REACTION KINETICS SELF-PROPOGATION REGIME DURING PRE-IGNITION PERIOD
Journal Title: Вісник Одеського національного університету. Хімія - Year 2015, Vol 20, Issue 3
Abstract
Self-propagation high temperature synthesis (SHS) technological regulations application is mainly limited by transformation processes taking place in the pre-ignition period. Zn-S, Zn-Se, Ti-C and 3Ni-Al small sample systems ignition experimental study was carried out under heating conditions in inert atmosphere with temperature values T = 1200K.It was shown that at this temperature level a chemical reaction can be initiated, turning into a self-sustaining mode. Wherein the reaction limiting factors can be mass transfer processes. Ignition temperatures were determined and plotted via the samples size. A physical ignition model was developed assuming the pre-ignition period limiting reaction Arrhenius law.The inverse combustion problem solution made it possible to calculate the low-temperature (T = 800 ÷ 1200K) reaction kinetic constant values. Comparison thus obtained values with the known data of other researchers showed their good agreement.Activation energy values for the Zn-S system were used to calculate the heat wave propagation speed. This value appeared to coincide with experimental values.Obtained results analysis leads to the conclusion about the availability and justification for the proposed method of express-analysis of presupposed, but previously not studied SHS systems. The results thus obtained allow us to estimate conditions for the SHS technology implementation, the reactor characteristic sizes and the thermal wave’s propagation speed.
Authors and Affiliations
D. D. Polishchuk
SORPTION-SPECTROPHOTOMETRIC DETERMINATION OF Al (III), Ga (III), In (III) ВY USING DIMETHYLCHLOROSILANEAEROSILE, IMPREGNATING BY POLARITY SOLVENT
The sorption-spectrophotometric determination techniques (metodic) of Al (III), Ga (III), In (III) microquantities has been developed, including previouslyseparation of elements-analogs with the use of dimethylchlorosila...
SPECTROPHOTOMETRIC DETERMINATION OF ASCORBIC ACID USING 18-MOLYBDODIPHOSPHATE IN INTENSELY COLORED JUICES
A simple, selective and highly sensitive method is proposed for spectrophotometric determination of ascorbic acid in juices, which have their own intense coloration with the use of a 18-molybdodiphosphate heteropoly comp...
INFLUENCE ON LUMINESCENT PROPERTIES OF THE AGGREGATE STATE OF LANTHANIDE β-DIKETONATES
The complexes Eu3+ and Tb3+ with thienyl, phenyl and alkyl derivatives of acetylacetone with different chain length and the structure of the fl uorinated substituent (RF) were studied. In accordance with the triplet leve...
ORGANIC SOLVENTS EFFECT ON THE AL, GA, IN EXTRACTION FROM AQUEOUS SOLUTIONS BY ORGANOSILICAS
The adsorption properties of organosilicas – dimethylchlorsilaneaerosil (DMCSA), previously hydrophilized by organic molecules of the polar nature (ethanol, acetone) to wards to aqueous solutions of Al, Ga, In were studi...
ТHE RADICAL POLYMERIZATION OF METHYL METHACRYLATE IN THE PRESENCE OF MANGANESE (II) 5-METHYL-5-HEXEN-2,4-DIONATE
presence of unsaturated β-diketonate - manganese (II) 5-methyl-5-hexene-2,4-dionate (Mn(m d)2·2Н2О) were investigated. It is shown that the presence of vinyl fragments in ligand structure leads to a significant decrease...