Jump to main content
Jump to site search


Contact mechanics for polydimethylsiloxane: from liquid to solid

Author affiliations

Abstract

Adhesion between a glass ball and a polydimethylsiloxane (PDMS) sample is dependent on the PDMS cross-link density, and the transformation of the material from the uncrosslinked liquid state to the fully crosslinked solid state is investigated in this study. The physical picture reflected a gradual transition from capillary forces driven contact mechanics to the classical Johnson–Kendall–Roberts (JKR)-type contact mechanics. PDMS was produced by mixing the base fluid and a cross-linker at a ratio of 10 : 1 and allowed to slowly cross-link at room temperature with simultaneous measurement of the ball–PDMS interaction force. The PDMS sample was in the liquid state during the first ≈16 hours, and in this case the ball–PDMS interaction was purely adhesive, i.e., no repulsive interaction was observed. Later at the PDMS gel-point the cross-linked PDMS clusters percolate, converting the fluid into a soft (fluid-filled) poroelastic solid. In the transition period, PDMS appears similar to pressure-sensitive adhesives. There we observe so-called “stringing” and permanent deformation of the material impacted by the ball. At room temperature, it takes more than ∼100 hours for PDMS to fully cross-link that can be confirmed by the comparison with the earlier-studied reference PDMS produced at elevated temperatures.

Graphical abstract: Contact mechanics for polydimethylsiloxane: from liquid to solid

Back to tab navigation

Publication details

The article was received on 10 Nov 2017, accepted on 29 Dec 2017 and first published on 02 Jan 2018


Article type: Paper
DOI: 10.1039/C7SM02216F
Citation: Soft Matter, 2018, Advance Article
  •   Request permissions

    Contact mechanics for polydimethylsiloxane: from liquid to solid

    L. Dorogin and B. N. J. Persson, Soft Matter, 2018, Advance Article , DOI: 10.1039/C7SM02216F

Search articles by author

Spotlight

Advertisements