Oxonitride pigments

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Gerhard Pfaff

Abstract Oxonitride pigments belong to the inorganic yellow, orange and red colorants. They were developed to complement the yellow, orange and red color range. Oxonitride compositions that are interesting for pigment uses crystallize in perovskite, chalcolamprite and spinel structures. The most suitable compositions for pigment purposes are most probably LaTaON2 and CaTaO2N. The synthesis of oxonitride pigments is technically difficult and takes place using a solid state-gas reaction. The pigments are characterized by excellent optical and application characteristics in particular regarding brilliance and color strength, strong hiding power, good dispersibility, light fastness and temperature stability.

2016 ◽  
Vol 675-676 ◽  
pp. 19-22 ◽  
Author(s):  
Ploysai Ohama ◽  
Sirilak Namwong ◽  
Saowanee Kumpun

The extractions of yellow and red pigments from safflower petals were studied. The pigment extracted was further utilized as a natural dye for silk dyeing. The safflower petals were water-extracted in order to remove the yellow pigment and the extraction of red pigment from the petals was done with alkali solution. The extracted red pigment was applied to a silk fabric by dyeing process. The effects of dye concentration and pH of dye bath were studied. The colourimetric analysis of each dyed material was done in terms of the CIELab (L*, a* and b*) and K/S values. Maximum color strength for red color was obtained at pH 4. Color fastness to washing and light was evaluated. Washing fastness was 4-5 but light fastness for red dyed silk was 1. The dyed silk did not display antimicrobial activity against the bacteria Staphylococcus aureus ATCC25923T and Escherichia coli ATCC25922T.


Author(s):  
Ali A. Zolriasatein

Background and Objective: Jute fiber is highly sensitive to the action of light. Significant features of the photochemical changes lose its tensile strength and develop a yellow color. It has been proved that the phenolic structure of lignin is responsible for the yellowing of jute fiber. In order to remove lignin, jute yarns were treated with laccase enzyme in different treatment times and ultrasonic powers. Lower whiteness index and higher yellowness index values were obtained by the laccase-ultrasound system in contrast to conventional laccase treatment. Methods: The laccase enzyme which entered the fibers by applying ultrasound, decreased the tensile strength while the loss in tensile strength was lower at high ultrasound intensities. FT-IR spectrum showed that the band at 1634 cm-1 assigned to lignin completely disappeared after laccase treatment in the presence of ultrasound. The absence of this peak in the laccase-ultrasound treated jute yarn suggests complete removal of lignin. Change in the morphology of fibers was observed by SEM before and after enzymatic delignification. The laccase-ultrasound treated yarns showed a rougher surface and more porosity. On the other hand, it was more effective in fibrillation of the jute fibers than the conventional method. Finally, bio-treated jute yarns were dyed with basic and reactive dyes. Results: The results indicated that at low intensities of ultrasound and relatively long reaction times, lignin can be more effectively removed and dye strength (K/S) increased to a higher extent. Laccase-ultrasound treatment increased the color strength by 33.65% and 23.40% for reactive and basic dyes respectively. Conclusion: In the case of light fastness, the conventional laccase treated yarns provided better protection than laccase-ultrasound treated yarns.


2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Gerhard Pfaff

Abstract Cadmium sulfide and selenide pigments (cadmium pigments) belong to the inorganic yellow, orange and red pigments. Cadmium sulfide pigments are based on the wurtzite lattice, where cadmium can be partially substituted by zinc or mercury and sulfide by selenide. Cadmium pigments are characterized by excellent optical and application characteristics in particular regarding brightness of shade, hiding power, tinting strength, and weather fastness. The declining use of cadmium-containing materials in the last decades is a result of the environmental discussion and the development of less problematic substitute products, especially of bismuth vanadate and high-value organic, temperature-stable yellow and red pigments.


2013 ◽  
Vol 781-784 ◽  
pp. 674-677
Author(s):  
Sudaporn Tangkawanit

This research was an intensive study on development of Hibiscus cannabinus L. fibers dyeing with natural dye. The result reflected that color shade and color strength value results were different depend on type of mordanted. The Hibiscus cannabinus L. washing with detergent dyeing with Caesalpinia sappan L. and various mordented showed that light fastness was in level 3-4, when CuSO4 and FeSO4 mordanted light fastness result was in level 4-5, mordants as lime, CuSO4 and FeSO4 were added washing fastness property was in level 5.


2011 ◽  
Vol 64 (9) ◽  
pp. 1211 ◽  
Author(s):  
Bin Du ◽  
Si-Chun Yuan ◽  
Jian Pei

Two dendrimers, D1 and D2, containing the cationic iridium complexes (C1 and C2) as cores and truxene-functionalized chromophores as the branches, have been developed by a convergent synthetic strategy. The cationic complexes employ 3-(pyridin-2-yl)-1H-1,2,4-triazole and 2-(pyridin-2-yl)-benzimidazole derivatives as the ancillary ligands. To avoid the change in emission colour arising from the iridium complex, the conjugation between the dendron and the ligand is decoupled by separating them using the alkyl chain. An investigation of their photoluminescent features reveals that efficient energy transfer happens from the dendrons to the core in the solid state. Likewise, the charged dendritic structure is demonstrated to be an efficient method to improve the compatibility between the polar charged iridium complexes and typical hydrophobic hosts with the additional benefit of excellent solution processability. Both dendrimers exhibit strong solvatochromic behaviours in solvents and exclusive green and yellow-orange light in the solid state.


2014 ◽  
Vol 700 ◽  
pp. 113-116
Author(s):  
Yu Jie Chen ◽  
Feng Lan Han ◽  
Zhao Luo

Na2BaMgP2O8phosphors were synthesized by a standard solid state reaction and their luminescent properties were investigated. The phase structure was analyzed by X-ray powder diffraction measurement. Under the excitation of 365nm, Na2BaMgP2O8:Tb3+, Eu3+phosphors show two color bands of green and red color due to5D4−7F5transition of Tb3+ions and5D0−7F2transition of Eu3+ions, respectively. The emission intensity of Tb3+deceased with the increasing concentration of Eu3+, which verified that an effective energy transfer occurred from Tb3+to Eu3+in Na2BaMgP2O8host. The present study indicated that the phosphors have a high potential application in solid state lighting.


2016 ◽  
Vol 4 (35) ◽  
pp. 8197-8205 ◽  
Author(s):  
Shuxing Li ◽  
Qiangqiang Zhu ◽  
Le Wang ◽  
Daiming Tang ◽  
Yujin Cho ◽  
...  

Translucent CaAlSiN3:Eu2+ ceramic with a unique microstructure shows enhanced thermal stability and high quantum efficiency.


Cotton leaves have been used to extract natural dye for dyeing of Egyptian cotton variety Giza 86 fabric and its blend with polyester 50:50, using different mordants such as iron (II) sulfate, copper (II) sulfate, and alum. The exhaust dyeing method was utilized using the pre-mordant technique. It is observed that both fabric samples can be dyed in different colors and depth of shades with Cotton leaves dye. Iron (II) sulfate ensures the best light fastness. Improved light fastness is obtained using abovementioned lower amounts of iron (II) sulfate and copper (II) sulfate. Alum is found to be less effective than iron (II) sulfate and copper (II) sulfate on the light fastness. As a novel alternative and potential natural dye, Cotton leaves extract solution can be used to get various colors and shades with satisfactory fastness properties. The mordanted and un-mordanted fabric samples were tested for their dyeing performance in terms of color parameters K/S, (L*), a*, b*, (C*) and (H*), and fastness properties (wash, perspiration, light and rubbing fastness) were studied. The samples showed high color strength, and high fastness properties. These results are very important for industrial application and with the production of a natural dye as an inexpensive source from cotton leaves as a by-product. Another objective is to increase the production of eco-textile garments with a good price for the Egyptian customers.


2020 ◽  
Vol 49 (3) ◽  
pp. 593-597 ◽  
Author(s):  
Alexander M. Polgar ◽  
Yannick J. Franzke ◽  
Sergei Lebedkin ◽  
Florian Weigend ◽  
John F. Corrigan

A hexadeca-nuclear, N-heterocyclic carbene stabilized gold(i)–copper(i)-sulfido cluster is reported, which emits yellow-orange in the solid state.


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