Aqueous molecular clusters isolated as liquid fragments by adiabatic expansion of liquid jets

Abstract

A new approach to solution chemistry and cluster physics has been developed by combining molecular beam mass-spectrometry with liquid jet expansion method. Many features characteristic of molecular association in aqueous solution were observed in the cluster mass spectra and some of them showed good agreement with reported values of euthalpy changes and entropy changes for molecular association-dissociation equilibria in liquid phase. Although it lacks persuadable theoretical analysis at this stage, several new findings obtained by this technique are introduced to appeal its potentialities of physical analysis of solution systems at molecular levels.

Action mechanism of water soluble ethanol on phospholipid monolayers using a quartz crystal oscillator

“…As mentioned in Introduction section, water molecules surround an alkyl chain of ethanol and thereby form a hydration in ethanol aqueous solution [6][7][8].…”

“…Changes in f and R should eventually reach a saturation value if the adsorption of ethanol hydrates on the monolayer/water interface is assumed to follow Langmuir's adsorption isotherm. Yamamoto and Nishi reported that the amount of hydrated water surrounding one ethanol molecule was 20 ± 3 [7,8,51,52]. Based on this value, we roughly estimated the mean molecular area of ethanol hydrate (A e-h ) using Sauerbrey's equation.…”

Structure and dynamics of hexafluoroisopropanol-water mixtures by x-ray diffraction, small-angle neutron scattering, NMR spectroscopy, and mass spectrometry

“…HFIP-water mixtures at x HFIP ϭ0.005, 0.01, 0.09, and 0.20 were measured by mass spectrometry, in which the method of adiabatic expansion of liquid droplets in vacuum was employed as described in detail elsewhere. [37][38][39][40] A drop-let flow was generated by hydrodynamic conversion of liquid stream from a small notched nozzle of diameter ϳ40 m. These droplets were introduced into the high vacuum chambers through two skimmers. We used two different mass spectrometers: a quadrupole mass spectrometer ͑Extrel 7-162-8 coupled with 311-12H͒ and a double focus spectrometer with electric and magnetic sectors ͑Kratos Analytical, Profile͒.…”

Crystal Structure and Accelerated Ion-Irradiation Effect of Water Clusters

“…The other state is the cluster state, which has a three-dimensional structure consisting of hydrogen bonding bridge networks between single water molecules. The properties of liquid water at the cluster state are not well known as they are influenced by both the liquid density as well as the network structure [5][6][7]. In addition, it is hard to distinguish between the molecular and cluster states because water in liquid form is unstable.…”