AVS 62nd International Symposium & Exhibition | |
Applied Surface Science | Tuesday Sessions |
Session AS+BI-TuA |
Session: | Challenges in the Characterization of Polymer/Organic/ Biological Systems |
Presenter: | Bonnie Tyler, National Physical Laboratory (NPL), UK |
Authors: | B.J. Tyler, National Physical Laboratory (NPL), UK A.L. Hook, University of Nottingham, UK M.R. Alexander, University of Nottingham, UK A. Giovannozzi, INRIM A. Pelster, University of Muenster, Germany H.F. Arlinghaus, University of Muenster, Germany |
Correspondent: | Click to Email |
Thin film coatings are widely used in medical devices in order to improve the biological response to the device without compromising its mechanical performance. These coatings are frequently organic in nature and are applied to a wide range of substrate materials. The challenge of ensuring a stable linkage between the coating and the underlying substrate is common to all of these systems. Defects at the interface between the coating and the substrate can result in failure of the medical device with potentially serious consequences. The study of buried interfaces in organic systems, like those common in medical devices, has in the past been a nearly intractable problem because sputter depth profiling with monatomic ions destroys the relevant chemical information. Recent advances in Gas Cluster Ion Beam technology have opened up exciting possibilities to better understand these buried interfaces. In this work, we have studied adhesion between an bacterial-biofilm resistant polymer coating and an oxygen plasma-treated polymer surface using Argon Cluster 3D-imaging Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS) and Raman Microscopy. Analysis has been performed in both dry and hydrated state. The analysis provided several analytical challenges. Because the overlayer was not of uniform thickness, a depth scale correction was needed to reduce misleading artefacts at the interface. Analysis of the hydrated catheters required cryogenic analysis conditions. From the ToF-SIMS data we have been able to observe the presence of particles, cracks and water, and to monitor hydrophobic recovery at the interface between the coating and the catheter. Raman analysis has provided complementary information on the Van-Der-Waal interactions at the interface. The results have been compared to mechanical adhesion tests and help to provide a better understanding of the processes that influence adhesion between the coating and the catheter.