Dissipative disassembly of colloidal microgel crystals driven by a coupled cyclic reaction network

Abstract

A plethora of natural systems rely on the consumption of chemical fuel or input of external energy to control the assembly and disassembly of functional structures on demand. While dissipative assembly has been demonstrated, the control of structural breakdown using a dissipative cycle remains almost unexplored. Here, we propose and realize a dissipative disassembly process using two coupled cyclic reactions, in which protons mediate the interaction between the cycles. We show how an ordered colloidal crystal, can cyclically transform into a disordered state by addition of energy to a chemical cycle, reversibly activating a photoacid. This cycle is coupled to the colloidal assembly cycle via the exchange of protons, which in turn trigger charging of the particles. This system is an experimental realization of a cyclic reaction-assembly network and its principle can be extended to other types of structure formation.

Light‐Responsive Dynamic DNA‐Origami‐Based Plasmonic Assemblies

“…Recently, spiropyran (SP) and its derivatives have emerged as attractive building blocks for constructing artificial dynamic self‐assembled structures and materials [33–36] . In particular, merocyanine‐based photoacids have been used as light‐responsive regulators for generating dynamic assemblies from intrinsically non‐photoresponsive components [37–41] . Despite the numerous advantages of spiropyran and its derivatives as light‐responsive molecular switches, their use in the context of DNA nanotechnology has thus far not been demonstrated.…”

The Many Ways to Assemble Nanoparticles Using Light

“…Water droplets could freely roll off the irradiated surface, suggesting possible applications in remotely controlled, self‐cleaning surfaces . Similarly, Kuehne and co‐workers demonstrated that the aggregation state of non‐photoresponsive microgel particles could be controlled by light in the presence of photoacid 3 (see Section ), whereas Santer and co‐workers showed that micrometer‐sized silica colloids could be assembled in the presence of an azobenzene surfactant (dubbed “photosoap”) in solution (compare with Section ).…”

Functional Microgels: Recent Advances in Their Biomedical Applications

“…The influence of this stimulus can be simply tuned without any contact by changing the wavelength, polarization direction and intensity . Taking advantage of this, a wide variety of chromophores including spiropyrans, o ‐nitrobenzyl derivatives, and azobenzene have been utilized to develop light‐sensitive polymers . Recently, increasing attempts have been made to synthesize microgel systems with chromophores included in their network to explore the potential of light stimulus for drug delivery applications …”

“…[137] Taking advantage of this, a wide variety of chromophores including spiropyrans, o-nitrobenzyl derivatives, and azobenzene have been utilized to develop light-sensitive polymers. [138][139][140] Recently, increasing attempts have been made to synthesize microgel systems with chromophores included in their network to explore the potential of light stimulus for drug delivery applications. [125] Light-responsive, 2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO)-oxidized Konjac Glucomannan (OKGM)-based delivery system was fabricated by Chen et al [135] The microspheres were stabilized by interaction between carboxylic (COO − ) groups and Fe 3+ ions.…”