Rationally Leveraging Polymer Chain-Length Heterogeneity for Robust Structural Engineering  

作　　者：Zhanhui Gan Luyang Li Dongdong Zhou Zhuoqi Xu Zhuang Ma Jiawen He Weihua Li Xue-Hui Dong 

机构地区：[1]South China Advanced Institute for Soft Matter Science and Technology,School of Emergent Soft Matter,South China University of Technology,Guangzhou 510640 [2]State Key Laboratory of Molecular Engineering of Polymers,Key Laboratory of Computational Physical Sciences,Department of Macromolecular Science,Fudan University,Shanghai 200433 [3]College of Polymer Science and Engineering,State Key Laboratory of Polymer Materials Engineering,Sichuan University,Chengdu 610065 [4]Guangdong Provincial Key Laboratory of Functional and Intelligent Hybrid Materials and Devices,South China University of Technology,Guangzhou 510640

出　　处：《CCS Chemistry》2024年第8期1965-1977,共13页中国化学会会刊（英文）

基　　金：supported by the National Natural Science Foundation of China(grant no.22273026);the Recruitment Program of Guangdong(grant no.2016ZT06C322);the Research Funds from State and Local Joint Engineering Laboratory for Novel Functional Polymeric Materials,Soochow University(grant no.SDGC2109);the 111 Project(grant no.B18023).

摘　　要：The inherent uncertainty of chain length in synthetic polymers casts doubt on the explicit understanding of fundamental principles.This study quantitatively assesses the critical role of chain-length distribution in the self-assembly process,aiming to identify the point at which discernible discrepancies begin to emerge.By blending discrete diblock copolymers of varying sizes,chain-length nonuniformity can be precisely regulated while the average composition remains constant.Introducing a minor heterogeneity leads to an expansion of lattice dimension,while a phase transition occurs as the difference exceeds a threshold.Interestingly,a transition from the Frank–Kasperσphase to the body-centered cubic phase was triggered by enlarging the size difference of the corona block,while introducing heterogeneity in the core block stabilized the hexagonally close-packed spheres.A self-consistent field theory calculation reveals that the synergy between the long and short chains effectively releases packing frustration,leading to substantial changes in the free-energy landscape and stabilizing unconventional phases otherwise inaccessible.This work calls particular attention to the importance of chain-length heterogeneity and provides a robust approach to finely tuning the phase behavior and physical properties of block copolymers without altering their chemical composition.

关 键 词：discrete polymer molecular weight distribution self-assembly hexagonally close-packed phase Frank-Kasper phases 

分 类 号：TQ317[化学工程—高聚物工业]