The solid state morphology of the tri block copolymer PS b PCEMA b PtBA, which was synthesized by anionic polymerization with narrow molecular weight distribution, was in lamella structure from TEM micrographs. After ...The solid state morphology of the tri block copolymer PS b PCEMA b PtBA, which was synthesized by anionic polymerization with narrow molecular weight distribution, was in lamella structure from TEM micrographs. After being blended with polystyrene with the mass ratio of 1∶0 4, the morphology showed cylinder structure. With PS as continous phase, PCEMA and PtBA phases formed cylinders with PCEMA as outer layer. The nanofibres can be got and dispersed in good solvents of PS when the PCEMA phase was crosslinked. The t butyl group in PtBA phase can be cleavaged by reacting with TMSI, and nanofibres changed to nanotubes finally. It has the great potential applications, such as in the preparation of nanowires, template polymerization, nano reactor etc ..展开更多
Topological phases of matter have been extensively investigated in solid-state materials and classical wave systems with integer dimensions. However, topological states in non-integer dimensions remain almost unexplor...Topological phases of matter have been extensively investigated in solid-state materials and classical wave systems with integer dimensions. However, topological states in non-integer dimensions remain almost unexplored. Fractals, being self-similar on different scales, are one of the intriguing complex geometries with non-integer dimensions. Here, we demonstrate fractal higher-order topological states with unprecedented emergent phenomena in a Sierpin? ski acoustic metamaterial. We uncover abundant topological edge and corner states in the acoustic metamaterial due to the fractal geometry. Interestingly,the numbers of the edge and corner states depend exponentially on the system size, and the leading exponent is the Hausdorff fractal dimension of the Sierpin? ski carpet. Furthermore, the results reveal the unconventional spectrum and rich wave patterns of the corner states with consistent simulations and experiments. This study thus unveils unconventional topological states in fractal geometry and may inspire future studies of topological phenomena in non-Euclidean geometries.展开更多
文摘The solid state morphology of the tri block copolymer PS b PCEMA b PtBA, which was synthesized by anionic polymerization with narrow molecular weight distribution, was in lamella structure from TEM micrographs. After being blended with polystyrene with the mass ratio of 1∶0 4, the morphology showed cylinder structure. With PS as continous phase, PCEMA and PtBA phases formed cylinders with PCEMA as outer layer. The nanofibres can be got and dispersed in good solvents of PS when the PCEMA phase was crosslinked. The t butyl group in PtBA phase can be cleavaged by reacting with TMSI, and nanofibres changed to nanotubes finally. It has the great potential applications, such as in the preparation of nanowires, template polymerization, nano reactor etc ..
基金supported by the National Natural Science Foundation of China(12125504,12072108,51621004,and 51905162)the Priority Academic Program Development(PAPD)of Jiangsu Higher Education Institutions+1 种基金the Hunan Provincial Natural Science Foundation of China(2021JJ40626)。
文摘Topological phases of matter have been extensively investigated in solid-state materials and classical wave systems with integer dimensions. However, topological states in non-integer dimensions remain almost unexplored. Fractals, being self-similar on different scales, are one of the intriguing complex geometries with non-integer dimensions. Here, we demonstrate fractal higher-order topological states with unprecedented emergent phenomena in a Sierpin? ski acoustic metamaterial. We uncover abundant topological edge and corner states in the acoustic metamaterial due to the fractal geometry. Interestingly,the numbers of the edge and corner states depend exponentially on the system size, and the leading exponent is the Hausdorff fractal dimension of the Sierpin? ski carpet. Furthermore, the results reveal the unconventional spectrum and rich wave patterns of the corner states with consistent simulations and experiments. This study thus unveils unconventional topological states in fractal geometry and may inspire future studies of topological phenomena in non-Euclidean geometries.
