Development and Characterization of Silver Doped Carbon Nanotube Membranes for Water Purification Application

Abstract

Membrane filtration technology is gaining interest because of its strong ability to block different pollutants present in water. Because of unique properties of carbon nanotubes (CNTs) they are also used for the development of water purification membranes whereas, silver (Ag) nano particles also have unique electrical and antibacterial properties due to which they are doped with CNTs for the development of MWCNTs-Ag water purification membranes. A unique approach was utilized to develop multi-walled carbon nanotubes (MWCNTs) silver (Ag) composite membranes. MWCNTs were impregnated with 1 wt% Ag loading, which resulted in a homogeneous dispersion of Ag in MWCNTs. MWCNTs impregnated with Ag were then uniaxially compacted at two different pressures of 80 MPa and 120 MPa to form green pellets. Compacted membranes were then sintered at two different temperatures of 800 ˚C and 900 ˚C to bind Ag particles with MWCNTs as Ag particles also act as a welding agent for CNTs. The powder mixture was characterized by FESEM, thermogravimetric analysis, and XRD, while the developed samples were characterized by calculating the porosity of membrane samples, contact angle, water flux and a diametrical compression strength. The developed membranes showed overall large water flux, while maximum porosity was found to decrease as the compaction load and sintering temperature increased. The diametrical strength of the membranes was found to increase as the compaction load increased. The hydrophilicity of the membranes remained unchanged after the addition of Ag particles. The developed membranes would be useful for removing a variety of contaminants from water