title: Capillary viscometer for fully automated measurement of the concentration and shear dependence of the viscosity of macromolecular solutions.
abstract: The construction and operation of a novel viscometer/rheometer are described. The instrument is designed to measure the viscosity of a macromolecular solution while automatically varying both solute concentration and shear rate. Viscosity is calculated directly from Poiseuille's law, given the measured difference in pressure between two ends of a capillary tube through which the solution is flowing at a known rate. The instrument requires as little as 0.75 mL of a solution to provide a full profile of viscosity as a function of concentration and shear rate, and it can measure viscosities as high as 500 cP and as low as 1 cP, at shear rates between 10 and 2 × 10(3) s(-1). The results of control experiments are presented to document the accuracy and precision of measurement at both low and high concentration of synthetic polymers and proteins.
authors.affiliation: Section on Physical Biochemistry, Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, U.S. Department of Health and Human Services, Bethesda, Maryland 20892-0830, USA. grupia@gmail.com
authors.forename: Asaf
authors.initials: A
authors.lastname: Grupi
authors.forename: Allen P
authors.initials: AP
authors.lastname: Minton
mesh_terms: D000818:Animals; D001809:Blood Viscosity / Q000502:physiology; D060166:Capillary Tubing; D002417:Cattle; D046911:Macromolecular Substances / Q000097:blood*; D033081:Shear Strength / Q000502:physiology; D014783:Viscosity
chemical_list: D046911:Macromolecular Substances