Halloysite nano-particles have recently become the subject of research attention as a new type of material.Halloysite nanotubes (HNTs) are readily obtainable and are much cheaper than other nano-particles such as carbon nanotubes(CNTs). More importantly, the unique crystal structure of HNTs not only resembles that of CNTs in terms of aspect ratio,but also has a highly ordered structure with aluminol groups bound in the inner surface and silanol groups on the external surface. Consequently HNTs not only have potential as additive for enhancing the mechanical performance of polymers but also make them attractive candidates for a variety of potential applications, including molecular adsorption, molecular encapsulation, storage and transport, catalyst or catalyst support in chemical reactions.This review summarizes the extensive but scattered literature on halloysite nanotubes’ application, from its crystal structure, chemical and characteristic of morphological, to its adsorption, transport and catalysis reactivity, involving the various valuable prospects. Finally, the future trends and prospects in the development of application research of HNTs are highlighted. Contents
1 Introduction
2 Chemical composition and crystalline structure of halloysite nanotubes
3 Adsorption,storage and transport properties of HNTs
3.1 Transport properties of hydrogen-bonding liquids such as water, methanol and ethanol
3.2 Adsorption storage properties of fuel gas CH₄, H₂ on HNTs
3.3 HNTs as the support for drugs or bioactive molecules
3.4 HNTs as sorbents for contaminants and pollutants
4 HNTs used as catalyst or catalyst support
4.1 Acid catalyst
4.2 Enzymatic carrier
4.3 The support of the catalyst metal complexes
5 Some other properties of HNTs
6 Outlook