Chemical Mapping of Planetary Surfaces

Six pharmaceutical pastes were prepared using chemically modified kaolin and talc powders. Tests were conducted to determine their structural and chemical characteristics as well as their antimicrobial protection, thus rendering them suitable for cosmetic and pharmaceutical uses. Kaolin and talc were treated chemically via the cation exchange method to load the clay particles with copper and zinc ions, two cations well known for their antimicrobial properties. Mineralogical analyses were conducted by using X-ray diffraction (XRD) before and after the modification, confirming the mineralogical purity of the samples. Scanning electron microscopy was also used in conjunction with energy dispersed spectroscopy (SEM-EDS) to obtain chemical mapping images, revealing the dispersion of the added metals upon the clay minerals surfaces. Moreover, chemical analysis has been performed (XRF) to validate the enrichment of the clays with each metal utilizing the cation exchange capacity. All modified samples showed the expected elevated concentration in copper or zinc in comparison to their unmodified versions. From the X-ray photoelectron spectroscopy (XPS), the chemical state of the samples’ surfaces was investigated, revealing the presence of salt compounds and indicating the oxidation state of adsorbed metals. Finally, the resistance of pastes in microbial growth when challenged with bacteria, molds, and yeasts was assessed. The evaluation is based on the European Pharmacopeia (EP) criteria.

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Hyperspectral Molecular Orientation Mapping in Metamaterials

Applied Sciences ◽

10.3390/app11041544 ◽

2021 ◽

Vol 11 (4) ◽

pp. 1544

Author(s):

Meguya Ryu ◽

Yoshiaki Nishijima ◽

Shinya Morimoto ◽

Naoki To ◽

Tomoki Hashizume ◽

...

Keyword(s):

Molecular Orientation ◽

Field Enhancement ◽

Chemical Mapping ◽

Metal Insulator ◽

Orientation Mapping ◽

Metal Insulator Metal ◽

Finger Printing ◽

Thermal Emitter ◽

Ir Bands ◽

Sub Wavelength

The four polarisation method is adopted for measurement of molecular orientation in dielectric nanolayers of metal-insulator-metal (MIM) metamaterials composed of gold nanodisks on polyimide and gold films. Hyperspectral mapping at the chemical finger printing spectral range of 4–20 μμm was carried out for MIM patterns of 1–2.5 μμm period (sub-wavelength). Overlay images taken at 0,π4,π2,3π4 orientation angles and subsequent baseline compensation are shown to be critically important for the interpretation of chemical mapping results and reduction of spurious artefacts. Light field enhancement in the 60-nm-thick polyimide (I in MIM) was responsible for strong absorption at the characteristic polyimide bands. Strong absorbance A at narrow IR bands can be used as a thermal emitter (emittance E=1−R), where R is the reflectance and A=1−R−T, where for optically thick samples the transmittance is T=0.

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Pervasive fluid-rock interaction in subducted oceanic crust revealed by oxygen isotope zoning in garnet

Contributions to Mineralogy and Petrology ◽

10.1007/s00410-021-01806-4 ◽

2021 ◽

Vol 176 (7) ◽

Author(s):

Thomas Bovay ◽

Daniela Rubatto ◽

Pierre Lanari

Keyword(s):

Oxygen Isotope ◽

Western Alps ◽

Large Contribution ◽

Chemical Mapping ◽

Rock Interaction ◽

Rock Density ◽

Chemical Zoning ◽

Dehydration Reactions ◽

Subducted Oceanic Crust ◽

Eclogite Facies

AbstractDehydration reactions in the subducting slab liberate fluids causing major changes in rock density, volume and permeability. Although it is well known that the fluids can migrate and interact with the surrounding rocks, fluid pathways remain challenging to track and the consequences of fluid-rock interaction processes are often overlooked. In this study, we investigate pervasive fluid-rock interaction in a sequence of schists and mafic felses exposed in the Theodul Glacier Unit (TGU), Western Alps. This unit is embedded within metaophiolites of the Zermatt-Saas Zone and reached eclogite-facies conditions during Alpine convergence. Chemical mapping and in situ oxygen isotope analyses of garnet from the schists reveal a sharp chemical zoning between a xenomorphic core and a euhedral rim, associated to a drop of ~ 8‰ in δ18O. Thermodynamic and δ18O models show that the large amount of low δ18O H2O required to change the reactive bulk δ18O composition cannot be produced by dehydration of the mafic fels from the TGU only, and requires a large contribution of the surrounding serpentinites. The calculated time-integrated fluid flux across the TGU rocks is 1.1 × 105 cm3/cm2, which is above the open-system behaviour threshold and argues for pervasive fluid flow at kilometre-scale under high-pressure conditions. The transient rock volume variations caused by lawsonite breakdown is identified as a possible trigger for the pervasive fluid influx. The calculated schist permeability at eclogite-facies conditions (~ 2 × 10–20 m2) is comparable to the permeability determined experimentally for blueschist and serpentinites.

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Chemical Mapping by Macroscopic X-ray Powder Diffraction (MA-XRPD) of Van Gogh's Sunflowers : Identification of Areas with Higher Degradation Risk

Angewandte Chemie ◽

10.1002/ange.201713293 ◽

2018 ◽

Vol 130 (25) ◽

pp. 7540-7544 ◽

Cited By ~ 3

Author(s):

Frederik Vanmeert ◽

Ella Hendriks ◽

Geert Van der Snickt ◽

Letizia Monico ◽

Joris Dik ◽

...

Keyword(s):

Powder Diffraction ◽

Chemical Mapping ◽

X Ray

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Nanoscale 3D Chemical Mapping by Spectroscopic Electron Tomography

MRS Proceedings ◽

10.1557/proc-738-g1.2 ◽

2002 ◽

Vol 738 ◽

Cited By ~ 1

Author(s):

Günter Möbus ◽

Ron C. Doole ◽

Beverley J. Inkson

Keyword(s):

Materials Science ◽

Electron Tomography ◽

Region Of Interest ◽

Atom Probe ◽

Lattice Plane ◽

Chemical Mapping ◽

Bragg Scattering ◽

Electron Spectroscopic Imaging ◽

Contrast Mechanism ◽

Data Volume

ABSTRACTElectron Tomography is shown to be applicable to problems of materials science if a contrast mechanism is used which provides a projection relationship for crystals not depending on lattice plane orientation. Energy filtered TEM (EFTEM) in its mode of electron spectroscopic imaging (ESI) and STEM-EDX-Mapping are, subject to limitations, suitable image formation techniques. The spectroscopic operation not only allows to overcome Bragg scattering artefacts, but offers the possibility of recording 4-dimensional data (volume and energy) of a region of interest, otherwise only known from NMR and XAS/XANES tomography at larger length-scales and from field-ion microscopy (atom probe) under restrictive conditions.

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