Polymeric thin films: Preparation, surface modification and morphology.

摘要

Polymeric thin films have very broad applications in industry. They have been employed as decorative, abrasive and anticorrosion coatings for many years. More recently, the application of polymer films in microelectronic, optical and biomedical devices has drawn a lot of attention. In this thesis, three common challenges in the field of polymeric films are addressed: surface modification, film preparation and morphology.; The new polymer surface functionalization method described in Chapter 3 can be widely used to deliver carboxylic acid functional groups to the surfaces of various polymers. Compared with traditional polymer surface modification methods, the new method will not cause deterioration of polymers. The process is simple and easy to control. The experimental results show that the spatial distribution of functional groups can be controlled using this method.; In chapter 4, supercritical CO2 combined with a small amount of organic solvent is successfully used to prepare diblock copolymer coatings. A huge amount of organic solvents are used every year worldwide as coating solvents. The utilization of supercritical fluids can significantly decrease the amount of organic solvents used and thus minimize the environmental hazards caused by the emission of organic solvents. The effects of pressure and the pressure release rate are investigated.; The morphological control of immiscible polymer blends is a topic of great interest because of the strong influence of phase geometry and dimensions on material properties and performance. Compared with bulk materials, much less work has been done concerning very thin films in the nanometer thickness regime. In Chapter 5, morphologies of thin films made from two immiscible polymers are investigated using Atomic Force Microscopy (AFM), X-ray Photoelectron Spectroscopy (XPS) and Fourier-Transform Infrared Spectroscopy (FTIR). The effects of composition, thickness, copolymer addition and annealing on the morphology were studied. A free-energy model is developed to explain the effects of annealing on morphology.