Kinetics of enzymatic cetyl palmitate production by esterification with fermented solid of Burkholderia contaminans in the presence of organic solvent

Author(s):  
Maynara Lurriele de Alcântara Santos ◽  
Evelyn Albini ◽  
Marcos Lúcio Corazza ◽  
Nadia Krieger ◽  
Fernando Augusto Pedersen Voll
2010 ◽  
Vol 101 (15) ◽  
pp. 5737-5742 ◽  
Author(s):  
Wei Li ◽  
Wei Du ◽  
Qiang Li ◽  
Ren-wang Li ◽  
Dehua Liu

2018 ◽  
Vol 7 (2) ◽  
pp. 64-66
Author(s):  
Ujvala P. Christian ◽  
Shrikant J. Wagh

Interfacial polycondensation (IP) is one of the most important step polymerization technique used for synthesis of polyurea microcapsules. IP reaction between diamine and diisocyanate monomers which are soluble in aqueous phase and organic phase respectively is very fast therefore the overall process of polyurea synthesis via interfacial polycondensation, by and large, mass transfer controlled reaction. Selection of proper organic solvent is one of the important parameter for IP reactions. The objective of this experimental work was to study the effect of n-Octane and Cyclohexane as an organic solvent on kinetics of polyurea microcapsules synthesized by interfacial polycondensation reaction. In this reaction system IP reaction occurs on organic side of the interface so reaction rate increased with increase in relative polarity of organic solvent. Characterization of polyurea was carried out by XRD and DSC which demonstrated that semi crystalline polyurea microcapsules with good thermal stability were synthesized.


1995 ◽  
Vol 72 (11) ◽  
pp. 1333-1337 ◽  
Author(s):  
Wakako Tsuzuki ◽  
Kazuaki Akasaka ◽  
Shoichi Kobayashi ◽  
Tateo Suzuki

2006 ◽  
Vol 76 (1) ◽  
pp. 45-47
Author(s):  
L. V. Kuritsyn ◽  
A. I. Sadovnikov ◽  
L. N. Khripkova ◽  
N. V. Kalinina ◽  
Yu. S. Shcherbakova

1974 ◽  
Vol 27 (7) ◽  
pp. 1423 ◽  
Author(s):  
DG Oakenfull

With the general aim of elucidating the role of water structure in the kinetics of hydrolysis, a comparative study has been made of the kinetics of the hydrolysis of acetic anhydride and the reaction of 4-nitrophenyl acetate with imidazole in mixtures of water with ethanol, t-butyl alcohol, dimethyl sulphoxide and dioxan. Both rate constants were always reduced by the addition of organic solvent. Transition state activity coefficients were measured for both reactions in dimethyl sulphoxide-water mixtures and compared with the activity coefficient of phenylalanine (a model zwitterionic transition state). Activation parameters were measured for the hydrolysis of aceticanhydride in t-butyl alcohol-water and dimethyl sulphoxide-water mixtures. Semilogarithmic plots of rate constant against Winstein's Y-value were non-linear for some of the solvents and this fact, coupled with the effect of dimethyl sulphoxide on the transition state activity coefficients, leads to the conclusion that specific interactions of the solvent with the reactants and with the transition state could be of major importance in controlling the reaction rate.There was no obvious relationship between the effect of an organic solvent on the kinetics of hydrolysis of acetic anhydride and its effect on the structure of water.


1978 ◽  
Vol 33 (1) ◽  
pp. 30-34
Author(s):  
I. M. Issa ◽  
E . M. Diefallah ◽  
M. R. Mahmoud ◽  
A. M. El-Nady

Abstract Alkaline Solvolysis, Trichloroacetate Ion The alkaline solvolysis of trichloroacetic acid in water-ethanol mixtures have been studied in the presence of 0.40-0.80 M sodium hydroxide within the temperature range 35-70 °C. The rate constant increased with progressive addition of the organic solvent. The dielectric constant effect on the reaction rate was investigated. The radius of the activated complex at different temperatures was calculated. The isocomposition and isodielectric energies as well as the thermodynamic parameters of activation were calculated and their significance in terms of solvent composition has been discussed. It was concluded that the reactant state is extensively higher solvated than the transition state by the highly polar (water) solvent.


2016 ◽  
Vol 17 (2) ◽  
pp. 247-250
Author(s):  
E.E. Hvozdiyevskyy ◽  
Z.F. Tomashik ◽  
V.M. Tomashyk ◽  
R.O. Denysyuk

The method of disk rotating kinetics of dissolution processes CdTe, ZnxCd1-xTe and Cd0,2Hg0,8Te in yodvydilyayuchyh etching compositions HNO3-NO-lactate acid. The dependence of etching rate of said material concentration oxidizer and organic solvent. Optimized polishing compositions herbalists and modes chemical dynamic polishing of semiconductor materials studied. The influence of Zn and Hg content in the composition of solid solutions on the quality of the resulting surface etching mixtures.


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