Papers by Keyword: Pigment

Abstract: In this work, the potential beneficial uses of palm oil fly ash (POFA) as a green pigment in paint technology via sintering process was studied. The POFA composites were sintered in the furnace at temperature 750°C. The obtained green pigment from POFA composites through the processes of mixing, reductive heating, ball milling and sieving was subsequently characterized by X-Ray diffraction technique.

Abstract: The chestnut shell pigment/SiO₂ composite was prepared by co-precipitation and thermal insolubilization and used to remove Cu (II) from water. The effect of the ratio of chestnut-shell-pigment to SiO₂ on the removal efficiency was studied. The sorption experiments were examined by batch method. The optimal initial pH of the copper solution ranges from 4 to 6. The equilibrium data were fitted with the Langmuir than the Freundlich, and the sorption mechanism of Cu (II) suits to the former. The maximum sorption capacity derived from the Langmuir was found to be 18.87 mg g⁻¹. The composite behaves an excellent potential for copper removal.

Abstract: Influence of possible fluctuations of a chemical composition of waste of galvanic productions on the mixed iron oxide pigment (MIP) main pigmentary properties is established. It is shown that introduction of samples of MIP with the raised content of these or those metals in such industrial paintwork materials as alkyd PF-115 enamel and a primer GF-021, practically doesn't change physic-mechanical properties and firmness of the coverings received on their basis. It allows to apply slimes of galvanic productions as the main raw materials by industrial production of MIP and to reduce prime cost of a pigment by 15-20%.

Abstract: The purpose of this research was to study the white resist printing with colour resistant material from flour of wild taro (Colocasia esculenta (L.) Schott) and using pigment as dyestuffs. The optimal ratio of colour resistant materials from flour of giant taro were compose of 19% wild taro corm, 30% water, 34% sodium chloride, 13% calcium hydroxide, and 3% vegetable oil. The fixation of printing by using hot air at 110 °C for 3 minutes can resist dyestuffs and also easy to remove the flour of giant taro. The pattern at resist printing area of fabrics shows sharpness and whiteness. The colour fastness results were ranging between fair to good level.

Abstract: An approach to synthesize melanin-formaldehyde resin has been developed. The pigment extracted from chestnut shells, a bio-waste from food industry, was employed as the melanin. The synthesis implemented by a double-catalyzed process, namely, base-catalysis and then acid catalysis. The process was optimized and its performance was evaluated on the basis of the cation exchange capacity of the obtained resin. The optimum reaction condition was found to be base-catalysis using NaOH at pH 11.2, 70 °C and the formaldehyde (37%, m/v) to melanin ratio of 2.33 mL/g for 4 hours and then acid-catalysis by HCl at pH 1.5 and 80 °C for 4 hours. The resin can be used as an effective and inexpensive sorbent for Cu (II) removal from aqueous solutions.

Abstract: Short sulfate process was developed to produce rutile TiO₂ white pigment by using low concentration industrial TiOSO₄ solution as raw material via self-generated seeded thermal hydrolysis route. The concentration of TiOSO₄ solution had significantly influenced the structure and pigment properties of rutile TiO₂ white pigment. The samples were characterized by XRD, particle size distribution and pigment properties test. Appropriate concentration of TiOSO₄ was beneficial to promoting hydrolysis process in a proper way and obtaining favorable structure and high quality white pigment. The optimized concentration of TiOSO₄ solution was of 191.20 g/L.

Abstract: The physical structure of coating layer have an important influence on transferring and setting of the printing ink. In this study, the effect of pigment on surface microstructure and surface free energy was investigated. The findings indicated that the pigment affected the pore size, depth and distribution of the coated paper surface. Kaolin pigment compared with calcium carbonate pigment was good to improve the paper surface smoothness. Surface free energy of kaolin pigment coating was higher than calcium carbonate pigment coating, which showed that surface wettability of coating with kaolin pigment was better than calcium carbonate pigment.

Abstract: With black soybean as raw materials, 50% ethanol as the extractant, at 70°C, pH1.0, solid-liquid ratio of 1:100(g:mL), at 90min were used to extract the pigment of black soybean Through the establishment of DPPH•,•OH, superoxide anion free radicals, reducing power and hydrogen peroxide. The results show: its ability of scavenging DPPH•, •OH, hydrogen peroxide is far better than ascorbic acid. The pigment at concentration of 0.6mg/mL shows a scavenging rate for DPPH• up to 88.29%,and for •OH 89.36%,for hydrogen peroxide89.75%.In addition，the general reducing power and scavenging rate for superoxide anion solution of the pigment are a little worse than those of ascorbic acid.

Abstract: Wool spherical-like Bi₂WO₆ nanoarchitectures were synthesized by hydrothermal method with using bismuth nitrate and sodium tungstate as raw materials. Ag was deposited on the surface of Bi₂WO₆ by a photoreduction process. The as-prepared products were characterized by XRD, and TEM. The XRD results revealed that the products have neglectable change in crystal with or without Ag, but obvious change in shape and intensity with different hydrothermal process time and optimal time is 12 h at 180 C. The TEM results shown that 7 h was chose as optimal hydrothermal process time. Rhodamine (RhB) and Light Green SF Yellowish (Light green) were chose as objects to evaluate the photocatalytic activities of the products under different light irradiation. The results showed that Ag loading greatly improved the photocatalytic activity of Bi₂WO₆. Meanwhile, the source of light is a very important affected factor for the photocatalyst degradation, ultraviolet light has the best efficiency, but visible light was chose as the light source finally due to conservation of energy and efficiency. The dynamic behavior of Ag-loaded Bi₂WO₆ photocatalyst degradation of two pigments obeys pseudo-first-order kinetics at 298 K. The as-synthesized photocatalysts are stable for degradation of two pigments and can be easily recycled.

Abstract: Hematite widely used since ancient times as a pigment but its chemical and thermal stability at high temperatures application is not enough. In this study, hematite nanoparticles were included into the zircon matrix and its stability was increased. Fe₂O₃ ZrSiO₄ nanocomposite with Fe/Zr molar ratio of 5 to 30% was synthesized from Si and Zr alkoxides by sol-gel method. The products of the solgel method were calcined in the 1200°C /2.5 h. The structural and morphological characteristics of nanocomposite are determined by X-ray diffraction (XRD), simultaneous thermal analysis (STA) and scanning electron microscopy (SEM) investigations. The results indicate that formation of zircon promoted with iron addition. Finally, colorimetric parameters of the glazed ceramic samples were measured by the CIE colorimetric method. It was found that the samples withe 20% molar Fe has the highest red shade and is the best color according to the a* parameter.