INVESTIGADORES
ELOLA Maria Dolores
artículos
Título:
Coaxial Cross-Diffusion through Carbon Nantoubes
Autor/es:
RODRIGUEZ JAVIER; ELOLA, MARÍA DOLORES; LARIA D
Revista:
JOURNAL OF PHYSICAL CHEMISTRY B - (Print)
Editorial:
AMER CHEMICAL SOC
Referencias:
Lugar: WASHINGTON, DC ; Año: 2009 vol. 113 p. 14844 - 14848
ISSN:
1520-6106
Resumen:
We present results from nonequilibrium molecular dynamics experiments
describing the relaxation of local concentrations at two reservoirs,
initially filled with water (W) and acetonitrile (ACN), as they become
connected through a membrane composed of (16,16) carbon nanotubes.
Within the hydrophobic nanotube cavities, the equilibrium
concentrations contrast sharply to those observed at the reservoirs,
with a clear enhancement of ACN, in detriment of W. From the dynamical
side, the relaxation involves three well-differentiated stages; the
first one corresponds to the equilibration of individual concentrations
within the nanotubes. An intermediate interval with Fickian
characteristics follows, during which the overall transport can be cast
in terms of coaxial opposite fluxes, with a central water domain
segregated from an external ACN shell, in close contact with the tube
walls. We also found evidence of a third, much slower, mechanism to
reach equilibration, which involves structural modifications of tightly
bound solvation shells, in close contact with the nanotube rims.