Synthesis and characterization of carbon nanotube membranes for water treatment

This work presents the synthesis and characterization of carbon nanotube (CNT) incorporated polyethersulfone (PES) membranes. Firstly, CNTs were prepared via a nebulized spray pyrolysis of toluene (carbon source) and ferrocene (catalyst) mixture at a temperature of 850 0C. The CNTs produced were then purified and functionalized by acid treatment to aid their interaction with the solvent and polymer during membrane preparation. Characterization techniques used for CNTs include scanning electron microscopy (SEM) analysis, Raman spectroscopy analysis, thermogravimetric analysis and X-ray photoelectron spectroscopy analysis. The outer diameters of CNTs measured from SEM micrographs using Image J software were in the range of 10 – 14 nm. TGA analysis revealed that the CNTs undergo complete thermal degradation after acid treatment; i.e. no catalyst particle residues were detected after 600 0C. Please click Additional Files below to see the full abstract

Photocatalytic Nanofiber Membranes for the Degradation of Micropollutants and Their Antimicrobial Activity: Recent Advances and Future Prospects

This review paper systematically evaluates current progress on the development and performance of photocatalytic nanofiber membranes often used in the removal of micropollutants from water systems. It is demonstrated that nanofiber membranes serve as excellent support materials for photocatalytic nanoparticles, leading to nanofiber membranes with enhanced optical properties, as well as improved recovery, recyclability, and reusability. The tremendous performance of photocatalytic membranes is attributed to the photogenerated reactive oxygen species such as hydroxyl radicals, singlet oxygen, and superoxide anion radicals introduced by catalytic nanoparticles such as TiO2 and ZnO upon light irradiation. Hydroxyl radicals are the most reactive species responsible for most of the photodegradation processes of these unwanted pollutants. The review also demonstrates that self-cleaning and antimicrobial nanofiber membranes are useful in the removal of microbial species in water. These unique materials are also applicable in other fields such as wound dressing since the membrane allows for oxygen flow in wounds to heal while antimicrobial agents protect wounds against infections. It is demonstrated that antimicrobial activities against bacteria and photocatalytic degradation of micropollutants significantly reduce membrane fouling. Therefore, the review demonstrates that electrospun photocatalytic nanofiber membranes with antimicrobial activity form efficient cost-effective multifunctional composite materials for the removal of unwanted species in water and for use in various other applications such as filtration, adsorption and electrocatalysis