High performance sulfonated poly(phthalazinone ether phosphine oxide)s for proton exchange membranes

Investigating the Role of Aniline Structure in Improving Proton Exchange Membranes for High Conductivity

Polybenzothiazole exhibits high proton conductivity; however, its rigid backbone limits its applicability, necessitating processes such as modification or doping. The aniline structure can participate in various reactions, including nucleophilic or electrophilic substitution reactions, salt formation, and acylation reactions. In this experiment, an aniline structure is integrated into the main chain of sulfonated polybenzothiazole to investigate the potential of aniline for enhancing proton exchange membranes. The incorporation of the aniline structure is confirmed through infrared and nuclear magnetic resonance analyses. A comparison of different proportions of aniline revealed that 12.5% aniline increased the tensile modulus to 274.40 MPa and the elongation at break to 6.26%. Furthermore, the water absorption rate reached 65.73%, while the expansion rate remained at 25%. The aniline structure exhibits inherent basicity and utilizes phosphoric acid adsorption to enhance proton conductivity. After aniline adsorbs phosphoric acid, the proton conductivity peaks at 0.157 S cm-1. Additionally, the introduction of amino groups provides further modification potential to the main chain of polybenzothiazole.

A novel proton exchange membrane derived from trisulfonated poly(arylene ether phosphine oxide) containing diphenyl ether moieties

A series of novel trisulfonated phosphine oxide polymers (tsPEPO-x) with different sulfonation degrees were prepared by intermolecular polymerization of trisulfonated phosphine monomer and 4,4′-dihydroxydiphenyl ether. The properties of these membranes were investigated in detail. The results showed that these membranes, especially those with high sulfonation degree, exhibited excellent overall performance. For example, the conductivity of tsPEPO-120 membrane reaches 0.093 S cm−1 at 80°C, which is higher than that (0.087 S cm−1) of Nafion 117. At the same time, the swelling rate is almost equivalent to that (20%) of Nafion 117. Moreover, the membrane also has good oxidation resistance in Fenton’s reagent. The obtained polymers showed good properties. The trisulfonated moieties and diphenyl ether simultaneously played important roles in improving the properties of the polymer.

Sulfonated polybenzothiazole cathode materials for Na-ion batteries

A new flexible aromatic polymer sulfonated polybenzothiazole (sPBT-SE) with sulphone and ether units is reported as an advanced cathode material for storing Na+, which delivers a high discharge capacity of 103 mA h g−1 after 350 cycles at 30 mA g−1.

Preparation and Characterization of a Novel Sulfonated Titanium Oxide Incorporated Chitosan Nanocomposite Membranes for Fuel Cell Application

In this study, nano-TiO₂ sulfonated with 1,3-propane sultone (STiO₂) was incorporated into the chitosan (CS) matrix for the preparation of CS/STiO₂ nanocomposite membranes for fuel cell applications. The grafting of sulfonic acid (–SO₃H) groups was confirmed by Fourier transform infrared spectroscopy, thermogravimetric analysis and energy-dispersive X-ray spectroscopy. The physicochemical properties of these prepared membranes, such as water uptake, swelling ratio, thermal and mechanical stability, ion exchange capacity and proton conductivity, were determined. The proton conducting groups on the surface of nano-TiO₂ can form continuous proton conducting pathways along the CS/STiO₂ interface and thus improve the proton conductivity of CS/STiO₂ nanocomposite membranes. The CS/STiO₂ nanocomposite membrane with 5 wt% of sulfonated TiO₂ showed a proton conductivity (0.035 S·cm⁻¹) equal to that of commercial Nafion 117 membrane (0.033 S·cm⁻¹). The thermal and mechanical stability of the nanocomposite membranes were improved because the interfacial interaction between the -SO₃H group of TiO₂ and the –NH₂ group of CS can restrict the mobility of CS chains to enhance the thermal and mechanical stability of the nanocomposite membranes. These CS/STiO₂ nanocomposite membranes have promising applications in proton exchange membrane fuel cells.

New sulfonated copoly(triazole imide)s synthesized by a click chemistry reaction with improved oxidative stability

New sulfonated copoly(triazole imide)s synthesized by a click chemistry reaction with improved oxidative stability.