Self-assembly of ionic and non-ionic surfactants in type IV cerium nitrate and urea based deep eutectic solvent

Understanding and manipulating micelle morphology are key to exploiting surfactants in various applications. Recent studies have shown surfactant self-assembly a variety of Deep Eutectic Solvents (DESs) where both the nature interaction molecule with solvent components influence size, shape, micelles formed. So far, formation has only been reported type III DESs, consisting solely organic species. In this work, we explored cationic dodecyl trimethylammonium nitrate/bromide (C12TANO3/C12TAB), anionic sodium sulfate (SDS), non-ionic hexaethylene glycol monododecyl ether (C12EO6) octaethylene monohexadecyl (C16EO8) IV DES comprising metal salt, cerium (III) nitrate hexahydrate, hydrogen bond donor, urea, molar ratio 1:3.5. C12TANO3, C12TAB, C12EO6, C16EO8 form spherical size dependent on alkyl chain length head group, whereas SDS forms cylindrical micelles. We hypothesize that difference shape can be explained by counterion stabilization headgroup polycations compared anion case or molecular urea salting out effect (CeNO3)3 chains/polyethoxy for surfactants. These deepen our understanding amphiphile novel, ionic, hydrogen-bonding solvent, raising opportunity use these structures as liquid crystalline templates generate porosity oxides (ceria) synthesized using DESs.