Effect of chemical structure of quaternary ammonium salt-type cationic surfactants and temperature on aggregate size

Effect of temperature on drag reduction behavior of quaternary ammonium sal t cationic surfactant solutions with sodium salicylate (NaSal) was investig ated in terms of 1) alkyl chain length and 2) number of 2-hydroxyethyl grou ps. Characterization concerning DR effect, pressure loss, first normal stre ss difference (N-1) and aggregate size for NaSal/cationics solutions were c arried out. NaSal/cationics solutions containing above 40 nm-sized aggregat ion had a large DR effect ranged from 65 - 80%. However, the effect suddenl y changed to 5-7% below 30 nm in aggregate size. The aggregate size apparen tly plays an important role in DR effect.