Uncatalysed oscillatory chemical reactions. Oxidation of 1,4-cyclohexanedione by bromate in perchloric or orthophosphoric acid solution

Abstract The optimal parameters of the anodic oxidation of aluminium in orthophosphoric acid solution was determined. In the pores of the obtained Al2O3 membranes with the ordered nanometric structure Co-Fe alloys were electrodeposited. The Al2O3 membranes were obtained in the two-stage anodic oxidation of aluminium in the 0.17 M H3PO4 solution in the temperature 1°C and at the electrolysis voltage 180 V. The influence of the anodizing process parameters on the thickness of oxide films and the diameter of pores and the distance between them in the alumina membranes were determined. The electrodeposition of Co-Fe alloys was carried out from sulphate baths containing sulphates (VI) of copper (II) and cobalt (II) of different composition, in potentiostatic conditions. The optimal electrolysis conditions were determined, where the cathodic deposits of the best quality were obtained. The conditions are: the electrolyte composition: 0.3 M Fe; 0.5 M Co; pH = 3, the potential: -0.760 V (vs. SHE1)).

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The Mechanical Properties and Microstructures of Cement Formed from Pyrophosphoric and Orthophosphoric Acids

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.284-286.125 ◽

2005 ◽

Vol 284-286 ◽

pp. 125-128 ◽

Cited By ~ 1

Author(s):

Liam M. Grover ◽

Uwe Gbureck ◽

David Farrar ◽

J.E. Barralet

Keyword(s):

Mechanical Properties ◽

Acid Solution ◽

Tricalcium Phosphate ◽

Orthophosphoric Acid ◽

Marked Change ◽

Solution Set ◽

Liquid Ratio ◽

Setting Times ◽

Pyrophosphoric Acid ◽

Orthophosphoric Acid Solution

In this study the setting times, compressive strengths and microstructures of cements formed using pyrophosphoric acid solution and b-tricalcium phosphate (β-TCP; Ca3(PO4)2) were compared with those of cement formed using orthophosphoric acid solution and b-TCP. It was found that cement formed using pyrophosphoric acid solution set more slowly than that formed using orthophosphoric acid and could be mixed to a higher powder to liquid ratio, facilitating the production of cement exhibiting compressive strengths, without pre-compaction, as high as 25 MPa. The use of pyrophosphoric acid as opposed to orthophosphoric acid resulted in a marked change in the microstructure of the cement.

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The growth mechanism of ordered nanoporous alumina

MATEC Web of Conferences ◽

10.1051/matecconf/202031506002 ◽

2020 ◽

Vol 315 ◽

pp. 06002

Author(s):

Marat Makhmud-Akhunov ◽

Artem Adamovich ◽

Igor Yavtushenko

Keyword(s):

Atomic Force Microscopy ◽

Acid Solution ◽

Orthophosphoric Acid ◽

Porous Alumina ◽

Force Microscopy ◽

Atomic Force ◽

Constant Potential ◽

Microscopy Data ◽

Electrochemical Anodic Oxidation ◽

Orthophosphoric Acid Solution

The paper scrutinizes the peculiarities of porous alumina growth during electrochemical anodic oxidation in the orthophosphoric acid solution at constant potential of 100 Volt. On the basis of atomic-force microscopy data the paper presents consecutive stages of ordering pores in the oxide with the formation of hexagonal dense package after two-stage anodic treatment.

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