Bifunctional Microcapsules with n-Octadecane/Thyme Oil Core and Polyurea Shell for High-Efficiency Thermal Energy Storage and Antibiosis

Abstract

A new kind of bifunctional microcapsule containing a n-octadecane (OD) and thyme oil (TO) core based on polyurea shell designed for thermal energy storage and antibiosis was prepared successfully through interfacial polymerization. The scanning electron microscopic investigations reveal that the obtained composite microcapsules present the regular spherical morphology and the transmission electron microscopic observations confirm the clear core–shell structure. Morphological and chemical structure analyses prove the successful synthesis of bifunctional microcapsules. Thermogravimetric analysis indicates that the polyurea shell can protect the composite cores effectively. Differential scanning calorimetry examination shows that the bifunctional microcapsules can maintain high thermal storage capacity and the encapsulation efficiency of OD increases with the increase in TO. The supercooling crystallization can be notably suppressed by adding 7 wt.% of n-octadecanol. A study on the release behavior of TO from the bifunctional microcapsules reveals that the Higuchi kinetic model could better fit the TO release profile. The antibacterial results demonstrate that the bifunctional microcapsules can effectively inhibit the growth of Staphylococcus aureus and the inhibition rate can reach as high as 99.9% when the mass concentration of microcapsules is over 3 wt.%.

Biocontrol Activity of Aspergillus terreus ANU-301 against Two Distinct Plant Diseases, Tomato Fusarium Wilt and Potato Soft Rot

“…Octadecane (C 18 H 38 ) and tetracosane (C 24 H 50 ) are aliphatic hydrocarbon (alkane) maintaining its general formula C n H 2n+2 , is a dangerous environmental toxic chemicals in petroleum-contaminated soil consisting of recalcitrant compound make it non-degradable ( Bajagain et al, 2018 ; Campo et al, 2017 ; Hamouda et al, 2016 ; Hussain et al, 2018 ; Meckenstock et al, 2016 ). Some recent reports proved that they also have significant antimicrobial properties ( Abiona et al, 2019 ; Barupal et al, 2019 ; Bouhlal et al, 2020 ; Li et al, 2021 ; Rajaofera et al, 2019 ; Ramírez et al, 2021 ; Wang et al, 2020 ).…”

Research progress of biomass materials in the application of organic phase change energy storage materials

“…The thermal conductivity of four shell materials, including polystyrene, phenolic resin, dense amine resin, and SiO 2 , increased from 0.080 W m −1 K −1 to 1.295 W m −1 K −1 . Additionally, the time for the complete phase transition of their prepared microcapsules decreased from 0.17 s to 0.12 s. 44 In a study conducted by Wang et al , 45 microcapsules were prepared with n -octadecane (OD) and thyme oil (TO) embedded in a polyurea shell using interfacial polymerization. These microcapsules served the dual purpose of storing thermal energy and sterilizing.…”

Encapsulation methods for phase change materials – A critical review

“…Wang et al [148] focused on the antibacterial properties of microencapsulated PCMs, which is promising and important in the textile and food industry. N-octadecane (OD) and thyme oil (TO), as dual-core materials, were combined and encapsulated within the PU shell.…”