Two dimensional diffusion-controlled triplet–triplet annihilation kinetics

Abstract : Diffusion controlled chemical reactions are usually observed in three dimensional media. In contrast, planar bimolecular reactions taking place between reagents adsorbed at a soft interface are two-dimensional and therefore cannot be studied within the same formalism. Indeed, soft interfaces allow the adsorbed species to freely diffuse in a liquid-like manner. Here, we present the first experimental observation of a diffusion-controlled reaction in an environment that is planar at the ångström scale. By means of time-resolved surface second harmonic generation, an inherently surface sensitive technique, we observed that the kinetics of the diffusion of the reagents in the plane decreases as the surface concentration of adsorbed species increases. This is of course not the case for bulk reactions where the rates always increase with the reactant concentration. Such changes in the kinetics regime were rationalised as the evolution from a regular 2D free diffusion regime to a geometry-controlled scheme.
Document type :
Journal articles
Complete list of metadatas

https://hal-univ-lyon1.archives-ouvertes.fr/hal-02367652
Contributor : Armelle Vidal <>
Submitted on : Monday, November 18, 2019 - 10:12:33 AM
Last modification on : Tuesday, November 19, 2019 - 2:38:44 AM

Links full text

Identifiers

Collections

Citation

Grégoire Gschwend, Morgan Kazmierczak, Astrid Olaya, Pierre-Francois Brevet, Hubert Girault. Two dimensional diffusion-controlled triplet–triplet annihilation kinetics. Chemical Science , The Royal Society of Chemistry, 2019, 10 (32), pp.7633-7640. ⟨10.1039/c9sc00957d⟩. ⟨hal-02367652⟩

Share

Metrics

Record views

19