2022.08.02 by 高棹 玄徳 Gentoku TakasaoA combination of a genetic algorithm and local geometry optimization enables non-empirical structure determination for complex materials such as solid catalysts. However, premature convergence in the genetic algorithm hinders the structure determination for complicated systems. Here, we implemented a distributed genetic algorithm based on migration from a structure database for avoiding the premature convergence, and thus realized the structure determination for TiCl4-capped MgCl2 nanoplates with experimentally consistent sizes. The obtained molecular models are featured with a realistic size and non-ideal surfaces, representing primary particles of Ziegler-Natta catalysts.
2022.05.17 by 瀧本 健 Ken TakimotoSynergistic combinations of stabilizers are essential for imparting durability to polymeric materials, but the low throughput of durability tests and the large number of combinations have hindered systematic research. In this study, we have established a novel protocol for high-throughput experimentation, which is based on solution film casting on microplates and absorbance measurement using a microplate reader. The developed protocol was combined with a genetic algorithm to explore stabilizer formulations for photo-induced yellowing inhibition of transparent plastics. The obtained data, amounting to seven years, were analyzed to successfully derive formulation design guidelines.
2022.03.02 by Dongzhi ZhuDue to its high breakdown voltage and low dielectric loss, biaxially oriented polypropylene (BOPP) is mainly used for thin-film capacitors in automobiles. Here, BOPP nanocomposites with dispersed titanium dioxide nanoparticles were prepared and their dielectric properties were investigated in detail. The nanocomposites exhibited permittivity far beyond the theoretical estimate, and we found out that the key is at the nature of the intermediate layer called interphase. Research on BOPP nanocomposites has been hardly reported due to the difficulty of stretching PP nanocomposites. By using the own reactor granule technology, we overcome the technical challenge, and obtained very important knowledge about thin-film capacitors.
2021.11.01 by 和田 透 Toru WadaThe analysis of Ziegler-Natta (ZN) catalysts is difficult due to its complex and heterogeneous nature. We have attempted to clarify the origin of the active structure of ZN catalysts by applying multifaceted characterization techniques, which track the evolution of the starting material to the final catalyst. The linkage between the polymerization performance and the formation of the active structure, like the nuc leation and growth of the δ-MgCl2 support, the types and abundance of chemical species present on the surfaces, and impurity formation and removal is important in rational design of catalysts with desired performance.
2021.10.28 by Hui YouMetal-organic framework (MOF)-based thin-film nanocomposite (TFN) membranes are promising for addressing the permeability-selectivity tradeoff in desalination. Key challenges have been identified at the dispersion and chemical stability of MOFs as well as at the interfacial bonding with the polymeric matrix. Here, we successfully demonstrated that polydopamine (PDA)-coating of MOF nanoparticles can address all these problems at once. Indeed, it almost doubled the permeability and improved the fouling resistance of the membrane without sacrificing the selectivity.