More Reliable Measurements of the Slip Length with the Atomic Force Microscope
Abstract
Further improvements are made to the non-linear data analysis algorithm for the atomic force microscope [P. Attard, arXiv:1212.3019v2 (2012)]. The algorithm is required when there is curvature in the compliance region due to photo-diode non-linearity. Results are obtained for the hydrodynamic drainage force, for three surfaces: hydrophilic silica (symmetric, Si-Si), hydrophobic dichlorodimethylsilane (symmetric, DCDMS-DCDMS), and hydrophobic octadecyltrichlorosilane (asymmetric, Si-OTS). The drainage force was measured in the viscous liquid di-n-octylphthalate. The slip-lengths are found to be 3nm for Si, 2nm for DCDMS, and 2nm for OTS, with an uncertainty on the order of a nanometer. These slip lengths are a factor of 4--15 times smaller than those obtained from previous analysis of the same raw data [L. Zhu et al., Langmuir, 27, 6712 (2011). Ibid, 28, 7768 (2012)].
Keywords
Cite
@article{arxiv.1302.6630,
title = {More Reliable Measurements of the Slip Length with the Atomic Force Microscope},
author = {Phil Attard},
journal= {arXiv preprint arXiv:1302.6630},
year = {2013}
}
Comments
18 pages, 11 figures (improved discussion of cantilever drag)