Kinetics of formation of fluorescent products from hexanal andl-lysine in a two-phase system

Lipids ◽  
1996 ◽  
Vol 31 (11) ◽  
pp. 1125-1132 ◽  
Author(s):  
Henrik Stapelfeldt ◽  
Leif H. Skibsted
Keyword(s):  
Phase System ◽  
Two Phase ◽  
Kinetics Of Formation ◽  
Fluorescent Products ◽  
Kinetics Of

Interphase distribution of 2-furylethylenes

1985 ◽  
Vol 50 (8) ◽  
pp. 1642-1647 ◽  
Author(s):  
Štefan Baláž ◽  
Anton Kuchár ◽  
Ernest Šturdík ◽  
Michal Rosenberg ◽  
Ladislav Štibrányi ◽  
...  
Keyword(s):  
Partition Coefficient ◽  
Partition Coefficients ◽  
Transport Rate ◽  
Phase System ◽  
Two Phase ◽  
Interphase Distribution ◽  
Distribution Kinetics ◽  
System 1 ◽  
Kinetics Of

The distribution kinetics of 35 2-furylethylene derivatives in two-phase system 1-octanol-water was investigated. The transport rate parameters in direction water-1-octanol (l1) and backwards (l2) are partition coefficient P = l1/l2 dependent according to equations l1 = logP - log(βP + 1) + const., l2 = -log(βP + 1) + const., const. = -5.600, β = 0.261. Importance of this finding for assesment of distribution of compounds under investigation in biosystems and also the suitability of the presented method for determination of partition coefficients are discussed.

scholarly journals A stepwise mechanism for aqueous two-phase system formation in concentrated antibody solutions

2019 ◽  
Vol 116 (32) ◽  
pp. 15784-15791 ◽  
Author(s):  
Bradley A. Rogers ◽  
Kelvin B. Rembert ◽  
Matthew F. Poyton ◽  
Halil I. Okur ◽  
Amanda R. Kale ◽  
...  
Keyword(s):  
Activation Energy ◽  
Phase Separation ◽  
Temperature Gradient ◽  
Apparent Activation Energy ◽  
Droplet Growth ◽  
Phase System ◽  
Two Phase ◽  
Aqueous Two Phase System ◽  
Kinetics Of ◽  
Spinodal Region

Aqueous two-phase system (ATPS) formation is the macroscopic completion of liquid–liquid phase separation (LLPS), a process by which aqueous solutions demix into 2 distinct phases. We report the temperature-dependent kinetics of ATPS formation for solutions containing a monoclonal antibody and polyethylene glycol. Measurements are made by capturing dark-field images of protein-rich droplet suspensions as a function of time along a linear temperature gradient. The rate constants for ATPS formation fall into 3 kinetically distinct categories that are directly visualized along the temperature gradient. In the metastable region, just below the phase separation temperature, Tph, ATPS formation is slow and has a large negative apparent activation energy. By contrast, ATPS formation proceeds more rapidly in the spinodal region, below the metastable temperature, Tmeta, and a small positive apparent activation energy is observed. These region-specific apparent activation energies suggest that ATPS formation involves 2 steps with opposite temperature dependencies. Droplet growth is the first step, which accelerates with decreasing temperature as the solution becomes increasingly supersaturated. The second step, however, involves droplet coalescence and is proportional to temperature. It becomes the rate-limiting step in the spinodal region. At even colder temperatures, below a gelation temperature, Tgel, the proteins assemble into a kinetically trapped gel state that arrests ATPS formation. The kinetics of ATPS formation near Tgel is associated with a remarkably fragile solid-like gel structure, which can form below either the metastable or the spinodal region of the phase diagram.

Dynamics of gas release during thermal oxidation of TBP solutions in Isopar-M in two-phase system

MRS Advances ◽  
2018 ◽  
Vol 3 (21) ◽  
pp. 1181-1190
Author(s):  
Elena V. Belova ◽  
Zayana V. Dzhivanova ◽  
Boris F. Myasoedov ◽  
Sergey V. Stefanovsky
Keyword(s):  
Thermal Oxidation ◽  
Electron Accelerator ◽  
Phase System ◽  
Phase Extraction ◽  
Gas Release ◽  
Gas Emission ◽  
Two Phase ◽  
Phase Systems ◽  
Kinetics Of ◽  
Autocatalytic Oxidation

ABSTRACTThe dynamics of the gas release at thermal oxidation of the two-phase systems of 30% solution of tri-n-butyl phosphate (TBP) in isoparaffinic diluent Isopar M – aqueous solution of 4.3, 8.2 and 12 mol/L of HNO3 has been investigated within the temperature range from 70°C to 110°C. The effect of pre-irradiation of the system TBP–Isopar-M–HNO3 on the kinetics of its thermolysis has been determined. All of the samples were irradiated with an electron accelerator at a dose rate of 10 kGy/h up to integrated doses of 0.5, 1 and 2 MGy. The parameters of heat and gas emission during thermolysis of the tested extraction system in an open apparatus have been determined experimentally. It has been demonstrated, that there are no conditions for extension of autocatalytic oxidation under heat treatment of two-phase extraction systems in open vessels.

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