Single-chain polymer nanoparticles for oil solubilization

We report on the oil solubilization of amphiphilic single chain nanoparticles (SCNPs) based on random copolymers composed of oligo(ethyleneglycol) methacrylate (OEGMA) and anthracene methacrylate (AnMA). Small-angle X-ray scattering (SAXS) combined with molecular dynamics simulations reveal that the copolymers self-assemble into single-chain nanoparticles resembling flexible cylinders, driven by the intra-molecular association of anthracene moieties. Higher AnMA content results in shorter, thicker worm-like structures due to enhanced compaction along their length. Despite their amphiphilic nature, the SCNPs remain as isolated entities without forming inter-chain aggregates. This stability is attributed to the steric repulsion imparted by the OEGMA segments, which prevents bridging or clustering even in the semidilute regime. SAXS and small angle neutron scattering (SANS) contrast-variation experiments revealed that toluene incorporation causes only a slight thickening of the cylindrical cross-section, without major changes in overall structure. Complementary diffusion nuclear magnetic resonance (NMR) confirmed successful solubilization of toluene within the single-chain nanoparticles. These findings underline the potential of amphiphilic SCNPs as oil nanocarriers, offering insights into the molecular architecture aspects that influence microstructure and stability.