6533b82ffe1ef96bd129504e
RESEARCH PRODUCT
Molecular mechanism of capillary condensation of acetonitrile vapor on MCM-41 with the aid of a time-correlation function analysis of IR spectroscopy
Naofumi UekawaKlaus K. UngerHideki TanakaTaku IiyamaKatsumi KanekoAkihiko MatsumotoMichael GrünTakaomi Suzukisubject
Hysteresischemistry.chemical_compoundAdsorptionMCM-41Capillary condensationChemistryAnalytical chemistryGeneral Physics and AstronomyMoleculeInfrared spectroscopyPhysical and Theoretical ChemistryAcetonitrileMesoporous materialdescription
Abstract The adsorption isotherm and IR spectra of acetonitrile adsorbed on MCM-41 (pore-width=3.2 nm) were measured at 303 K. The adsorption isotherm had a sharp jump at P / P 0 =0.3 without adsorption hysteresis. The CN stretching ν 2 -band of adsorbed acetonitrile had two-component α- and β-bands at 2263 and 2254 cm −1 , respectively, assigned to hydrogen-bonded molecules on surface hydroxyls of MCM-41 and physisorbed molecules in mesopores whose walls are coated with hydrogen-bonded molecules, respectively. The β-band was analyzed with a time correlation function, giving a reorientation time τ . The τ value of the adsorbed molecule before capillary condensation was smaller than that of the bulk liquid, indicating a gas-like state. After capillary condensation, τ was the same as for the bulk liquid.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 1998-09-01 | Chemical Physics Letters |