scholarly journals Effect of a SO2 Rich Atmosphere on Tempera Paint Mock-Ups. Part 2: Accelerated Aging of Azurite- and Malachite-Based Paints

Minerals ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 424
Author(s):  
Jose Santiago Pozo-Antonio ◽  
Carolina Cardell ◽  
Diana Barral ◽  
Amelia Dionisio ◽  
Teresa Rivas
Keyword(s):  
Crack Formation ◽  
Accelerated Aging ◽  
Egg Yolk ◽  
Chemical Degradation ◽  
X Ray Diffraction ◽  
X Ray ◽  
Sulfate Salts ◽  
Physical Changes ◽  
Significant Chemical ◽  
Industrial Atmosphere

In order to improve our knowledge of the weathering response of tempera paints exposed to an industrial atmosphere, azurite- and malachite-based paint mock-ups prepared with either rabbit glue or egg yolk binders were artificially aged in an SO2 rich atmosphere. The aim was to identify the different alteration mechanisms and forms of degradation in the paints by observing their physical (color, gloss, reflectance, and roughness), mineralogical, chemical, and micro-textural characteristics. Superficial physical changes were evaluated by stereomicroscopy, spectrophotometry, gloss measurement, hyperspectral imaging, and roughness measurements. Chemical and mineralogical changes were evaluated by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy with microanalysis (SEM-EDS), which was also used to evaluate the micro-texture of the paints. The differences between the fresh temperas were due mainly to the binder (egg yolk or rabbit glue) used in the paint mixture, which also played a crucial role in the different deterioration patterns in the artificially aged paint mock-ups. Thus, the egg yolk-based paints remained physically quite intact after SO2 exposure, although they suffered more significant chemical degradation, above all in the form of copious precipitation of Cu and Ca-rich sulfate salts and the subsequent yellowing of the egg yolk binder. The SO2 aged rabbit glue-based mock-ups showed microscopically important crack formation and binder loss and fewer sulfated salts precipitated on the surface of the paints.

Synthesis of Supergrowth VACNTs and Nanostructured ZnO by Immerse Method

2011 ◽  
Vol 312-315 ◽  
pp. 1044-1048
Author(s):  
Salina Muhamad ◽  
Abu Bakar Suriani ◽  
Mohamad Zainizan Sahdan ◽  
Anuar Ahmad ◽  
Yosri M. Siran ◽  
...  
Keyword(s):  
Crystal Orientation ◽  
Zinc Nitrate ◽  
Zinc Nitrate Hexahydrate ◽  
Nitrate Hexahydrate ◽  
X Ray Diffraction ◽  
Vertically Aligned Carbon Nanotubes ◽  
X Ray ◽  
Aligned Carbon Nanotubes ◽  
Vertically Aligned ◽  
Physical Changes

In this paper, the study of supergrowth VACNTs after being immersed in zinc oxide solution were presented. Vertically aligned carbon nanotubes (VACNTs) were first deposited on silicon with the orientation of [1 0 0] before being immersed in an aqueous solution of zinc nitrate hexahydrate and hexamethylenetetramine. Physical changes have been observed by scanning electron microscopy, SEM in the VACNTs, where the significant expansion of length of up to almost 0.8 mm was achieved after the immersion of 4.5 hr. The supergrowth of VACNTs was observed and analyzed by energy dispersive x-ray spectroscopy, EDX to substantiate the incorporation of CNTs and ZnO of the sample. Raman spectroscopy and x-ray diffraction, XRD were used to inspect the crystal orientation to support our findings.

scholarly journals A non-calorimetric approach for investigating the moisture-induced ageing of a pyrotechnic delay material using spectroscopies

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Ji-Hoon Ryu ◽  
Jun-Ho Yang ◽  
Jack J. Yoh
Keyword(s):  
Photoelectron Spectroscopy ◽  
Heat Of Reaction ◽  
X Ray Diffraction ◽  
Calorimetric Analysis ◽  
X Ray ◽  
Breakdown Spectroscopy ◽  
Long Term Storage ◽  
Laser Induced Breakdown ◽  
Metal Fuel ◽  
Physical Changes

Abstract The degradation of thermal properties due to ageing such as burning rate and exothermic heat release are unsolved issues faced during a long-term storage of the pyrotechnic substances. Accordingly, we employed various non-calorimetric methods to investigate the thermal performance of pyrotechnic delay, which is exposed to various moisture-rich conditions at extended durations. The chemical and physical changes in the compositions of a pyrotechnic delay comprised of metal fuel (Zr-Ni alloy) and oxidants (KClO4, BaCrO4) are analysed for four different relative humidity levels using X-ray photoelectron spectroscopy, X-ray diffraction, scanning electron microscope and laser-induced breakdown spectroscopy. The calculations using the NASA Chemical Equilibrium with Applications (CEA) software indicated that the heat of reaction for the components stored under the moisture-rich conditions is reduced by more than 50%. Unlike the conventional calorimetric analysis, the present non-calorimetric approach provided the compositional changes as well as the cause and effect of the relevant ageing process of pyrotechnic delay.

scholarly journals Study of the Red Iron Paints for Rubrics and Miniatures: Accelerated Aging and Analytical Data

2021 ◽  
Vol 27 (1) ◽  
pp. 77-83
Author(s):  
Aušra ČIULADIENĖ ◽  
Aldona BEGANSKIENĖ ◽  
Jūratė SENVAITIENĖ ◽  
Aivaras KAREIVA
Keyword(s):  
Analytical Data ◽  
Accelerated Aging ◽  
Gum Arabic ◽  
Xrd Analysis ◽  
X Ray Diffraction ◽  
Binding Media ◽  
X Ray ◽  
Accelerated Aging Test ◽  
Ancient Manuscripts ◽  
Hematite Fe2o3

In this study, the red iron paints used in ancient manuscripts for rubrics and miniatures were fabricated and investigated. The commercial three different iron pigments (red ochre (Fe2O3), red bolus (Fe2O3.xSiO2.yAl2O3), and hematite (Fe2O3)) and three binding media (gum Arabic, fish glue and parchment glue) were used for the preparation of analogous to historical red iron paints. The obtained model red iron paints were analyzed with the aim to create a short data library which could be used for the characterization of different model compositions of red paints as well as real historical and archaeological red paints. The obtained red paints and binding media were characterized using Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy (SEM/EDX), X-ray diffraction (XRD) analysis and thermal (TG/DSC) analysis techniques. The accelerated aging test was also applied for the analogous to historical red iron paints. These results are useful to develop red paint guidelines for the storage and display for improved conservation and accessibility of manuscripts.

scholarly journals NMR-Enhanced Crystallography Aids Open Metal-Organic Framework Discovery Using Solvent-Free Accelerated Aging

2019 ◽  
Author(s):  
Christopher A. O’Keefe ◽  
Cristina Mottillo ◽  
László Fábián ◽  
Tomislav Friscic ◽  
Robert W. Schurko
Keyword(s):  
Solid State Nmr ◽  
Metal Organic Framework ◽  
Accelerated Aging ◽  
Solvent Free ◽  
X Ray Diffraction ◽  
X Ray ◽  
Metal Organic ◽  
It Application ◽  
Organic Framework

NMR-enhanced crystallography enables the characterization of a novel cadmium-based, open metal-organic framework (MOF) from a solvent-free "accelerated aging" process. Whereas accelerated aging was devised as a clean, mild route for making MOFs, these results highlight how it application in materials discovery and characterization is aided by a combination of X-ray diffraction and solid-state NMR spectroscopy.<br>

Multi-Analytical Study of Copper-Based Historic Pigments and their Alteration Products

2019 ◽  
pp. 000370281985660
Author(s):  
Marcie B. Wiggins ◽  
Emma Heath ◽  
Karl S. Booksh ◽  
Jocelyn Alcántara-García
Keyword(s):  
Photoelectron Spectroscopy ◽  
Analytical Study ◽  
Accelerated Aging ◽  
Gum Arabic ◽  
Art Conservation ◽  
X Ray Diffraction ◽  
Medieval Period ◽  
X Ray ◽  
Accelerated Degradation ◽  
Works Of Art

Copper-containing materials such as verdigris are commonly found in historic and artistic works of art, often at advanced states of decay. Applied on paper as inks and watercolors, many of which needed a binder such as gum arabic, the intrinsic instability of this pigment was known since the medieval period. The decay of verdigris (a mixture of copper acetates) as a pigment, as watercolor, and as a dye, was studied using a combination of vibrational (Fourier transform infrared) and X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD) instrumental techniques. Changes in the copper oxidative states and the formation of copper oxide were monitored during accelerated degradation as powdered solids and applied on mockup samples (with and without binder). Accelerated aging of both commercially available and synthesized verdigris pigments showed the presence of an intermediate species, Cu(CH3COO)2•3Cu(OH)2•2H2O, which points to the beginning of the decay processes, that culminates in the formation of Cu(II) oxide. However, the presence of gum arabic seems to delay deterioration, by temporarily reducing Cu(II) to Cu(I), even when the final product includes Cu(II). This novel application of XPS and supporting techniques has significant implications in art conservation, as the identified behavior helps explain the better preservation state of some works of art.

Improved weathering performance and wettability of wood protected by CeO2 coating deposited onto the surface

Holzforschung ◽  
2014 ◽  
Vol 68 (3) ◽  
pp. 345-351 ◽  
Author(s):  
Yun Lu ◽  
Shaoliang Xiao ◽  
Runan Gao ◽  
Jian Li ◽  
Qingfeng Sun
Keyword(s):  
Electron Microscopy ◽  
Accelerated Aging ◽  
Outdoor Exposure ◽  
Photochemical Degradation ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Ceo2 Coating ◽  
Weathering Resistance ◽  
Modified Wood

Abstract Wood in outdoor exposure undergoes photochemical degradation mainly caused by the combination of UV radiation and moisture, thus appropriate coatings are desirable. In this paper, the wood surface was first treated with CeO2 sol and then treated with a layer of octadecyltrichlorosilane (OTS) and the created coating was characterized by field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), energy dispersive spectroscopy (EDXA), X-ray diffraction (XRD), and FTIR spectroscopy (FTIR). The surface became superhydrophobic as the contact angle (CA) for water of the modified wood was 152°. Accelerated aging tests revealed that the modified wood has an excellent weathering resistance.

scholarly journals A role for iron and oxygen chemistry in preserving soft tissues, cells and molecules from deep time

2014 ◽  
Vol 281 (1775) ◽  
pp. 20132741 ◽  
Author(s):  
Mary H. Schweitzer ◽  
Wenxia Zheng ◽  
Timothy P. Cleland ◽  
Mark B. Goodwin ◽  
Elizabeth Boatman ◽  
...  
Keyword(s):  
Soft Tissues ◽  
Iron Chelation ◽  
Chemical Degradation ◽  
X Ray Diffraction ◽  
Deep Time ◽  
Edge Structure ◽  
X Ray ◽  
Transmission Electron ◽  
Degradation Models ◽  
Electron Energy Loss

The persistence of original soft tissues in Mesozoic fossil bone is not explained by current chemical degradation models. We identified iron particles (goethite-αFeO(OH)) associated with soft tissues recovered from two Mesozoic dinosaurs, using transmission electron microscopy, electron energy loss spectroscopy, micro-X-ray diffraction and Fe micro-X-ray absorption near-edge structure. Iron chelators increased fossil tissue immunoreactivity to multiple antibodies dramatically, suggesting a role for iron in both preserving and masking proteins in fossil tissues. Haemoglobin (HB) increased tissue stability more than 200-fold, from approximately 3 days to more than two years at room temperature (25°C) in an ostrich blood vessel model developed to test post-mortem ‘tissue fixation’ by cross-linking or peroxidation. HB-induced solution hypoxia coupled with iron chelation enhances preservation as follows: HB + O 2 > HB − O 2 > −O 2 ≫ +O 2 . The well-known O 2 /haeme interactions in the chemistry of life, such as respiration and bioenergetics, are complemented by O 2 /haeme interactions in the preservation of fossil soft tissues.

scholarly journals NMR-Enhanced Crystallography Aids Open Metal-Organic Framework Discovery Using Solvent-Free Accelerated Aging

2019 ◽  
Author(s):  
Christopher A. O’Keefe ◽  
Cristina Mottillo ◽  
László Fábián ◽  
Tomislav Friscic ◽  
Robert W. Schurko
Keyword(s):  
Solid State Nmr ◽  
Metal Organic Framework ◽  
Accelerated Aging ◽  
Solvent Free ◽  
X Ray Diffraction ◽  
X Ray ◽  
Metal Organic ◽  
It Application ◽  
Organic Framework

NMR-enhanced crystallography enables the characterization of a novel cadmium-based, open metal-organic framework (MOF) from a solvent-free "accelerated aging" process. Whereas accelerated aging was devised as a clean, mild route for making MOFs, these results highlight how it application in materials discovery and characterization is aided by a combination of X-ray diffraction and solid-state NMR spectroscopy.<br>

Characterization of copper-based pigment preparation and alteration products

MRS Advances ◽  
2017 ◽  
Vol 2 (63) ◽  
pp. 3973-3981 ◽  
Author(s):  
Marcie B. Wiggins ◽  
Jocelyn Alcántara-García ◽  
Karl S. Booksh
Keyword(s):  
Photoelectron Spectroscopy ◽  
Degradation Products ◽  
Copper Acetate ◽  
Accelerated Aging ◽  
Organic Substrates ◽  
X Ray Diffraction ◽  
X Ray ◽  
Complex Interactions ◽  
Historical Methods

ABSTRACTCopper-based pigments are common in works of art that show signs of decay on green and blue areas and are frequently associated with the degradation of organic substrates and/or media (drying oils, cellulose, etc.). The exact causes of degradation remain unknown. This prompted us to study possible starting and degradation products of one especially reactive copper pigment, verdigris (copper acetate), as well as pigments of the same family (salt and soap greens). Preparation of pigments using historical methods was followed by spectroscopic and crystallographic characterization using Fourier-transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). Synthesis of verdigris and verdigris-like pigments resulted in a mixture of starting polymorphs of verdigris, including neutral and basic verdigris. With accelerated aging, pigments degraded to a polymorph of basic verdigris when not affected by organic media, whereas pigments on cellulosic substrates showed oxidized copper species. With this study, we are beginning to understand verdigris starting materials and highlight the complex interactions between pigments and substrates that influence pigment degradation pathways.

scholarly journals Adding complexity to the garnet supergroup: monteneveite, Ca<sub>3</sub>Sb<sup>5+</sup><sub>2</sub>(Fe<sup>3+</sup><sub>2</sub>Fe<sup>2+</sup>)O<sub>12</sub>, a new mineral from the Monteneve mine, Bolzano Province, Italy

2020 ◽  
Vol 32 (1) ◽  
pp. 77-87
Author(s):  
Andreas Karlsson ◽  
Dan Holtstam ◽  
Luca Bindi ◽  
Paola Bonazzi ◽  
Matthias Konrad-Schmolke
Keyword(s):  
Divalent Cations ◽  
New Mineral ◽  
Crystal Chemical Formula ◽  
X Ray Diffraction ◽  
Calculated Density ◽  
X Ray ◽  
Reflected Light ◽  
Peak Metamorphism ◽  
Significant Chemical ◽  
Mineralogical Evidence

Abstract. Monteneveite, ideally Ca3Sb25+(Fe23+Fe2+)O12, is a new member of the garnet supergroup (IMA 2018-060). The mineral was discovered in a small specimen belonging to the Swedish Museum of Natural History coming from the now abandoned Monteneve Pb–Zn mine in Passiria Valley, Bolzano Province, Alto Adige (South Tyrol), Italy. The specimen consists of mainly magnetite, sphalerite, tetrahedrite-(Fe) and oxycalcioroméite. Monteneveite occurs as black, subhedral crystals with adamantine lustre. They are equidimensional and up to 400 µm in size, with a subconchoidal fracture. Monteneveite is opaque, grey in reflected light, and isotropic under crossed polars. Measured reflectance values (%) at the four COM wavelengths are 12.6 (470 nm), 12.0 (546 nm), 11.6 (589 nm) and 11.4 (650 nm). The Vickers hardness (VHN100) is 1141 kg mm−2, corresponding to H=6.5–7, and the calculated density is 4.72(1) g cm−3. A mean of 10 electron microprobe analyses gave (wt %) CaO 23.67, FeO 3.75, Fe2O3 29.54, Sb2O5 39.81, SnO2 2.22, ZnO 2.29, MgO 0.15, MnO 0.03 and CoO 0.03. The crystal chemical formula calculated on the basis of a total of eight cations and 12 anions, and taking into account the available structural and spectroscopic data, is (Ca2.97Mg0.03)Σ=3.00 (Sb1.735+Sn0.104+Fe0.173+)Σ=2.00(Fe2.433+Fe0.372+Zn0.20)Σ=3.00O12. The most significant chemical variations encountered in the sample are related to a substitution of the type YSn4++ZFe3+→YSb5++ZFe2+. Mössbauer data obtained at RT and 77 K indicate the presence of tetrahedrally coordinated Fe2+. Raman spectroscopy demonstrates that there is no measurable hydrogarnet component in monteneveite. The six strongest Bragg peaks in the powder X-ray diffraction pattern are [d (Å), I (%), (hkl)]: 4.45, 100, (220); 3.147, 60, (400); 2.814, 40, (420); 2.571, 80, (422); 1.993, 40, (620); 1.683, 60, (642). Monteneveite is cubic, space group Ia-3‾d, with a=12.6093(2) Å, V=2004.8(1) Å3, and Z=8. The crystal structure was refined up to R1=0.0197 for 305 reflections with Fo>4σ(Fo) and 19 parameters. Monteneveite is related to the other Ca-, Sb- and Fe-bearing, nominally Si-free members of the bitikleite group, but it differs in that it is the only known garnet species with mixed trivalent and divalent cations (2:1) at the tetrahedral Z site. Textural and mineralogical evidence suggests that monteneveite formed during peak metamorphism (at ca. 600 ∘C) during partial breakdown of tetrahedrite-(Fe) by reactions with carbonate, under relatively oxidizing conditions. The mineral is named after the type locality, the Monteneve (Schneeberg) mine.

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