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Unidirectional Droplet Propulsion onto Gradient Brushes without External Energy Supply.

ABSTRACT: Using extensive molecular dynamics simulation of a coarse-grained model, we demonstrate the possibility of sustained unidirectional motion (durotaxis) of droplets without external energy supply when placed on a polymer brush substrate with stiffness gradient in a certain direction. The governing key parameters for the specific substrate design studied, which determine the durotaxis efficiency, are found to be the grafting density of the brush and the droplet adhesion to the brush surface, whereas the strength of the stiffness gradient, the viscosity of the droplet, or the length of the polymer chains of the brush have only a minor effect on the process. It is shown that this durotaxial motion is driven by the steady increase of the interfacial energy between droplet and brush as the droplet moves from softer to stiffer parts of the substrate whereby the mean driving force gradually declines with decreasing roughness of the brush surface. We anticipate that our findings indicate further possibilities in the area of nanoscale motion without external energy supply.

SUBMITTER: Kajouri R

PROVIDER: S-EPMC9948540 | biostudies-literature | 2023 Feb

REPOSITORIES: biostudies-literature

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Unidirectional Droplet Propulsion onto Gradient Brushes without External Energy Supply.

Kajouri Russell R Theodorakis Panagiotis E PE Deuar Piotr P Bennacer Rachid R Židek Jan J Egorov Sergei A SA Milchev Andrey A

Langmuir : the ACS journal of surfaces and colloids 20230209 7

Using extensive molecular dynamics simulation of a coarse-grained model, we demonstrate the possibility of sustained unidirectional motion (durotaxis) of droplets without external energy supply when placed on a polymer brush substrate with stiffness gradient in a certain direction. The governing key parameters for the specific substrate design studied, which determine the durotaxis efficiency, are found to be the grafting density of the brush and the droplet adhesion to the brush surface, wherea ...[more]

PMID: 36758225

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Dataset Information

Unidirectional Droplet Propulsion onto Gradient Brushes without External Energy Supply.

Publications

Unidirectional Droplet Propulsion onto Gradient Brushes without External Energy Supply.

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