Colloidal ZnS Nanoparticles: Exploring the Role of Surfactants

Preparation and characterization of semiconductor materials consisting of particles with dimensions in nanometers scale has gained tremendous attention. The surface coating of particles with surfactants to prevent unlimited growth of Nanoparticles (NPs) has been extensively explored as a simple, effective and economical method. In this book, the role of surfactants in stabilization and altering the properties of ZnS NPs synthesized using chemical precipitation in aqueous medium has been discussed in detail. Broadly, a series of cationic and anionic surfactants have been investigated to describe and discuss the effect of hydrophobic chain length, head group functionalities, counter ions and polarity of surfactants on size, stability and various properties of ZnS NPs. Since the adsorbed surfactant is located on or near the NPs surface, the emphasis have been given on the modification of the surface state energetics of ZnS NPs in relation to the surfactant structures which has been analyzed by monitoring the varying photoluminescence emission of the NPs during different stages of their growth under different conditions of photoactivation.