Takeoka Yuko

S-6X multi-block copolymers can be developed by direct one-pot copolymerization via Ni(0) coupling reaction, allowing high conductivity and strength on a wide-range of IECs.

Abstract 2D/3D perovskite heterostructure solar cells with orientation controlled 2D perovskite were realized. The obliquely and horizontally oriented Dion-Jacobson (DJ) 2D perovskites were fabricated by templated growth onto (200)/(112)-oriented MAPbI₃ and (110)-oriented MAPbI₂Br, respectively. The obliquely oriented 2D perovskite exhibited the excellent carrier transport properties, while the horizontally oriented 2D perovskite inhibited the carrier transport and drastically deteriorated the solar cell performances. In addition, the 2D/3D heterostructure solar cell with obliquely oriented DJ 2D perovskite demonstrated the enhanced stability. The excellent carrier transport properties of orientation-controlled 2D perovskite would contribute to the 2D/3D heterostructure solar cells with high stability and performance.

A few kinds of thermoresponsive diblock copolymers have been synthesized and utilized for palladium-catalyzed coupling reactions in water. Poly(N-isopropylacrylamide) (PNIPAAm) and poly(N,N-diethylacrylamide) (PDEAAm) are employed for thermoresponsive segments and poly(sodium 4-styrenesulfonate) (PSSNa) and poly(sodium 2-acrylamido-methylpropanesulfonate) (PAMPSNa) are employed for hydrophilic segments. Palladium-catalyzed Mizoroki–Heck reactions are performed in water and the efficiency of the extraction process is studied. More efficient extraction was observed for the PDEAAm copolymers when compared with the PNIPAAm copolymers and conventional surfactants. In the study of the Sonogashira coupling reactions in water, aggregative precipitation of the products was observed. Washing the precipitate with water gave the product with satisfactory purity with a good yield.

Cellulose is the main component of biomass and is the most abundant biopolymer on earth; it is a non-toxic, low-cost material that is biocompatible and biodegradable. Cellulose gels are receiving increasing attention as medical products, e.g., as wound dressings. However, the preparation of cellulose hydrogels employing unmodified cellulose is scarcely reported because of the cumbersome dissolution of cellulose. In previous studies, we developed the new promising cellulose solvent N-butyl-N-methylpyrrolidinium hydroxide in an aqueous solution, which can dissolve up to 20 wt% cellulose within a short time at room temperature. In this study, we employed this solvent system and investigated the gelation behavior of cellulose after crosslinker addition. The swelling behavior in water (swelling ratio, water uptake), the mechanical properties under compression, and the antibacterial activity against Escherichia coli and Bacillus subtilis were investigated. We have developed a simple and fast one-pot method for the preparation of cellulose gels, in which aqueous pyrrolidinium hydroxide solution was acting as the solvent and as an antibacterial reagent. The pyrrolidinium hydroxide content of the gels was controlled by adjustment of the water volume employed for swelling. Simple recovery of the solvent system was also possible, which makes this preparation method environmentally benign.