Allophane, a natural nanoparticle present in andisols of equatorial Ecuador, properties and applications

Abstract

Allophane is a natural nanoparticle present in soils of volcanic origin such as andisols, which are distributed around the world in countries with volcanic activity. In Ecuador, andisols constitute 30% of the territory in high and humid areas of the northern highlands. Allophane can be obtained from andisols through physical and chemical processes, or it can be synthesized. This nanomaterial has multiple properties for various applications in different areas. There is a lot of research on these nanoparticles and this type of soils, but they have not been studied yet in Ecuador. In this article, the structural characteristics, properties, formation, isolation, synthesis and uses of allophane are presented, with the finish of generating knowledge and encouraging research on these soils that are the source of the aforementioned nanoparticle. The literature search was performed in Science Direct and Google Scholar databases, and high impact articles related to natural or synthetic allophane research were used. The particular characteristics that allophane has allows it to be used as an environmental remediator, bactericide, anti-inflammatory, flame retardant, enzyme support, but in addition it has been studied in catalysis, photocatalysis and electrocatalysis. Considering the area covered by allophane in the Ecuadorian territory and its availability, it can be used for research based on international studies that have been developed to take advantage of it in the environmental and medical areas.