Molecular Patchy Clusters with Controllable Symmetry Breaking for Structural Engineering

作者:Li, Gang; Gan, Zhanhui; Liu, Yuchu; Wang, Shuai; Guo, Qing-Yun; Liu, Zhongguo; Tan, Rui; Zhou, Dongdong; Kong, Deyu; Wen, Tao; Dong, Xue-Hui*
来源:ACS Nano, 2020, 14(10): 13816-13823.
DOI:10.1021/acsnano.0c06189

摘要

Anisotropic patchy particles with molecular precision are exquisite building blocks for constructing diverse meso-structures of high complexity. In this research, a library of molecular patchy clusters consisting of a collection of functional polyhedral oligomeric silsesquioxane cages with exact regio-configuration and composition were prepared through a robust and modular approach. By meticulously tuning the composition, molecular symmetry, and other parameters, these patchy clusters could assemble into diverse nanostructures, including unconventional complex spherical phases (i.e., Frank-Kasper sigma phase and dodecagonal quasicrystalline phase). As the size of the hydrophilic patch expands, a transition sequence from disorder to hexagonally packed cylinders and then to double gyroids was recorded, corresponding to a progressive decrease of interfacial curvature. On the other hand, regioisomers with the same composition but different regio-configuration adopt similar molecular packing but varied phase stability, as a result of the local self-sorting process to alleviate excess unfavorable interfacial contact. These precisely defined molecular patchy clusters provide a model system for a general understanding of the hierarchical structure formation and evolution based on anisotropic spherical building blocks at the nanoscale.