title: Viscosity measurements of methanol-water and acetonitrile-water mixtures at pressures up to 3500 bar using a novel capillary time-of-flight viscometer.
abstract: A new type of viscometer based on the Poiseuille flow principle has been developed that is capable of measuring solution viscosities at ultrahigh pressures. The capillary time-of-flight (CTOF) viscometer has been used to measure the viscosity of methanol-water and acetonitrile-water mixtures in decade volume% increments from atmospheric pressure to 3500 bar (50,000 psi), at 25 degrees C. This instrument works by utilizing a relatively small pressure drop (approximately 200 bar) across a capillary which has both inlet and outlet pressurized so that the average column pressure can be significantly elevated (up to 3500 bar). Measurements from the CTOF viscometer match high-pressure viscosity data collected previously using falling-body viscometers of the Bridgman design. This manuscript serves to bring viscosity data at ultrahigh pressures for the two most common liquid chromatographic mobile phases into the chromatographic literature.
authors.affiliation: Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599 USA.
authors.forename: J Will
authors.initials: JW
authors.lastname: Thompson
authors.forename: Theodore J
authors.initials: TJ
authors.lastname: Kaiser
authors.forename: James W
authors.initials: JW
authors.lastname: Jorgenson
mesh_terms: D000097:Acetonitriles / Q000737:chemistry*; D001274:Atmospheric Pressure; D004058:Diffusion; D000432:Methanol / Q000737:chemistry*; D015203:Reproducibility of Results; D012997:Solvents; D014783:Viscosity; D014867:Water / Q000737:chemistry*
chemical_list: D000097:Acetonitriles; D012997:Solvents; D014867:Water; D000432:Methanol; C032159:acetonitrile