Controlled preparation of micro–nano hierarchical hollow calcium carbonate microspheres by pressurized-CO2 carbonization and their CaCO3:Eu3+ photoluminescence properties

CrystEngComm ◽  
2021 ◽  
Vol 23 (16) ◽  
pp. 3033-3042
Author(s):  
Liubin Shi ◽  
Mingde Tang ◽  
Yaseen Muhammad ◽  
Yong Tang ◽  
Lulu He ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Calcium Carbonate ◽  
Calcium Hydroxide ◽  
Hierarchical Structure ◽  
Ethylenediaminetetraacetic Acid ◽  
Disodium Salt ◽  
Hollow Microspheres ◽  
Photoluminescence Properties ◽  
Controlled Preparation

Herein, calcium carbonate hollow microspheres with a micro–nano hierarchical structure were successfully synthesized using disodium salt of ethylenediaminetetraacetic acid (EDTA-2Na) as an additive, by bubbling pressurized carbon dioxide and calcium hydroxide at 120 °C.

Equilibria of Reactions Between Nitrogen Oxides and Calcium Hydroxide

1995 ◽  
Vol 60 (5) ◽  
pp. 751-762
Author(s):  
Emerich Erdös ◽  
Karel Mocek
Keyword(s):  
Carbon Dioxide ◽  
Water Vapor ◽  
Calcium Carbonate ◽  
Nitrogen Oxides ◽  
Calcium Hydroxide ◽  
Nitrogen Monoxide ◽  
Equilibrium Equations ◽  
Gaseous Nitrogen ◽  
Chemical Equilibria ◽  
Partial Pressures

A general analysis of chemical equilibria in a system consisting of the gaseous nitrogen monoxide, nitrogen dioxide, water vapor, carbon dioxide, oxygen, and the solid calcium hydroxide is carried out with respect to the equilibrium partial pressures of nitrogen oxides. The conditions are defined, under which the calcium hydroxide is transformed to the calcium carbonate. The corresponding equilibrium equations are derived for all nine regions of existence of described system. The results are illustrated graphically and discussed from the point of removing the nitrogen oxides from waste gases.

scholarly journals Photosensitized Reduction of Carbon Dioxide in Solution Using Noble-Metal Clusters for Electron Transfer

1995 ◽  
Vol 50 (2-3) ◽  
pp. 283-291 ◽  
Author(s):  
Naoki Toshima ◽  
Yumi Yamaji ◽  
Toshiharu Teranishi ◽  
Tetsu Yonezawa
Keyword(s):  
Carbon Dioxide ◽  
Noble Metal ◽  
Methyl Viologen ◽  
Metal Clusters ◽  
Ethylenediaminetetraacetic Acid ◽  
Colloidal Dispersion ◽  
Disodium Salt ◽  
Air Treatment ◽  
Alcohol Reduction ◽  
Ethylenediaminetetraacetic Acid Disodium Salt

Abstract Carbon dioxide was reduced to methane by visible-light irradiation of a solution composed of tris(bipyridine)ruthenium(III) as photosensitizer, ethylenediaminetetraacetic acid disodium salt as sacrificial reagent, methyl viologen as electron relay, and a colloidal dispersion of polymer-protected noble-metal clusters, prepared by alcohol-reduction, as catalyst. Among the noble-metal clusters examined, Pt clusters showed the highest activity for the formation of methane as well as hydrogen. In order to improve the activity, oxidized clusters and bimetallic clusters were also applied. For example, the CH4 yield in 3-h irradiation increased from 51 x 10-3 μmol with unoxidized Pt clusters to 72 x 10-3 μmol with partially oxidized ones. In the case of Pt/Ru bimetalic systems, the improvement of the catalytic activity by air treatment was much greater than in case of monometallic clusters.

Bubble-Liquid Membrane Method for Preparing Spherical Calcium Carbonate Nanoparticles

2021 ◽  
Vol 21 (10) ◽  
pp. 5241-5246
Author(s):  
Jun-Xian Ma ◽  
Xue-Feng Lei ◽  
Sha Jiang ◽  
Jian-Chun Wang ◽  
Yue-Hui Wang
Keyword(s):  
Calcium Carbonate ◽  
Membrane Reactor ◽  
Liquid Membrane ◽  
Ethylenediaminetetraacetic Acid ◽  
Particle Size Analysis ◽  
Disodium Salt ◽  
Size Analysis ◽  
Bubble Liquid ◽  
Coating Agent ◽  
Uniform Dispersion

In this work, we describe the principle and operation of a bubble-liquid membrane reactor, and use of the reactor to prepare spherical calcium carbonate nanoparticles. The products were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, and laser particle size analysis. The effects of additives to control crystal morphology, coating agents, and the stirring speed of the bubble-liquid membrane reactor were investigated. Spherical calcium carbonate nanoparticles with uniform dispersion and no agglomeration were obtained when a disodium hydrogen phosphate/ethylenediaminetetraacetic acid disodium salt mixture (1:1 mass ratio) was used as the additive, oleic acid was used as the coating agent (1.5 wt%), and the stirring speed was 5000–6000 r/min. The results indicate that the bubble-liquid membrane reactor may be suitable for continuous industrial production of calcium carbonate nanoparticles.

Photooxidation at Platinum Colloidal TiO2 Aqueous-Solution Interfaces. I. Ethylenediaminetetraacetic Acid and Related-Compounds

1986 ◽  
Vol 39 (5) ◽  
pp. 757 ◽  
Author(s):  
DN Furlong ◽  
D Wells ◽  
WHF Sasse
Keyword(s):  
Carbon Dioxide ◽  
Aqueous Solution ◽  
Ethylenediaminetetraacetic Acid ◽  
Oxidation Potential ◽  
Illumination Time ◽  
Carbonium Ions ◽  
Production Of Hydrogen ◽  
Glycine Derivatives ◽  
Lactic Acids ◽  
Exhaustive Oxidation

The photooxidation of ethylenediaminetetraacetic acid ( edta ) and related glycine derivatives, at Pt/TiO2/aqueous solution interfaces, has been monitored via the production of hydrogen and carbon dioxide. Yields are consistent with the exhaustive oxidation of methoxycarbonyl groups and the rate varied with the number and distribution of such groups. A photooxidation pathway is proposed which involves the oxidation of intermediate carbonium ions. Plausible molecular intermediates, such as formic acid and formaldehyde in the case of edta , have been shown in separate experiments to be photooxidized according to the proposed pathway. The maximum rate of oxidation for each donor depends on its oxidation potential and its tendency to adsorb on TiO2 surfaces. Desorption due to pH increase, as well as consumption of the donor, causes the rate to decline rapidly with illumination time. Acetic and malonic acids gave some hydrogen but underwent mainly (> c. 80%) photo-Kolbe decarboxylation to yield carbon dioxide and methane. By contrast the oxidation of oxomalonic, pyruvic and lactic acids proceeded mainly via a H2 producing pathway similar to that established for edta. The oxidation of pyruvic and lactic acids ceased at a yield of one mole of CO2 per mole of acid.

scholarly journals Optimized protocol for the extraction of RNA and DNA from frozen whole blood sample stored in a single EDTA tube

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Hirotaka Yamagata ◽  
Ayumi Kobayashi ◽  
Ryouichi Tsunedomi ◽  
Tomoe Seki ◽  
Masaaki Kobayashi ◽  
...  
Keyword(s):  
Whole Blood ◽  
Ethylenediaminetetraacetic Acid ◽  
Rna Extraction ◽  
Basic Research ◽  
Rna Degradation ◽  
Disodium Salt ◽  
Water Bath ◽  
High Quality ◽  
Blood Samples ◽  
Rna And Dna

AbstractCryopreservation of whole blood is useful for DNA collection, and clinical and basic research. Blood samples in ethylenediaminetetraacetic acid disodium salt (EDTA) tubes stored at − 80 °C are suitable for DNA extraction, but not for high-quality RNA extraction. Herein, a new methodology for high-quality RNA extraction from human blood samples is described. Quickly thawing frozen whole blood on aluminum blocks at room temperature could minimize RNA degradation, and improve RNA yield and quality compared with thawing the samples in a 37 °C water bath. Furthermore, the use of the NucleoSpin RNA kit increased RNA yield by fivefold compared with the PAXgene Blood RNA Kit. Thawing blood samples on aluminum blocks significantly increased the DNA yield by ~ 20% compared with thawing in a 37 °C water bath or on ice. Moreover, by thawing on aluminum blocks and using the NucleoSpin RNA and QIAamp DNA Blood kits, the extraction of RNA and DNA of sufficient quality and quantity was achieved from frozen EDTA whole blood samples that were stored for up to 8.5 years. Thus, extracting RNA from frozen whole blood in EDTA tubes after long-term storage is feasible. These findings may help advance gene expression analysis, as well as biomarker research for various diseases.

PREPARATION OF PRECIPITATED CALCIUMCARBONATE USING ADDITIVE AND WITHOUT ADDITIVE

2015 ◽  
Vol 77 (3) ◽  
Author(s):  
Anuar Othman ◽  
Nasharuddin Isa ◽  
Rohaya Othman
Keyword(s):  
Calcium Carbonate ◽  
Calcium Hydroxide ◽  
Mineral Composition ◽  
Hydrated Lime ◽  
Raw Material ◽  
Precipitated Calcium Carbonate ◽  
Uniform Size ◽  
The One

Precipitated calcium carbonate (PCC) chemically can be synthesized in the laboratory. In this study, hydrated lime or calcium hydroxide was used as raw material with sucrose as additive to produce PCC. The process was compared with the one without additive. PCC produced was observed based on morphology, mineral composition and size by using Fesem-Edx and LPSA, respectively. PCC products without additive demonstrated fine and more uniform size of calcite PCC as compared to the one with additive. Nevertheless, the process with additive produced more PCC product than without additive.

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