Synthetic asters as elastic and radial skeletons

Qingqiao Xie,Tianli Wu,Tiankuo Wang,Yuchao Li,Lingxiang Jiang,Yi Cao,Steve Granick,Xixi Chen

doi:10.1038/s41467-019-13009-4

Abstract

The radial geometry with rays radiated from a common core occurs ubiquitously in nature for its symmetry and functions. Herein, we report a class of synthetic asters with well-defined core-ray geometry that can function as elastic and radial skeletons to harbor nano- and microparticles. We fabricate the asters in a single, facile, and high-yield step that can be readily scaled up; specifically, amphiphilic gemini molecules self-assemble in water into asters with an amorphous core and divergently growing, twisted crystalline ribbons. The asters can spontaneously position microparticles in the cores, along the radial ribbons, or by the outer rims depending on particle sizes and surface chemistry. Their mechanical properties are determined on single- and multiple-aster levels. We further maneuver the synthetic asters as building blocks to form higher-order structures in virtue of aster-aster adhesion induced by ribbon intertwining. We envision the astral structures to act as rudimentary spatial organizers in nanoscience for coordinated multicomponent systems, possibly leading to emergent, synergistic functions.

Highlights

The radial geometry with rays radiated from a common core occurs ubiquitously in nature for its symmetry and functions
Looking for a positioning scheme, we notice the radial geometry with rays radiated from a common core that occurs ubiquitously in nature for its symmetry and functions, such as flowers for reproduction and hedgehog spines to defend themselves
We fabricate a class of synthetic asters with welldefined core-ray morphology that can function as elastic, radial skeletons to harbor nano- and microparticles (Fig. 1b–e)

Summary

Introduction

The radial geometry with rays radiated from a common core occurs ubiquitously in nature for its symmetry and functions. We report a class of synthetic asters with well-defined core-ray geometry that can function as elastic and radial skeletons to harbor nano- and microparticles. The asters can spontaneously position microparticles in the cores, along the radial ribbons, or by the outer rims depending on particle sizes and surface chemistry Their mechanical properties are determined on single- and multiple-aster levels. The asters are produced in a simple, robust, and high-yield step—the supramolecular self-assembly of a cationic gemini surfactant [ethylene-1,2-bis(cetyldimethylammonium)] with chiral counterions (a mixture of D- and L-tartrate) in water upon cooling (Fig. 1c) Their formation proceeds with multiple stages, in which surfactant micelles first aggregate to form amorphous cores that gradually transform into divergently growing, twisted crystalline ribbons. We discuss the similarities and differences between the current asters and the biological ones

Methods

Results

Conclusion