Water in Contact with Magnetite Nanoparticles, as Seen from Experiments and Computer Simulations

• DOI: 10.1021/la901875f
• Publication Date: 2009-11-10T08:37:36Z
• Authors: Etelka Tombácz; Angéla Hajdú; Erzsébet Illés; Krisztina László; Giovanni Garberoglio; Pál Jedlovszky
• Keywords: Physisorption; Chemisorption

The adsorption of water vapor at the surface magnetite nanoparticles has been investigated both by experimental and computer simulation methods. adsorption/desorption isotherm measured on freshly prepared nanocrystals size below 10 nm. change isosteric heat with coverage determined from temperature dependence this using method. also performing a set grand canonical Monte Carlo simulations 300 K. X-ray photoelectron spectroscopy results as well clearly indicates that dissociative chemisorption molecules in first layer occurs bare surface, resulting high density hydroxyl groups. This is followed multilayer physisorption higher pressures. Computer can reproduce excellently beyond chemisorbed water. Results reveal physisorbed forms several well-distinguished molecular layers surface; however, these are not built up sequentially. Instead, building simultaneously. range appears to be nucleation-like process, rather rough external layer.