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The Relevance of Solubility and Miscibility for the Performance of Organic Solar Cells
Published in John R. Reynolds, Barry C. Thompson, Terje A. Skotheim, Conjugated Polymers, 2019
Stefan Langner, Jose Dario Perea Ospina, Chaohong Zhang, Ning Li, Christoph J. Brabec
The regular solution is a useful theory for the description and analysis of mixtures and solubilities of solvents, small molecules and polymers. In this regular solution model, the Hildebrand solubility parameter δT provides a good estimation of the degree of interaction between materials. δT is related to the cohesion energy density c, which is defined as the increase of internal energy per mole upon removal of the intermolecular interactions within a given volume, as shown in Equation (15.2): δT=c=ETV=ΔHv−RTV,
Scoping Process Development and Design
Published in David A. Palmer, Handbook of Applied Thermodynamics, 2019
The earliest success in predicting the properties of mixtures from those of the pure components was based on “regular solution theory”. Using “solubility parameters”, Scatchard and Hildebrand devised simple equations for activity coefficients. The solubility parameters are obtained when the square root of the energy of vaporization into a vacuum is divided by the molar volume. The equation is not presented here because it is primarily of historical interest. Reference 22 gives a discussion in succinct terms and shows that the theory can be used to fit the benzene + n-heptane system. Research continues on extensions of the idea which may bear fruit in the future.
The Behavior of Solutions
Published in David R. Gaskell, David E. Laughlin, Introduction to the Thermodynamics of Materials, 2017
A regular solution is one which has an ideal entropy of formation and a nonzero heat of formation from its pure components. The activity coefficients of the components of a regular binary solution are given by the expression
Binary micellar schemes of cationic gemini and conventional surfactants: chain length effect
Published in Journal of Dispersion Science and Technology, 2022
Smarling Suting, Tariq Ahmad Wagay, Anushmita Charingia, Hassan Askari
The experimental results were interpreted quantitatively using regular solution theory. The theory helps to evaluate the deviation from ideality, the nature of interaction among the surfactant components and the various other parameters. Adsorption and micellization of the mixed surfactant systems were analyzed with the help of Rosen’s and Rubingh’s models.[1,37,38] Rosen’s model was applied to understand the behavior of the mixtures at the interface.[1] Parameters like and were calculated using this model applying the equations, where and are the respective bulk mole fractions of conventional and gemini surfactants; is the mole fraction of conventional surfactant at the interface; and are respectively the concentrations of pure conventional surfactant, pure gemini surfactant and their mixtures for a fixed γ value just before cmc. is the molecular interaction parameter at the interface. For micellization Rubingh’s model was applied. Similarly, parameters (micellar mole fraction of gemini surfactant) and (micellar interaction parameter) were calculated using Equations (3) and (4) respectively where the concentration terms ( and ) were replaced by their respective cmc values. The ideal mole fraction of conventional surfactant in mixed micelles was calculated using Equation (5),