He Feng Group, Department of chemistry, South University of science and technology, has made important progress in the field of two-dimensional polymer supramolecular self-assembly

Recently, he Feng, associate professor of Chemistry Department of South University of science and technology, has made important research progress in the field of polymer two-dimensional supramolecular self-assembly, which was published in the famous journal Nature communications The paper title is "uniformtwo dimensional square assemblies from converged block polymers driven by π - π interactions with controllable sizes" This research work was mainly completed by Han Liang (the first author) and Wang Meijing (the second author), postdoctoral of He Feng research group The Department of chemistry of South University of science and technology is the first research unit, and he Feng, associate professor, is the only corresponding author The two-dimensional nano micron materials have unique ultra-thin flat plane structure, so they have unique carrier transport characteristics, stimulation response characteristics and processing characteristics However, at present, it is not common to get two-dimensional micro and nano materials in the literature It is still a promising and challenging topic to design and synthesize building unit molecules that can form regular and uniform two-dimensional nano and micro structures by stable in-situ self-assembly Most of the commonly used methods to construct two-dimensional self-assembled micro nano structure are driven by crystallization However, most of the two-dimensional materials obtained by this method are "hard materials", which is not conducive to manufacturing and processing in application On the other hand, due to the crystal symmetry, the shape of two-dimensional materials driven by crystallization is mostly triangle, rectangle, hexagon and so on, while highly symmetrical square and circular two-dimensional self-assembled materials are rare He Feng Group focused on using conjugated block copolymers as building units to drive the self-assembly process through the non crystalline process of intermolecular π - π interaction, so as to realize the preparation of high symmetrical two-dimensional self-assembly soft materials with larger specific surface area, higher stability and flexibility a) The structure of ppv-b-p2vp block copolymer; b) tem photo of two-dimensional self-assembled square micelle block copolymer; c) laser confocal photo of two-dimensional square micelle; d) schematic diagram of the formation process of two-dimensional self-assembled micelle driven by ppv-b-p2vp through π - π interaction source: He Feng group of South University of science and technology designed and synthesized the conjugated PPV block as the nucleation block Ppv-b-p2vp, a amphiphilic block copolymer, was used as a building unit to make it undergo the simple process of "dissolution cooling aging" in isopropanol solution A two-dimensional square self-assembled micelle with uniform dispersion was prepared By adjusting the block length ratio and the solution concentration, the size of the two-dimensional square self-assembled structure can be precisely adjusted Based on the good optical properties of PPV blocks, the assembly process of two-dimensional structure was traced and characterized Combined with high-resolution microscopy, sead, giwaxs and molecular dynamics simulation, we can confirm the amorphous state of two-dimensional materials and the driving effect of π - π interaction between PPV blocks on the formation of two-dimensional square micelles In this study, the formation of polymer controllable two-dimensional self-assembly micelles was successfully realized by means of non crystallization, which provided a new idea for the construction of two-dimensional micro nano materials and made an important contribution to the research of two-dimensional self-assembly of polymers At the same time, the two-dimensional square soft material obtained by simple means has good optical and electrical properties, and is a kind of functional micro nano material with potential application value The giwaxs experiment and molecular dynamics simulation in this work were respectively assisted by Professor Chen Wei of Argonne National Laboratory and Professor Qian Hujun of Jilin University At the same time, the research was supported by the start-up funds of South University of science and technology, the national youth project, the National Natural Science Fund, Guangdong Natural Science Fund, Shenzhen peacock team and Shenzhen Science and technology innovation Commission He Feng research group is committed to the design and synthesis of organic conjugated polymer materials, and has expanded its application in many directions such as supramolecular self-assembly, organic polymer solar cells and organic conjugated polymer optoelectronics Since its establishment, the research group has published many papers in the top journals in the fields of NAT Commun., chem Mater., ACS Energy lett., J mater Chem A, macrolecules, etc., of which 2 were selected as the magazine cover Paper link: https:// profile of Associate Professor He Feng: http:// / F / he_feng Associate Professor He Feng