The contact angles of several liquids on human skin were measured before and after extraction of surface lipids with acetone. The critical surface tension of the skin was determined by extrapolating the cosines of the contact angles of the liquids as a function of their surface tensions to unity. The critical surface tensions for untreated and extracted skin were in the range of 22-30 dynes/cm. These low values are probably caused by reductions in contact angles resulting from furrows in the skin and by small amounts of air trapped at the furrows underneath the drops rather than by low free energy or polarity of the skin surface. Application of benzalkonium chloride and of a hand lotion reduced the contact angles of water on the skin.
Keyphrases
Skin, human-measurement of contact angles of liquids before and after extraction of surface lipids Contact angles and wettability-liquids on human skin, critical surface tension determined Surface tension, critical-correlation to contact angles, human skin 0 Wettability and contact anglesseveral liquids on human skin, critical surface tension determined