scholarly journals Solid state interactions in the systems CaO(CaCO3)-Fe2O3 and CuFe2O4-CaO

2005 ◽  
Vol 41 (1) ◽  
pp. 67-77 ◽  
Author(s):  
B.S. Boyanov
Keyword(s):  
Sulfuric Acid ◽  
Solid State ◽  
Acid Solution ◽  
Diffraction Analysis ◽  
Sulfuric Acid Solution ◽  
Formation Process ◽  
X Ray Diffraction ◽  
Exchange Reactions ◽  
X Ray ◽  
Ferrite Formation

The solid state interactions in the systems CaO(CaCO3)-Fe2O3 and CuFe2O4-CaO have been studied using X-ray diffraction analysis. The influence of the temperature on the ferrite formation process has been investigated in the range of 900-1200 oC and duration up to 360 min. It has been shown that a mixture of ferrites forms at 1000 oC and interaction of 240 min. The exchange reactions in the systems CuFe2O4-CaO and Cu0.5Zn0.5Fe2O4-CaO have been studied, too. It has been established that Ca2+ ions exchange Cu2+ and Zn2 partially and the solubility of copper and zinc in a 7 % sulfuric acid solution increases 10-15 times.

scholarly journals Evaluation of an Epoxy-Based Nanosilicacomposite Lining in H2SO4 Solution for Anticorrosion of Sewerage Concrete Structures

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Chau Van Dinh
Keyword(s):  
Electron Microscopy ◽  
Sulfuric Acid ◽  
Acid Solution ◽  
Sulfuric Acid Solution ◽  
Substrate Surface ◽  
Concrete Structures ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Corrosive Environments

This work presents the performance of a SiO2-epoxy nanocomposite lining for the anticorrosion of the concrete structures in sewer networks. Nanocomposite lining on the concrete substrate surface of the 15 phr (part per hundred epoxy resin) amine-cured epoxy polymer containing 3.0 phr of nano-SiO2 was prepared by intercalating epoxy into the SiO2 via direct mixing process. The silica exfoliation was monitored by X-ray diffraction (XRD) and transmission electron microscopy (TEM). The barrier feature of epoxy the base nanocomposite against water and sulfuric acid solution was evaluated. The results showed that the nanocomposite lining was of a great barrier against these corrosive environments due to the intercalation and exfoliation caused by the dispersion of the SiO2 nanoparticles into the epoxy matrix. The rate of the H2SO4 into the nanocomposite lining was also investigated by measurement of the depth of the sulfur element penetrated layer using the coupled Scanning Electron Microscopy (SEM)/Energy dispersive X-ray spectrometer (EDS). Deterioration behavior of the adhesion strength of the nanocomposite lining was studied. The nanocomposite lining shows a significant improvement of bond strength in comparison to the neat epoxy lining. The durability of the nanocomposite lining adhesion when the lining systems exposed to water and the sulfuric acid solution is also improved significantly.

scholarly journals Study of solid state interactions in the systems ZnFe2O4 - CaO, ZnFe2O4 - MgO and zinc cake with CaO and MgO

2013 ◽  
Vol 49 (3) ◽  
pp. 339-346 ◽  
Author(s):  
A.B. Peltekov ◽  
B.S. Boyanov
Keyword(s):  
Sulfuric Acid ◽  
Solid State ◽  
Acid Solution ◽  
Sulfuric Acid Solution ◽  
Xrd Analysis ◽  
Exchange Reactions ◽  
Ssbauer Spectroscopy ◽  
Zinc Hydrometallurgy

The solid state interactions of CaO and MgO with synthetic and industrial ZnFe2O4 (in zinc cake) have been studied using chemical, XRD analysis and M?ssbauer spectroscopy. The exchange reactions in the systems ZnFe2O4 - CaO and ZnFe2O4 - MgO have been investigated in the range of 850-1200?C and duration up to 180 min. It has been established that Ca2+ and Mg2+ ions exchange Zn2+ in ferrite partially and the solubility of zinc in a 7% sulfuric acid solution increases. The possibilities for utilization of the obtained results in zinc hydrometallurgy have been discussed.

scholarly journals Influence of the reaction time during the treatment of bacterial cellulose with sulfuric acid solution

2019 ◽  
Vol 9 (5) ◽  
pp. 4301-4304 ◽  
Keyword(s):  
Sulfuric Acid ◽  
Reaction Time ◽  
Acid Solution ◽  
Bacterial Cellulose ◽  
Sulfuric Acid Solution ◽  
Crystallinity Index ◽  
Acid Solutions ◽  
X Ray Diffraction ◽  
X Ray ◽  
Sulfuric Acid Solutions

Biomaterials are one of the most important parts of the medical device industry. Being used frequently in the development of Scaffolds for the tecidual regeneration. Bacterial cellulose is a biomaterial widely used in tissue regeneration. Due to its high content of hydrogen bonds, its crystallinity is high and its solubility is low, which makes its use difficult. Studies carried out with anteriority showed the modification suffered by bacterial cellulose treated with sulfuric acid solutions. The objective of this work was to study the influence of reaction time on crystallinity in the treatment of bacterial cellulose with sulfuric acid solution. Bacterial cellulose was modified by acid hydrolysis with sulfuric acid solutions of 48 or 64% for 60, 120 and 240 min. In all cases, the hydrolysed cellulose was washed with distilled water until pH 7, subsequently the cellulose was washed with ethanol and dried in an oven at 37 ° C until a constant mass. The samples obtained were characterized by X-ray diffraction and the crystallinity index, the apparent crystallite size, the crystallite inner chains and the Z-discriminant function were determined. The results showed that the reaction time has a statistically significant influence on the crystallinity of bacterial cellulose.

Bindung von Metall-Ionen an Dipeptide: Struktur von Thallium(I)-(3-benzyl-6-carboxylatomethyl-2,5-diketopiperazin) / Binding of Metal Ions by Dipeptides: Structure of Thallium(I) 3-Benzyl-6-carboxylatomethyl-2,5-diketopiperazine

1992 ◽  
Vol 47 (7) ◽  
pp. 952-956
Author(s):  
P. Mikulcik ◽  
P. Bissinger ◽  
J. Riede ◽  
H. Schmidbaur
Keyword(s):  
Solid State ◽  
Nitrogen Atom ◽  
Hydrogen Bonds ◽  
Diffraction Analysis ◽  
Carbonyl Oxygen ◽  
State Structure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Crystalline Product ◽  
Oxygen Atoms

Ester cleavage of aspartame (L-α-aspartyl-L-phenylalanine methylester) (1), by equimolar quantities of thallium ethoxide is accompanied by intramolecular cyclisation to give thallium 3-benzyl-6-(carboxylatomethyl)-2,5-dioxopiperazine (2). The solid state structure of the crystalline product was determined by single-crystal X-ray diffraction analysis. The cations were found to form four short and four elongated contacts to seven oxygen atoms and one nitrogen atom of a total of six neighbouring 3-benzyl-6-(carboxylatomethyl)-2,5-dioxopiperazine anions. There are inter-anionic hydrogen bonds only between the imino groups and the carbonyl oxygen atoms (O3, O4), featuring a pattern similar to that found for cytosine-guanosine contacts in DNA.

Study on the Behavior and Durability of Reinforced Concrete in Boric Acid Environment

2008 ◽  
Vol 400-402 ◽  
pp. 441-446 ◽  
Author(s):  
Xian Yu Jin ◽  
Nan Guo Jin ◽  
Ye Tian
Keyword(s):  
Reinforced Concrete ◽  
Acid Solution ◽  
Boric Acid ◽  
Diffraction Analysis ◽  
Boric Acid Solution ◽  
X Ray Diffraction ◽  
X Ray ◽  
Weight Losses ◽  
Steel Bars ◽  
Acid Environment

By method of artificial simulating acid environment to celebrating corrosion, the effects of boric acid on the physical properties and performance of reinforced concrete were investigated. The experimental study of concrete in nature and in various boric solutions (2000ppm, 8000ppm, 30000ppm) was carried out. The compressive strength, splitting tensile strength and elastic modulus of concrete were measured. The weight losses of steel bars and bond strength of reinforced concrete were calculated to analysis the influence of boric acid on reinforced bars. The ingredient change of concrete submerged in boric acid solution was studied with X-ray diffraction analysis. The experiments show that, in general, the mechanical strength of corrupted concrete increases with time. While comparing to the specimen curried in nature environment, the fundamental properties of concrete in boric acid solution decrease slightly. In this research, the influence of boric acid on the corrosion of the steel bars and the interacting between the concrete and the steel bars are insignificant. Three kinds of borides are detected in the X-ray diffraction analysis. It can be concluded from the research that boric acid will not generate apparent influence on the mechanics performance of concrete and steel bars. The same conclusion can be drawn on the bond properties between concrete and steel bars. Generally, corrosiveness of boric acid to reinforced concrete is quite weak.

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