Photothermally Reconfigurable Colloidal Crystals at a Fluid Interface, a Generic Approach for Optically Tunable Lattice Properties
METADATA ONLY
Loading...
Author / Producer
Date
2021-08-04
Publication Type
Journal Article
ETH Bibliography
yes
Citations
Altmetric
METADATA ONLY
Data
Rights / License
Abstract
Optically addressable colloidal assembly at fluid interfaces is a highly desired component to generate reconfigurable 2D materials but has rarely been achieved and only with specific interface engineering. Here we describe a generic method to get optically reconfigurable colloidal crystals at the air/water interface and emphasize a new mechanism to convert light into tunable lattice properties. We use light-absorbing anionic particles adsorbed at the air/water interface in the presence of minute amounts of cationic surfactant, which self-assembled into closely packed polycrystalline structures by collectively deforming the surrounding interface. Low-intensity irradiation of these colloidal crystals results in unprecedented control of the interparticle spacing in a preserved crystalline state while, at a higher intensity, cycles of melting/recrystallization with a controllable transition kinetics can be achieved upon successive on/off stimulations. We show that this photoreversible melting originates from an initial thermocapillary stress, expanding the colloidal assembly against the local confinement, and an increase in particles diffusivity imposing the transition kinetics. With this mechanism, local irradiation leads to highly dynamic patterns, including self-healing or self-fed "living" crystals, while multiresponsive assembly is also achieved by controlling particle organization with both light and magnetic stimuli.
Permanent link
Publication status
published
External links
Editor
Book title
Journal / series
Volume
143 (30)
Pages / Article No.
11535 - 11543
Publisher
American Chemical Society