scholarly journals From lapis lazuli to ultramarine blue: investigating Cennino Cennini’s recipe using sulfur K-edge XANES

2018 ◽  
Vol 90 (3) ◽  
pp. 463-475 ◽  
Author(s):  
Monica Ganio ◽  
Emeline S. Pouyet ◽  
Samuel M. Webb ◽  
Catherine M. Schmidt Patterson ◽  
Marc S. Walton
Keyword(s):  
Prolonged Exposure ◽  
Purification Process ◽  
X Ray ◽  
First Order ◽  
Ultramarine Blue ◽  
First Order Kinetics ◽  
Blue Component ◽  
Rosin Gum ◽  
Ultramarine Pigments ◽  
Lapis Lazuli

AbstractAs one of the most desired and expensive artists’ materials throughout history, there has long been interest in studying natural lapis lazuli. The traditional method of extracting the blue component, lazurite, from lapis lazuli, as outlined in Cennini’sIl Libro dell’Arte, involves a lengthy purification process: (1) finely grind the rock; (2) mix with pine rosin, gum mastic, and beeswax; (3) massage in water to collect the lazurite. Repeating the process produces several grades of the pigment, typically referred to as ultramarine blue. Here, we investigate the sulfur environment within the aluminosilicate framework of lazurite during its extraction from lapis lazuli. The sulfur XANES fingerprint from samples taken at the different stages in Cennini’s extraction method were examined. All spectra contain a strong absorption peak at 2483 eV, attributable to sulfate present in the lazurite structure. However, intensity variations appear in the broad envelope of peaks between 2470 and 2475 eV and the pre-peak at 2469.1 eV, indicating a variation in the content of trisulfur (S3−˙) radicals. By studying the effect of each step of Cennini’s process, this study elucidates the changes occurring during the extraction and the variability within different grades of the precious coloring material. The increasing application of XANES to the study of artist’s materials and works of art motivated extending the research to assess the possibility of X-ray induced damage. Direct comparison of micro-focused and unfocused beam experiments suggests an increase of the S3−˙ radicals with prolonged exposure. Analysis indicates that induced damage follows first-order kinetics, providing a first assessment on the acceptable amount of radiation exposure to define the optimal acquisition parameters to allow safe analyses of lapis lazuli and ultramarine pigments.

scholarly journals Photoperoxidation of ciprofloxacin antibiotic in aqueous medium using Fe3-XO4-Y-TiO2 particles as catalyst

2022 ◽  
Vol 47 (1) ◽  
pp. 55-63
Author(s):  
Ismael Laurindo Costa Junior ◽  
Kevin Augusto Ferreira ◽  
Cesar Augusto Kappes ◽  
Renata Mello Giona
Keyword(s):  
Conventional Treatment ◽  
H2o2 Concentration ◽  
X Ray Diffraction ◽  
X Ray ◽  
First Order ◽  
Tio2 Particles ◽  
Treatment Processes ◽  
First Order Kinetics ◽  
Heat Treated ◽  
Oxidative Processes

Conventional treatment processes are not effective in removing micropollutants such as antibiotics and other drugs present in wastewater, and degradation methods based on advanced oxidative processes become attractive. Herein, it was synthesized Fe3-xO4-y-TiO2 particles by coprecipitation method and they were heat-treated at 100, 400, and 800 �C. The obtained solids were characterized by X-ray diffraction and thermogravimetric analysis and analytical determinations were performed using ultraviolet-visible (UV-Vis) spectrophotometry. The particles were evaluated in photoperoxidation processes on the degradation of the ciprofloxacin antimicrobial in an aqueous solution. The studies took place at pH 9; with an H2O2 concentration of 31 mg L�1 and particle mass 0.22 g L�1 previously defined and, in these conditions, degradation percentages between 40 and 85% were observed, with the removal in the Photo/H2O2/Fe3-xO4-y-TiO2 800 �C. The kinetic study performed for this process revealed the process adjusts to the first-order kinetics during the 120 min of reaction. The use of the catalyst can be attractive with the potential for degradation of the studied antimicrobial.

Photocatalytic Degradation of Reactive Brilliant Blue KN-R by N, Fe- TiO2/FFA

2011 ◽  
Vol 183-185 ◽  
pp. 2028-2031
Author(s):  
Gui Rong Wang
Keyword(s):  
Ph Value ◽  
Sol Gel ◽  
Dip Coating ◽  
Brilliant Blue ◽  
X Ray Diffraction ◽  
X Ray ◽  
First Order ◽  
Operation Conditions ◽  
First Order Kinetics ◽  
Fe Ions

TiO2 photocatalyst modified by N and Fe ions was loaded on self-made fly ash forming adsorbent (FFA) using the sol-gel dip-coating process. The crystal structure and photoadsorption ability was characterized by X-ray diffraction (XRD) and UV-Vis spectrophotometer, respectively. The photo catalytic degradation of Reactive Brilliant Blue KN-R using N, Fe-TiO2/FFA was examined. Effects of initial dye concentration, pH value and hydrogen peroxide dosage on degradation were studied. The degradation of the organic molecule followed a pseudo-first-order kinetics according to the Langmuir model. Under the optimum operation conditions, 30 mg/L KN-R could be decolorized over 97.47% within 75 min.

Preparation of immobilized Cu2O using microwave irradiation and its catalytic activity for bisphenol A: comparisons of Cu2O/H2O2 and visible-light/Cu2O/H2O2 systems

2014 ◽  
Vol 70 (8) ◽  
pp. 1428-1433 ◽  
Author(s):  
C. Y. Kuo ◽  
C. H. Wu ◽  
J. T. Wu ◽  
Y. C. Chen
Keyword(s):  
Catalytic Activity ◽  
Microwave Irradiation ◽  
Visible Light ◽  
Degradation Rate ◽  
X Ray Diffraction ◽  
X Ray ◽  
First Order ◽  
First Order Kinetics ◽  
Vis Spectroscopy ◽  
H2o2 System

This study produced immobilized Cu2O via microwave irradiation. The surface properties of Cu2O were assessed by X-ray diffraction, scanning electron microscopy, and UV–vis spectroscopy. The catalytic activity of the generated Cu2O was examined for bisphenol (BPA) degradation in Cu2O/H2O2 and visible-light/Cu2O/H2O2 systems under various H2O2 concentrations. Cu2O can decompose H2O2 to generate radicals, similar to the Fenton-like process. The BPA degradation rate followed pseudo-first-order kinetics. The optimal H2O2 concentration was 30 mM and the BPA degradation rate under 30 mM H2O2 in the Cu2O/H2O2 and visible-light/Cu2O/H2O2 systems was 1.43 and 2.69 h−1, respectively. The original Cu2O partly oxidized into CuO in the visible-light/Cu2O/H2O2 system and the BPA degradation percentage declined to 51% from 100% after the fifth cycle.

scholarly journals Effects of different water activities on the stability of carotenoids in puff-dried yellow peach powder during storage

2021 ◽  
Vol 13 (SP2) ◽  
pp. 1-8
Author(s):  
Gorby Gonzalles ◽  
Ningning Geng ◽  
Shuwei Luo ◽  
Chenchen Zhang ◽  
Caie Wu ◽  
...  
Keyword(s):  
Water Absorption ◽  
Water Activity ◽  
Adsorbed Water ◽  
X Ray Diffraction ◽  
Total Carotenoids ◽  
X Ray ◽  
First Order ◽  
First Order Kinetics ◽  
The Stability ◽  
Β Carotene

The stability of carotenoids in puff-dried yellow peach powder during commercial storage under different water activity conditions was studied. The results showed that when the corresponding water activity was above 0.576, the loss of adsorbed water in yellow peach powder was closely related to the crystallinity of the amorphous sugar matrix. However, the adsorption isotherms confirmed by water absorption behavior, X-ray diffraction (XRD) pat-terns, and scanning electron microscopy did not clearly indicate this loss of adsorbed water. The content changes of individual carotenoids (lutein, zeaxanthin, β-cryptoxanthin, α-carotene, and β-carotene) during storage followed pseudo first-order kinetics, and the degradation of lutein and zeaxanthin occurred quickly over time. The stability of total carotenoids gradually increased when the water activity was less than 0.576, but the carotenoids degraded sharply when the water activity was between 0.753 and 0.843. The loss of carotenoids was related to the water absorption and crystallization of the sugar matrix in the powder.

Kinetics and mechanism of Mn2+ removal from groundwater using iron–manganese co-oxide filter film

2019 ◽  
Vol 19 (6) ◽  
pp. 1711-1717
Author(s):  
Yingming Guo ◽  
Jianmin Zhang ◽  
Xi Chen ◽  
Jing Yang ◽  
Jianxiong Huang ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Oxidation Process ◽  
Oxidation Mechanism ◽  
X Ray ◽  
First Order ◽  
Sand Surface ◽  
First Order Kinetics ◽  
Start Up ◽  
Do Concentration ◽  
Iron Manganese

AbstractTo shorten the ripening period of filter sand, iron–manganese co-oxide filter film (MeOx) was formed quickly on the virgin quartz sand surface by oxidizing Mn2+ and Fe2+ from groundwater using KMnO4 continuously. After the start-up period, we found that Mn2+ could be removed efficiently by MeOx, even if the dissolved oxygen (DO) concentration in the influent was only about 1.0–1.5 mg/L. This means that the removal process of Mn2+ does not need to consume DO. The kinetic experiments for Mn2+ indicated that the adsorption and oxidation kinetics followed pseudo-first-order kinetics. The film (MeOx) was characterized by X-ray photoelectron spectroscopy (XPS). All manganese adsorbed on the surface of the sand was the oxidized form, and the manganese oxide coated onto the sand effectively oxidized Mn2+ to Mn3+ or Mn4+. The binding energy of the observed photoelectron peaks of O(1s) showed the existence of [≡Mn-OH] on the surface of the film by XPS, which might be a key intermediate in the mechanism of Mn2+ oxidation. Finally, a chemical catalytic oxidation mechanism for Mn2+ removal was proposed by the analysis of the oxidation process.

scholarly journals Synthesis, X-ray and antimicrobial activity of isatin-3-phenylhydrazone

2008 ◽  
Vol 14 (1) ◽  
pp. 27-34 ◽  
Author(s):  
Sandra Konstantinovic ◽  
Agnes Kapor ◽  
Blaga Radovanovic ◽  
Andrea Deak
Keyword(s):  
Crystal Structure ◽  
Antimicrobial Activity ◽  
Spectroscopic Method ◽  
Proteus Vulgaris ◽  
X Ray ◽  
First Order ◽  
H Nmr ◽  
First Order Kinetics ◽  
Bacillus Subtilus ◽  
Isatin Derivative

Isatin-3-phenylhydrazone was synthesized and X-ray crystal structure of this compound has been solved. Its structure was also established using FTIR, UV/Vis and H-NMR spectroscopic method. The compound was tested for antimicrobial activity against Staphylococcus aureus, Bacillus subtilus, Enterococcus D, Escherichia coli, Proteus vulgaris, Pseudomonas aeruginosa and Candida albicans. Stability of isatin-3-phenylhydrazone toward UV-A irradiation has been studied in this work. Isatin derivative undergoes bleaching following first-order kinetics.

Study of Modified Dry Desulfurization Ash in a Power Plant for Sequestering CO2 from a Micron-Nanoscale Perspective

2021 ◽  
Vol 21 (1) ◽  
pp. 382-391
Author(s):  
Jieying Cai ◽  
Xiangdong Li ◽  
Di Chen ◽  
Qiyan Feng
Keyword(s):  
Carbon Sequestration ◽  
Initial Pressure ◽  
Kinetics Equation ◽  
Liquid Ratio ◽  
Experimental Conditions ◽  
X Ray ◽  
First Order ◽  
First Order Kinetics ◽  
Before And After ◽  
Solid Liquid

To improve the CO2 fixation ability of dry desulfurization ash (DDA), a DDA must be modified by chemical methods. At the micron level, the changes in microstructure and chemical composition before and after DDA modification were analysed by Scanning Electron Microscope (SEM) and Energy Dispersive Spectroscopy (EDS), and the reaction mechanism of the modification process was inferred. On the other hand, the chemical and mineral phase compositions of the modified DDA and its solid products were analysed by X ray Fluorescence (XRF) and X-ray diffraction (XRD). In addition, the microstructure of the modified DDA before and after sequestration at nanometre resolution was studied by SEM-EDS so that the curing mechanism of the modified DDA was clearly defined. Then, the effects of the solid–liquid ratio, temperature, pressure and reaction time on the sequestration of CO2 in the modified DDA were studied with aqueous carbonation. The results showed that the higher the temperature is, the higher the solid–liquid ratio, and the lower initial pressure is, the less the CO2 sequestered in the modified DDA and the less the carbon sequestration capacity of the modified DDA. Under the experimental conditions, the carbonation efficiency of the modified DDA could reach 94.42%, and 1 ton of modified DDA could sequester up to 50.61 kg CO2. Compared with conventional DDA, the carbon sequestration capacity is effectively improved. The kinetic data confirmed that the fitting correlation of the quasi-first-order kinetics equation is more significant. The smaller the solid–liquid ratio is, the lower the temperature, the higher the initial pressure, and the higher the rate constant of the quasi-first-order kinetics equation.

scholarly journals Quantum Sized Zinc Oxide Immobilized on Bentonite Clay and Degradation of C.I. Acid Red 35 in Aqueous under Ultraviolet Light

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Hang Xu ◽  
Dandan Zhang ◽  
Airong Xu ◽  
Fengmin Wu ◽  
Renqiang Cao
Keyword(s):  
Ultraviolet Light ◽  
Sol Gel ◽  
Bentonite Clay ◽  
X Ray Diffraction ◽  
Nano Zno ◽  
Composite Photocatalyst ◽  
X Ray ◽  
First Order ◽  
First Order Kinetics ◽  
Transmission Electron

Nano-ZnO supported on bentonite was prepared to form composite photocatalyst by sol-gel method. The photocatalyst was analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscope (TEM). C.I. Acid Red 35 was used as simulating contaminant to be treated by ultraviolet light synergistic with nano-ZnO/bentonite. The results show that 5.7 nm ZnO particle was acquired and uniformly dispersed on the surface of the bentonite at calcination temperature of 200°C. The removal of C.I. Acid Red 35 could reach 84.9% after 200 min under optimum ZnO/bentonite dosage of 0.6 g L−1. The 60% ZnO content in ZnO/bentonite composite exhibited a great photocatalytic activity to treat C.I. Acid Red 35. The photocatalytic process followed pseudo-first-order kinetics and the best apparent rate constant was 0.00927 min−1with correlation coefficient (R2) of above 0.98.

Photo-catalytic degradation of gaseous pollutants in paper mills of southern China

TAPPI Journal ◽  
2018 ◽  
Vol 17 (03) ◽  
pp. 167-178 ◽  
Author(s):  
Xin Tong ◽  
Jiao Li ◽  
Jun Ma ◽  
Xiaoquan Chen ◽  
Wenhao Shen
Keyword(s):  
Degradation Rate ◽  
Southern China ◽  
Catalytic Degradation ◽  
Pulp And Paper ◽  
Gaseous Pollutants ◽  
Pulp And Paper Mills ◽  
Paper Mills ◽  
Initial Concentration ◽  
First Order ◽  
First Order Kinetics

Studies were undertaken to evaluate gaseous pollutants in workplace air within pulp and paper mills and to consider the effectiveness of photo-catalytic treatment of this air. Ambient air at 30 sampling sites in five pulp and paper mills of southern China were sampled and analyzed. The results revealed that formaldehyde and various benzene-based molecules were the main gaseous pollutants at these five mills. A photo-catalytic reactor system with titanium dioxide (TiO2) was developed and evaluated for degradation of formaldehyde, benzene and their mixtures. The experimental results demonstrated that both formaldehyde and benzene in their pure forms could be completely photo-catalytic degraded, though the degradation of benzene was much more difficult than that for formaldehyde. Study of the photo-catalytic degradation kinetics revealed that the degradation rate of formaldehyde increased with initial concentration fitting a first-order kinetics reaction. In contrast, the degradation rate of benzene had no relationship with initial concentration and degradation did not conform to first-order kinetics. The photo-catalytic degradation of formaldehyde-benzene mixtures indicated that formaldehyde behaved differently than when treated in its pure form. The degradation time was two times longer and the kinetics did not reflect a first-order reaction. The degradation of benzene was similar in both pure form and when mixed with formaldehyde.

Kinetic of oxidation of methyl orange by vanadium(V) under conditions VO2+ and decavanadates coexist: Catalysis by Triton X-100 micellar medium

2019 ◽  
Author(s):  
Chem Int
Keyword(s):  
Methyl Orange ◽  
Solution Ph ◽  
Vanadium Concentration ◽  
Limiting Behavior ◽  
First Order ◽  
First Order Kinetics ◽  
Ph Range ◽  
Kinetic Pattern ◽  
Triton X ◽  
Kinetics Of

The kinetics of oxidation of methyl orange by vanadium(V) {V(V)} has been investigated in the pH range 2.3-3.79. In this pH range V(V) exists both in the form of decavanadates and VO2+. The kinetic results are distinctly different from the results obtained for the same reaction in highly acidic solution (pH < 1) where V(V) exists only in the form of VO2+. The reaction obeys first order kinetics with respect to methyl orange but the rate has very little dependence on total vanadium concentration. The reaction is accelerated by H+ ion but the dependence of rate on [H+] is less than that corresponding to first order dependence. The equilibrium between decavanadates and VO2+ explains the different kinetic pattern observed in this pH range. The reaction is markedly accelerated by Triton X-100 micelles. The rate-[surfactant] profile shows a limiting behavior indicative of a unimolecular pathway in the micellar pseudophase.

Sign in / Sign up

Export Citation Format

Share Document