Characterization and leaching studies of cobalt and nickel-polysulfone nanocomposite membranes for potential water treatment

Abstract

In spite of the undeniable importance of water for survival, a considerable number of people have no access to clean usable water as a result of high contamination of the water sources available to them. The consumption of the unclean water leads to epidemic diseases such as cholera and some other diseases whose adverse effect on the health of the people can range from mild to fatal. Although the conventional methods of water treatment are available, the challenges associated with their applications prompts researches towards finding more efficient alternatives. Application of nanotechnology in water treatment membranes is one of such unconditional means that is gaining ground in the field of membrane technology. This work aimed at preparing nanocomposite membranes with a potential application in water treatment. This was done by modifying polysulfone using nickel and cobalt nanoparticles aimed at improving the polysulfone for effective usage in water treatment. The properties of the modified membranes were obtained and the stability of the embedded nanoparticles assessed. The synthesized nickel and cobalt nanoparticles were characterized using X-ray diffraction, and Transmission electron miscroscopy. The properties of the membranes were determined using Scanning electron miscroscopy, Atomic force miscroscopy, Thermogravimetric analysis, Contact angle measurements. The leaching of the nanoparticles from the nanocomposite polysulfone membranes was assessed using Inductively coupled plasma mass spectroscopy. For the membranes modified with Ni, the hydrophilicity improved from 89.05o to 75.49o. Co nanoparticles also improved the hydrophicity from 89.05o to 80.52o, however the PSF-10 membrane exhibited contact angle of 89.45o as a result of agglomeration at such high amount of Co. The pore sizes were increased from 0.307 µm to 0.833 µm and 0.307 µm to 1.79µm for the Co and Ni modified membranes respectively. In addition, the embedded nanoparticles were stable in the PSF matrix.