Achieving Different Color Changes for Photochromic Compounds by Controlling Coordination Modes

2020 ◽  
Vol 124 (50) ◽  
pp. 27680-27686
Author(s):  
Yong-Fang Han ◽  
Ning-Ning Zhang ◽  
Ming-Sheng Wang ◽  
Guo-Cong Guo
Keyword(s):  
Coordination Modes ◽  
Photochromic Compounds ◽  
Color Changes ◽  
Different Color

scholarly journals Study of Mural Paintings Using In Situ XRF, Confocal Synchrotron-μ-XRF, μ-XRD, Optical Microscopy, and SEM-EDS—The Case of the Frescoes from Misericordia Church of Odemira

2011 ◽  
Vol 17 (5) ◽  
pp. 702-709 ◽  
Author(s):  
S. Valadas ◽  
A. Candeias ◽  
J. Mirão ◽  
D. Tavares ◽  
J. Coroado ◽  
...  
Keyword(s):  
Optical Microscopy ◽  
Cross Sections ◽  
Fluorescence Spectrometry ◽  
Pigment Identification ◽  
X Ray ◽  
Color Changes ◽  
Spatially Resolved ◽  
Mural Paintings ◽  
Different Color

AbstractIn this work, we present the results of an analytical method developed for detailed pigment identification, stratigraphy, and degradation of the paint layers of mural paintings applied in the study of the 17th century frescoes from the Misericordia Church of Odemira (Southwest Portugal). In situ X-ray fluorescence spectrometry analyses were performed on three panels of the mural paintings and complemented by colorimetric measurements. The different color areas were also sampled as microfragments (approx. 1 mm2) that were studied as taken or mounted in epoxy resin to expose the different paint layers. The microfragments of paint layers and their cross sections were characterized by optical microscopy and scanning electron microscopy coupled with energy dispersive X-ray spectrometry. Furthermore, elemental analysis was obtained with spatially resolved confocal synchrotron radiation μ-X-ray fluorescence spectrometry performed at ANKA synchrotron FLUO beamline. Occasionally, phase analysis by μ-X-ray diffraction was also performed. Results from the different techniques allowed pigment identification and, in some cases, the evaluation of color changes due to degradation processes and, considering the Southern Portugal geology, the identification of their possible provenance. The pigments used were essentially yellow, brown and red ochres, smalt blue, copper green, and black earths, probably from local sources.

scholarly journals Assessment of Enzymatic Browning and Evaluation of Antibrowning Methods on Dates

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Mariam Al-Amrani ◽  
Ahmed Al-Alawi ◽  
Insaaf Al-Marhobi
Keyword(s):  
Modified Atmosphere Packaging ◽  
Structural Difference ◽  
Melanin Production ◽  
Color Changes ◽  
Structural And Functional Properties ◽  
Color Deterioration ◽  
Different Color ◽  
Golden Color ◽  
Color Preservation

Dates’ color is known to play a crucial role in determining the value and quality of the fruit. The color changes from the natural accepted golden color to unfavorable dark brown color during storage. In this study, the effect of different color preservation methods (modified atmosphere packaging, cold storage (4°C), sulfur dioxide gas (SO2), and blanching) and its relation to darkening due to action of the browning enzymes and melanin production were investigated. Polyphenol oxidase was shown to be active in all treatments except the samples treated with SO2 gas and steam blanching for ten minutes. Likewise, peroxidase activity showed a similar trend in all samples, but a decrease in activity was observed in sulfated samples and total inactivation in steam blanching for ten minutes. Moreover, sulfated samples have shown improvement in color compared to all other treatments, whereas the steamed samples showed the highest color deterioration. Concurrently, melanin content increased in all samples over the period of storage except in the sulfated samples. FTIR analyses of dates’ melanin have revealed similar structural feature to the reference melanin; however, some differences were noticed in the regions 2850–2950 cm-1 and 1690–1705 cm-1 which indicated major structural difference between the two melanin samples. More work is suggested to reveal structural and functional properties of dates’ melanin.

scholarly journals Study of Complexes of Tannic Acid with Fe(III) and Fe(II)

2019 ◽  
Vol 2019 ◽  
pp. 1-6 ◽  
Author(s):  
Zhaofeng Fu ◽  
Rui Chen
Keyword(s):  
Tannic Acid ◽  
Ph Value ◽  
Ratio Method ◽  
Iron Ions ◽  
Test Paper ◽  
Buffer Solution ◽  
Carbonate Buffer ◽  
Color Changes ◽  
Different Color ◽  
Complex Ratio

UV-Vis absorption spectra of tannic acid were gained at pH 1.0∼9.0. Due to the pH value dependence of complex, the stoichiometry of tannic acid with iron ions was tested in buffer solution by the mole ratio method. The result suggests that the complex ratio of tannic acid to Fe(III) is 1 : 1 and to Fe(II) 3 : 1 in the carbonate buffer solution, and the complex ratio of iron-tannic complexes is 1 : 1 at pH 2.2. Due to the different color changes of tannic acid with iron ions in the coordination reactions, a tannic acid test paper was designed. The concentrations of Fe(III) more than 5.000 × 10−6 mol/L and the concentrations of Fe(II) more than 1.000 × 10−5 mol/L in aqueous solution can be detected by this test paper.

scholarly journals Preparation, Characterization and Application of a Low Water-Sensitive Artemisia sphaerocephala Krasch. Gum Intelligent Film Incorporated with Anionic Cellulose Nanofiber as a Reinforcing Component

Polymers ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 247
Author(s):  
Tieqiang Liang ◽  
Lijuan Wang
Keyword(s):  
Electrostatic Interactions ◽  
Light Transmission ◽  
Gas Sensing ◽  
Barrier Properties ◽  
Cellulose Nanofiber ◽  
Elongation At Break ◽  
Color Changes ◽  
Buffer Solutions ◽  
Artemisia Sphaerocephala ◽  
Different Color

A low-water-sensitive Artemisia sphaerocephala Krasch. gum (ASKG) based intelligent film was developed. Red cabbage extracts (RCE) was selected as a natural pH-sensitive indicator, and anionic cellulose nanofiber (ACNF) was added as a hydrophobic and locking host. The zeta potential, rheology, Fourier-transform infrared spectroscopy, X-ray diffractometry, and release results indicated that the RCE was locked by the ACNF via electrostatic interactions, moreover, broke the original complicated network and ordered arrangement of polymer molecules in the developed intelligent films. RCE addition decreased the tensile strength, oxygen, and water vapor barrier properties and light transmission of the developed intelligent films, while increasing the elongation at break. The films could respond to buffer solutions and NH3 through different color changes. The developed intelligent film was hydrophobic, which could precisely detect the freshwater shrimp freshness in real time via color changes, which indicated that the films have potential in intelligent packaging and gas-sensing label fields.

Investigation of the effect of light fastness on the color changes of maps prepared by electrophotographic digital printing

2022 ◽  
Vol 0 (0) ◽  
Author(s):  
Zafer Özomay ◽  
Çağla Koşak Söz ◽  
Sinan Sönmez
Keyword(s):  
The Other ◽  
Digital Printing ◽  
Light Fastness ◽  
Color Changes ◽  
Before And After ◽  
Printing System ◽  
Different Color ◽  
Coated Surfaces ◽  
Electrophotographic Printing ◽  
Effect Of Light

Abstract In this study the prints were made on paper substrates, which were thought as map substrate alternatives, with 3 different surface properties at 1200 dpi by using the electrophotographic printing system. Color and gloss values of the samples were determined both before and after exposure to light for a period of 42 hours to determine the light fastness of the substrate and the print on it. The studies revealed that after the light fastness tests (i) the width of the color universe of the papers with matte surfaces is more than that of the papers with glossy surfaces, (ii) the loss of brightness of woodfree paper is higher than that of the other paper samples and (iii) the print chroma values obtained in woodfree paper is lower than those of the coated surfaces. Moreover, (iv) the delta E 00 {E_{00}} measurements revealed that all paper samples experienced different color losses in different colors, and the most significant differences in these color losses were in magenta and black.

scholarly journals PROSES PEMBUNGAAN BEBERAPA VARIETAS Hoya coronaria DARI KAWASAN HUTAN KERANGAS AIR ANYIR, BANGKA

2018 ◽  
Vol 2 (1) ◽  
pp. 10-19
Author(s):  
Risti Annisa ◽  
Yulian Fakhrurrozi ◽  
Sri Rahayu
Keyword(s):  
Flower Development ◽  
Development Process ◽  
Color Change ◽  
Flower Color ◽  
Color Changes ◽  
Light Yellow ◽  
Heath Forest ◽  
The Difference ◽  
Different Color ◽  
Flowering Process

Hoya coronaria found in heath forest of Air Anyir, Bangka has diverse colors. Flowers color diversity sometimes correlated varieties or the result of color changes during flowering process. The flowers development process observed from 5 H. coronaria varieties with different color from heath forest of Air Anyir, Bangka.The purpose of this research to know the flowering process and flower color change process some varieties of H. coronaria. This research done from September 2015-January 2016. This study used qualitative method to made detail and systematic description about flowering phase. H.coronaria flowering process consists of flower initation, flower estabilisment and flower development. Flower initation needs 13-15 days, flower estabilisment needs 10-12 days and flower development consists of early blooming process, full blooming and senescene. Early blooming process needs 1-3 days, full blooming needs 5-12 days and senescene needs 1-3 days. During the development process changes from rounded to pentagonal shape and there is a change in size. The observation result showed that 5 varieties are different from one another based on the difference between the colors of the flowers. Variety 1 has yellow corolla without honey line and deep pink corona. Variety 2 has light yellow green corolla with strong pink honey line and moderate red corona. Variety 3 has moderate red corolla with moderate red honey line and moderate red corona. Variety 4 has light yellow green corolla with moderate pink honey line and light yellow green corona. Variety 5 has moderate red without honey line and grayish red corona

scholarly journals Tooth color change due to different etching and debonding procedures

2018 ◽  
Vol 88 (6) ◽  
pp. 779-784 ◽  
Author(s):  
Hande Gorucu–Coskuner ◽  
Ezgi Atik ◽  
Tulin Taner
Keyword(s):  
Tungsten Carbide ◽  
Orthodontic Treatment ◽  
Color Change ◽  
Wilcoxon Test ◽  
Tooth Color ◽  
Group Iii ◽  
Color Changes ◽  
Intergroup Comparison ◽  
Different Color ◽  
Self Etch

ABSTRACT Objectives: To compare the effects of different etching techniques, 12–, 24–bladed tungsten carbide burs, and polishing discs on tooth color changes during orthodontic treatment. Materials and Methods: 59 individuals (mean age: 15.20 ± 1.59 years) were divided into four groups: 37% phosphoric acid and adhesive primer was used in Groups I and II whereas self–etch primer was used in Groups III and IV for enamel preparation. After orthodontic treatment, residual adhesives were cleaned with 12–bladed tungsten carbide burs in Groups I and III, while 24–bladed tungsten carbide burs were used in Groups II and IV. All teeth were polished with medium and fine Sof–Lex XT discs (3M ESPE, St Paul, Minnesota). Color measurements were taken from upper incisors and canines at pretreatment (T0), after cleaning with tungsten carbide burs (T1) and polishing with discs (T2). Wilcoxon test was used for evaluation of L*, a*, b* changes and Kruskal–Wallis for intergroup comparison of color changes. Results: L*, a*, b* values, except a* at Groups I, II, IV, and b* at Group III, changed significantly (P < .05). Groups III and IV showed significantly different color alterations from T0 to T1 (P < .05). After polishing, tooth color alterations were not significantly different among the groups. Conclusions: In self–etch bonding groups, a 12–bladed tungsten carbide bur caused less color change than the 24–bladed tungsten carbide bur. Orthodontic treatment resulted with visible and clinically unacceptable tooth color alterations regardless of the enamel preparation and clean–up techniques. Polishing reduced the effect of tungsten carbide burs, but did not affect the total influence of orthodontic treatment on the tooth color.

scholarly journals Color Characteristics of Red False Heartwood and Mature Wood of Beech (Fagus sylvatica L.) Determining by Different Chromacity Coordinates

2019 ◽  
Vol 11 (3) ◽  
pp. 690 ◽  
Author(s):  
Ivan Klement ◽  
Tatiana Vilkovská
Keyword(s):  
Color Change ◽  
Free Water ◽  
Color Difference ◽  
Mature Wood ◽  
Affect Intensity ◽  
Drying Time ◽  
Color Changes ◽  
Hue Angle ◽  
Saturated Color ◽  
Different Color

Structure of wood can affect intensity of color change in remarkable ways. This article was focused on the analysis of the color changes red false heartwood and mature wood by different methods such as ΔE* (Total color difference), h* (Hue angle), C*ab (Color saturation) and Sab (Saturation). The aim of this study was to evaluate the color properties of red false heartwood and mature wood by using different chromacity coordinates. Our observations suggested that the density in the absolute dry state was equal between the red false heartwood and mature wood. The biggest difference was in the area of the free water domain, thus from an initial MC value to the fiber saturation point (FSP). The shorter drying time of the red false heartwood samples was caused by their lower initial MC. Due to the different MC, the temperature created a different color intensity of the compared samples. Mature wood samples achieved more saturated color in the drying process than did the samples of red false heartwood.

A New Azo Dye Based Sensor for Selective and Sensitive Detection of Cu(II), Sn(II), and Al(III) Ions

2021 ◽  
Author(s):  
Vivekshinh Kshtriya ◽  
Bharti Koshti ◽  
Nidhi Gour
Keyword(s):  
Metal Ions ◽  
Azo Dye ◽  
Bathochromic Shift ◽  
Sensitive Detection ◽  
Visible Spectroscopy ◽  
Absorption Properties ◽  
Color Changes ◽  
Uv Visible ◽  
Different Color ◽  
First Time

<p>In this manuscript, we report for the very first time synthesis of a new purple azo dye (E)-1-((5-methoxy thiazolo[4,5-b]pyridin-2-yl) diazenyl) naphthalen-2-ol (<b>TPN1</b>). <b>TPN1</b> also exhibits very interesting sensing behavior and can be potentially used for highly selective and sensitive detection of Cu<sup>2+</sup>, Sn<sup>2+</sup> and Al<sup>3+</sup>. The changes in the absorption properties of <b>TPN1 </b>in the presence of various cations were studied extensively by UV visible spectroscopy. <b>TPN1 </b>dye which exhibits purple color changes to blue, orange, and lavender color respectively on addition of Cu<sup>2+</sup>, Sn<sup>2+,</sup> and Al<sup>3+</sup> ions respectively. Notably, <b>TPN1</b> reveal different color with the number of metal ions but the peak shifting could be observed only with three metal ions in solution. Addition of Cu<sup>2+</sup> to <b>TPN1</b> caused bathochromic shift, while in the case of Sn<sup>2+</sup> and Al<sup>3+</sup> a hypsochromic effect could be observed through UV-visible spectroscopy.</p>

A New Azo Dye Based Sensor for Selective and Sensitive Detection of Cu(II), Sn(II), and Al(III) Ions

2021 ◽  
Author(s):  
Vivekshinh Kshtriya ◽  
Bharti Koshti ◽  
Nidhi Gour
Keyword(s):  
Metal Ions ◽  
Azo Dye ◽  
Bathochromic Shift ◽  
Sensitive Detection ◽  
Visible Spectroscopy ◽  
Absorption Properties ◽  
Color Changes ◽  
Uv Visible ◽  
Different Color ◽  
First Time

<p>In this manuscript, we report for the very first time synthesis of a new purple azo dye (E)-1-((5-methoxy thiazolo[4,5-b]pyridin-2-yl) diazenyl) naphthalen-2-ol (<b>TPN1</b>). <b>TPN1</b> also exhibits very interesting sensing behavior and can be potentially used for highly selective and sensitive detection of Cu<sup>2+</sup>, Sn<sup>2+</sup> and Al<sup>3+</sup>. The changes in the absorption properties of <b>TPN1 </b>in the presence of various cations were studied extensively by UV visible spectroscopy. <b>TPN1 </b>dye which exhibits purple color changes to blue, orange, and lavender color respectively on addition of Cu<sup>2+</sup>, Sn<sup>2+,</sup> and Al<sup>3+</sup> ions respectively. Notably, <b>TPN1</b> reveal different color with the number of metal ions but the peak shifting could be observed only with three metal ions in solution. Addition of Cu<sup>2+</sup> to <b>TPN1</b> caused bathochromic shift, while in the case of Sn<sup>2+</sup> and Al<sup>3+</sup> a hypsochromic effect could be observed through UV-visible spectroscopy.</p>

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