LAUSR

Sulfonated polyimide (SPI) membranes are regarded as the potential alternative to Nafion as a polymer electrolyte membrane (PEM) for fuel cells. Herein, sulfonated copolyimide is synthesized through a direct polymerization method using 1,4,5,8-naphthalene tetra carboxylic dianhydride (NDTA), and sulfonated diamine 4,4′-diamino diphenyl-2,2′-disulfonic acid (BDSA). Sulfonated copolyimide is re-dissolved in dimethyl sulfoxide for the fabrication of thin films. The nanocomposites of both 1.0 and 2.0% of the functionalized TiO2-reinforced (SPI/TiO2) are fabricated by blending and casting method. TiO2 nanoparticles are surface-functionalized using (3-aminopropyl)triethoxysilane (APTES). Scanning electron microscopy (SEM), thermogravimetric analysis (TGA), X-ray diffraction (XRD), Fourier transform infrared FTIR), and Brunauer-Emmitt-Teller (BET) techniques are used to reveal the distinctive characteristics of the newly synthesized SPI/TiO2 nanocomposite membranes. The as-synthesized SPI/TiO2 membranes are used to investigate their physicochemical and electrochemical parameters, including water uptake, ion exchange capacity (IEC), swelling property, oxidation stability, and dimensional change stability. The SPI and SPI/TiO2 composite membranes exhibit an ion-exchange value of 1.412 to 1.286 mmol/g. The SPI/TiO2 composite membranes show excellent H2O stability at room temperature. Overall, the results indicate that the SPI/TiO2 membranes exhibit the potential as PEM for direct methanol fuel cell applications. These nanocomposite membranes are also applicable in clean energy production from environment-friendly sources.