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Published on: September 9, 2022
A drag reducing surfactant threadlike micelle system with unusual rheological responses to pH
Haifeng Shi1, Wu Ge1, Yi Wang2
1Department of Chemical and Biomolecular Engineering, The Ohio State University, 140 W 19th Ave, Columbus, OH 43210, USA.
Abstract:
A pH-responsive threadlike micellar system was developed by mixing alkyl bis(2-hydroxyethyl)methylammonium chloride (EO12) and trans-o-coumaric acid (tOCA). The rheological response of this system to pH is unusual in that it has viscoelasticity at both high and low pH levels, while it shows water-like behaviors at medium pH. Cryogenic transmission electron microscopy (Cryo-TEM) images confirmed the presence of TLMs at pH 3.5 and pH 9.8. This system also had DR (drag reduction) capability at low and high pH. The unusual rheological and micellar responses of this system to pH are caused by the dual pK(a)'s of tOCA. (1)H NMR and zeta potential results support this hypothesis.
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