Synthesis of poly(caprolactone)-block-poly[oligo(ethylene glycol)methyl methacrylate] amphiphilic grafted nanoparticles (AGNs) as improved oil dispersants

Abstract

Linear-bottlebrush, amphiphilic copolymers were grafted from the surface of silica (SiO₂) nanoparticles to form “nanoparticle micelles” that, regardless of the concentration, possess the capability to encapsulate and stabilize non-polar structures in aqueous media. These nanoparticles afford high water dispersibility and enhanced oil encapsulation from their inherent architectural design. Utilizing well-established techniques, such as surface-initiated ring-opening polymerization (SI-ROP) and surface-initiated atom transfer radical polymerization (SI-ATRP), to effectively fine-tune the ratio of hydrophobic (poly(caprolactone), PCL) to hydrophilic (poly[oligo(ethylene glycol)methyl methacrylate mono-methyl ether], POEGMA) copolymer composition, enhances oil encapsulation while maintaining aqueous solubility. Preliminary oil encapsulation was quantified with differential scanning calorimetry (DSC) using two different types of crude oil. These nanoparticles offer an alternative dispersant system to replace commercially used Corexit™ 9500 by effectively breaking up disastrous oil slicks and minimizing the long-term effects of dispersant additives in the environment.