Chromium(III) oxide

About: Chromium(III) oxide is a research topic. Over the lifetime, 163 publications have been published within this topic receiving 2526 citations. The topic is also known as: green oxide of chromium & green chromium oxide.

n‐Type Behavior of Chromium (III) Oxide

Abstract: The character of the electronic charge carriers under various conditions in chromium (III) oxide was investigated using Seebeck measurements on sintered compacts of in the temperature range 800–1800 K. The compacts were prepared by various sintering procedures. Depending on the pretreatment of the compacts, n‐ or p‐type materials were obtained. p‐Type material resulted after sintering in an atmosphere with a high oxygen partial pressure. Sintering in an atmosphere with low oxygen partial pressure, however gave n‐type material. This n‐type behavior could be frozen in by cooling the compacts below 1100 K. These experimental results provide evidence for Cr interstitials being the predominating point defects in at low oxygen partial pressure.

Heterogeneous Exchange between Chromium (III)-oxide and Chromate

Abstract: Andersen and Maddock1 have doubted whether Libby's hypothesis, that the transition metal oxyanions in the Szilard Chalmers reaction yielded fragments containing the metal in its original oxidation state, is still tenable. From their experiments and results published by Libby2 and Harbottle3 I suggest that the oxidation state of the chromium fragments must be determined in the crystal and not by reaction taking place on dissolution.

Biological Synthesis and Characterization of Chromium (iii) Oxide Nanoparticles

Abstract: Nanoparticles are nanosized clusters with dimensions less than 100nm. Nanoparticles are fabricated by physical, chemical, and biological methods. Physical and chemical methods are energy intensive and involve hazards of contaminations. Biological synthesis of nanoparticles is environment friendly, less toxic and cost effective process. Plants, microorganisms, and biomolecules are commonly exploited species for merging of nanoparticles in this method. In present work we synthesize Chromium oxide nanoparticles by biological method using fungal extract of Aspargillus Niger. The synthesized nanoparticles are characterized by XRD (X-Ray Diffraction), SEM (Scanning Electron Microscopy) and UV-Vis (Ultraviolet Visible) techniques.

Synthetic polyacrylamide as a potential flocculent to remove commercial chromium(III) oxide from aqueous suspension

Abstract: The effects of solution pH and cationic group contents in polyacrylamide (PAM) macromolecules on the polymer adsorption mechanism on chromium(III) oxide surface were studied. The structure of PAM adsorption layer was also characterized to explain the changes in solid suspension stability. The following methods were applied: turbidimetry, spectrophotometry, potentiometric titration and microelectrophoresis. Thanks to them, the stability of the Cr2O3–polymer systems, polymer-adsorbed amount, surface charge density and zeta potential of solid particles were determined. The experimental results indicate that adsorption of cationic PAM increases with the rising pH. The larger the content of cationic groups in PAM chains is, the higher the adsorption level is observed. The most effective chromium(III) oxide removal is achieved at pH 9 after addition of PAM with the largest content of cationic groups (i.e. 80 %). The neutralization of solid surface negative charge by positively charged polymer chains (assuming more coiled conformation) is responsible for this.

Investigation of removal possibilities of chromium(III) oxide from water solution in the presence of albumins

Abstract: System destabilization is a highly desirable phenomenon during colloidal impurity removal from sewages and wastewaters Therefore, in this study, the stability of chromium(III) oxide suspension in the absence and presence of albumins [bovine serum albumin (BSA), ovalbumin (OVA), human serum albumin (HSA)] was investigated Based on the analysis of experimental results, ie, measurements of adsorption amount, electrokinetic potential, and metal oxide surface charge density as well as system stability, the mechanism of the suspension stabilization/destabilization was proposed The examined system without the albumins is relatively stable at pH 3, 46, and 9 (TSI = 348, 366, 3422, respectively), which is associated with the electrostatic stabilization phenomenon In turn, the least stable is the suspension at pH 76 (TSI = 5543) This is the result of the adsorbent zero surface charge Regardless of solution pH, the BSA, OVA, or HSA adsorption causes an increase in the system stability (1755 < TSI < 30) Probably, the steric stabilization is involved in this phenomenon, which results from the mutual repulsion of the adsorption layers formed on the solid surface Thus, it can be concluded that the albumin presence in the industrial wastewaters impedes the chromium(III) oxide removal