The primary theme of this thesis is the design, synthesis and evaluation of novel functional materials which display potent antibacterial activity. I also discuss some fundamental aspects of the influence of the chemical structure of a polymer on its biocidal activity. In chapter 2, I discuss how the chemical structure of the alkyl tail and the degree of positive charge affects the antibacterial potency of amphiphilic pyridinium polymers. In chapter 3, I talk about the effect of spatial positioning of positive charge and the pendant hydrophobic tail on the antibacterial activity of amphiphilic pyridinium-methacrylate copolymers. In chapter 4, I explore the fundamental basis of cell killing viz. membrane disruption, by observing the effect of structurally homologous pyridinium polymers on model lipid membrane systems. In chapter 5, I describe a simple method of fabricating highly potent dual action antibacterial composites consisting of a cationic polymer matrix and embedded silver bromide nanoparticles which leach biocidal Ag+ ions. In chapter 6, I describe the design and synthesis of novel polymers containing reactive methoxysilane groups which form durable long lasting coatings on oxide surfaces. Finally in chapter 7, in a diverse theme, I describe my research towards designing a method for quantifying the carbon dioxide poisoning in air breathing alkaline fuel cells.