Skip to main content
U.S. Department of Energy
Office of Scientific and Technical Information

Effect of nonionic surfactant on ion adsorption and hydration forces

Journal Article · · Langmuir; (USA)
DOI:https://doi.org/10.1021/la00096a010· OSTI ID:6307115
;  [1]
  1. Australian National Univ., Canberra (Australia)

Measurements have been carried out of the force between mica surfaces immersed in aqueous micellar solutions of the nonionic surfactant penta(oxyethylene) n-dodecyl ether with sodium sulfate as a background electrolyte. At surfactant concentrations below about 5 {times} 10{sup {minus}3} M ({approx} 100 {times} cmc), adsorption to the mica surface is weak and can only be indirectly inferred from a reduction in the surface potential in dilute electrolyte solution. Further evidence for adsorption is provided by a decrease in the measured adhesion between the surfaces and an enhanced viscous drag at small (< 5.0 nm) separations. In more concentrated salt solution, there is a decrease in the magnitude of the hydration force due to surfactant adsorption. Unlike the case with cationic surfactants, the adsorbed surfactants do not give rise to any steric force; they are easily pushed out as the surfaces are brought together.

OSTI ID:
6307115
Journal Information:
Langmuir; (USA), Journal Name: Langmuir; (USA) Vol. 6:6; ISSN LANGD; ISSN 0743-7463
Country of Publication:
United States
Language:
English