Detailed analysis of size-separation of silver nanoparticles by density gradient centrifugation method.

In this research, silver nanoparticles were synthesized by chemical precipitation method and stabilized by chitosan biopolymer in the range of 15 to 235 nm. Then, the silver nanoparticles were separated by density gradient centrifugation method at different gradients and centrifuged at various duration and speed. The best separation was done with the gradient chosen at 10%, 20%, 30% and 40% for a duration of 2 h at 6000 rpm. The UV-visible spectra demonstrated the proper synthesis of silver nanoparticles, while FTIR spectrum and XRD data revealed the structure of prepared Ag-NPs. The FESEM and TEM analysis were used to check for the exact shape and size of Ag-NPs, respectively. However, the separation of silver nanoparticles was assessed making use of DLS analysis.