Competition between Intra- and Intermolecular Association of Chain Molecules with Water-like Solvent

Abstract

Fluid properties and phase behavior of systems such as glycol ethers, carboxylic acids, and proteins are affected by the competition between intra- and intermolecular hydrogen bonding. Here we study this competition by extending Wertheim's first-order thermodynamic perturbation theory to include intramolecular hydrogen bonding in chain molecules in the presence of an explicit water-like solvent. The theory derived here is found to be in good agreement with molecular simulation. It is shown that intramolecular association is most important for shorter chains at low temperature, low density, and high chain concentration. The theory is also extended into a density functional theory formalism to study the effect of intramolecular association on the structuring of the different segments of the molecules close to a hydrophobic surface. Intramolecular association is found to be enhanced close to the surface, with the total density of the system having the most effect on structuring close to the surface.

Competition of Intra- and Intermolecular Forces in Anthraquinone and Its Selected Derivatives

“…Our quest to shed more light onto self-assembly of molecules, and reveal how atoms and molecules form larger structures at nanoscale, requires detailed description of intra- and intermolecular forces. Especially interesting cases are those in which these types of forces compete, and the final outcome is a result of a delicate balance [ 9 , 10 , 11 , 12 , 13 ]. Herein, we present a study of anthraquinone derivatives in which diverse types of intermolecular forces are affected by intramolecular hydrogen bonding and substituent effects.…”

Measurement and Correlation of the Solubility of Sodium 2-Chlorotoluene-4-sulfonate in Selected Pure Solvents and Aqueous Organic Solutions

“…Also, each association structure model changed with the water content of alcohol–water mixtures and temperature. − Ethanol, methanol, and water used in our work are associated liquids whose molecules are held together by hydrogen bonds which can interact with each other. Probably the hydrogen bonds competition between like and unlike molecules is an important factor to determine the phase behavior. , …”

“…Probably the hydrogen bonds competition between like and unlike molecules is an important factor to determine the phase behavior. 28,29 Table 5 contains the parameters of the solubility product for CTSNa in different solvents, which is defined by eq 4. Table 6 represents the correlated E-NRTL model parameters.…”

Extensions of the SAFT model for complex association in the bulk and interface

“…In this section, we will focus on inhomogeneous systems with the presence of surfactants and the application of interfacial Statistical Associating Fluid Theory or iSAFT [25,68] for such systems. iSAFT has been applied to block copolymers [69,70], polymer brushes [71][72][73], associating molecules [74][75][76][77][78], and surfactants [79,80]. Here we consider micelle formation.…”