Ionic Surfactant‐Induced Electrokinetic Modulation and Hydrodynamic Size Modulation of POE‐ Based Nonionic Micelles: Insights From Dynamic Light Scattering

Abstract

This study investigates the influence of varied ionic surfactants, such as zwitterionic N ‐dodecyl‐ N , N ‐dimethyl‐3‐ammonio‐1‐propanesulfonate (DPS), cationic dodecyltrimethylammonium bromide (DTAB), and anionic sodium dodecyl sulfate (SDS), on the micellization of architecturally distinct biocompatible polyoxyethylene (POE)‐ based nonionic surfactants, namely, Kolliphor EL, Kolliphor HS15, Tyloxapol, Akypo, Pluronic P103, and Tetronic T1304 in an aqueous environment. The solution behavior based on cloud point (CP) measurements and micellar characteristics, determined by dynamic light scattering (DLS) is presented. It was observed that the addition of ionic surfactants consistently and concentration‐dependently increased the CP, indicating enhanced micellar hydration and thermal stability in all the tested systems. Interestingly, the addition of ionic surfactants reduced hydrodynamic diameter ( D h ) and increased polydispersity index (PDI) following the order: SDS > DTAB > DPS, consistent with the CP data. In contrast, zeta potential (ζ) measurements showed progressive charge neutralization, with limited positive charging in some DTAB‐containing systems, while SDS‐containing systems exhibited moderate negative surface charge, and DPS‐containing systems showed minimal changes due to internal charge compensation. A comparative evaluation of structurally diverse POE‐ based surfactants highlights how molecular architecture and ionic headgroup chemistry jointly regulate micellar charge, hydration behavior, and structural stability in mixed surfactant environments.