ACS Materials Au最新文献

Novel ether-free bond polymer backbones were synthesized through polycondensation in a superacid medium by using p-terphenyl and 4-(1H-imidazol-1-yl)benzaldehyde. The presence of imidazolium groups enabled further modifications through a highly efficient nucleophilic substitution reaction introducing cationic sites essential for anionic transport. Characterization by NMR and FTIR analyses confirmed the structures and the complete functionalization of the base polymer. Critical properties for potential anion exchange membrane applications, including water uptake, ion exchange capacity, ion conductivity, morphology, and thermal and mechanical stabilities were investigated. Results indicated that these polymers form stable ion transport channels, with the formation of distinctive hydrophilic/hydrophobic microphase separation in the membranes observed through AFM, HR-TEM, and SAXS analyses. This structural configuration of the membranes exhibited high hydroxide conductivities of 61.33 and 80.33 mS/cm at 80 °C for 1AIM (quaternization with iodomethane) and 1ABPTA (quaternization with (3-bromopropyl)trimethylammonium bromide), respectively, with a thermal stability up to 240 °C, underscoring their suitability for electrochemical applications. Additionally, an organometallic polymer was successfully synthesized from the 1ABPTA polymer due to the presence of an imidazolium salt, N-heterocyclic carbene (NHC) ligand precursor. SEM images displayed the homogeneous distribution of metal atoms, and XPS spectra confirmed the formation of the C-M bond. The material obtained was utilized as a heterogeneous catalyst in a C-C Suzuki-Miyaura coupling reaction, achieving catalytic conversion percentages of 70% and 60% for the first and second cycles, respectively.

This work focuses on biobased reactive diluents' synthesis, continuing with optimized oil-based resin precursor production. Our approach introduces vanillin methacrylate (VanMMA), cinnamyl methacrylate (CinMMA), and vanillyl dimethacrylate (VanDiMMA) synthesis using methacrylic anhydride. The introduced approach involves an innovative and available catalyst, potassium acetate, which possesses much suitable potential compared with the usually used 4-dimethylaminopyridine (DMAP). Moreover, we separated the formed secondary product, methacrylic acid (MA), and used it to modify rapeseed oil to prepare a curable thermoset. All synthesized products were structurally verified via complex cross-analysis (NMR, ESI-MS, and FTIR). The reactive systems were mixed to form a multicomponent mixture appropriate for stereolithography (SLA) and 3D printing. It was found that VanDiMMA exhibited comparable diluting properties to the commercially available and used compound, isobornyl methacrylate (IBOMA), while achieving better mechanical, thermo-mechanical, and thermal properties than IBOMA. VanDiMMA-containing SLA resin reached a tensile strength of 12.7 ± 0.3 MPa, a flexural strength of 16.8 ± 0.4 MPa, a storage modulus of 570 MPa at 30 °C, a glass-transition temperature of 83.7 °C, and the heat-resistant index of 169.5 °C.

We prepared rutile TiO₂ particles doped with Ni²⁺, Al³⁺, Nb⁵⁺, and Ta⁵⁺ by hydrothermal synthesis as anode materials for Na-ion batteries and investigated the effect of doping cation valence on the anode performance and the Na⁺ diffusion behavior. In situ X-ray diffraction analyses confirmed the insertion and extraction of Na⁺ while maintaining the rutile structure. Among the various doped TiO₂ electrodes, the Ni-doped TiO₂ one exhibited the best anode performance with a high reversible capacity of 135 mA h g^-1 even at 50C (16.75 A g^-1). This electrode showed a very long cycle life: the capacity of 225 mA h g^-1 could be attained even after 10,000 cycles. The first-principles calculation suggested the formation of impurity levels in the forbidden band of TiO₂ by various cation dopings. Electrochemical impedance analyses revealed that the Ni-doped TiO₂ electrode showed lower charge-transfer resistance (R _ct) compared with other cation-doped TiO₂ electrodes. Measurements using the galvanostatic intermittent titration technique found that the Na⁺ diffusion coefficient (D _Na+) of Ni-doped TiO₂ has a higher value of 1.2 × 10^-13 cm² s^-1 compared with D _Na+ of 4.8 × 10^-14 cm² s^-1 in the case of undoped TiO₂. The first-principle calculation supported this result: the Ni²⁺ doping could reduce the activation energy required for Na⁺ diffusion in rutile TiO₂. Therefore, we suggest that an easier migration of Na⁺ was promoted in the Ni-doped TiO₂, effectively enhancing the charge-discharge capacity and the cycle life. Although rutile TiO₂ as an anode has had a difficult history, this study proved that impurity element doping such as Ni²⁺ can transform it into a very attractive anode material.