Size controlled synthesis of Ag and Cu nanocrystals in F-AOT/n-butanol/SC CO2 microemulsions

The application of di-HCF6 (sodium bis(1H,1H,7H,dodecafluoroheptyl)sulfosuccinate)/n-butanol/SC CO2 microemulsion was tested for the synthesis of Ag and Cu nanocrystals of controlled size. The aqueous core of microemulsion droplet acted as a nanoreactor and surfactant monolayer stabilized the synthesized nanoparticles. The size of the particles was tuned by adjusting the water content (W0, the molar ratio of water-to-surfactant) of microemulsions. Transmission electron microscopy (TEM) revealed that the average diameter of Ag particles increased from 3.0 nm (σ = 1.1) to 5.2 nm (σ = 0.86) by raising the water content of microemulsion from W0 = 10 to 15, whereas raising the water content of microemulsion from W0 = 5 to 15 increased the size of Cu nanoparticles from 7.5 nm (σ = 2.42) to 15.2 nm (σ = 5.47). Surface plasmon absorption spectrum recorded for synthesized Ag nanocrystal in microemulsion exhibited an increase in the intensity and blue-shifted absorption maximum on increasing the water content of microemulsion from W0 = 10 to 15 which are the characteristics of increasing the size of nanoparticles.