14.1 Introduction 327 precursor and is used for the synthesis of functional gradient nanomaterials and characterization of materials was carried out in term of composition, microstructure and specific surface area. The write-up provides simple and convenient routes to many building blocks for assembling the structure with novel properties and its functional use in nanotechnology. 14.1 INTRODUCTION During the Stone Age, the material research was limited to the mechani- cal treatment of natural products. When Dalton discovered atomicity and Mendeleev revealed the periodic table, the research trends drastically changed in the intervening period and research was focussed on funda- mental principles of basic molecular structure and simple chemical reac- tions. During the late twentieth century and the early twenty-first century, an exciting revolution in chemistry has taken place, with multidisciplinary approaches in nanoscience and nanotechnology to the creation of mole-