Details

Autor(en) / Beteiligte

• Šimonová Baranyaiová, Tímea
• Mészáros, Róbert
• Sebechlebská, Tá a
• Bujdák, Juraj

Titel

Non-Arrhenius kinetics and slowed-diffusion mechanism of molecular aggregation of a rhodamine dye on colloidal particles

Ist Teil von

• Physical chemistry chemical physics : PCCP, 2021-08, Vol.23 (32), p.17177-17185

Ort / Verlag

Cambridge: Royal Society of Chemistry

Erscheinungsjahr

2021

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• The non-covalent association is important for many fields of science, including processes in living systems. This work elucidates the mechanism of rhodamine 123 molecular aggregation in dispersions of a layered silicate and explains the mystery of the slow kinetics of this process. Chemometric analysis of thousands of spectra recorded by stopped-flow visible spectroscopy identified two parallel diffusion processes described by a two-phase exponential function. The slow and fast processes followed the super-Arrhenius kinetics and were assigned to lateral (surface) diffusion and inter-particle diffusion of dye cations, respectively. This work, supported by a large amount of data and their in-depth analysis, provides the first evidence of how these processes coexist together and provides quantitative analysis of their dependence on the reaction conditions. The implications of this work can be crucial for understanding the mechanism of the non-covalent association of adsorbed molecules in nature. The formation of dye molecular aggregates takes place through two parallel diffusion processes: by intermittent lateral diffusion of dye cations and by their inter-particle diffusion initiated by the collisions between the colloidal particles.