Preparation of Colloidal Ag Nanoparticles Using the Biologically Compatible Polymers and Reducing Agents

Abstract

Silver (Ag) nanoparticles have been studied extensively due to its possible applications such as catalysts, electronic devices, anti-bacterial, medical applications and sanitation. For medical applications and sanitations, the colloidal Ag nanoparticles must be stable for a long period and biocompatible. In this contribution, we report on the preparation of silver nano-colloids in the biologically compatible polymers of chitosan, as opposed to synthetic polymers, and biocompatible reducing agents. The Ag colloids with nanometer size of 20-80 nm in diameter are prepared by reducing silver ions in the concentration range of 100-300 mg/L in the 1% chitosan solution at 95 oC. The piper beetle leaves extract was added as a biocompatible reducing agent. The silver nano colloid is stable for up to 6 weeks. The colloidal Ag nanoparticle has a UV-Vis absorption spectra with wavelength maxima at around 420-450 nm. The silver nanoparticle has an fcc crystal system with a unit cell of 4.07 angstrom. The results were comparable to the previous findings obtained in the polyvinyl alcohol and the addition of ascorbic acid as a reducing agent.