Comparative analyses on isothermal kinetics of water evaporation and hydrogel dehydration by a novel nucleation kinetics model

The kinetics of the thermal decomposition of Huadian oil shale was studied at five different isothermal atmospheres of 623K, 648K, 673K, 698K, and 723K. The temperature recorded was that of the sample that the temperature error between furnace and sample will eliminate. According to conversion data, the effect of increased temperature is to decrease the pyrolysis time. The conversion data described the oil shale pyrolysis as two stages, rapid conversion and modest conversion. The Arrhenius equations of ki=1.40×105e-109828/RT and kii=1.76×106e-130463/RT were obtain by isothermal kinetics model for each stage.

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Comparison of the swelling kinetics of a partially neutralized poly(acrylic acid) hydrogel in distilled water and physiological solution

Journal of the Serbian Chemical Society ◽

10.2298/jsc0711139k ◽

2007 ◽

Vol 72 (11) ◽

pp. 1139-1153 ◽

Cited By ~ 17

Author(s):

Aleksandar Kostic ◽

Borivoj Adnadjevic ◽

Aleksandar Popovic ◽

Jelena Jovanovic

Keyword(s):

Acrylic Acid ◽

Physiological Solution ◽

Kinetics Model ◽

Isothermal Kinetics ◽

Swelling Kinetics ◽

Distilled Water ◽

Equilibrium Degree ◽

Swelling Rate ◽

Kinetics Of ◽

Poly Acrylic Acid

The isothermal kinetics curves of the swelling of a poly(acrylic acid) hydrogel in distilled water and physiological solution at temperatures ranging from 20 to 40 ?C were determined. The possibility of applying both the Fick?s kinetics model and kinetics model of the first order chemical reaction to the swelling kinetics of the PAA hydrogel in distilled water and physiological solution were examined. It was found that the possibilities of applying these models were limited. The new model of the kinetics of swelling in distilled water and physiological solution was established. The kinetic parameters (Ea, ln A) for the swelling in distilled water and physiological solution were determined. The decrease of the equilibrium degree of swelling and the saturation swelling rate of the swelling of the PAA hydrogel in physiological solution compared to swelling in distilled water could be explained by the decreased differences in the ionic osmotic pressures between the hydrogel and the swelling medium. The increase of the initial swelling rate in the physiological solution might be caused by an increased density of charges at the network and by an increased affinity of the network towards the water molecules. The increase of the activation energy of the swelling of the PAA hydrogel in the physiological solution is a consequence of its additional "ionic crosslinking".

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The Effect of Methacrylic Acid and Maleic Acid on the Isothermal Kinetics of Acrylic Acid Crosslinking Co-polymerization under Conventional and Microwave Heating

Non-Metallic Material Science ◽

10.30564/omms.v1i2.692 ◽

2019 ◽

Vol 1 (2) ◽

Author(s):

Jelena Dragoslav Jovanovic ◽

Borivoj Adnadjevic

Keyword(s):

Acrylic Acid ◽

Kinetic Parameters ◽

Microwave Heating ◽

Methacrylic Acid ◽

Maleic Acid ◽

Kinetics Model ◽

Conventional Heating ◽

Isothermal Kinetics ◽

Synthesis Process ◽

Kinetics Of

The kinetics of free-radical crosslinking co-polymerization (FRCCP) of acrylic acid (AA) with both methacrylic acid (MA) (PAMA hydrogel ) and maleic acid (MAL) (PAMAL hydrogel) was investigated under the conditions of isothermal conventional heating (CH) and under the conditions of microwave heating (MWH) with controlled cooling. The kinetics curves of FRCCP of PAMA and PAMAL hydrogels under the conditions of CH are described with the kinetics model of second order chemical reaction, whereas the kinetics curves under the conditions of CH are described with the kinetics model of Polany-Winger. It is proved that MWH leads to the changes in the rate of FRCCP and to the changes in the values of the kinetic parameters (activation energy (Ea) and pre-exponential factor (lnA). It was found the existence of relationship between the values of the kinetic parameters calculated for MWH and CH for PAMA and PAMAL hydrogel synthesis process, which is well-known as compensation effect. The effect of MWH on the kinetics of FRCCP for PAMA and PAMAL hydrogel formation were explained by applying the model of activation by selective energy transfer (SET). The changes in kinetics model, rate of FRCCP and kinetics parameters, caused with the MWH can found wide application in designing novel technologies for obtaining polymers and for synthesis of polymers with novel physico-chemical properties. The suggested mechanism of activation for polymerisation under the conditions of MWH also enables development of novel reaction systems and technologies for polymers productions.

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Kinetics of Water Evaporation from Emulsions

Heat Transfer Research ◽

10.1615/heattransres.v36.i5.100 ◽

2005 ◽

Vol 36 (5) ◽

pp. 425-430 ◽

Cited By ~ 3

Author(s):

A. M. Pavlenko ◽

B. I. Basok

Keyword(s):

Water Evaporation ◽

Kinetics Of

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Non-isothermal Kinetics of Free Radical Polymerization of 2-Phenylethyl (Meth)acrylate

Journal of Chemistry and Chemical Sciences ◽

10.29055/jccs/643 ◽

2018 ◽

Vol 8 (3) ◽

pp. 585-594

Author(s):

Khdbudin Mulani ◽

Ravindra Ghorpade ◽

Surendra Ponrathnam ◽

Nayaku Chavan ◽

Kamini Donde

Keyword(s):

Free Radical ◽

Radical Polymerization ◽

Free Radical Polymerization ◽

Isothermal Kinetics ◽

Kinetics Of

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Isobaric and isothermal kinetics of gelatinization of waxy maize starch

Journal of Food Engineering ◽

10.1016/j.jfoodeng.2007.02.056 ◽

2007 ◽

Vol 82 (4) ◽

pp. 443-449 ◽

Cited By ~ 11

Author(s):

Shyam S. Sablani ◽

S. Kasapis ◽

Z.H. Al-Tarqe ◽

I. Al-Marhubi ◽

M. Al-Khuseibi ◽

...

Keyword(s):

Isothermal Kinetics ◽

Maize Starch ◽

Waxy Maize ◽

Kinetics Of

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The application of an automated crystallization cell used to study the nucleation kinetics of potash alum

Journal of Materials Science Letters ◽

10.1007/bf00517597 ◽

1993 ◽

Vol 12 (22) ◽

pp. 1741-1744 ◽

Cited By ~ 4

Author(s):

P. Meenan ◽

K. J. Roberts

Keyword(s):

Nucleation Kinetics ◽

Kinetics Of

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Isothermal and non-isothermal kinetics of hydrolysis of 1-[2-(2- pentyloxyphenylcarbamoyloxy)-(2-methoxymethyl)-ethyl]- perhydroazepinium chloride (BK 129)

Acta Facultatis Pharmaceuticae Universitatis Comenianae ◽

10.2478/afpuc-2013-0018 ◽

2013 ◽

Vol 60 (2) ◽

pp. 43-48

Author(s):

Stankovičová M. ◽

Bezáková Ž. ◽

Beňo P. ◽

Húšťavová P.

Keyword(s):

Biological Activity ◽

Alkaline Hydrolysis ◽

Functional Group ◽

Isothermal Kinetics ◽

Basic Part ◽

Buffer Solutions ◽

Kinetics Of Hydrolysis ◽

Short Time ◽

Kinetics Of ◽

Hydrolysis Of

Abstract The substance BK 129 - 1-[2-(2-pentyloxyphenylcarbamoyloxy)-(2-methoxymethyl)-ethyl]-perhydroazepinium chloride was prepared in terms of influence of the connecting chain between the carbamate functional group and the basic part of molecule on biological activity. Such a structural feature is important with regard to its stability. In this work we determined the rate constants of alkaline hydrolysis of this compound at increased temperature under isothermal and non-isothermal conditions. The hydrolysis was also performed in buffer solutions with the purpose of evaluating its stability. Non-isothermal tests of stability enable to reduce the number of analyses. The necessary data for stability of compound are in this way achieved in a short time.

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