Wetting of biological lipids on aqueous substrates

Phys Rev E Stat Nonlin Soft Matter Phys. 2001 Aug;64(2 Pt 1):021911. doi: 10.1103/PhysRevE.64.021911. Epub 2001 Jul 24.

Abstract

We study the dynamics and final wetting state of skin lipids on water and brine by fluorescence microscopy and ellipsometry. When a lipid droplet is brought into contact with the water surface, a lipid wetting film spreads out rapidly by a Marangoni effect. Subsequently, this film undergoes a dewetting instability. However, the final equilibrium is not partial wetting. The film breaks up into droplets with a mesoscopic (approximately 50 A) film in between. These observations result from a subtle interplay between short- and long-range forces: surfactants naturally present in the lipids favor wetting, while the van der Waals forces oppose it. In addition, this reveals the likely organization of the hydrolipid film that covers and protects the skin.

Publication types

  • Comparative Study

MeSH terms

  • Lipids / chemistry*
  • Microscopy, Fluorescence / methods*
  • Microscopy, Polarization / methods*
  • Molecular Conformation
  • Phase Transition
  • Sebum / chemistry*
  • Solutions
  • Spectrometry, Fluorescence / methods*
  • Sweat / chemistry*
  • Water / chemistry*
  • Wettability*

Substances

  • Lipids
  • Solutions
  • Water