A Continuous Gradient Colloidal Glass. Issue 7 (28th December 2022)

• Record Type: Journal Article
• Authors: Schöttle, Marius; Lauster, Tobias; Roemling, Lukas J.; Vogel, Nicolas; Retsch, Markus
• Is Part Of: Advanced materials. Volume 35:Issue 7(2023)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-12-28
• Subjects: colloidal self‐assembly -- gradient size distribution -- light scattering -- mesoscale gradients; Materials -- Periodicals; Chemical vapor deposition -- Periodicals; 620.11
• DOI: 10.1002/adma.202208745
• Languages: English
• ISSNs: 0935-9648

Abstract

Abstract: Colloidal crystals and glasses manipulate light propagation depending on their chemical composition, particle morphology, and mesoscopic structure. This light–matter interaction has been intensely investigated, but a knowledge gap remains for mesostructures comprising a continuous property gradient of the constituting particles. Here, a general synthetic approach to bottom‐up fabrication of continuous size gradient colloidal ensembles is introduced. First, the technique synthesizes a dispersion with a specifically designed gradual particle size distribution. Second, self‐assembly of this dispersion yields a photonic colloidal glass with a continuous size gradient from top to bottom. Local and bulk characterization methods are used to highlight the significant potential of this mesostructure, resulting in vivid structural colors along, and in superior light scattering across the gradient. The process describes a general pathway to mesoscopic gradients. It can expectedly be transferred to a variety of other particle‐based systems where continuous gradients will provide novel physical insights and functionalities. Abstract : A controlled extraction emulsion process (CrEEP) allows the synthesis of monodisperse latex particles with a continuous size gradient. Subsequent self‐assembly into a photonic glass results in a thin film with a continuous photonic gradient and structural colors ranging over the full visible spectrum. This concept is shown to improve the broadband reflectance of such a mesostructure compared to a non‐gradient mixture.