title: Switchable water: microfluidic investigation of liquid-liquid phase separation mediated by carbon dioxide.
abstract: Increase in the ionic strength of water that is mediated by the reaction of carbon dioxide (CO2) with nitrogenous bases is a promising approach toward phase separation in mixtures of water with organic solvents and potentially water purification. Conventional macroscale studies of this complicated process are challenging, due to its occurrence via several consecutive and concurrent steps, mass transfer limitation, and lack of control over gas-liquid interfaces. We report a new microfluidic strategy for fundamental studies of liquid-liquid phase separation mediated by CO2 as well as screening of the efficiency of nitrogenous agents. A single set of microfluidic experiments provided qualitative and quantitative information on the kinetics and completeness of water-tetrahydrofuran phase separation, the minimum amount of CO2 required to complete phase separation, the total CO2 uptake, and the rate of CO2 consumption by the liquid mixture. The efficiency of tertiary diamines with different lengths of alkyl chain was examined in a time- and labor-efficient manner and characterized with the proposed efficiency parameter. A wealth of information obtained using the MF methodology can facilitate the development of new additives for switchable solvents in green chemistry applications.
authors: Department of Chemical Engineering and Applied Chemistry, University of Toronto , 200 College Street, Toronto, Ontario M5S 3E5, Canada.
authors: Gabriella
authors: G
authors: Lestari
authors: Milad
authors: M
authors: Abolhasani
authors: Darla
authors: D
authors: Bennett
authors: Preston
authors: P
authors: Chase
authors: Axel
authors: A
authors: Günther
authors: Eugenia
authors: E
authors: Kumacheva
mesh_terms: D002245:Carbon Dioxide / Q000737:chemistry*; D005591:Chemical Fractionation / Q000295:instrumentation / Q000379:methods*; D005663:Furans / Q000737:chemistry; D044085:Microfluidics / Q000295:instrumentation / Q000379:methods*; D009994:Osmolar Concentration; D011700:Putrescine / Q000031:analogs & derivatives / Q000737:chemistry; D012997:Solvents / Q000737:chemistry; D014867:Water / Q000737:chemistry*; D018508:Water Purification / Q000295:instrumentation / Q000379:methods
chemical_list: D005663:Furans; D012997:Solvents; D014867:Water; D002245:Carbon Dioxide; C018674:tetrahydrofuran; C009433:tetramethylputrescine; D011700:Putrescine