pH-Sensitive Nanocapsules with Barrier Properties: Fragrance Encapsulation and Controlled Release

A facile synthesis method for polymer nanocapsules with high diffusion barrier and stimuli-responsive release properties is presented. The highly volatile fragrance α-pinene was used as hydrophobic model compound for the encapsulation process, which is based on a miniemulsion-analogous free radical polymerization process. The copolymer composition was systematically varied, and increasing contents of methacrylic acid as functional monomer in combination with high glass transition temperatures enabled unusually high encapsulation efficiencies of ≥90% for capsules with <i>z</i>-average diameters of