Biointerphases

Journal for Biophysical Chemistry

Biointerphases Cover Image
Open Access

Cosmetic powder suspensions in compliant, fingerprintlike contacts

  • K. Timm1, 2,
  • C. Myant3Email author,
  • H. A. Spikes3,
  • M. Schneider4,
  • T. Ladnorg5 and
  • M. Grunze2
Biointerphases6:5

https://doi.org/10.1116/1.3640042

Received: 8 July 2011

Accepted: 29 August 2011

Abstract

Cosmetic powders are regularly employed in skin creams and cosmetic formulations to improve performance and enhance skin feel. A previous study investigated the effect of particle concentration and size on the lubricating properties of powder suspensions in smooth, compliant contacts [Timm et al., Tribol. Int. (2011)]. In this paper the tribological properties of cosmetic powder suspensions are investigated in compliant contacts having model fingerprintlike surface topography. Friction coefficients were measured for a series of powder suspensions with varying particle size and concentration in a polydimethylsiloxane (PDMS)/PDMS contact. A commercial tribometer (MTM, PCS Instruments) was employed to measure friction as a function of rubbing time (20 min), under pure sliding (50 mm/s) and low load (0.5 N) conditions. Compared to results using smooth surfaces, it was clear that surface topography has a pronounced affect on the timedependent tribological behavior of the cosmetic powder suspensions studied. A two-stage friction coefficient versus time curve was observed. By varying the particle size and concentration it was shown that the duration and magnitude of each stage can be controlled.