Self-Assembly of Poly(Janus particle)s into Unimolecular and Oligomeric Spherical Micelles

Zhan Li; Zongxin Li; Junfei Hu; Xingwei Feng; Minghua Zhang; Gaigai Duan; Ruimeng Zhang; Yiwen Li

doi:10.1021/acsmacrolett.1c00620

Self-Assembly of Poly(Janus particle)s into Unimolecular and Oligomeric Spherical Micelles

ACS Macro Lett. 2021 Dec 21;10(12):1563-1569. doi: 10.1021/acsmacrolett.1c00620. Epub 2021 Nov 19.

Authors

Zhan Li¹, Zongxin Li¹, Junfei Hu¹, Xingwei Feng¹, Minghua Zhang¹, Gaigai Duan², Ruimeng Zhang³, Yiwen Li¹

Affiliations

¹ College of Polymer Science and Engineering, State Key Laboratory of Polymer Materials Engineering, Sichuan University, Chengdu 610065, China.
² Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, International Innovation Center for Forest Chemicals and Materials, College of Materials Science and Engineering, Nanjing Forestry University, Nanjing, 210037, China.
³ Department of Chemical and Biological Engineering, Northwestern University, Evanston, Illinois 60208 United States.

PMID: 35549135
DOI: 10.1021/acsmacrolett.1c00620

Abstract

Using shape-persistent Janus particles to construct poly(Janus particle)s and studying their self-assembly behaviors are of great interest, but remain largely unexplored. In this work, we reported a type of amphiphiles constructed by the ring-opening metathesis polymerization of nonspherical molecular Janus particles (APOSS-BPOSS), called poly(Janus particle)s (poly(APOSS-BPOSS)_n, n = 12, 17, 22, and 35, and M_n = 35-100 kg/mol). Unlike traditional bottlebrush polymers consisting of flexible side chains, these poly(Janus particles) consist of rigid hydrophilic and hydrophobic polyhedral oligomeric silsesquioxane (POSS) cages as side chains. Interestingly, instead of maintaining an expected extended chain conformation, they could also collapse and then self-assemble to form unconventional unimolecular or oligomeric spherical micelles in solutions with a feature size smaller than 7 nm. More importantly, unlike traditional amphiphilic polymer brushes that could form unimolecular micelles at a relatively high degree of polymerization by self-assembly, these poly(Janus particles)s could accomplish self-assembly at a quite low degree of polymerization because of their unique chemical structure and molecular topology. The formation of unimolecular and oligomeric micelles was also further confirmed by dissipative particle dynamics simulations. This study of introducing the POSS-based poly(Janus particle)s as a class of shape amphiphiles will provide a model system for generating unimolecular and oligomeric micellar nanostructures through solution self-assembly.