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

Abstract

The allophane is a natural nanoparticle present in soils from volcanic origin such as andisols, which are distributed worldwide, especially in countries that have active volcanoes. In Ecuador, andisols are in high and humid areas from the Highland/North region, constituting 30% of the territory. The allophane can be obtained from andisols through physical and chemical processes or it can be also synthesized. This nanomaterial has multiple properties for various applications in different areas; and there are studies about these nanoparticles and this kind of soil, but they have not yet been conducted in Ecuador. This article presents a review of structural characteristics, properties, formation, isolation, synthesis and uses of allophane to extend knowledge and encourage the conduction of research in these soils, which are the source of the aforementioned nanoparticle. The literature review was performed on Science Direct and Google Scholar databases using high impact articles related to natural or synthetic allophane. Allophane has characteristics that allow it to be used as an environmental remediator, bactericidal, anti-inflammatory, flame retardant, enzyme support and also in catalysis, photocatalysis and electrocatalysis. Considering the availability and the large area covered by andisols in Ecuador, research based on international investigations can be perform to take advantage of it.