Quasi-2D micro-objects from patterned, surface-initiated polymers

A ‘quasi-2D’ object is a structure whose lateral dimensions are orders of magnitude larger than its width. This thesis describes the fabrication of quasi-2D polymeric objects with lateral dimensions on the scale of microns and thicknesses on the scale of nanometres. The fabrication of such objects is of interest due to the possibility of interesting conformational changes that could occur in response to external conditions. The fabrication of ‘quasi-2D’ objects from patterned polymer ‘brushes’ (arrays of polymer chains, each of which is tethered to a surface) is studied. Poly(glycidyl methacrylate) (PGMA) brushes are capable of undergoing ring-opening reactions with a range of different nucleophilic reagents. The functionalised PGMA brushes are studied using ellipsometry. Fourier-Transform Infra-Red spectroscopy (FT-IR), and atomic force microscopy (AFM). After functionalisation, the resulting polymer films can be lifted from the surface without loss of structural integrity, either by etching a sacrificial gold layer from underneath the polymer or by severing the bond between the polymer and the gold surface electrolytically. ‘Hybrid’ objects, containing a gold component and a polymer layer, can be formed by partial etching of a gold layer from underneath a hydrophobic polymer object. The formation of intriguing ‘buckling’ patterns in the polymer is observed after the objects’ release from the surface. It is also possible to create quasi-2D objects from diblock copolymers, of which one polymer block contains a crosslinking monomer and the second block incorporates interesting chemical functionality. The use of this method in the formation of quasi-2D objects incorporating a potentially ‘responsive’ component is explored.EThOS - Electronic Theses Online ServiceGBUnited Kingdo