Miscibility

About: Miscibility is a research topic. Over the lifetime, 5521 publications have been published within this topic receiving 133547 citations. The topic is also known as: miscible.

Fluorocarbon‐hydrocarbon interactions in interfacial and micellar systems

Abstract: The interactions of fluorocarbons and hydrocarbons in liquid mixtures are known to be highly nonideal. Recent research has indicated that the unusual characteristics of such interactions have a significant influence on the behavior of many interfacial and micellar systems in which such interactions occur. Results from several different studies are presented. These involve (a) properties of partially fluorinated surfactants and lipids, including comments on the use of fluorine substituted groups as spectroscopic probes; (b) surface tensions of nonideal mixtures of liquid fluorocarbons and hydrocarbons and their interfacial tensions against water; (c) adsorptions of fluorocarbon and hydrocarbon surfactants to air/water, hexane/water, and perfluorohexane/water interfaces and a comparison of relative affinities; (d) formation of mixed micelles of fluorocarbon and hydrocarbon surfactants and evidence of partial miscibility of micelles; (e) comparison of adsorption of fluorocarbon and hydrocarbon surfactants to graphon; and (f) comparison of wetting of hydrocarbon-like solids by aqueous solutions of fluorocarbon and hydrocarbon surfactants.

Interactions in SMA‐SAN blends

Abstract: Styrene/maleic anhydride (SMA) and styrene/acrylonitrile (SAN) copolymers have previously been shown to form miscible blends when the MA and AN contents do not differ too greatly. It is shown here that this is the result of a weak exothermic interaction between the MA and AN units by measuring the heats of mixing for appropriate liquid analogs of the various monomer units. The region of copolymer compositions for miscibility of SMA-SAN blends is predicted from the Sanchez-Lacombe mixture theory using net interaction parameters calculated from the analog calorimetry results via a simple binary interaction model for copolymers. Lower critical solution temperature behavior was observed for blends of copolymers having compositions near the edge of the miscibility region. Various glass transition, volumetric, and FTIR results are discussed in terms of the interactions observed.

Influence of monomer molecular structure on the miscibility of polymer blends

Abstract: Polymer blends are formulated by mixing polymers with different chemical structures to create new material with beneficial properties of the individual components. While Flory-Huggins (FH) theory explains some basic trends in blend miscibility, the theory completely neglects the dissimilarity in monomer structures that is central to the fabrication of real blends. We systematically investigate the influence of monomer structure on blend miscibility using the lattice cluster theory (LCT) generalization of the FH model in the limit of incompressible, high molecular weight blends where analytical calculations are tractable. The well-known miscibility pattern predicted by FH theory is recovered only for a limited range of monomer size and shape asymmetries, but additional contributions to the LCT entropy and internal energy of mixing for polymers with dissimilarly shaped monomers leads to three additional blend miscibility classes whose behavior is quite different from the prediction of classical FH theory. Several illustrative applications of the LCT provide new molecular-scale interpretations for many nontrivial phenomena occurring in polymer systems. The applications also illustrate the predictive ability of the theory and its usefulness in analyzing thermodynamic data for a wide variety of polymer mixtures, ranging from binary homopolymer blends to various types of copolymer systems.