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Composition of Fracking Water
Published in Frank R. Spellman, Hydraulic Fracturing Wastewater, 2017
Substances that are miscible are capable of being mixed in all proportions. Simply, when two or more substances disperse themselves uniformly in all proportions when brought into contact, they are said to be completely soluble in one another, or completely miscible. The precise chemistry definition is a “homogeneous molecular dispersion of two or more substances” (Jost, 1992). Examples include the following observations: All gases are completely miscible.Water and alcohol are completely miscible.Water and mercury (in its liquid form) are immiscible liquids.
Ignitable and Explosive Atmospheric Hazards
Published in Neil McManus, Safety and Health in Confined Spaces, 2018
Liquids occurring in mixtures may be completely miscible, partly miscible, or completely immiscible in each other. In an ideal solution containing completely miscible liquids, interactions between molecules of solute and solvent are the same as solute–solute and solvent–solvent interactions. Raoult’s law provides a basis for predicting vapor pressure of components of ideal solutions in equilibrium situations. According to Raoult’s law, the partial pressure of a vapor above a solution is equal to the product of the mole fraction of the liquid in the solution times the partial pressure of the pure liquid at the same temperature. Raoult’s law applies, for example, to solutions of volatile hydrocarbons such as butane and propane in a nonvolatile liquid, such as a hydrocarbon oil (Treybal 1980). Raoult’s law holds for a component that approaches 100% in solution. For mixtures where the mole fraction of the organic material in solution is 0.8 or more, Raoult’s law holds with an error of 7% or less, except in extremely unusual cases (Perry et al. 1984). Physical and chemical interactions between components of the mixture affect their individual vapor pressures. Most solutions are nonideal at some composition. In nonideal solutions, interactions between solute and solvent differ in magnitude from solvent–solvent and solute–solute interactions. This can result in greater or lesser vapor pressure for individual components than that predicted by Raoult’s law (Moore 1962). In the case of complete immiscibility, the vapor pressure of the mixture is the sum of the vapor pressures of each component. Partial miscibility produces complex relationships.
Compatibilization of Polymer Blends
Published in Nicholas P. Cheremisinoff, Elastomer Technology Handbook, 2020
For many years, the term “compatibility” was used in the literature as a synonym for “miscibility.” More recently, the terms have been differentiated by most authors. In this chapter, “compatibility” will refer to the state of an immiscible blend in which it provides a combination of properties and characteristics that make it more useful than the original mixture of polymers. “Compatibilization” will refer to the approach used to reach this state. “Miscible” will refer to a blend in which the components are mixed on the molecular level.
Morphology Evolution of Block Copolymer Blend Thin Films Induced by Solvent Vapor Annealing
Published in Soft Materials, 2021
Yang Cong, Wei Zhai, Changsong Wu
where VS is the molar volume of the solvent, R is the gas constant, T is the Kelvin temperature, δd for nonspecific dispersive, δp for specific polar, and δh for specific hydrogen bonding interactions between solvent and polymer. The solubility parameters of PS, P2VP, and THF are δPS = 18.6 (J/cm3)1/2, δP2VP = 20.5 (J/cm3)1/2 and δTHF = 19.41 (J/cm3)1/2.[28] Thus the χP-S values for PS-THF and P2VP-THF pairs in this study at room temperature can be calculated according to eq 1 as χPS-THF = 0.41 and χP2VP-THF = 0.13.[26] According to the Flory–Huggins theory criterion, the polymer and solvent are completely miscible over the entire composition range at χP-S < 0.5. Thus, THF is a good solvent for PS and P2VP blocks, and has a slightly preferential affinity to P2VP. The incompatible PS and P2VP blocks separate in THF solutions and self-assemble into spherical nanostructures.
The role of thermodynamics and kinetics in rubber–bitumen systems: a theoretical overview
Published in International Journal of Pavement Engineering, 2021
Haopeng Wang, Panos Apostolidis, Jiqing Zhu, Xueyan Liu, Athanasios Skarpas, Sandra Erkens
Several methods (Liu and Shi 2008), such as vapour pressure lowering, osmometry, light scattering and inverse gas chromatography, were proposed to estimate the value of . However, these tests are generally time-consuming and need cautious operations. With the help of solubility parameters, the interaction parameter can be rapidly estimated. The solubility parameter is a good indicator of solubility of a specific solvent. It is very useful to predict miscibility and compatibility of polymers. Liquids with similar solubility parameters will be miscible, and polymers will dissolve into solvents whose solubility parameters are close to their own (Rubinstein and Colby 2003). For non-polar, non-associating polymer–solvent system with species interacting mainly by dispersion forces, the interaction parameter can be estimated from the Hildebrand solubility parameters as (Hansen 2002)where is the molar volume of the solvent; and are the Hildebrand solubility parameters for the solvent and polymer, respectively; R is the universal gas constant; T is the absolute temperature; is the empirical constant. However, for complex polymer systems, the Hansen solubility parameters (HSP), which consider the non-polar/dispersion forces, the polar forces and hydrogen bonding forces, usually provides a better approximation. Previous studies have successfully applied the HSP to express the solubility and internal stability of bitumen (Redelius 2004). A similar equation to estimate the interaction parameter based on the HSP can be obtained (Hansen 2002)where , and are, respectively, the dispersive, polar and hydrogen bonding components of the HSP. Because polymers are not volatile, is often obtained through an indirect method in which polymers are mixed with a series of solvents of varying but known solubility parameters. The solubility parameter of the polymer is taken as the value of the solvent which enables the maximum extent of swelling (Redelius 2000, 2004). Comparing to the average solubility parameter values, the solubility body of a material in the three-dimensional Hansen space is more realistic and useful (Zhu et al.2019).