Non-linear rheology of a nanoconfined simple fluid
Abstract
We probe the rheology of the model liquid octamethylcyclotetrasiloxane (OMCTS) confined into molecularly thin films, using a unique Surface Forces Apparatus allowing to explore a large range of shear rates and confinement. We thus show that OMCTS under increasing confinement exhibits the viscosity enhancement and the non-linear flow properties characteristic of a sheared supercooled liquid approaching its glass transition. Besides, we study the drainage of confined OMCTS via the propagation of "squeeze-out" fronts. The hydrodynamic model proposed by Becker and Mugele [Phys. Rev. Lett. {\bf 91}, 166104 (2003)] to describe such front dynamics leads to a conclusion in apparent contradiction with the dynamical slowdown evidenced by rheology measurements, which suggests that front propagation is not controlled by large scale flow in the confined films.
Keywords
Cite
@article{arxiv.0912.2179,
title = {Non-linear rheology of a nanoconfined simple fluid},
author = {Lionel Bureau},
journal= {arXiv preprint arXiv:0912.2179},
year = {2010}
}