Halloysite nanotubes: Design, characterization and applications. A review

Abstract

Halloysite nanotubes (HNTs) have several exciting potential applications in polymer nanocomposites. These are naturally sourced nanomaterials obtained from the mines as a natural deposit. The hollow tubular nanostructure with biocompatibility, environmental friendly and low-cost possessing makes halloysite as trendsetter in green nanotechnology. These are composed of double-layered, aluminosilicate minerals with an ultra-tiny hollow tubular structure in submicron range. The specific characteristics of HNTs lead to plentiful range of applications in environmental sciences, dye removal, anticorrosive coatings, in cosmetics, flame retardants, forensic science, etc. HNTs display remarkable thermal stability, faster adsorption rates, tuneable release rates, excellent drug encapsulation, biocompatibility, mechanical properties and ease of availability, therefore with numerous pharmaceutical applications. Nanomedical applications are gene delivery, tissue engineering, cancer and stem cells isolation and bio-imaging. This review is focused on the detailing HNTs for its structure features, functionalization methods, drug loading and their versatile applications.