Surface modified polymers for controlled macroscopic functions

• Main Author: Chng, Shuyun
• Other Authors: Moloney, Mark
• Published: University of Oxford 2016
• Online Access: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.730450

This thesis is concerned with the chemical modification of polymer surfaces to confer various functionalities for controlled macroscopic functions, and in particular, photochromic activity and drug delivery. In this collaboration project, the first two years spent in Oxford placed emphasis on the development of a versatile synthetic route for surface modification of polymers with proof of concept. The next two years were spent at the Singapore Institute of Manufacturing Technology (SIMTech) for translational research, which involved the application of the processes developed in Oxford for large area surface engineering, and testing of the surface modified polymers. Different approaches to modify surface of polymer by chemical methods were investigated, and compared to analogous chemistry in solution. The best surface modification approach was then optimised to determine the most suitable system for translation. A library of polymers with variation in end group, and with expansion of substrate scope, was characterised in detail for chemical and macroscopic properties. In particular, drug delivery properties were investigated using hole-plate bioassays and HPLC-MS methods, and it was found that the antibiotic, Penicillin V, was still active after being loaded onto the polymer scaffolds, with surface modified polymers binding and releasing more drug than the corresponding controls. Incorporation of the spiropyran units on to the polymer surfaces also demonstrated good photochromic activities. With the transfer of the technology to SIMTech, surface modification processes were re-designed and tested on a variety of 2D engineering polymers. Macroscopic function of photochromic activity, change in surface wettability and drug delivery were investigated. Lastly, a surprising finding on adhesion function generated from the diaryldiazo compound is disclosed, with preliminary results of lap-shear and t-peel tests showing high levels of adhesion. Moreover, when tested with sol-gel coatings, enhanced adhesion of the coating was found.