Polyethyleneimine-Capped Silver Nanoparticles as Antifouling Photocatalyst for Wastewater Treatment

• Main Authors: -Li Yee, Maxine Swee, Khiew, Poi-Sim, Chiu, Wee Siong, Tan, Yuen-Fen, Leong, Chee-Onn
• Format: Conference Proceeding
• Language: English
• Subjects: Ag-PEI; Antifouling; Biofilm inhibition; Halomonas pacifica; Methylene blue; Photocatalyst
• ISSN: 2214-7853; 2214-7853
• DOI: 10.1016/j.matpr.2019.11.174

Water pollution is one of the most urgent challenges of the 21st century, with water security having widespread consequences on society and the global economy. Methylene blue (MB) is a toxic by-product of textile and dye industries which has polluted wastewaters. Biofouling of man-made surfaces is a longstanding issue with serious consequences in the maritime and water treatment industries. Ag and its compounds are historically well-known as antibacterial agents, whilst polyethyleneimine (PEI) has good stabilizing and adsorption properties. In this work, colloidal Ag nanomaterials (diameter ∼2.6 ± 1.1 nm) produced using PEI as the capping agent demonstrated potential as antifouling photocatalysts for water treatment applications. The photocatalytic effect of Ag-PEI was studied using UV-visible spectrophotometry on the decomposition of methylene blue, with a 90.2% peak reduction of its UV-visible spectral peaks and decoloration recorded after 90 minutes of UV-irradiation. Separately, Ag-PEI demonstrated a 63% reduction of biofilm formation by Halomonas pacifica, a model marine-biofilm bacterium, through a static biofilm assay.