Papers by Keyword: Cr³⁺

Abstract: In order to explore more functional supported probe material, the ultraviolet absorbance together with fluorescence properties of a probe with the structure of salicylaldehyde Schiff-base in various solvents and pHs were investigated after its synthesis. When the concentration of Cr³⁺ ion was in the range of 3~7×10^-5 mol•L^-1, the complex reaction between the probe and Cr³⁺ could be used for quantitation of the latter, which was developed by UV absorbance intensity of the complex and the concentration of Cr³⁺ ion. Ultraviolet analytic results determined that they were complexed in the molar ratio of 1:1. Finally, the MOF-supported probe material was successfully synthesized for further application, which realized the immobilization of the probe through simple operations.

Abstract: High temperature solid state reaction has been used to prepare the new red long-lasting phosphorescence (LLP) material ZnGa₂O₄:Cr³⁺ with different doping concentration. The afterglow properties of the samples have been investigated. Our study has shown that ZnGa₂O₄ samples without Cr³⁺ doping have blue-green afterglow. While the blue-green afterglow has disappeared and the red long-lasting phosphorescence according to the Cr³⁺ luminescence center covering 650 nm-750 nm has been observed when Cr³⁺ has been doped. In terms of brightness and decay time of the afterglow, the red afterglow and the blue-green afterglow have been entirely different. In this article the influence on LLP due to different doping concentrations of ZnGa₂O₄:Cr³⁺ has been discussed and the possible LLP mechanism has been proposed.

Abstract: The static adsorption of stainless steel pickling wastewater by ion resin exchange and activated carbon adsorption was studied respectively. The results shown that, the static saturate adsorption capacity of 001×7 dry resin for Cr3+and Fe3+ in the wastewater was 60.34mg/g and 65.3mg/g respectively, and the elution rate of saturated resin by using Na2SO4 and H2SO4 can reach 99%. The saturate adsorption capacity of activated carbon for Cr3+and Fe3+ in the wastewater was 4.55 mg/g and 40.76 mg/g respectively, and NaOH as desorption reagent had a good desorption effect to activated carbon. The regeneration of activated carbon was also carried out.

Abstract: The ultra-zeolite is an important research topic at present. Using ultra-zeolite 4A to treat wastewater has the advantage that traditional methods do not have, so it has been concerned by many experts and scholars. This subject adopts microwave method to synthesize ultra-zeolite 4A. Then using the prepared ultra-zeolite 4A to adsorb Cr³⁺ in wastewater. Study on the effect factors such as pH value, adsorption temperature, etc. The conclusion shows that ultra-molecular sieve 4A has been successfully synthsized by microwave method. In experiment of absorption wastewater containing Cr^{3 +} we has found when the concentration of solution containing Cr^{3 +} is 400mg / L, pH =4, temperature is 25 and adsorption time is10 minutes, which ultra-zeolite 4A removes Cr³⁺ is better.

Abstract: Na_0.5Bi_0.5TiO₃ microcubes with the side size ca. 20-30um were successfully fabricated by a Cr³⁺-assisted hydrothermal method. The obtained samples were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Results show that Cr³⁺ played a significant role in the formation of Na_0.5Bi_0.5TiO₃ microcubes. Possible mechanisms for the growth of Na_0.5Bi_0.5TiO₃ microcubes are discussed. The results presented in this study would be important in investigating the correlation between morphology and basic physical properties, and may offer a route to control the morphology and size of crystals.

Abstract: The correlations between of lightness, chroma, Cr3+ and color index were studied to analyze the impact of all these three elements on ruby red color; and with the color difference research, the lightness difference is testified to be the key affecting color appearance. Based on the uniform color space CIE 1976L*a*b*, the ruby displays the best red color when the content of Cr3+ is within (1555, 5183ppm), L* (32.64, 44.25) and ho  (354.14, 0.7). With the help of partial correlation analysis of color difference, it is illustrated that the correlation between L* and E* (r=0.999) is relatively higher than that between L* and E* (r=0.948); and with high significance level ( = 0.129) of H* and E*, it shows that H* has little impact on E*. It is concluded that the color change of ruby from red to purple are mostly affected by lightness change; lightness difference should be considered as the most important factor when evaluating the red color of ruby, and then followed by the chroma and hue jointly.