Exploring the Optical Properties of CTAB-Coated Silver Nanoparticles

This study explores the impact of coating on the linear and nonlinear optical properties of silver nanoparticle. Two samples of Ag nanoparticles were synthesized using the chemical reduction method: uncoated Ag NPs and coated Ag NPs with cetyltrimethylammonium bromide (CTAB). Coated and uncoated particles exhibited a single absorption band peaked around 400 nm. Coated particles show a slightly narrower absorption band indicating narrower size distribution due to the particle-stabilization effect of CTAB. Coating Ag nanoparticles does not significantly alter the linear optical properties of nanoparticles. However, it does cause wavelength-dependent changes in the nonlinear response of the nanoparticles. The changes are attributed to the size distribution differences and the nature of the contact between the particles and the liquid. Both coated and uncoated samples show good optical switching properties which make them good candidates for many photonics applications.