This book presents the dynamics of colloids and interfaces in various materials such as assemblies of surfactants, lipids, nanoparticles, and surfaces of biomaterials, catalysts and engineering materials. It covers a wide range of topics, from basics to applications, on fabrication, functions, and understanding the mechanisms of those systems. The book highlights the importance of understanding from the perspective of colloidal and interfacial chemistry for the materials exhibiting dynamic behaviors. Readers can find a new direction for the development of nano-stimulus-responsive systems consisting of molecular assemblies by understanding the relationships between the dynamics of molecules, the dynamics of molecular assemblies, and the dynamics of the functions of molecular assemblies. Also, the book provides useful knowledge for the development of new photocatalysts through a detailed explanation of the complex dynamics of electron transfer on the catalyst surface. The authors hope that common denominators will be found in different materials from the perspective of the dynamics of colloids and interfaces, and that readers will find guidelines for the development of new nanomaterials.