This volume includes six chapters and presents some of the latest advancements in materials science research. Chapter One describes the structural characterization, the polyelectrolyte properties and the proton dynamics of imidazole-based materials, with special emphasis on the application for proton conductors, gene delivery systems, pollutant adsorbents, fluorescent sensors and OLED technologies. Chapter Two details various characteristics of polyethylene terephthalate fiber. Chapter Three explains the foundation of photonic crystals from one-dimension to higher-order and introduces topological ideas in photonic crystals. Chapter Four includes research on production, properties and applications of polyethylene terephthalate. Chapter Five explores the potential application of antimonene as an anode material in sodium-ion batteries. Finally, Chapter Six summarizes recent advances on the role of fullerene additions for structural behaviors of thermoplastic matrices.