(694d) Novel Double-Shell Lignin Nanocapsules Are a Stable Vehicle for Fungicide Encapsulation and Release

This paper describes the fabrication and characterization of a newly developed lignin nanocapsule, its performance towards encapsulating a fungicide, and effectiveness at controlling its release. Lignin nanoparticles are biologically and environmentally compatible, the amphiphilic properties of lignin, adsorption capacity, as well as its natural cross-linking tendency make it suitable for use as a vessel for stable cargo delivery. Here we report a sustainable approach for producing hollow, double-shell capsules from hardwood kraft lignin. The recovered lignin was dissolved without further modification in tetrahydrofuran and inserted dropwise into a water/ethanol solution containing sacrificial surfactant templates. Monodispersed, hollow, double-shell lignin capsules were produced via a two-step self-assembly. The water/ethanol solution acted as a non-solvent while simultaneously providing strategic sites for controlled-size production. The internal shells of the nanoparticles were cross-linked with biodegradable maleic anhydride to bolster the structural stability. The average hydrodynamic diameter of the particles was 202.2 ±66 nm, and these were stable in water for a period of four months. Following synthesis, the nanoparticles were loaded with propiconazole at a drug loading of 16%. This system could represent an effective wood preservative.