title: Synergistic effects of mixed aromatic counterions on nanostructures and drag reducing effectiveness of aqueous cationic surfactant solutions.
abstract: Drag reduction effectiveness of two dilute quaternary ammonium surfactant aqueous solutions with different pairs of mixed aromatic counterions was investigated along with their micellar nanostructures revealed by cryo-TEM imaging, zeta potential, particle size, and (1)H NMR measurements. Certain combinations of aromatic counterion mixtures showed significant synergistic effects. They dramatically improved drag reduction effectiveness relative to either single aromatic counterion. Using mixed aromatic counterions with different sizes and binding abilities, the effective drag reducing temperature range can be significantly expanded and higher shear stress stability can be achieved. The synergistic effects are believed to be induced by increased degree of branching in the surfactant micellar networks as shown by cryo-TEM images.
authors.affiliation: Department of Chemical and Biomolecular Engineering, The Ohio State University, Columbus, Ohio 43210, USA.
authors.forename: Wu
authors.initials: W
authors.lastname: Ge
authors.forename: Haifeng
authors.initials: H
authors.lastname: Shi
authors.forename: Yeshayahu
authors.initials: Y
authors.lastname: Talmon
authors.forename: David J
authors.initials: DJ
authors.lastname: Hart
authors.forename: Jacques L
authors.initials: JL
authors.lastname: Zakin