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

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.

2021 ◽  
Vol 27 (1) ◽  
pp. 77-83
Author(s):  
Aušra ČIULADIENĖ ◽  
Aldona BEGANSKIENĖ ◽  
Jūratė SENVAITIENĖ ◽  
Aivaras KAREIVA

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.


MRS Advances ◽  
2017 ◽  
Vol 2 (63) ◽  
pp. 3973-3981 ◽  
Author(s):  
Marcie B. Wiggins ◽  
Jocelyn Alcántara-García ◽  
Karl S. Booksh

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.


Chemija ◽  
2020 ◽  
Vol 31 (4) ◽  
Author(s):  
Aušra Čiuladienė ◽  
Aivaras Kareiva ◽  
Rimantas Raudonis

This study focuses on the characterization of cinnabar, red lead and realgar paints, since the red colour was very often used for the illuminations and rubrics of medieval manuscript. The commercial pigments (cinnabar (HgS), red lead (Pb3O4), realgar (As4S4)) and binding media (gum Arabic, fish and parchment glue) were used for the preparation of analogous to historical paints. This work is on-going and at this stage, the resulting red paint samples were analysed to create a short data library that could be used to describe the various red paints and their compositions. The obtained paints were characterized before and after accelerated aging using Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy (SEM/EDX), X-ray diffraction (XRD) and thermal (TG/DSC) analysis techniques. These results of versatile characterization are useful to develop red paint guidelines for the storage and how they affect current and future conservation of these objects.


2003 ◽  
Vol 780 ◽  
Author(s):  
C. Essary ◽  
V. Craciun ◽  
J. M. Howard ◽  
R. K. Singh

AbstractHf metal thin films were deposited on Si substrates using a pulsed laser deposition technique in vacuum and in ammonia ambients. The films were then oxidized at 400 °C in 300 Torr of O2. Half the samples were oxidized in the presence of ultraviolet (UV) radiation from a Hg lamp array. X-ray photoelectron spectroscopy, atomic force microscopy, and grazing angle X-ray diffraction were used to compare the crystallinity, roughness, and composition of the films. It has been found that UV radiation causes roughening of the films and also promotes crystallization at lower temperatures.Furthermore, increased silicon oxidation at the interface was noted with the UVirradiated samples and was shown to be in the form of a mixed layer using angle-resolved X-ray photoelectron spectroscopy. Incorporation of nitrogen into the film reduces the oxidation of the silicon interface.


Polymers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 581
Author(s):  
Gajanan S. Ghodake ◽  
Surendra K. Shinde ◽  
Ganesh D. Saratale ◽  
Rijuta G. Saratale ◽  
Min Kim ◽  
...  

The utilization of waste-paper-biomass for extraction of important α-cellulose biopolymer, and modification of extracted α-cellulose for application in enzyme immobilization can be extremely vital for green circular bio-economy. Thus, in this study, α-cellulose fibers were super-magnetized (Fe3O4), grafted with chitosan (CTNs), and thiol (-SH) modified for laccase immobilization. The developed material was characterized by high-resolution transmission electron microscopy (HR-TEM), HR-TEM energy dispersive X-ray spectroscopy (HR-TEM-EDS), X-ray diffraction (XRD), vibrating sample magnetometer (VSM), X-ray photoelectron spectroscopy (XPS), and Fourier transform infrared spectroscopy (FT-IR) analyses. Laccase immobilized on α-Cellulose-Fe3O4-CTNs (α-Cellulose-Fe3O4-CTNs-Laccase) gave significant activity recovery (99.16%) and laccase loading potential (169.36 mg/g). The α-Cellulose-Fe3O4-CTNs-Laccase displayed excellent stabilities for temperature, pH, and storage time. The α-Cellulose-Fe3O4-CTNs-Laccase applied in repeated cycles shown remarkable consistency of activity retention for 10 cycles. After the 10th cycle, α-Cellulose-Fe3O4-CTNs possessed 80.65% relative activity. Furthermore, α-Cellulose-Fe3O4-CTNs-Laccase shown excellent degradation of pharmaceutical contaminant sulfamethoxazole (SMX). The SMX degradation by α-Cellulose-Fe3O4-CTNs-Laccase was found optimum at incubation time (20 h), pH (3), temperatures (30 °C), and shaking conditions (200 rpm). Finally, α-Cellulose-Fe3O4-CTNs-Laccase gave repeated degradation of SMX. Thus, this study presents a novel, waste-derived, highly capable, and super-magnetic nanocomposite for enzyme immobilization applications.


Catalysts ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 346
Author(s):  
Sonam Goyal ◽  
Maizatul Shima Shaharun ◽  
Ganaga Suriya Jayabal ◽  
Chong Fai Kait ◽  
Bawadi Abdullah ◽  
...  

A set of novel photocatalysts, i.e., copper-zirconia imidazolate (CuZrIm) frameworks, were synthesized using different zirconia molar ratios (i.e., 0.5, 1, and 1.5 mmol). The photoreduction process of CO2 to methanol in a continuous-flow stirred photoreactor at pressure and temperature of 1 atm and 25 °C, respectively, was studied. The physicochemical properties of the synthesized catalysts were studied using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and photoluminescence (PL) spectroscopy. The highest methanol activity of 818.59 µmol/L.g was recorded when the CuZrIm1 catalyst with Cu/Zr/Im/NH4OH molar ratio of 2:1:4:2 (mmol/mmol/mmol/M) was employed. The enhanced yield is attributed to the presence of Cu2+ oxidation state and the uniformly dispersed active metals. The response surface methodology (RSM) was used to optimize the reaction parameters. The predicted results agreed well with the experimental ones with the correlation coefficient (R2) of 0.99. The optimization results showed that the highest methanol activity of 1054 µmol/L.g was recorded when the optimum parameters were employed, i.e., stirring rate (540 rpm), intensity of light (275 W/m2) and photocatalyst loading (1.3 g/L). The redox potential value for the CuZrIm1 shows that the reduction potential is −1.70 V and the oxidation potential is +1.28 V for the photoreduction of CO2 to methanol. The current work has established the potential utilization of the imidazolate framework as catalyst support for the photoreduction of CO2 to methanol.


Coatings ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 937
Author(s):  
Yingying Hu ◽  
Md Rasadujjaman ◽  
Yanrong Wang ◽  
Jing Zhang ◽  
Jiang Yan ◽  
...  

By reactive DC magnetron sputtering from a pure Ta target onto silicon substrates, Ta(N) films were prepared with different N2 flow rates of 0, 12, 17, 25, 38, and 58 sccm. The effects of N2 flow rate on the electrical properties, crystal structure, elemental composition, and optical properties of Ta(N) were studied. These properties were characterized by the four-probe method, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and spectroscopic ellipsometry (SE). Results show that the deposition rate decreases with an increase of N2 flows. Furthermore, as resistivity increases, the crystal size decreases, the crystal structure transitions from β-Ta to TaN(111), and finally becomes the N-rich phase Ta3N5(130, 040). Studying the optical properties, it is found that there are differences in the refractive index (n) and extinction coefficient (k) of Ta(N) with different thicknesses and different N2 flow rates, depending on the crystal size and crystal phase structure.


2009 ◽  
Vol 2009 ◽  
pp. 1-8 ◽  
Author(s):  
Valentina Krylova ◽  
Mindaugas Andrulevičius

Copper sulfide layers were formed on polyamide PA 6 surface using the sorption-diffusion method. Polymer samples were immersed for 4 and 5 h in 0.15 mol⋅  solutions and acidified with HCl (0.1 mol⋅) at . After washing and drying, the samples were treated with Cu(I) salt solution. The samples were studied by UV/VIS, X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) methods. All methods confirmed that on the surface of the polyamide film a layer of copper sulfide was formed. The copper sulfide layers are indirect band-gap semiconductors. The values of are 1.25 and 1.3 eV for 4 h and 5 h sulfured PA 6 respectively. Copper XPS spectra analyses showed Cu(I) bonds only in deeper layers of the formed film, while in sulfur XPS S 2p spectra dominating sulfide bonds were found after cleaning the surface with ions. It has been established by the XRD method that, beside , the layer contains as well. For PA 6 initially sulfured 4 h, grain size forchalcocite, , was  nm and fordjurleite, , it was 54.17 nm. The sheet resistance of the obtained layer varies from 6300 to 102 .


Materials ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 48
Author(s):  
Pawel Mierczynski ◽  
Magdalena Mosińska ◽  
Lukasz Szkudlarek ◽  
Karolina Chalupka ◽  
Misa Tatsuzawa ◽  
...  

Biodiesel production from rapeseed oil and methanol via transesterification reaction facilitated by various monometallic catalyst supported on natural zeolite (NZ) was investigated. The physicochemical characteristics of the synthesized catalysts were studied by X-ray diffraction (XRD), Brunauer–Emmett–Teller method (BET), temperature-programmed-reduction in hydrogen (H2-TPR), temperature-programmed-desorption of ammonia (NH3-TPD), Scanning Electron Microscope equipped with EDX detector (SEM-EDS), and X-ray photoelectron spectroscopy (XPS) methods. The highest activity and methyl ester yields were obtained for the Pt/NZ catalyst. This catalyst showed the highest triglycerides conversion of 98.9% and fatty acids methyl esters yields of 94.6%. The activity results also confirmed the high activity of the carrier material (NZ) itself in the investigated reaction. Support material exhibited 90.5% of TG conversion and the Fatty Acid Methyl Esters yield (FAME) of 67.2%. Introduction of noble metals improves the TG conversion and FAME yield values. Increasing of the metal loading from 0.5 to 2 wt.% improves the reactivity properties of the investigated catalysts.


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