Fundamentals of hierarchical nanostructures

Abstract

The properties of nanomaterials are substantially different from those of their bulk counterparts. In this chapter, the unique characteristics of nanomaterials including thermal, electrical, phonon transport, mechanical, optical and magnetic properties were discussed. The unique characteristics arise from many different aspects, for example, the huge surface area of the nanomaterial is responsible for the reduction in thermal stability and the supermagnetism; the increased surface scattering is responsible for the reduced electrical conductivity; size confinement results in a change of both electronic and optical properties; and the reduction in size decreases the defects and increases the perfection and mechanical properties. Hierarchical nanostructures still hold the unique characteristics of the nanomaterials and they can even be amplified by smart design of the functional nanostructures. Especially, the hierarchical nanostructures are designed to possess larger surface areas with enhanced electrical transport characteristics for fast carrier transport. That is the reason this book focuses more on the energy devices than any other applications such as bioengineering. All of the energy devices explained in this book will basically be based on the unique characteristics explained in this chapter. © 2015 The Royal Society of Chemistry.