Polymer thin films are widely used for surface modification for a wide range of applications including surface antifouling, friction tuning, anti-icing, and controlled cell growth. A variety of methods is available for preparing polymer-coated surfaces. Layer-by-layer (LbL) assembly is regarded as a facile, flexible, and versatile method to prepare polymer thin films with controlled thickness. In a typical LbL process, two oppositely charged polyelectrolytes are alternately deposited onto the target surface, giving rise to a polyelectrolyte multilayer (PEM) film.
The physicochemical properties of a PEM film are vital to its functionalities. It is important to develop approaches that can systematically tune the properties of a PEM film according to the specific application. The primary focus of this PhD work is to tune the physicochemical properties of a PEM film by careful design and synthesis of the building materials and the post-assembly film modification. It has been demonstrated that the hydration level, pH-responsiveness, and the interfacial property of a PEM film can be tuned systematically. This work provides novel methodologies for the preparation of tailor-designed polymer thin films for applications such as bio-antifouling, separation membranes, and selective surface adsorption, among others.