Development and Evaluation of NI-P-PTFE Based Nano-Composite Coatings for Medical Devices

  • Jian Gou

    Student thesis: Doctoral ThesisDoctor of Philosophy


    Medical device-associated infections and corrosion behaviour of medical devices always impose considerable inconvenience and distress to patients and place a substantial economic burden on health care systems. The aim of this research is to solve this problem by developing a new coating which can reduce bacterial adhesion and slow down the corrosion behaviour efficiently.

    In this study, two kinds of Ni-P-PTFE based coatings including Ni-P-PTFE-ZrO2 and Ni-P-PTFE-ZrO2-TiO2 were developed by electroless plating technique. The assays of bacterial adhesion and removal were conducted on nano-composite Ni-P-PTFE-ZrO2 and Ni-P-PTFE-ZrO2-TiO2 coatings to see whether or not they have the capability of effectively resisting bacterial adhesion or reducing adhered bacteria. The anticorrosive properties of these Ni-P-PTFE based coatings were also investigated by electrochemical test.

    In the assay of bacterial adhesion and removal, two different bacteria were used including Escherichia coli and Staphylococcus aureus. The Ni-P-PTFE-ZrO2 and Ni-P-PTFE-ZrO2-TiO2 coatings prepared with the different concentrations of PTFE, ZrO2 and TiO2 showed that the concentrations had significant influence on the bacterial adhesion and removal using a dipping process. The effect of surface free energy and its components of the coatings on the performance of bacterial adhesion and removal were also investigated. Extended DLVO theory also explained why some coatings adhered less bacteria than others by analysing total interaction energy between bacteria and the coatings. While in the corrosion test, open circuit potential, polarization resistance (Rp), corrosion current density (Icorr), and corrosion rate (CR) were obtained by measuring the open circuit potential and anodic, cathodic tafel plots of Ni-P-PTFE-ZrO2 and Ni-P-PTFE-ZrO2-TiO2 coatings to evaluate their anticorrosive performances.

    In conclusion, the new nano-composite Ni-P-PTFE-ZrO2 and Ni-P-PTFE-ZrO2-TiO2 coatings showed the better capability of resisting bacterial adhesion and reducing adhered bacteria after dipping process than Ni-P and Ni-P-PTFE coatings and also have better anticorrosive property than Ni-P and Ni-P-PTFE coatings. These two new coatings have great potential to be used in the medical device market.
    Date of Award2015
    Original languageEnglish
    SponsorsChina Scholarship Council
    SupervisorQi Zhao (Supervisor) & Robert Keatch (Supervisor)

    Cite this