Synthesis of core–shell (nano)particles involving TiO2, SiO2, Al2O3 and polylactide

The synthesis of core–shell particles of TiO2, SiO2 and basic Al2O3 are described based on surface modification of the particles and a solution reaction involving l-lactide and a catalyst such as tin octanoate or 4-dimethylaminopyridine. Surface modification involves treating the particles with titanium isopropoxide, lactic acid or glycolic acid. A similar approach taken with sand, Fe3O4, Co3O4, BaTiO3, montmorillonite clay or starch yielded varying results. Polymer coatings were characterized by Fourier-transform infrared spectrometry, solid-state 13C NMR and mass balance.

Syntheses are described for the growth of polylactide on various oxide particles.Figure optionsDownload as PowerPoint slideHighlights
► Polylactide was grown from TiO2, SiO2 and Al2O3 nanoparticles.
► An initiator such as lactic acid was used on the surface to initiate ring-opening.
► The method used is a one-pot, cost-efficient reaction.
► Particles with up to 66% polymer by mass were obtained.
► These particles could have applications in drug delivery.