Antimicrobial surfaces hinder the growth of microorganisms and they can be used in a wide range of applications, such as: to reduce the spread of pathogens on public surfaces (elevator buttons, door handles and ATMs), to eliminate biofouling in systems that operate in wet or high humidity conditions (air conditioners, drain filters) and to decrease the incidence of infection after implantation of biomedical devices (plates, pins, screws). The antimicrobial effect can be associated with the presence of an active element (silver, copper, zinc) or by the surface morphology (roughness, pore size). This project will explore the use of plasma electrolytic oxidation (PEO) to create antimicrobial surfaces on aluminium and titanium alloys.
The electric discharge conditions will be adjusted to modify the morphology of the treated surfaces. What is more, the surface chemistry of the coatings will be modified by changing the PEO electrolyte composition, either by introducing elements in solution and/or nanoparticles in suspension (Ag, Cu, Zn nanoparticles), and by conducting post treatments in water and in different sealing solutions.
The coatings will be analysed using advanced characterisation techniques (electron microscopy, atomic force microscopy, x-ray diffraction, etc.). The antimicrobial activity of the coatings will be assessed using cell cultures. The testing program will also include hardness measurements, scratch resistance and electrochemical corrosion testing to assess the durability of the coatings and their antimicrobial effect.