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Title: Concentration Dependent Speciation and Mass Transport Properties of Switchable Polarity Solvents

Tertiary amine switchable polarity solvents (SPS) consisting of predominantly water, tertiary amine, and tertiary ammonium and bicarbonate ions were produced at various concentrations for three different amines: N,N-dimethylcyclohexylamine, N,N-dimethyloctylamine, and 1 cyclohexylpiperidine. For all concentrations, physical properties were measured including viscosity, molecular diffusion coefficients, freezing point depression, and density. Based on these measurements a variation on the Mark Houwink equation was developed to predict the viscosity of any tertiary amine SPS as a function of concentration using the amine’s molecular mass. The observed physical properties allowed the identification of solution state speciation of non-osmotic SPS, where the amine to carbonic acid ratio is significantly greater than one. These results indicate that at most concentrations the stoichiometric excess amine is involved in solvating a proton with two amines. The physical properties of osmotic SPS have consistent concentration dependence behavior over a wide range of concentrations; this consistence suggests osmotic pressures based on low concentrations freezing point studies can be reliably extrapolated to higher concentrations.
Authors:
;
Publication Date:
OSTI Identifier:
1177611
Report Number(s):
INL/JOU-14-32773
Journal ID: ISSN 2046--2069
DOE Contract Number:
DE-AC07-05ID14517
Resource Type:
Journal Article
Resource Relation:
Journal Name: RSC Advances; Journal Volume: 5; Journal Issue: 10
Research Org:
Idaho National Laboratory (INL)
Sponsoring Org:
USDOE
Country of Publication:
United States
Language:
English
Subject:
03 NATURAL GAS; 04 OIL SHALES AND TAR SANDS; 37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY Switchable Polarity Solvent; Water Treatment