Incorporation of Carbon Nanotubes in Polydimethylsiloxane to Control Escherichia coli Adhesion

Abstract

Polydimethylsiloxane (PDMS) is widely used as a coating material and in the fabrication of medical implants for the urinary tract and also in biofilm reactors. When this polymer is used in biomedical devices, bacterial adhesion to the surface must be avoided to prevent implant-related infections, whereas in biofilm reactors, adhesion has to be promoted. In this work, incorporation of carbon nanotubes (CNTs) on PDMS composites was tested to control Escherichia coli adhesion. Pristine and functionalized CNTs were used and the adhesion assays were performed in the hydrodynamic conditions prevailing in the urinary tract. Surfaces were chemically and morphologically characterized by contact angle measurements, scanning electron microscopy, and X-ray photoelectron microscopy. Incorporation of small amounts (0.1%) of pristine CNTs decreased bacterial adhesion by 20%, whereas functionalized CNTs increased bacterial adhesion also by 20%. This demonstrates that bacterial adhesion can be modulated by incorporating different types of CNTs in the polymer. It is likely that incorporation of higher amounts of CNTs in polymer composites can affect bacterial adhesion by more than 40%. (C) 2018 Society of Plastics Engineers