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

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.

Preparation of Non‐Spherical Janus Particles via an Orthogonal Dissolution Approach

“…Over the years, various strategies have been proposed and developed for preparing anisotropic particles and colloids. [1][2][3][4][5][6] More specifically, Janus and patchy particles, both with and without spherical symmetry, have shown unique properties and are promising candidates for applications in various fields, such as sensing, [7] drug delivery, [8][9][10] or as active materials. [11,12] DOI: 10.1002/marc.…”

A Brief Review on Selected Applications of Hybrid Materials Based on Functionalized Cage-like Silsesquioxanes

“…However, the research and design of innovative materials with new functions require not reaching for commercially available additives (POSS, DDSQ, etc. ); it is crucial to combine the efforts of synthetics offering unique cage systems and to incorporate them into the structures of other materials, such as an advancement in material design with tailor-made function, literally made-to-order [ 108 , 109 , 110 ]. One question remains whether material chemistry is interesting in this field because, currently, cages are used mainly instrumentally, considering only their classical possibilities, i.e., add if the goal is to increase thermal stability or improve mechanical properties.…”

Exploring Polyol-Functionalized Dendrimers with Silsesquioxane Cores

“…SQs are a family of structures, which could be divided into random resins or defined architectures, i.e., ladder, open- and closed-cage silsesquioxanes and double-decker silsesquioxanes (DDSQ). − The multiplicity of structures and the presence of various reactive groups, e.g., Si–OH, Si–H, Si–HCCH 2 , enable their modification by stoichiometric (condensation, nucleophilic substitution) and catalytic reactions (hydrosilylation, metathesis, Heck or Sonogashira coupling, O -silylation) . As a result, diverse silsesquioxane-based functionalized systems are obtained that may exhibit interesting physicochemical properties that affect their possible application, resulting in the use of, i.e., materials chemistry, OLEDs, catalysis, or medicine. − Within the great variety of functional groups, the SQs possessing hydroxyl-terminated aliphatic substituents may be of special concern. − There are numerous scientific reports on the use of diol derivatives of SQs as comonomers of polyesters or polyurethanes − and also in the chemistry of biomedical materials . In addition, they have been reported in materials to remove dyes from wastewater or Ag­(I) ions from aqueous solutions. , …”