Micellelike

Micellelike describes assemblies of amphiphilic molecules that resemble micelles in size, shape, or function, but may not conform exactly to classical micelles. In aqueous environments these aggregates typically feature a hydrophobic core surrounded by a hydrophilic shell, formed when amphiphiles self-assemble above a threshold concentration called the critical aggregation concentration (CAC) or, for traditional surfactants, the critical micelle concentration (CMC). The term is used when the structures are not strictly conventional micelles but share key characteristics such as solvent exclusion of nonpolar regions and surface exposure of polar groups.

Common examples include classical surfactant micelles, polymeric micelles formed from block copolymers, and reverse micelles in nonpolar solvents where polar groups form the core. Micellelike assemblies can be spherical or near-spherical, but some systems produce elongated, wormlike, or complex morphologies. Size generally spans a few to several tens of nanometers. They exhibit dynamic exchange of constituent molecules and can encapsulate hydrophobic solutes within the core, aiding solubilization and delivery.

Characterization methods frequently used include dynamic light scattering, small-angle X-ray or neutron scattering, cryo-electron microscopy, and NMR. CAC or CMC values are often determined by surface tension, fluorescence probes, or conductometry.

Applications of micellelike assemblies span drug delivery, solubilization of poorly water-soluble compounds, catalysis, cosmetics, and environmental remediation. The term emphasizes resemblance to micelles while acknowledging possible deviations in structure or assembly conditions.