title: Controlled formation of polymer nanocapsules with high diffusion-barrier properties and prediction of encapsulation efficiency.
abstract: Polymer nanocapsules with high diffusion-barrier performance were designed following simple thermodynamic considerations. Hindered diffusion of the enclosed material leads to high encapsulation efficiencies (EEs), which was demonstrated based on the encapsulation of highly volatile compounds of different chemical natures. Low interactions between core and shell materials are key factors to achieve phase separation and a high diffusion barrier of the resulting polymeric shell. These interactions can be characterized and quantified using the Hansen solubility parameters. A systematic study of our copolymer system revealed a linear relationship between the Hansen parameter for hydrogen bonding (δh ) and encapsulation efficiencies which enables the prediction of encapsulated amounts for any material. Furthermore EEs of poorly encapsulated materials can be increased by mixing them with a mediator compound to give lower overall δh values.
authors.affiliation: Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz (Germany); Henkel AG & Co. KGaA, Adhesive Research, Henkelstrasse 67, 40191 Düsseldorf (Germany).
authors.forename: Ines
authors.initials: I
authors.lastname: Hofmeister
authors.forename: Katharina
authors.initials: K
authors.lastname: Landfester
authors.forename: Andreas
authors.initials: A
authors.lastname: Taden
keywords: Hansen solubility parameters; barrier properties; encapsulation; nanoparticles; polymers