A new hyperbranched sulfonated poly(arylene aliphatic ketones) (HB‐SPAAK) has been synthesized and loaded with titania nanoparticles to obtain HB‐SPAAK/TiO2 nanocomposites for thermally stable proton‐conducting electrolyte membrane fuel cell (PEMFC) applications. The synthesis of HB‐SPAAKs was carried out through the polycondensation reaction of different aliphatic and aromatic acids with simultaneous loss of H2O, trifluromethane sulfonic acid used as catalyst. The long chain hyperbranched polymers and TiO2‐loaded nanocomposites were characterized by FT‐IR, 1H‐NMR, SEM and HR‐TEM. Proton conductivity (PC), swelling ratio, water uptake and oxidative stability. The SEM image of TiO2 NPs and HB‐SPAAKs/TiO2 nanocomposites membrane clearly showed the spherical of TiO2 and porous structure of HB‐SPAAKs with a pore diameter of 2–50 μm. TEM image reveals the uniform particle size distribution of TiO2 nanoparticles having a nanosize of 100 nm. TiO2 loaded polymer nanocomposites showed lower values of W/U and S/R when compared to the unmodified HB‐SPAAK, while 3% TiO2 loaded HB‐SPAAKs exhibited a threefold increment of proton conductivity of 1.439 × 10−2 S cm−1 compared to HB‐SPAAKs (0.41 x 10−2 S cm−1) and lower than that of Nafion 117 (0.1003 S cm−1 at 80°C). The 5% TiO2 NPs‐embedded with HB‐SPAAKs nanocomposites membranes also presented admirable oxidative stability with a degradation value of 13.8% during immersion in Fenton reagent for 8 h at 70°C.

The new 2,3-diphenylquinoxalin-6-amine (dpqa) was designed and synthesized through efficient yielded condensation process. Data from FTIR and 1H-NMR spectroscopy have been adopted to ascertain the molecular structure of benzoxazine compunds....

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Nonlinear optical organic materials of N,N-diphenylbenzamide (NNDPB) and 4-fluoro-N,N-diphenylbenzamide (FNNDPB) are synthesized from benzoylation of N,N-diphenylamine using the substituted benzoyl chlorides. The single crystals of NNDPB and FNNDPB are grown by a slow evaporation technique. Single-crystal X-ray diffraction shows that both the crystals belong to orthorhombic crystallographic system with space group Pbca. Fourier transform infrared spectrum shows the chemical bonding and various functional groups, the carbonyl peak appeared at 1647 and 1651 cm −1 in NNDPB and FNNDPB compounds, respectively. 1 H and 13 C nuclear magnetic resonance analysis examines the placement of aromatic protons and carbons are identified to the synthesized materials. UV-vis near IR spectra analysis showed 100% transmission in the visible region for both NNDPB and FNNDPB crystals. As-grown crystal dielectric constant and dielectric loss are inversely proportional to the frequency at all the temperatures. The thermal properties of NNDPB and FNNDPB crystals are studied from thermogravimetric analysis/differential thermal analysis analysis, it is thermally stable up to 483 and 503 K. Crystal growth mechanism and defects are observed from etching studies. The relative second harmonic generation efficiency is measured by Kurtz-Perry powder technique and is found to be 1.55 and 1.7 times as that of potassium dihydrogen phosphate.

To replace commercial Nafion membranes in polymer electrolyte membrane fuel cell (PEMFC) applications, high-level research has lately focused heavily on developing polymer nanocomposite membranes with greater proton conductivity (PC), peak power density (PD), open circuit voltage (OCV), and cheaper cost. The aminated triazine containing poly(aryl-aliphatic ethers) (PA-APAAEs) are synthesized via the Schiff base approach, and their functional groups and chemical structure were analyzed using Fourier transform infrared (FTIR), 1H NMR, 13C NMR, and DEPT 13C NMR. PbS nanoparticles (NPs) are prepared through a one-pot hydrothermal method, and their particle size, morphology, and crystallographic nature were investigated through high-resolution transmission electron microscopy (HR-TEM), scanning electron microscopy (SEM), and powder X-ray diffraction (PXRD) analyses. The present study describes a solvent-casting process for producing PbS nanoparticles (1–7 wt %) dispersed in phosphoric acid (PA)-doped triazine ring-containing aminated poly(arylene-aliphatic ethers) (PA-APAAEs) polymer nanocomposite (PNC) foams, and their high-temperature polymer electrolyte membrane fuel cell (HT-PEMFC) performance was evaluated. Additionally, the evaluation of typical physiochemical properties, including ion exchange capacity (IEC), water uptake (WU), swelling ratio (SR), porosity, proton conductivity (PC), and oxidative stability (OS), was done on both bare and PbS NPs-loaded PA/PA-APAAEs polymer nanocomposite (PNC) foams. 5 wt % PbS nanoparticles introduced into PA/PA-APAAEs PNC foams had the greatest IEC rate of 3.46 mmol g–1 at room temperature (RT), as well as a PC value of 3.42 10–2 S cm–1 at 150 °C for the PA-APAAEs foams. Furthermore, under anhydrous circumstances, the fuel cell test of the 5% PbS NPs-loaded PA-APAAEs PNC foam membrane yielded PD and OCV values of 0.525 W cm–2 and 0.55 V at 150 °C, respectively. At 100 °C for 6 h, the PNC exhibited excellent OS with 93.6% deterioration toward the Fenton reagent.

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