Role of hydration and water structure in biological and colloidal interactions

Israelachvili, Jacob
Wennerstrom, Hakan

J. Israelachvili is at the Department of Chemical Engineering and the Materials Department, University of California, Santa Barbara, California 93106, USA. H. Wennerstrom is at Physical Chemistry 1, Chemical Center, University of Lund, PO Box 124, S-22100 Lund, Sweden.

Nature 379(6562):p 219-225, January 18, 1996.

The conventional explanation of why hydrophilic surfaces and macromolecules remain well separated in water is that they experience a monotonically repulsive hydration force owing to structuring of water molecules at the surfaces. A consideration of recent experimental and theoretical results suggests an alternative interpretation in which hydration forces are either attractive or oscillatory, and where repulsions have a totally different origin. Further experiments are needed to distinguish between these possibilities.