Solubility of Some Mineral Salts in Polyethylene Glycol and Related Surfactants

Abstract

The ambient solubility of the mineral salts NaCl, KCl, CsCl, KBr, K2SO4 and CuSO4 is reported as a function of composition of mixed binary solvents consisting of water with polyethylene glycol (PEG 200), ethoxylated C9–11 alcohols (C10E6) and ethoxylated, or propoxylated C10–12 alcohols (C11E6P1). Solubility gradually decreases with decreasing water content and follows the order PEG 200 > C10E6 > C11E6P1. Solubility of CsCl and KBr was found to be surprisingly high in neat PEG 200, on the order of 1 mol kg−1, and in neat C10E6, on the order of 0.1 mol · kg−1. The observed solubility trends are explained by the theory of hard and soft acids and bases under the consideration of the polarity of the surfactants.

Densities, Viscosities, and Self-Diffusion Coefficients of Ethylene Glycol Oligomers

“…Early works have been reviewed in 2005. , Since then, much progress has been made. Especially, one-pot synthesis type reactions, where many different components react in one step, have been successfully carried out in PEG due to its ability to dissolve a wide range of compounds. − In fact, PEG can also dissolve mineral salts, , a contributing factor for its successful use as the reaction medium for the synthesis of metal–organic frameworks . Pd-catalyzed reactions (the importance of these can be seen in the 2010 Nobel prize award for their discovery) have also been carried out in PEG under both homocatalytic and heterocatalytic conditions where Pd is immobilized onto a porous silica material. − PEGs have also been successfully used as components in deep eutectic solvents. − Despite all of these successes, there are only limited experimental and theoretical studies on the dynamics of neat PEG. − Experimental physicochemical properties of PEGs are needed to further this effort.…”

“…Especially, one-pot synthesis type reactions, where many different components react in one step, have been successfully carried out in PEG due to its ability to dissolve a wide range of compounds. 7−11 In fact, PEG can also dissolve mineral salts, 5,12 a contributing factor for its successful use as the reaction medium for the synthesis of metal−organic frameworks. 13 Pdcatalyzed reactions (the importance of these can be seen in the 2010 Nobel prize award for their discovery 14 ) have also been carried out in PEG under both homocatalytic and heterocatalytic conditions where Pd is immobilized onto a porous silica material.…”

Direct and Indirect Dynamic Nuclear Polarization Transfer Observed in Mesoporous Materials Impregnated with Nonionic Surfactant Solutions of Polar Polarizing Agents

“…Each mesoporous material was impregnated with four different solutions, representing varying combinations of two different biradical polarization sources in two different polydisperse surfactant solvents shown and defined in Scheme c. These surfactants are of interest as green solvents due to their environmentally benign properties. ,− 13 C MAS spectra were recorded for each of the total of eight different combinations of the mesoporous material, polarization source, and surfactant solvent at two different DNP buildup times, 8 and 50 s. Additional DSC measurements were undertaken to inspect whether the surfactant solutions were indeed confined into the pores. The potential impact of our presented findings for surface studies by ssNMR is discussed.…”

Foam Silica Films Synthesized by Calcium Chloride-Assisted Emulsification

“…This analysis can explain why both polymers are able to stabilize the emulsion. Indeed, PEG-400 is known as a hydrophilic polymer, but it can present a “surfactant-like” behavior because it decreases the surface tension of water. − These observations may also explain the observed differences in the obtained porous structures and how a conventional surfactant like F-127 can stabilize small droplets longer, thus delaying the coalescence, while PEG-400 has a weaker ability to stabilize droplets. Contact angle measurements (on the PTFE substrate) were also performed with water.…”

“…Indeed, the PEG-400 is known as an hydrophilic polymer but it can display a "surfactant-like" behavior as it decreases the surface tension of water. [40][41][42][43][44][45][46][47][48] These observations may also explain the differences observed in the obtained porous structures, and how a classical surfactant like F-127 can stabilize for a longer time smaller droplets, delaying the coalescence, while the PEG-400 has a weaker ability to stabilize the droplets. Contact angles measurements (on PTFE substrate) have also been done using water.…”