Electrostatically Directed Self-Assembly of Ultrathin Supramolecular Polymer Microcapsules.

Richard M Parker,Roger J Coulston,Chris Abell,Clive A Smith,Jing Zhang,Andrew R Salmon,Ziyi Yu,Oren A Scherman,Yu Zheng

doi:10.1002/adfm.201501079

Richard M Parker, Roger J Coulston + Show 7 more

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https://doi.org/10.1002/adfm.201501079

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Abstract

Supramolecular self-assembly offers routes to challenging architectures on the molecular and macroscopic scale. Coupled with microfluidics it has been used to make microcapsules—where a 2D sheet is shaped in 3D, encapsulating the volume within. In this paper, a versatile methodology to direct the accumulation of capsule-forming components to the droplet interface using electrostatic interactions is described. In this approach, charged copolymers are selectively partitioned to the microdroplet interface by a complementary charged surfactant for subsequent supramolecular cross-linking via cucurbit[8]uril. This dynamic assembly process is employed to selectively form both hollow, ultrathin microcapsules and solid microparticles from a single solution. The ability to dictate the distribution of a mixture of charged copolymers within the microdroplet, as demonstrated by the single-step fabrication of distinct core–shell microcapsules, gives access to a new generation of innovative self-assembled constructs.

Highlights

Supramolecular self-assembly offers routes to challenging architectures on microcapsules typically rely on sacrificial core templates,[12] polyelectrolyte interacthe molecular and macroscopic scale
A versatile methodology to direct the accumulation of capsule-forming components to the droplet interface using electrostatic interactions is described
Aqueous microdroplets were generated in a single step as an aqueous emulsion in oil within a polydimethylsiloxane (PDMS) microfluidic device, consisting of two inlets meeting at a single flow-focusing junction (60 × 50 μm, Figure 1A and Figure S1A, Supporting Information)

Summary

Introduction

Supramolecular self-assembly offers routes to challenging architectures on microcapsules typically rely on sacrificial core templates,[12] polyelectrolyte interacthe molecular and macroscopic scale. Microdroplets containing a uniform distribution of copolymer throughout the droplet yield a solid, smooth microparticle upon evaporation, with only the successful partitioning of capsule-forming components to the droplet interface leading to the formation of a microcapsule.

Results

Conclusion