Synthesis and Characterization of Nano/Ultrafine Sized Silver Bromide Particles in Microemulsions

Silver bromide nanoparticles of different sizes down to 5nm in diameter have been synthesized by mixing two microemulsions containing the precursor salts AgNO₃ and KBr. The microemulsions used in the synthesis are composed of Triton X-100/1-hexanol/cyclohexane/water. This study focused on the various parameters controlling the size of silver bromide particles in nanometer range, such as W₀ and concentration of the precursor salts. The size and morphology of the particles were ascertained by QELS and TEM. It was observed that the size of nanoparticles was always larger than the size of the aqueous core in which they are formed. In the W₀, range, 5-20, there is an increase in the particle size with increase of the water pool size. However, with the increase in the concentration of either Ag⁺ or Br^- ion, the size of the AgBr nanoparticles decreased significantly. Furthermore the morphology of the particles was not always the same and depends upon the reaction conditions at which the synthesis is carried out.