Publications by authors named "Chisa Higuchi"

Marine plastic pollution is progressing worldwide and will become increasingly serious if plastic waste emissions continue at the current rate or increase with economic growth. Here, we report a particle tracking-based probability distribution model for predicting the abundances of marine macroplastics and microplastics, which undergo generation, transport, and removal processes in the world's upper ocean, under various scenarios of future land-to-sea plastic waste emissions. To achieve the Osaka Blue Ocean Vision, which aims to reduce additional pollution by marine plastic litter to zero by 2050, plastic waste emission in ∼2035 should be reduced by at least 32 % relative to 2019.

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We investigate the adhesive interaction energy (Δ) between an epoxy resin and a silica surface using pair interaction energy decomposition analysis (PIEDA), which decomposes Δ into four components: electrostatic (Δ), exchange repulsion (Δ), charge-transfer (Δ), and dispersion (Δ) energies based on quantum chemistry. Our previous study with PIEDA showed that synergistic effects of Δ and Δ are critical at the interface between an epoxy resin fragment and a hydrophilic surface. The present study is designed to show in detail that the synergistic effects are significant at the interface between an epoxy layer model consisting of 20 epoxy monomers and a hydrophilic silica surface.

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Tetraalkoxyphenanthrylene-hexaynylene and -octaynylene macrocycles, which represent the first examples of isolable arylene-alkynylene macrocycles (AAMs) that contain polyyne chains longer than tetrayne, were synthesized and their self-association behavior was examined. Extending the polyyne chain from diyne to tetrayne, hexayne, and octayne exponentially increased the self-association constant of the macrocycles.

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The molecular mechanism of the adhesion between silica surface and epoxy resin under atmospheric conditions is investigated by periodic density-functional-theory (DFT) calculations. Slab models of the adhesion interface were built by integrating a fragment of epoxy resin and hydroxylated (0 0 1) surface of α-cristobalite in the presence of adsorbed water molecules. Effects of adsorbed water on the adhesion interaction are evaluated on the basis of geometry-optimized structures, adhesion energies, and forces.

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