Halloysite nanotubes: prospects and challenges of their use as additives and carriers - A focused review

There is increasing research interest in potential applications of halloysite as fillers for polymer composites, controlled drug delivery, carriers for the supply and sustained release of active agents for anticorrosion coatings, in nanoreactors or nanotemplates, and for the uptake of contaminants or pollutants and support for catalysts. In this review, recent findings in terms of the prospects and challenges of using halloysite nanotubes (HNTs) in different polymeric matrices targeting a range of old and new applications are discussed and evaluated. The compositions include chitosan/halloysite membranes as bone-tissue scaffolds, polylactic acid (PLA)/halloysite membranes for food-packaging applications and their antimicrobial activities, instrumented impact properties of epoxy/halloysite nanocomposites and the role of halloysite in the self-healing of epoxy composites, polyacryronitrile (PAN)/halloysite membranes for use in water filtration as well as a review of some recent applications of halloysite/alginate beads in the adsorption of contaminants such as lead.