Scientific article

Excited-State Dynamics of Charged Dyes at Alkane/Water Interfaces in the Presence of Salts and Ionic Surfactants

Published inLangmuir, vol. 29, no. 48, p. 14865-14872
Publication date2013

The excited-state dynamics of the cationic dye malachite green (MG) and of the dianionic dye eosin B at the dodecane/water interface has been investigated using femtosecond time-resolved surface second harmonic generation (TR-SSHG). By using different probe wavelengths, the contributions of monomeric and aggregated MG to the signal could be spectroscopically distinguished. The effect of the addition of a small amount of surfactants was found to strongly depend on the relative charges of surfactant and dye. For surfactant/dye pairs with opposite charges, the TR-SSHG signal is dominated by the contribution from aggregates, whereas for pairs with the same charges, the signal intensity becomes vanishingly small. These effects are explained in terms of electrostatic interactions between surfactants and dyes that favor either attraction of the dye toward the interface or its repulsion toward the bulk. As a very similar behavior is observed with MG upon addition of NaSCN, we conclude that, in this case, this effect reflects the affinity of SCN¯ for the interface. On the other hand, the guanidinium cation was found to have a different effect than that of a positively charged surfactant on the SSHG signal of MG, indicating this cation does not accumulate in the interfacial region.

Research group
Citation (ISO format)
FEDOSEEVA, Marina, FITA, Piotr, VAUTHEY, Eric. Excited-State Dynamics of Charged Dyes at Alkane/Water Interfaces in the Presence of Salts and Ionic Surfactants. In: Langmuir, 2013, vol. 29, n° 48, p. 14865–14872. doi: 10.1021/la402191p
Main files (1)
Article (Published version)
ISSN of the journal0743-7463

Technical informations

Creation12/13/2013 9:05:00 AM
First validation12/13/2013 9:05:00 AM
Update time03/14/2023 8:43:04 PM
Status update03/14/2023 8:43:04 PM
Last indexation10/18/2023 5:21:31 PM
All rights reserved by Archive ouverte UNIGE and the University of GenevaunigeBlack