Carbon nanotube membranes: synthesis, properties, and future filtration applications

Over the course of the past decade, there has been growing interest in the development of different types of membranes composed of carbon nanotubes (CNTs), including buckypapers and composite materials, for an ever-widening range of filtration applications. This article provides an overview of how different types of CNT membranes are prepared and the results obtained from investigations into their suitability for different applications. The latter involve the removal of small particles from air samples, the filtration of aqueous solutions containing organic compounds and/or bacteria, and the separation of individual liquids present in mixtures. A growing number of reports have demonstrated that the incorporation of CNTs into composite membranes confers an improved resistance to fouling caused by biomacromolecules and bacteria. These results are discussed, along with evidence that demonstrates it is possible to further reduce fouling by taking advantage of the inherent conductivity of composite membranes containing CNTs, as well as by using different types of electrochemical stimuli.