skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Interfacial Water Features at Air-Water Interfaces as Influenced by Charged Surfactants

Journal Article · · Journal of Physical Chemistry B
 [1];  [2];  [3];  [2]
  1. UNIVERSITY OF UTAH
  2. University of Utah
  3. BATTELLE (PACIFIC NW LAB)

The features of interfacial water at air-water interfaces of anionic sodium dodecyl sulfate (SDS) and cationic dodecyl amine hydrochloride (DDA) solutions were examined by combining sum frequency generation (SFG) vibrational spectroscopy measurements and molecular dynamics simulations (MDS). The SFG spectra and MDS results revealed that interfacial water molecules for SDS solutions were highly-ordered compared with those for DDA solutions. Also, SFG results showed that interfacial water molecules at pH 9 in both SDS and DDA solutions were less-ordered than at pH 7. Experiments on foam stability and foam weight were conducted under the same conditions. Foams for SDS solutions were more stable at pH 7 than at pH 9. The opposite was observed for DDA solutions, in which case stability decreased when pH increased. Results were explained based on the extent of surfactant hydration at interfaces, which is thought to account for film rupture based on foam stability results. This research was supported by the US Department of Energy, Office of Science, Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences, and Biosciences.

Research Organization:
Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
Sponsoring Organization:
USDOE
DOE Contract Number:
AC05-76RL01830
OSTI ID:
1515851
Report Number(s):
PNNL-SA-135083
Journal Information:
Journal of Physical Chemistry B, Vol. 123, Issue 10
Country of Publication:
United States
Language:
English