In this work, the scCO₂-assisted incorporation of thymol in LDPE nanocomposites with different concentrations of an organo-modified montmorillonite (OM-MMT) nanoclay is proposed as the preparation method of an antimicrobial food packaging system. Mass transfer characterization of thymol, for both incorporation and release processes, as a function of the nanoclay content of the material and the CO₂ pressure during the impregnation at 313 K was carried out as well as the structural characterization of the nanocomposites, which was developed for a better understanding of the impregnation and release processes. From the incorporation and release experiments and their theoretical analysis, it was obtained that the intercalated structure of the nanocomposite materials did not involve an additional resistance to the thymol incorporation in the polymer structure during the scCO₂-assisted impregnation process. Nevertheless, the decrease of the diffusion coefficient of thymol in the nanocomposite, D_eff, during the release process from the material to a food simulant was observed. Thus, the D_eff associated to thymol uptake in the nanocomposite materials took values between 2.17 × 10⁻¹² and 2.44 × 10^-11 m² s^-1. Meanwhile, the D_eff of thymol associated to its release from the nanocomposite took values between 7.0 and 9.0 × 10^-14 m² s^-1. Finally, the developed nanocomposite materials showed a thymol concentration that allows a strong antibacterial activity against S. aureus and E. coli.

在这项工作中，提出了scCO ₂辅助将百里酚掺入具有不同浓度的有机改性蒙脱土（OM-MMT）纳米粘土的LDPE纳米复合材料中，作为抗菌食品包装系统的制备方法。百里香酚在掺入和释放过程中的传质特性与材料中纳米粘土含量和CO _2的关系进行了313 K浸渍过程中的压力以及纳米复合材料的结构表征，这是为了更好地了解浸渍和释放过程而开发的。从掺入和释放实验及其理论分析，可以得出，在scCO ₂辅助浸渍过程中，纳米复合材料的插层结构不对百里香酚掺入聚合物结构产生额外的抵抗。然而，在从材料到食品模拟物的释放过程中，观察到百里香酚在纳米复合材料中的扩散系数D _eff降低。因此，D _eff与百里香酚在纳米复合材料中吸收相关的值在2.17×10 ^-12和2.44×10 ^-11 m ² s ^-1之间。同时，与百里酚从纳米复合物中释放相关的百里酚D _eff的值在7.0和9.0×10 ^-14 m ² s ^-1之间。最后，已开发的纳米复合材料显示出百里酚浓度，可对金黄色葡萄球菌和大肠杆菌具有很强的抗菌活性。