Construction of consumer-friendly essential oil microcapsules with viscous cores to provide extra long-lasting release

Essential oil microcapsules with viscous cores were formulated by encapsulating oil droplets with intermediate non-crosslinked polymer shells and crosslinked polymer outer shells, followed by dissolution of the intermediate shells with essential oil to form viscous cores. The study found that when the core/shell ratios of the intermediate shell = 3:2, the rotational speed = 500 rpm, the concentration of the protective colloid = 1.0 wt%, the concentration of the crosslinking agent = 20 wt% and the core/shell ratio of the outer shell = 10:1 by using three times' addition method, caprylic/capric triglyceride (GTCC) microcapsules with viscous cores were obtained. The release profile, mechanical strength and adsorption performance of GTCC microcapsules were evaluated in comparison with melamine-formaldehyde microcapsules. It was found that the viscous cores microcapsules had better heat resistance, extreme long-lasting release property, viscoelasticity and been more adhesive to cotton fabrics, which were more consumer-friendly compared with that of melamine-formaldehyde microcapsules.