Papers by Keyword: Cosolvent

Abstract: Mangiferin, a polyphenol of C-glycosylxanthone, exhibits various bioactivities with poor aqueous solubility. It is known as a potent antioxidant, which leads to remarkable UV protection and anti-aging properties. Mangiferin can be found in many plant species, among which the mango leaf is one of the primary sources. From our study, the extraction yield of mangifein obtained from the leaves of Mangifera indica L. variety Nam Doc Mai was 3.17% with 95.02% ± 0.064 purity (HPTLC analysis). The solubility of mangiferin in the studied pure solvents arranging in descending order were ethoxydiglycol, dimethyl isosorbide, polyethylene glycol 400, polyethylene glycol 600, propylene glycol, dipropylene glycol, glycerin, isopentyldiol, methanol, ethanol and water, whereas the addition of the solvent in water could increase the aqueous solubility of mangiferin. In several cases, the solubility was apparently higher than that dissolved in its pure solvent state. The log-linear solubility model for the cosolvent system was used to calculate the volume fractions of the selected solvents needed to solubilize mangiferin content at the twenty times of the IC₅₀ against DPPH radicals. In conclusion, the developed aqueous formulation contained 0.5% w/v of mangiferin and 20% w/v of polyethylene glycol 600 or dipropylene glycol as a solubilizer in water.

Abstract: A cleaning process for dyeing apparatus was investigated by employed a self-developed supercritical equipment. The solubility of C.I. Disperse Red 167 was evaluated with acetone, ethanol and carbinol in supercritical carbon dioxide at temperatures of 60, 80,100 and 120 °C and pressures ranging from 12 to 28 MPa. As revealed from the experimental results, the optimal cleaning conditions were as follows: cleaning temperature 100 °C, cleaning pressure 18 MPa, and cleaning time 40 min. Acetone was the most suitable cosolvent and the best cleaning effect was obtained when its concentration was 1%.

Abstract: Isothermal Vapour-liquid equilibrium for cyclohexane (1) + benzene (2) binary system, cyclohexane (1) + benzene (2) dimethylformamide (3) ternary system and cyclohexane (1) + benzene (2) dimethylformamide (3) + cosolvent (4) quaternary systems were obtained. The effects of cosolvents (diethyl glycol, dimethylsulfoxide, N-methylformamide) on the performance of dimethylformamide in benzene-cyclohexane separation were studied. The result shows the selected cosolvents suppress the effectiveness of dimethylformamide. The result also shows that the ratio of cosolvents to dimethylformamide affects the separation factor.

Abstract: In order to discuss the effects that cosolvent takes on ink used in water-borne pen performance and quality, select and use ethanol, methanol, isopropanol, Ethylene glycol monobutyl ether, ethanediol and propanediol six common water-soluble cosolvent, using them to prepare the samples of ink used in Water-borne pen, testing the surface tension, viscosity, drying rate and adhesionforce. Select three kinds of cosolvent to carry the formula experiment. The results of the study show that: the ink prepared with different kinds csolvent have different performance. The ink prepared by isopropyl alcohol has good quality performance.

Abstract: In this study, the measurement and correlation of the solubility of the rhodamine B in supercritical carbon dioxide (scCO₂) with or without a cosolvent were determined. The results were obtained using a flow-type apparatus, at 308.15 and 318.15 K, in a pressure range 8.0 - 24.0 MPa. The results show that, at a fixed temperature, the solubility of the dye in scCO₂ fluids increases with increasing pressure. In the presence of 5 mol% methanol as a cosolvent, the solubility of dyes increased significantly. The experimental data correlated with the Chrastil and Sovova equations.

Abstract: The glossiness is an important indicator of evaluation polishing printed matter. The water-soluble varnish consisting of different content and kinds of promoter is prepared. Then proofs are coating by wire rods. Measuring glossiness of proofs, we analyze the influence of promoter on glossiness of water-soluble varnish. The results show that adding cosolvent, substrate wetting agent, flow agent, wax emulsion and other promoter in water-soluble varnish can improve the glossiness of water-soluble varnish film. When cosolvent ethanol was adding to 3%, the film glossiness achieves about 80 and adding a small amount of wax emulsion, flow agents, the film glossiness can be increased about 10%.