Molecular‐thermodynamic approach to predict micellization, phase behavior and phase separation of micellar solutions. I. Application to nonionic surfactants

1990 ◽  
Vol 92 (6) ◽  
pp. 3710-3724 ◽  
Author(s):  
Sudhakar Puvvada ◽  
Daniel Blankschtein
Keyword(s):  
Phase Separation ◽  
Phase Behavior ◽  
Nonionic Surfactants ◽  
Thermodynamic Approach ◽  
Micellar Solutions

Molecular-Thermodynamic Approach to Predict Micellar Solution Properties

1989 ◽  
Vol 177 ◽  
Author(s):  
Daniel Blankschtein ◽  
Sudhakar Puvvada
Keyword(s):  
Phase Separation ◽  
Thermodynamic Properties ◽  
Micellar Solution ◽  
Thermodynamic Approach ◽  
Solution Properties ◽  
Micellar Solutions ◽  
Detailed Exposition ◽  
Conceptual Overview

IntroductionIn this paper we present a conceptual overview of our recently developed molecular-thermodynamic approach to predict micellization, thermodynamic properties, and phase separation of micellar solutions. A detailed exposition may be found in Ref..

The Effect of Several Polymers on the Phase Behavior of Micellar Fluids

1982 ◽  
Vol 22 (06) ◽  
pp. 816-830 ◽  
Author(s):  
Gary A. Pope ◽  
Kerming Tsaur ◽  
Robert S. Schechter ◽  
Ben Wang
Keyword(s):  
Phase Behavior ◽  
Nonionic Surfactants ◽  
Polymer Concentration ◽  
Salinity Range ◽  
Lower Phase ◽  
Optimal Salinity ◽  
Rich Phase ◽  
Three Phase ◽  
Phase Systems ◽  
Increasing Temperature

Abstract We made static measurements of the phase volumes of mixtures of surfactant, polymer, alcohol, water, oil, sodium chloride, and in some cases polymer additives. We also made a limited number of viscosity, phase concentration, and interfacial tension (IFT) measurements. The purpose was to determine systematically the effect of various polymers on the phase behavior of various surfactant formulations. We made measurements with and without oil (n-octane and n-octane/benzene mixtures) across a range of salinity appropriate to the particular surfactant at temperatures between 24 and 75 degrees C. Introduction The oil-free (i.e., no added oil) solutions showed a characteristic phase separation into an aqueous surfactant-rich phase and an aqueous polymer-rich phase at some sufficiently high salinity (NaCl concentration), which we call the critical electrolyte concentration (CEC). The CEC was found to be a characteristic of a given surfactant/alcohol combination that shifts with the solubility of the surfactant qualitatively the same way as does the optimal salinity: but the CEC was found independent of the polymer type, polymer concentration (between the 100- and 1,000-ppm limits investigated), and surfactant concentration. The CEC increases with increasing temperature for the anionic surfactants and decreases with increasing temperature for the nonionic surfactants. When oil was added to the mixtures, an entirely different pattern of phase behavior was observed. As salinity increases, the particular formulations form the typical sequence of lower-phase microemulsion and excess oil, middle-phase microemulsion. excess oil, and excess brine: and upper-phase microemulsion and excess brine. The sequence with polymer was precisely the same over most of the salinity range but deviated over a limited range of salinity; the three-phase region simply shifted a small distance to the left on the salinity scale. Also, and probably more significantly, some of the aqueous phases in the critical region of the shift (which is also just above oil-free CEC salinity) were found to be gel-like in nature. These apparently occur under conditions such that the polymer concentration in the excess brine of the three-phase systems becomes very high because almost all the polymer is always in the brine phase, even when the brine phase is very small. Thus an overall 1,000 ppm of polymer easily can be concentrated to 10,000 ppm or more. One of the most remarkable aspects of the phase behavior of the surfactant/polymer systems is that the same patterns are observed for all combinations of anionic and nonionic surfactants and polymers. Also, little difference was observed in the IFT values with and without polymer. The three-phase systems still exhibited ultralow IFT values. Obviously, significant differences did occur in the brine viscosities when polymer was added. The polymer-free mixtures were themselves quite viscous, however, and the viscosity of the oil-free surfactant-rich phases (above the CEC) was significantly higher when the phases were in equilibrium with a polymer-rich aqueous phase, even though they apparently contained almost no polymer. We found that the polymer-rich phases had normal viscosities, as judged by the same polymer in the same brine at the expected concentration, assuming all the polymer was in the polymer-rich phase. The effect of polymer on the systems with oil was to increase the viscosity of the water-rich phase only, with little effect on the microemulsion phase unless it was the water-rich phase. SPEJ P. 816^

scholarly journals Phase Behavior of Engkabang Fat with Nonionic Surfactants

2009 ◽  
Vol 46 (4) ◽  
pp. 195-198 ◽  
Author(s):  
S. S. A. Gani ◽  
M. Basri ◽  
M. B. A. Rahman ◽  
A. Kassim ◽  
A. B. Salleh ◽  
...  
Keyword(s):  
Phase Behavior ◽  
Nonionic Surfactants

Producing PVP Nanofibers by Electrospinning in N2

2012 ◽  
Vol 560-561 ◽  
pp. 701-708 ◽  
Author(s):  
Lu Li ◽  
Jie Xu ◽  
Tao Fang ◽  
Jin Geng ◽  
Detlef Freitag ◽  
...  
Keyword(s):  
Mass Transfer ◽  
Phase Equilibrium ◽  
Phase Separation ◽  
Phase Behavior ◽  
Polymer Solution ◽  
Aspen Plus ◽  
Good Choice ◽  
The Other ◽  
Binary Phase ◽  
Novel Method

Electrospinning combined with nonsolvent-induced phase separation is a simple and novel method to produce porous nanofibers. In the study, Poly (vinylpyrrolidone) (PVP) nanofibers were fabricated using an electrospinning approach complemented by compressed nitrogen (N). N2 was used as the nonsolvent of choice. Besides, the tun2ning of N2 pressure and temperature can impact the nanofibers’ morphologies by altering phase behavior and mass transfer. Also, the other parameters affecting electrospinning of polymer solution were discussed. The results were demonstrated by extending the technique to PVP/dichloromethane (DCM) and PVP/ethanol (EtOH) systems. And the binary phase equilibrium of solvents (dichloromethane or ethanol) and N simulated by ASPEN PLUS 2006 demonstrates that N is not a 2good choice for producing hollow or po2rous polymer nanofibers.

Solubilization of Dodecane, Tetrachloroethylene, and 1,2-Dichlorobenzene in Micellar Solutions of Ethoxylated Nonionic Surfactants

1997 ◽  
Vol 31 (5) ◽  
pp. 1382-1389 ◽  
Author(s):  
Kurt D. Pennell ◽  
Andrew M. Adinolfi ◽  
Linda M. Abriola ◽  
Mamadou S. Diallo
Keyword(s):  
Nonionic Surfactants ◽  
Micellar Solutions
Sign in / Sign up

Export Citation Format

Share Document