A comprehensive review of varied applications of modified halloysite nanocomposites

Abstract

The recent past has evidenced the technological development in the evolution of nanoscience, with a key role of naturally occurring nanomaterials. Halloysite Nanotubes (HNTs) are 1D dioctahedral 1:1 kaolin-derived clay minerals, with Al2Si2O5(OH)4.nH2O as their chemical formula. The dual functionality of the HNT multiwalled nanotube due to siloxane, aluminol, and silanol groups on the outer surface (negative charge) and aluminol groups on the inner surface (positive charge) makes it unique and pertinent for varied applications. Owning to this charge distribution, several advantages accompanied by feasible modes of synthesis have led to an escalation in the applications of halloysite heterostructure in material science. Various modification strategies and applications have been reported in the last decade with an emphasis on facilitating analytes for the benefit of mankind. Key techniques like hydrothermal, electrospinning/electrostatic fiber spinning, polymerization and co-polymerization, ultrasonication, magnetic stirring, and other hyphenated methods are well exploited for fabricating HNT composites. Innumerable applications, in domains like catalysis, sensing, drug delivery, environmental applications, flame retardants, etc. have been implemented and have paved the way for future research. Thus, the present review articulates the varied fabrication approaches of HNT- nanocomposite and their applications, providing a blueprint for young researchers.