Epoxy asphalt, a thermosetting polymer, is characterized by stable, irreversible internal chemical bonds that prevent recovery and spontaneous micro-crack healing, unlike conventional asphalt. This study introduces a renewable nano-modifier synthesized via esterification of carboxyl-functionalized carbon nanotubes (CNTs-COOH) and furfuryl alcohol (FA), termed CNTs-FA. The successful synthesis of CNTs-FA was confirmed through various microscopic techniques. Integrating CNTs-FA into epoxy asphalt materials, the optimal dosage was identified as 0.05% of the total epoxy asphalt mass using tensile tests and fluorescence microscopy. Thermal reversible effects and mechanisms were further analyzed through multiple regeneration cycles using tensile properties, fluorescence microscopy, and infrared spectroscopy. The study elucidates that the thermal reversibility in epoxy asphalt is facilitated by the Diels-Alder (DA) reaction between the conjugated diene structure in FA and the curing agent oleylamine. This research provides an effective solution to the non-recoverability and unrepairable micro-cracks of traditional epoxy asphalt mixtures. Highlights CNTs-FA was successfully prepared by esterification reaction. Using nano modification methods, introduce DA reaction into curing system. Renewable function of epoxy asphalt by DA reversible reaction.
The Ni-rich cathode holds great promise for high energy density lithium-ion batteries because of its high capacity and operating voltage. However, crucial problems such as cation disorder, structural degradation, side reactions, and microcracks become serious with increasing nickel content. Herein, a novel and facile sol/antisolvent coating modification of Ni-rich layered oxide LiNi0.85Co0.1Mn0.05O2 (NCM) is developed where we use ethanol to disperse the nanosized LiBO2 to form the sol and adopt tetrahydrofuran (THF) as antisolvent to prepare the cluster of nanoparticles to be coated on the surface of NCM. The coating thickness can be tuned through the THF addition amount. The LiBO2 nanorod deposition is formed as well over the crack of the NCM cathode, likely acting as a patch to repair the original defect of the intrinsic crack. The uniform LiBO2 nanospherical particle coating together with LiBO2 nanorod wrapping provides a double protection against electrolytes. Compared with the raw material, LiBO2-coated LiNi0.85Co0.1Mn0.05O2 (LiBO2-coated NCM) exhibits a high initial Coulombic efficiency of 90.3% at 0.2 C between 2.8 and 4.3 V vs Li+/Li, a superior rate capability, enhanced fast charge property at 3 C, and restricted microcrack formation. This simple in-site modification and repairing technology guarantees a good mechanical integrity of the polycrystalline Ni-rich cathode.
Low temperature tolerant adhesive with high flexibility and adhesion strength is highly desired yet challenging owing to the presence of obvious volume shrinkage, increased brittleness, and reduced transmission of mechanical stress at low temperature. Inspired by the cobweb, we hereby develop a kind of flexible adhesive that can be used at low temperature by in-situ polymerization of disulfide bond-based polymer with polyoxometalate. This low-temperature tolerant adhesive presents high flexibility and adhesion strength, good processability and reversible adhesion ability, a wide tolerable temperature range (i.e., −196 to 50 °C), and a long-lasting adhesion effect (>80 days, −196 °C) that is significantly better than commercial solvent-free adhesives. The adhesive can be processed into high-strength cobwebs, injected into tiny tube models, and adhered onto complicated interfaces. Notably, it enables to be kilogram-scale produced through a solvent-free method, holding promise for potential utilization in fields like repairing artifacts or precision instruments with micro-fractures at low temperature.
危险品化学品经营许可证（带存储）