Spatial programming of self-organizing chemical systems using sustained physicochemical gradients from reaction, diffusion and hydrodynamics. Issue 39 (29th September 2022)

• Record Type: Journal Article
• Authors: Nguindjel, Anne-Déborah C.; de Visser, Pieter J.; Winkens, Mitch; Korevaar, Peter A.
• Is Part Of: Physical chemistry chemical physics. Volume 24:Issue 39(2022)
• Page Start: 23980
• Page End: 24001
• Publication Date: 2022-09-29
• Subjects: Chemistry, Physical and theoretical -- Periodicals; 541.3
• DOI: 10.1039/d2cp02542f
• Languages: English
• ISSNs: 1463-9076

Abstract

Abstract : We highlight four different concepts that can be used as a design principe to establish self-organization using chemical reactions as a driving force to sustain gradients: reaction–diffusion, reaction–convection, Marangoni flow and diffusiophoresis. Abstract : Living organisms employ chemical self-organization to build structures, and inspire new strategies to design synthetic systems that spontaneously take a particular form, via a combination of integrated chemical reactions, assembly pathways and physicochemical processes. However, spatial programmability that is required to direct such self-organization is a challenge to control. Thermodynamic equilibrium typically brings about a homogeneous solution, or equilibrium structures such as supramolecular complexes and crystals. This perspective addresses out-of-equilibrium gradients that can be driven by coupling chemical reaction, diffusion and hydrodynamics, and provide spatial differentiation in the self-organization of molecular, ionic or colloidal building blocks in solution. These physicochemical gradients are required to (1) direct the organization from the starting conditions ( e.g. a homogeneous solution), and (2) sustain the organization, to prevent it from decaying towards thermodynamic equilibrium. We highlight four different concepts that can be used as a design principle to establish such self-organization, using chemical reactions as a driving force to sustain the gradient and, ultimately, program the characteristics of the gradient: (1) reaction–diffusion coupling; (2) reaction–convection; (3) the Marangoni effect and (4) diffusiophoresis. Furthermore, we outline their potential as attractive pathways to translate chemical reactions and molecular/colloidal assembly into organization of patterns in solution, (dynamic) self-assembled architectures and collectively moving swarms at the micro-, meso- and macroscale, exemplified by recent demonstrations in the literature.