Issue 19, 2017

Role of uncrosslinked chains in droplets dynamics on silicone elastomers

Abstract

We report an unexpected behavior in wetting dynamics on soft silicone substrates: the dynamics of aqueous droplets deposited on vertical plates of such elastomers exhibits two successive speed regimes. This macroscopic observation is found to be closely related to microscopic phenomena occurring at the scale of the polymer network: we show that uncrosslinked chains found in most widely used commercial silicone elastomers are responsible for this surprising behavior. A direct visualization of the uncrosslinked oligomers collected by water droplets is performed, evidencing that a capillarity-induced phase separation occurs: uncrosslinked oligomers are extracted from the silicone elastomer network by the water–glycerol mixture droplet. The sharp speed change is shown to coincide with an abrupt transition in surface tension of the droplets, when a critical surface concentration in uncrosslinked oligomer chains is reached. We infer that a droplet shifts to a second regime with a faster speed when it is completely covered with a homogeneous oil film.

Graphical abstract: Role of uncrosslinked chains in droplets dynamics on silicone elastomers

Supplementary files

Article information

Article type
Paper
Submitted
03 Mar 2017
Accepted
05 Apr 2017
First published
06 Apr 2017

Soft Matter, 2017,13, 3484-3491

Role of uncrosslinked chains in droplets dynamics on silicone elastomers

A. Hourlier-Fargette, A. Antkowiak, A. Chateauminois and S. Neukirch, Soft Matter, 2017, 13, 3484 DOI: 10.1039/C7SM00447H

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements