Development of a polydimethylsiloxane–Eucalyptus essential oil antibacterial coating

This study presents a novel antibacterial surface comprised of Eucalyptus essential oil trapped within the micro-nanostructures of a polydimethylsiloxane (PDMS) substrate. A wettability study showed that the replication of the micro-nanostructure on PDMS led to a superhydrophobic behavior of the surface. The SEM images revealed that the micro-nanostructure increased the contact angle of the PDMS surfaces. Fourier transform infrared spectroscopy analysis led to the conclusion that the essential oil was entrapped in the PDMS, thereby promoting its antibacterial activity. Multiple tests demonstrate the antibacterial ability of these superhydrophobic surfaces in preventing the establishment of Escherichia coli and Bacillus cereus bacterial colonies and biofilms. These surfaces reduce contamination by 99.98% when exposed to a bacteria-rich water droplet. Our observations highlight the role of Eucalyptus essential oil in limiting initial bacterial growth and biofilm formation on exposed surfaces.