Cinnamon essential oil microcapsules loaded gypsum fiberboard: Improve long-term safety and antibacterial properties for sustainable green and healthy room decoration materials

Indoor bacteria, fungi, viruses, and other harmful microorganisms pose a significant threat to human health, highlighting the need for green, sustainable indoor materials. Cinnamon Essential Oil (CEO), a natural, highly efficient, broad-spectrum antibacterial plant extract, has emerged as a low-carbon, environmentally friendly natural antibacterial agent. In this study, CEO microcapsules (G/GA@CEO) were prepared using gelatin (G) and gum arabic (GA) as wall materials the complex coacervation method. The microencapsulation process was optimized using single-factor and response surface method. The optimal core-to-wall ratio was determined to be 1.6:1, with a pH of 3.5 and a stirring speed of 340 rpm, resulting in an embedding ratio of 80.8 %. The microcapsules exhibited a spherical morphology with an average particle size of 76 μm, and the system demonstrated stability over time. The Minimum Inhibitory Concentrations (MIC) and Minimum Bactericidal Concentrations (MBC) for Escherichia coli ( E.coli ) and Staphylococcus aureus ( S.aureus ) were 0.782 mg/mL and 1.563 mg/mL (MIC), and 3.125 mg/mL and 6.25 mg/mL (MBC), respectively. The G/GA@CEO significantly enhanced the persistence of antibacterial activity and demonstrated slow-release performance, following Avrami’s model. When G/GA@CEO was applied to gypsum fiber board (GFB), the antibacterial ratios against E.coli and S.aureus could reach 99.9 % with a 4 % addition, while maintaining favorable mechanical properties. After a 120-day durability test, the antibacterial ratios remained high at 95.1 % and 98.7 %, respectively. This study innovatively introduced plant essential oil microcapsules into GFB, offering practical guidance for the development of sustainable, green, and healthy indoor decorative materials.