title: Clustering mechanism of ethanol-water mixtures investigated with photothermal microfluidic cantilever deflection spectroscopy.
abstract: The infrared-active (IR) vibrational mode of ethanol (EtOH) associated with the asymmetrical stretching of the C-C-O bond in pico-liter volumes of EtOH-water binary mixtures is calorimetrically measured using photothermal microfluidic cantilever deflection spectroscopy (PMCDS). IR absorption by the confined liquid results in wavelength dependent cantilever deflections, thus providing a complementary response to IR absorption revealing a complex dipole moment dependence on mixture concentration. Solvent-induced blue shifts of the C-C-O asymmetric vibrational stretch for both anti and gauche conformers of EtOH were precisely monitored for EtOH concentrations ranging from 20-100% w/w. Variations in IR absorption peak maxima show an inverse dependence on induced EtOH dipole moment (μ) and is attributed to the complex clustering mechanism of EtOH-water mixtures.
authors.affiliation: Department of Chemical and Material Engineering, University of Alberta, Edmonton, Canada.
authors.forename: M S
authors.initials: MS
authors.lastname: Ghoraishi
authors.affiliation: Department of Chemical and Material Engineering, University of Alberta, Edmonton, Canada.
authors.forename: J E
authors.initials: JE
authors.lastname: Hawk
authors.affiliation: Department of Chemical and Material Engineering, University of Alberta, Edmonton, Canada.
authors.forename: Arindam
authors.initials: A
authors.lastname: Phani
authors.affiliation: Department of Chemical and Material Engineering, University of Alberta, Edmonton, Canada.
authors.forename: M F
authors.initials: MF
authors.lastname: Khan
authors.affiliation: Department of Chemical and Material Engineering, University of Alberta, Edmonton, Canada.
authors.forename: T
authors.initials: T
authors.lastname: Thundat