To access the full text documents, please follow this link: http://hdl.handle.net/2117/16982

Excess protons in mesoscopic water-acetone nanoclusters
Semino, Rocío; Martí Rabassa, Jordi; Guàrdia Manuel, Elvira; Laria, Daniel
Universitat Politècnica de Catalunya. Departament de Física i Enginyeria Nuclear; Universitat Politècnica de Catalunya. SIMCON - Grup de Recerca de Simulació per Ordinador en Matèria Condensada
We carried out molecular dynamics simulation experiments to examine equilibrium and dynamical characteristics of the solvation of excess protons in mesoscopic, [m:n] binary polar clusters comprising m = 50 water molecules and n = 6, 25, and 100 acetone molecules. Contrasting from what is found in conventional macroscopic phases, the characteristics of the proton solvation are dictated, to a large extent, by the nature of the concentration fluctuations prevailing within the clusters. At low acetone contents, the overall cluster morphology corresponds to a segregated aqueous nucleus coated by an external aprotic phase. Under these circumstances, the proton remains localized at the surface of the water core, in a region locally deprived from acetone molecules. At higher acetone concentrations, we found clear evidence of the onset of the mixing process. The cluster structures present aqueous domains with irregular shape, fully embedded within the acetone phase. Still, the proton remains coordinated to the aqueous phase, with its closest solvation shell composed exclusively by three water molecules. As the relative concentration of acetone increases, the time scales characterizing proton transfer events between neighboring water molecules show considerable retardations, stretching into the nanosecond time domain already for n ∼ 25. In water-rich aggregates, and similarly to what is found in the bulk, proton transfers are controlled by acetone/water exchange processes taking place at the second solvation shell of the proton. As a distinctive feature of the transfer mechanism, translocation pathways also include diffusive motions of the proton from the surface down into inner regions of the underlying water domain.
Àrees temàtiques de la UPC::Física
Stereochemistry
Microclusters
Nanostructured materials
Organic compounds
Acetone
Estereoquímica
Microclústers
Materials nanoestructurats
Compostos orgànics
Acetona
Attribution-NonCommercial-NoDerivs 3.0 Spain
http://creativecommons.org/licenses/by-nc-nd/3.0/es/
info:eu-repo/semantics/publishedVersion
Article
         

Show full item record

Related documents

Other documents of the same author

Videla, Pablo; Sala Viñas, Jonàs; Martí Rabassa, Jordi; Guàrdia Manuel, Elvira; Laria, Daniel
Calero Borrallo, Carles; Martí Rabassa, Jordi; Guàrdia Manuel, Elvira
Laria, D; Martí Rabassa, Jordi; Guàrdia Manuel, Elvira
RODRIGUEZ, J; Martí Rabassa, Jordi; Guàrdia Manuel, Elvira; Laria, D
Martí Rabassa, Jordi; Sala Viñas, Jonàs; Guàrdia Manuel, Elvira; Gordillo Bargueño, Maria Carmen
 

Coordination

 

Supporters