Rheological Properties of Wormlike Micelles Formed by Anionic Double‐Tailed Surfactants With Varying Hydrophobic Chain Lengths

ABSTRACT Wormlike micelles are dynamic, self‐assembled structures formed by surfactants in aqueous solutions, characterized by their unique viscoelastic properties and potential applications in fields such as enhanced oil recovery, drag reduction, and personal care products. This study focuses on the rheological behavior of wormlike micellar systems formed by anionic double‐tailed surfactants (DTS2‐6, DTS2‐8, and DTS2‐10) with varying hydrophobic chain lengths. Longer hydrophobic chains, such as DTS2‐10, were found to significantly enhance the viscoelasticity and promote the formation of wormlike micelles at lower concentrations. Rheological experiments revealed that DTS2‐8 and DTS2‐10 solutions exhibited shear‐thinning behavior and viscoelastic fluid properties, conforming to the Maxwell fluid model at low to moderate frequencies. The Cole‐Cole plots confirmed a fast‐breaking regime, while increasing KCl concentrations initially promoted micelle elongation but led to branching and reduced viscosity at higher concentrations. These findings highlight the critical role of hydrophobic chain length and salt concentration in influencing micellar structure and rheological properties, offering valuable insights for optimizing their industrial and commercial applications.