The mesoporous silica wall materials can achieve controlled load and sustained-release of active agents. An antimicrobial nanoscale silica microcapsule containing cinnamaldehyde (CA) was prepared by the sol-gel method and applied in poly (butyleneadipate-co-terephthalate) (PBAT) film. The surface morphology, physical and chemical properties, and antibacterial properties of microcapsules and films were studied. The effects of different temperatures and humidities on the release behavior of microcapsules were also evaluated. Results showed that CA was successfully encapsulated in silica microcapsule which had a diameter of 450–700 nm. The antibacterial CA agent had a long-lasting release time under lower temperature and relative humidity (RH) environment. At low temperature (4 °C), the microcapsules released CA 32.35% in the first 18 h, and then slowly released to 56.08% in 216 h; however, the microcapsules released more than 70% in 18 h at 40 °C. At low humidity (50%RH), the release rates of microcapsules at the 18th h and 9th d were 43.04% and 78.01%, respectively, while it reached to equilibrium state at 72 h under 90% RH. The sustained release process of CA in SiO₂-CA microcapsules follows a first-order kinetic model. Physicochemical properties of PBAT films loaded with different amounts of microcapsules were also characterized. Results showed that the tensile strength and water vapor transmission rate (WVTR) of the composite film containing 2.5% microcapsules were increased by 26.98% and 14.61%, respectively, compared to the raw film, while the light transmittance was slightly reduced. The crystallinity of the film was improved and can be kept stable up to 384.1 °C. Furthermore, microcapsules and composite film both exhibited distinctive antibacterial effect on Escherichia coli and Listeria monocytogenes. Therefore, SiO₂-CA microcapsules and composite films could be a promising material for the active packaging.

中文翻译：

---

Sol-Gel法制备PBAT薄膜功能添加剂长期抗菌SiO2-肉桂醛微胶囊

介孔二氧化硅壁材料可以控制负载并持续释放活性剂。的含抗菌剂纳米级二氧化硅微囊肉桂醛（CA）中的溶液通过溶胶-凝胶方法制备和聚施加（butyleneadipate-共-对苯二甲酸酯（PBAT）薄膜。研究了微囊和薄膜的表面形态，理化性质和抗菌性能。还评估了不同温度和湿度对微胶囊释放行为的影响。结果表明，CA已成功封装在直径为450-700 nm的二氧化硅微囊中。抗菌CA剂在较低的温度和相对湿度（RH）环境下具有较长的释放时间。在低温（4°C）下，微胶囊在最初的18 h释放CA 32.35％，然后在216 h缓慢释放至56.08％。然而，微胶囊在40°C下18 h释放了70％以上。在低湿度（50％RH）下，第18 h和第9 d微囊的释放率分别为43.04％和78.01％，而在90％RH下72 h达到平衡状态。CA在SiO中的缓释过程₂ -CA微胶囊遵循一级动力学模型。还表征了负载不同量微胶囊的PBAT膜的理化性质。结果表明，与原始膜相比，包含2.5％微胶囊的复合膜的拉伸强度和水蒸气透过率（WVTR）分别比原始膜增加了26.98％和14.61％，而透光率则有所降低。薄膜的结晶度得到了改善，可以在高达384.1°C的温度下保持稳定。此外，微胶囊和复合膜均对大肠杆菌和单核细胞增生李斯特菌表现出独特的抗菌作用。因此，SiO ₂-CA微胶囊和复合膜可能是用于主动包装的有前途的材料。