Adsorption of Dianionic Surfactants Based on Amino Acids at Different Surfaces Studied by QCM-D and SPR
Journal article, 2010

The adsorption of three dicarboxylic amino acid-based surfactants, disodium N-lauroylaminomalonate, disodium N-lauroylaspartate, and disodium N-lauroylglutamate, has been studied by surface plasmon resonance (SPR) and the quartz crystal microbalance with dissipation monitoring (QCM-D). These surfactants have high cmc values, which means that the unimer concentration is high at the plateau value of adsorption. This gives rise to a considerable "bulk effect", which must be deducted from the observed value in order to obtain the true value of the adsorbed amount. In this article, we show how this can be done for the QCM-D technique. Adsorption is studied on silica, gold, gold hydrophobized by a self-assembled layer of an alkane thiol, and hydroxyapatite. Adsorption on hydroxyapatite differs very much among the three surfactants, with the aspartate derivative giving the strongest and the glutamate giving the weakest adsorption. This difference is explained as the difference in ability of the dicarboxylic amphiphiles to chelate calcium in the crystal lattice.

nonionic surfactants

self-assembled monolayers

dissipation

water interface

immobilization

quartz-crystal microbalance

plasmon

resonance

ellipsometry

solvent

gold surface

Author

Romain Bordes

SuMo Biomaterials

Chalmers, Chemical and Biological Engineering, Applied Surface Chemistry

J. Tropsch

Basf Se

Krister Holmberg

Chalmers, Chemical and Biological Engineering, Applied Surface Chemistry

Langmuir

07437463 (ISSN) 15205827 (eISSN)

Vol. 26 13 10935-10942

Subject Categories

Chemical Sciences

DOI

10.1021/la100909x

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7/2/2018 1