Host ‐Guest Interaction Mediated Interfacial Co‐Assembly of Cyclodextrin and Bottlebrush Surfactants for Precisely Tunable Photonic Supraballs

Precisely tunable photonic supraballs are achieved through the host-guest interaction betweenα-cyclodextrin and bottlebrush block copolymer at oil-water interfaces during organized spontaneous emulsification (OSE) process. The increased asymmetry of BBCP molecules, resulting from the complexation ofα-CD and PEG within BBCPs, induces increased spherical curvature of internal droplets, leading to a distinct blueshift of structural color. AbstractInvestigations of host-guest interactions at water-oil (w/o) interfaces are limited in single emulsion systems producing simple self-assembled objects with limited uses. Here, within hierarchically ordered water-in-oil-in-water (w/o/w) multiple emulsion droplets, interfacial self-assembly of (polynorbornene-graft-polystyrene)-block-(polynorbornene-graft-polyethylene glycol) (PNPS-b-PNPEG) bottlebrush block copolymers can be precisely controlled through host-guest interactions.α-Cyclodextrin (α-CD) in the aqueous phase can thread onto PEG side chains of the bottlebrush surfactants adsorbed at the w/o interface, leading to dehydration and collapsed chain conformation of the PEG block. Consequently, spherical curvature of the w/o internal droplets increases with the increased asymmetry of the bottlebrush molecules, producing photonic supraballs with precisely tailored structural parameters as well as photonic bandgaps. This work provides a simple but highly effective strategy for precise manipulation of complex emulsion systems applica...
Source: Small - Category: Nanotechnology Authors: Tags: Research Article Source Type: research