Microwave-assisted Synthesis of Silver Nanoparticles in Alginate and a Preliminary Study on the Capture of Silver Nanoparticles by Sulphur/Alginate Composite

Lee, Koon Ming (2018) Microwave-assisted Synthesis of Silver Nanoparticles in Alginate and a Preliminary Study on the Capture of Silver Nanoparticles by Sulphur/Alginate Composite. Final Year Project (Bachelor), Tunku Abdul Rahman University College.

Text Lee Koon Ming_Full Text.pdf Restricted to Registered users only Download (2MB)

Abstract

A green, microwave-assisted method to produce uniformly sized silver nanoparticles in aqueous medium within minutes was successfully developed using sodium alginate as reducing agent and stabilizer. The microwave-synthesized silver nanoparticles were characterized by UV-vis spectroscopy and FTIR spectroscopy. The intra-assay and intermediate precisions for the synthesis were determined. The effects of ageing and purification on the stability of alginate-capped silver nanoparticles were studied. By coating the uniformly sized silver nanoparticles with sodium alginate, their solubility was ensured and thus mimicking those found in the environment/wastewater which was ideal for the preliminary capture study. In the preliminary study on capture of silver nanoparticles, sulfur nanoparticles/ alginate gel fibrous composite were successfully produced. The absorption of silver nanoparticles by sulfur nanoparticles in alginate was monitored by UV-vis spectroscopy given that the effects of surfactant and chloride on silver nanoparticles removal were minimized. The study has shown the consistent formation of uniformly sized silver nanoparticles in the same laboratory. The fabricated silver nanoparticles were stable up to 13 days upon storage in dark at room temperature but their stability was affected by the purification step. In the latter part, the preliminary capture study indicated the successful development of a “solid phase separation” technique with the ability to capture silver nanoparticles up to 90% efficiency using sulfur nanoparticles- encapsulated alginate fibers. This implies the potential use of sulfur/alginate composite to remove silver nanoparticles during wastewater treatment.