Halloysite clay nanotubes: Innovative applications by smart systems

Halloysite clay nanotubes (HNTs) are unique porous aluminosilicates that have assumed the role of a multiplex, adaptable, low-cost, and sustainably sourced nanocomposite across a vast array of applications. HNTs have presented diverse opportunities to researchers from different fields, leading to substantial advances in the applications and innovative uses of HNT as a multifaceted nanocomposite in smart system designs. This review focuses on the role of HNTs in intelligent systems that have wholly realized the potential of HNTs and discusses the important structural, chemical, and physical properties of HNTs concerning different applications and as a core element in complex systems. This review highlights the key challenges HNT-based nanocomposites address and provides prospects for the potential applications of HNTs. This review found that smart materials take advantage of the structure, composition, and morphology of HNTs simultaneously, achieving application-specific results due to the passive and active impact of the HNTs on other elements of the smart system and the surrounding environment. Pioneering efforts stemming from the assortment of performance-enhancing options HNTs can offer have revived the application potential of sustainable materials, which have conventionally suffered from low stability, retention, effectiveness, poor mechanical performance, or overall material incompatibility. Furthermore, the dynamic behavior of the HNTs rising from the structural stability of these natural nanotubes across various physical and chemical conditions has permitted researchers to design smart systems based on the operative contributions of HNTs to application-oriented material performance under fluctuating settings. This review highlighted how HNTs are poised to be a component of next-generation materials in sectors vital to sustainable development, ranging from biotechnology to energy storage.