Nanoparticles and Their Applications

Nanoparticles (NP s) are synthesized from several classes of materials including inorganic, organic, hybrid and biological materials. Inorganic NPs are synthesized by ball milling, vapor deposition, electrospraying, reduction of metal salts, sol-gel, coprecipitation and thermal decomposition. Organic NPs are synthesized by microemulsion, nanoprecipitation, dialysis and rapid expansion of supercritical solutions. Hybrid NPs are synthesized from both organic and inorganic materials. There are a number of naturally occurring biological NPs including lipoproteins, exosomes, ferritin, and viruses. Further, NPs can be synthesized from biomolecules including proteins, peptides and polysaccharides. The surface to volume ratio, superparamagnetism, hardness, Coulomb energy and catalytic activity of NPs are generally higher than those of bulk materials. Due to their unique structural, magnetic, mechanical and electrical properties, NPs are used in a wide range of applications including biosensing, drug delivery, bioimaging, catalysis, nanomanufacturing, lubrication, electronics, textile manufacturing, and water treatment systems. This chapter covers the classification, synthesis, properties and applications of NPs.