Controlled release of essential oils using laminar nanoclay and porous halloysite / essential oil composites in a multilayer film reservoir

In this work the preparation and characterization of a multilayer film reservoir with clay/essential oil (EO) composites is described. The goal is to analyze the potential use of these reservoirs with clay/EOs composites as aroma-controlled release for various applications such as pesticide or attractant for pest control as well as antimicrobial. Two types of clays were analyzed, porous halloysite (HNT) and octadecyl modified montmorillonite (MMT) nanoclay as well as two types of essential oils, orange (OO) and thyme oil (TO). The characterization was performed by elemental analysis, Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), transmission electron microscopy (TEM) and gas chromatography (GC) analysis. FTIR confirmed that both clays adsorbed the EOs. The DRX and TGA results showed that MMT clay showed higher thyme oil adsorption and better interactions than with orange oil. The Clay/EO composites encapsulated in Polyethylene/ tie/Polyamide/tie/Polyethylene multilayer film showed a continuous aroma release for longer periods. It was found that the Polyamide (PA) barrier layer thickness had has an effect on the liberation of the volatile compounds through the multilayer film. On the other hand, the highest cymene aroma release at 72 h was 800 mu g for the MMT clay/thyme oil encapsulated in the multilayer film with lower PA layer thickness. This multilayer film encapsulated clay/EO composites could be an option to prepare aroma-controlled release systems for pest control and food packaging applications as antimicrobial or fungicidal systems.