Synthesis of inorganic/organic hybrid-shell antibacterial polyurea microcapsules loaded with Ag/TiO2 nanoparticles

Silver/titanium dioxide (Ag/TiO 2 ) nanoparticles, renowned as effective inorganic antibacterial agents with a wide spectrum of activity and minimal resistance induction, encounter challenges when incorporated into organic substrates. This integration often leads to particle aggregation, resulting in a substantial reduction in antibacterial efficacy. This study devised a novel approach involving loading Ag/TiO 2 nanoparticles onto polyurea microcapsules (PUMC), forming hybrid -shelled microcapsules (Ag/TiO 2 -PUMC) using silane coupling agents. The preparation of polyurea microcapsules offers the advantages of rapid synthesis and mild reaction conditions, facilitating industrial -scale production. Additionally, loading Ag/TiO 2 nanoparticles onto polyurea microcapsules helps alleviate the aggregation issue, and the organic nature of polyurea microcapsules enhances compatibility with organic substrates. Characterization techniques, including SEM, TEM, FTIR, XRD, UV - visible absorption spectroscopy, EPR and thermogravimetric analysis, were employed to confirm the successful grafting of Ag/TiO 2 nanoparticles onto the PUMC. A comparative analysis between the two silane coupling agents, KH550 and KH792, revealed that the dual amino -functional silane coupling agent, KH792, played a pivotal role in chain extension during the microcapsule self -polymerization process. The antibacterial activity of the Ag/TiO 2 -PUMC was evaluated against Escherichia coli and Staphylococcus aureus . Remarkably, the hybrid -shelled microcapsules exhibited outstanding antibacterial efficacy, achieving a 99.99% antibacterial rate within just 0.5 hours. This performance surpassed unmodified Ag/TiO 2 nanoparticles, highlighting the enhanced antibacterial efficacy of the hybrid -shelled microcapsule structure. This study presents a successful synthesis strategy for inorganic/ organic hybrid -shelled antibacterial microcapsules and provides valuable insights for refining inorganic antibacterial agents. The demonstrated approach holds substantial promise for advancing the field of organic antibacterial materials.