranes (PEMs). Considering factors such as film-forming ability, cost-effectiveness, ease of handling, availability, and proton conductivity, we optimized the blend of polyvinyl alcohol (PVA) and chitosan polymers. To enhance the proton conductivity of the blend membrane, the sulfonic group was incorporated into the polymer chain through a sulfonation process. We successfully synthesized SPVA/SCS membranes by varying the mass ratios of SPVA/SCS, specifically 90:10, 50:50, and 10:90. The thermal stability and chemical structure of the blend membrane were analyzed using Thermogravimetric and FTIR techniques. Moreover, a multicore design of microbial fuel cell was used to analyze the performance of membrane. The membrane was kept inside the cell for 48 h and the maximum voltage and current obtained was found to be 630–750 mV and 0.93–1.03 mA respectively.

Synthesis of Polymer Electrolyte Membranes from Sulfonated Poly(Arylene Ether Ketones) with Partial Substitution of Carboxylate Acid Group

AbstractChemical modification of Sulfonated poly(arylene ether ketone) with carboxylate acid side chain (C‐SPAEK) membranes has been conducted through partially substitution of the 4,4‐bis(4‐hydroxyphenyl)‐valeric acid (DPA) with 4,4‐bis(4‐hydroxyphenyl)‐propane (BPA) at varies different compositions of sulfonate. FTIR and EDS analysis of the synthesized SPAEK revealed the presence of carboxylic acid, methyl, sulfonate groups and aromatic ether bonds in the SPAEK membrane. The effect of different compositions of carboxylic acid and sulfonate groups on mechanical strength, thermal stability, oxidative stability, water absorption, swelling ratio and proton conductivity of the membranes was studied. The SPAEK‐50/50 membrane exhibits superior properties with high mechanical strength, high thermal and oxidative stability, good water absorption, low swelling ratio, high dimensional stability and has a proton conductivity at 80 °C of 0.102 S/cm close to the Nafion‐117 membrane of 0.120 S/cm. This finding confirms that the partial substitution of the hydrophilic monomer of DPA with 50 % mole of BPA with a sulfonate group composition of 50 % resulted in an excellent SPAEK membrane.

Synergistic Effect of 2-Acrylamido-2-methyl-1-propanesulfonic Acid on the Enhanced Conductivity for Fuel Cell at Low Temperature.

This present work focused on the aromatic polymer (poly (1,4-phenylene ether-ether-sulfone); SPEES) interconnected/ cross-linked with the aliphatic monomer (2-acrylamido-2-methyl-1-propanesulfonic; AMPS) with the sulfonic group to enhance the conductivity and make it flexible with aliphatic chain of AMPS. Surprisingly, it produced higher conductivity than that of other reported work after the chemical stability was measured. It allows optimizing the synthesis of polymer electrolyte membranes with tailor-made combinations of conductivity and stability. Membrane structure is characterized by 1H NMR and FT-IR. Weight loss of the membrane in Fenton’s reagent is not too high during the oxidative stability test. The thermal stability of the membrane is characterized by TGA and its morphology by SEM and SAXS. The prepared membranes improved proton conductivity up to 0.125 Scm−1 which is much higher than that of Nafion N115 which is 0.059 Scm−1. Therefore, the SPEES-AM membranes are adequate for fuel cell at 50 °C with reduced relative humidity (RH).

Synthesis of Moderate Water-Uptake and Low Methanol Permeable Polymer Electrolyte Membrane from Functionalized Polyisoprene Impregnated Carbon Nanotubes

The study of the synthesis of polymer electrolyte membrane exhibiting moderate water uptake and low methanol permeation for fuel cell application using functionalized polyisoprene impregnated with carbon nanotubes (CNTs) was carried out. The functionalization of the polymer with chlorosulphonic acid of different initial concentrations of 0.0013, 0.001, 0.0017, and 0.0023 mol/L at the minimum time of 1hr produced ion exchange capacities (IEC) of 1.22, 1.92, 2.74, and 4.92 mmol/g, respectively, and at the maximum sulphonation time of 18hrs the IEC were 7.74, 8.78, 11.10, and 16.93 mmol/g, respectively. Their corresponding degrees of sulphonation (DS) for 1hr were 3.53, 5.55, 7.91, and 14.21%, respectively, and while at 18hrs their corresponding DS were 22.35, 25.37, 32.04, and 48.88%, respectively, which implies that IEC and DS are directly proportional to the concentration of acid used and reaction time. Result also showed that synthesized membrane without carbon nanotubes absorbed so much of it weight in water; 31.34 and 73.97% of its weight in both 1 day and 6 days for membrane with 48.88% DS. Whereas the membrane that was impregnated with CNTs of the same DS exhibited a lesser absorption of 23.23 and 53.23% of its weight in both 1 day and 6 days, thereby reducing the high water uptake of the membrane that would have affected it negatively by 1.3 fold. Apart from the conductivity of the synthesized membrane witnessing an increase by 1 order with the membrane impregnated with CNTs from 10^-3 S/cm to 10^-2 S/cm, it was also found out that the methanol crossover was lower than that of commercial Nafion, where membrane impregnated with CNTs had methanol crossover improvement with a difference of 0.48 Mol/L over its counterpart without CNTs as a result of the presence of CNTs.

Ionic liquid grafted graphene oxide composite to create proton transfer pathways in polymer electrolyte membrane

For the synthesis of polymer electrolyte membrane (PEM), high ionic conductivity and stability are the key challenge. This paper deals with the preparation of polymer electrolyte membranes based on ionic liquid (IL) functionalized graphene oxide (GO) and sulfonated polyether sulfone (SPES). Using a simple solution casting technique, composite membranes have been prepared possessing good physicochemical properties and mechanical stability. Methanol crossover resistance have been measured across the composite membranes and found to be low for IG- 05 membrane (0.53×10−7cm2s−1) with the selectivity of 7.99×105. Composite IG- 05 membrane also exhibit high ionic conductivity of 7.27×10−2S.cm−1 which is around 66% higher than that of SPES membrane.

Synthesis of Polymer Electrolyte Membrane based on Acid-Base Complex Pair and Its Characteristics

In this work, acid-base complex pair polymer electrolyte membranes on sulfonated polysulfone with 1H-benzotriazole were investigated. Polysulfone was sulfonated in 1,2-dichloroethane using the homogeneous method with trimethylsilyl chlorosulfonate as sulfonating agent. The monomer mole ratio between polysulfone and trimethysilyl chlorosulfonate was 1:1.5.The sulfonated polysulfone was added with 1H-benzotriazole at mole ratios of x = 0.5 and x =1. The proton transfer from 1H-benzotriazole to the sulfonated polysulfone was measured using FTIR. Thermo-gravimetry analysis showed that the samples were thermally stable up to approximately 250°C and the maximum proton conductivity was found to be 3.34 x 10-4 S cm-1 at 150°C.

Synthesis of polymer electrolyte membranes based on poly(norbornene)s functionalized with pendant difluoroalkyl sulfonic acids

A novel difluoroalkanesulfonyl fluoride monomer, 2-(bicyclo[2.2.1]hept-5-en-2-yl)-1,1-difluoro-2- methoxypropane-1-sulfonyl fluoride, was synthesized in two steps. Nucleophilic addition of 2-acetyl-5-norbornene with difluoromethyl 2-pyridyl sulfone, followed by methylation with methyl trifluoromethanesulfonate produced substituted difluoromethyl 2-pyridyl sulfone. Removal of the pyridyl group with KOH/MeOH, and fluorination with Selectfluor afforded the desired monomer. Novel poly(norbornene)s containing pendent difluoroalkanesulfonic acids were synthesized by copolymerization of varying molar ratios of norbornene with difluoroalkanesulfonyl fluoride monomer by ring opening metathesis polymerization (ROMP) using Grubbs second-generation catalyst, followed by hydrolyzing under basic condition and treatment with aqueous HCl. Room temperature proton conductivity (12?49 mS/cm) was observed with these new type of membranes.