BME PhD Defense Announcement for Rashed Almousa (D. Xie and K. Park, Co-Chairs) Everyone is invited to attend the public presentation beginning at 9:00 am. Research title: Surface Modification of PVC/PU for Enhanced Biofouling Resistance Thesis Committee members: Prof. Dong Xie (Co-Chair), Prof. Kinam Park (Co-Chair), Prof. Jiliang Li, Prof. Sungsoo Na Date: March 21, 2023 Time: 9:00 am Location: https://purdue-edu.zoom.us/j/99594936275 Abstract: Medical devices are at risk of biofouling within seconds after implantation, which can lead to thrombus formation and bacterial contamination. These issues can negatively impact the performance and reliability of the device. Poly(vinyl chloride) (PVC) and polyurethane (PU) are popular synthetic polymers used in biomedical applications, but their hydrophobic nature makes them susceptible to biofouling. To improve their biocompatibility, their surfaces must be modified to be antifouling. However, achieving a thoroughly coated surface through homogeneous activation and effective modification with antifouling polymers remains a challenge, despite recent advancements in polymer surface modification. In this dissertation, we modified the surfaces of medical-grade PVC and PU using hydrophilic and biocompatible polymer brushes via wet chemistry approaches in an aqueous medium. Specifically, we activated the PVC surface with amino groups and then modified it with either modified or synthesized hydrophilic polymers end-capped with reactive groups. Additionally, we coupled a functionalized surface initiator to the activated PVC surface to allow the grafting of different hydrophilic polymers via conventional in situ free-radical polymerization. We followed a similar process to activate the PU surface with amino groups and then coupled a co-initiator derivative to allow the grafting of different hydrophilic polymers via conventional in situ free radical polymerization as a redox initiation system. All the modified surfaces of PVC and PU have exhibited a significant increase in wettability, as well as extremely effective antifouling effects against cell and bacterial adhesion. Overall, the findings of this work demonstrate the applicability of wet chemistry surface modification for PVC- or PU-based medical devices and supplies in biofouling-resistant applications.