Document Type

Theses, Masters


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Publication Details

A Thesis Presented for the Award of Master of Science, Technological University Dublin, 2021.


The aim of this project was to develop new coatings for titanium based implants, most particularly stents, incorporating heterocyclic functional groups in their structure that will have the potential to bind to a titanium surface and prevent or reduce metal corrosion. Many of the current coatings are chemically bound onto metallic surfaces, but this project looks at electropolymerising the coatings onto the surface of the Ti6Al4V stents. Hence, polymerising functional groups have been incorporated with azoles in the structure of the synthesised compounds. Additionally, surface characterisation and preliminary corrosion studies have been carried out on a series of coated TI6Al4V stents.

In this study, the compounds synthesised have been divided into three groups. Compounds from series 1 have been synthesised from the core unit 2-(1H-tetrazol-5- yl)pyridine, while compounds from series 2 have been derived from pyrrole or 1,2- dimethyltetrahydrofuran. Series 3 compounds were obtained by reacting compounds 1 and 2 together. This in turn created a series of tetrazole/pyrrole based compounds. A total of 16 compounds are reported in this thesis. The compounds were isolated and identified by spectroscopic techniques (1H and 13C NMR, IR) as well as elemental analysis. A selection of series 3 compounds were subsequently chosen based on their polymerisation properties and coated onto a Ti6Al4V stent surface. The coatings were characterised by microscopy (SEM and AFM) and subjected to electrochemical corrosion testing via Tafel analysis.

The preliminary results indicated that some of the synthesised coatings display a good coating ability and improved anti-corrosion properties, relative to coatings currently on the medical device market. Compounds 2-(2,2-diethoxyethane-3amino-pyrrol-1-yl ethyl-(1-tetrazol-5-yl) pyridine and 2-(n-ethylphenylpyrrole-(2H-tetrazol-5-yl) pyridine demonstrated the best reduction in corrosion, with a 5 fold reduction when compared to the uncoated Ti6Al4V stent.

New tetrazole/pyrrole based coatings have been synthesised in this project, that have the capabilities of adhering to metallic surfaces and reduce metal corrosion. It is hoped that this exploratory work could lead to an introduction of new corrosion reducing iv coatings onto the medical stent market. However, further research is needed to bring the application of this project to the market.