Watching paint dry - From colloidal droplets to complex nanostructures

Date

Jan 25, 2024

Time

1:00 PM - 3:00 PM

Speaker

Arash Nikoubashman

Affiliation

Leibniz-Institut für Polymerforschung Dresden e. V.

Series

TUD nanoSeminar

Language

en

Main Topic

Materialien

Other Topics

Materialien

Host

Arezoo Dianat

Description

Drying colloidal dispersions are encountered in many technologies, including painting, inkjet printing, and manufacturing polymer LED displays. In these applications, colloidal nanoparticles (NPs) are typically initially dispersed in a liquid solvent such as water, which then evaporates, leaving behind a dried residue of NPs. We aim at understanding the structure formation of supraparticles made from spherical, rod-shaped NPs and their mixtures. In conjunction with experiments, we performed particle-based simulations to better understand the ordering of the confined NPs during drying. Simulations were performed at various evaporation rates using both implicit and explicit solvents to probe the role of hydrodynamic interactions. We observed in drying droplets containing bidisperse spheres, that the smaller species accumulated in the shell of the resulting supraparticles followed by a homogeneously mixed core-region of small and big NPs. When examining supraparticles created from pure rod suspensions, we observed long-range orientational order of the anisotropic NPs on the supraparticle surface during slow drying compared to fast drying, regardless of the aspect ratio being investigated. For supraparticless created from a mixture of rods and spheres, we observed the rods forming a thin shell around a uniformly distributed core of both rods and spheres.

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Last modified: Feb 6, 2024, 7:35:25 AM