Abstract
Interfacial tensiometry and second harmonic generation (SHG) spectroscopy were applied to examine the adsorption behavior of lauric acid (LA) at a heptane/water interface. From interfacial tensiometry measurements, the adsorption kinetics of LA was revealed to be diffusion-controlled, and the adsorption constant of LA was estimated to be 9.6 × 104 M -1. The adsorption isotherms obtained by SHG measurements were analyzed by taking account of both the molecular orientation of LA at the interface and a surface electric field generated by the adsorbed LA layer. It was confirmed that the carboxylic groups of adsorbed LA molecules were well ordered at the heptane/water interface and the orientation of the carboxylate group was invariant during the adsorption process.
Original language | English |
---|---|
Pages (from-to) | 1523-1527 |
Number of pages | 5 |
Journal | Analytical Sciences |
Volume | 20 |
Issue number | 11 |
DOIs | |
Publication status | Published - 2004 Nov |
ASJC Scopus subject areas
- Analytical Chemistry