Why does ice films

Measurements were made on minerals of varied i composition, ii structure, iii morphology, iv particle size and v surface roughness. Loadings, measured by a microgravimetric Dynamic Vapour Sorption technique, were of a few monolayers in sub-micrometer-sized particles but of several hundreds to thousands of water layers in micrometer-sized particles Paper I.

This was seen in the Fourier Transform Infrared FTIR spectra of sub-micrometer-sized particles with different hydrogen bonding environments than liquid water. Micrometer-sized particles formed liquid-like films regardless of the mineral. Similar observations were made in the spectra of the thinnest water films remaining on these minerals after long periods of sublimation of ice overcoatings at sub-freezing temperatures Paper II.

In Part B of this work Papers III-V , focus on the expandable clay mineral montmorillonite was made to study i intercalated water, ii ice and cryosalt formation inside microporous gels, and iii its interactions with intercalated CO 2.

FTIR also showed that frozen wet gels of montmorillonite form ice and the cryosalt mineral hydrohalite. Ice was seen in rigid gels and aggregated compact particles, as well as low particle density with low salt content.

Finally, release rates of CO 2 trapped in interlayers of montmorillonite, monitored by FTIR spectroscopy, were larger in the presence of W. This study highlights that the most stabilised CO 2 occur in of dry and cold conditions. This thesis will hopefully serve as a springboard for further work exploring the chemistry and physics of water and ice films at minerals surfaces.

Atmospheric water vapour interacting with hydrophilic mineral surfaces can produce water films of various thicknesses and structures. All films exhibited vibrational spectroscopic signals akin to liquid water, yet with a disrupted network of hydrogen bonds. Water adsorption isotherms were predicted using models 1- or 2- term Freundlich and Do-Do models describing an adsorption and a condensation regime, respectively pertaining to the binding of water onto mineral surfaces and water film growth by water-water interactions.

The Hygroscopic Growth Theory could also account for the particle size dependence on condensable water loadings under the premise that larger particles have a greater propensity of exhibiting of surface regions and interparticle spacings facilitating water condensation reactions.

Our work should impact our ability to predict water film formation at mineral surfaces of contrasting particle sizes, and should thus contribute to our understanding of water adsorption and condensation reactions occuring in nature. This is an intriguing idea that will be explored further in projects spawned by the ESF workshop. This may provide a new twist to the idea that life arrived from space.

It may be that the precursors of life came from space, but that the actual carbon based biochemistry of all organisms on Earth evolved on this planet. The workshop, Euroice , was held in Granada, Spain in October Materials provided by European Science Foundation. Note: Content may be edited for style and length. Science News. ScienceDaily, 5 November European Science Foundation. Retrieved November 11, from www. The scientists used the latest electron microscopy techniques to see the atomic details of the Zika virus This liquid-like ice may enhance the formation of organic compounds The deposition angle-dependent density of amorphous solid water films.

The index of refraction and thickness of amorphous solid water ASW films are determined using laser optical interferometry. From the film thickness, the density of ASW can be calculated directly … Expand. Refractive index and density of ammonia ice at different temperatures of deposition. Abstract The optical properties and density of ammonia have not been exhaustively studied despite the relevance of these characteristics in astrophysical scenarios.

This work presents new data … Expand. Refractive index measurements of ammonia and hydrocarbon ices at Abstract Optical constants in a broad temperature and wavelength range are important input parameters in radiative transfer models used in studies of planetary atmospheres.

In the laboratory, the … Expand. A new technique for determining the refractive index of ices at cryogenic temperatures. Infrared and vapor flux studies of vapor-deposited amorphous and crystalline water ice films between 90 and K. Three methods were simultaneously employed to investigate vapor-deposited water ice films K in a high-vacuum chamber: grazing-angle Fourier transform infrared FTIR -reflection absorption … Expand. Infrared spectra of thin films of cryocondensates of an isotopic water mixture.

The cryocondensates are obtained on a … Expand. Heterogeneous nucleation and wetting of water thin films on a metal surface: A study by optical second harmonic generation. The condensation of water thin films on a hydrophobic metal surface, Ag , was examined using optical second harmonic generation.

Condensation coefficient and the fraction of metal surface area … Expand. Characterization of porosity in vapor-deposited amorphous solid water from methane adsorption. Spontaneous cracking of amorphous solid water films and the dependence on microporous structure.

Vapor-deposited, porous, amorphous, water-ice films, also called amorphous solid water ASW , crack spontaneously during growth when the film thickness exceeds a critical value Lc.