Preparation of effective antibacterial composites of low-density polyethylene modified with quaternary ammonium functionalized zinc oxide nanoparticles

The antibacterial activity of biomedical polymer materials is an important basis for their resistance to biofilm contamination as implantable medical devices. However, developing durable and stable antibacterial composites through a universal manufacturing method remains a challenge. Herein, based on an organic–inorganic synergistic antibacterial strategy, functional nanoparticles with high antibacterial performance and better polymer compatibility were prepared by combining zinc oxide nanoparticles (ZnO NPs) with quaternary ammonium compound 3-(trimethoxysilyl)-propyldimethyloctadecyl ammonium chloride (QAS), which containing siloxane group. The ZnO-QAS nanoparticles were then introduced to low-density polyethylene (LDPE) by simple melt blending to manufacture synergistic antibacterial composites. The organic–inorganic hybrid strategy significantly improved the antibacterial activity of the composites, the PE/ZnO-QAS composites possess satisfactory antibacterial efficiency of 99.9% and 99.75% against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus), respectively, and it could effectively inhibit biofilms. In addition, the functionalization of organic compound QAS provides excellent polymer compatibility for ZnO NPs, which is conducive to their uniform dispersion in LDPE, and comprehensively improves the thermal stability, mechanical properties, and crystallinity of the composites. This provides potential application value for the preparation of long-term stable antibacterial biomedical materials.

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