info:eu-repo/semantics/article
Dynamics of water nanodroplets and aqueous protons in non-ionic reverse micelles
Registro en:
Rodriguez, Javier; Laria, Daniel Hector; Guàrdia, E.; Martí, J.; Dynamics of water nanodroplets and aqueous protons in non-ionic reverse micelles; Royal Society of Chemistry; Physical Chemistry Chemical Physics; 11; 10; 5-2009; 1484-1490
1463-9076
CONICET Digital
CONICET
Autor
Rodriguez, Javier
Laria, Daniel Hector
Guàrdia, E.
Martí, J.
Resumen
We present a study of the microscopic dynamics of water trapped in reverse non-ionic micelles by means of a series of molecular dynamics simulations. The analysis of the effects of micellar confinement on spectroscopical properties of an excess proton has also been considered. Our micelles were microemulsions made with the neutral surfactant diethylene glycol monodecyl ether [CH 3(CH2)11(OC2H4) 2OH]. Simulation experiments including the proton species were performed using a multistate empirical valence bond Hamiltonian model. Diffusion of water in the micelle is markedly slower than that in the bulk liquid, in the same fashion as happens with reorientational dynamics. Spectral densities of hydrogens revealed a blue-shift of the OH-stretching vibration together with a split of the main band into two components. Absorption lineshapes of the solvated proton in the vicinity of the internal surface of the micelle indicate the coexistence of Eigen-like and Zundel-like structures and a tendency to red-shifting (compared to the aqueous unconstrained excess proton case) of the two relevant spectral bands (around 2000 and 2500 wavenumbers) mainly due to the slower dynamics of proton vibrations in water near interfaces. Fil: Rodriguez, Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química, Física de los Materiales, Medioambiente y Energía. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química, Física de los Materiales, Medioambiente y Energía; Argentina. Comisión Nacional de Energía Atómica; Argentina Fil: Laria, Daniel Hector. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química, Física de los Materiales, Medioambiente y Energía. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química, Física de los Materiales, Medioambiente y Energía; Argentina. Comisión Nacional de Energía Atómica; Argentina Fil: Guàrdia, E.. Universidad Politécnica de Catalunya; España Fil: Martí, J.. Universidad Politécnica de Catalunya; España