Dielectric, Mechanical, Magnetic and Electromagnetic Shielding properties of Carbon nanomaterial embedded Polydimethylsiloxane composites

Abstract

Composites are the advanced engineering materials invented by men with exceptional properties over traditional materials. These attractive and delightful materials are the result of developments in the area of engineering and materials science. Composites are heterogeneous materials, obtained by combining two or more components known as matrix and fillers. The matrix may be metallic, ceramic or polymeric in nature. It decides the shape, surface quality, environmental tolerance and durability of the composite while the filler, change or improve the mechanical and physical properties of matrix. Hence, the composites are wonderful materials with a combination of most desirable properties of matrix and filler, suppressing their unwanted properties. Since the last few decades, developments in the field of nanotechnology has been inspired by the discovery of various carbon structures in nanoscale. The era of carbon nanostructures started and gathered massive attention from researchers, with the finding of fullerene in 1985 and has continued till today. Outstanding work by Andre Geim and Konstantin Novoselov on carbon flake of just 1-atom thickness or graphene fetching them the Nobel prize in the year 2010, opened another new chapter in the history of carbon nanostructures. Even a small variation in the orbital or macroscopic structures of carbon, can give rise to variety of new and fascinating properties. Thus, carbon nanomaterials such as carbon nanotubes, graphene, bucky balls, carbon nanofibers and many more are the supreme filler materials in the growth of nanotechnology. The area of research based on carbon nanomaterials is extraordinary, motivated by exceptional and ground-breaking findings evolving both science and technology. This has encouraged the birth of research journals dedicated to research findings exclusively in the field of carbon nanotechnology. The study of composites with these superior filler materials over the last decade, have given birth to polymer nanocomposites with enhanced electrical, thermal and mechanical properties in addition to lower density and ease of processability. Here we are reporting about polymer composites with polydimethylsiloxane (PDMS) as matrix which has distinctive properties such as optical transparency, flexibility, biocompatibility and ease of moulding. PDMS composites with carbon nanostructures make them ideal candidates for various applications. In this thesis, dielectric, electrical, mechanical and electromagnetic shielding properties of various PDMS-carbon nanostructure composites are compared and discussed to understand the effect of macroscopic structural forms of carbon on PDMS. The thesis is divided into eight chapters to put forward the understanding of PDMS composites with variety of carbon-based fillers from different aspects.