Halloysite-based material with improved cation sorption properties

Abstract

Halloysite is 1:1 layered, dioctahedral phyllosilicate. It belongs to kaolinite subgroup of kaolinite-serpentine group. Halloysite is often defined as a hydrated phase of kaolinite. Two types of this mineral are distinguished: hydrated 10 Å-halloysite, with water molecules in the interlayer space and dehydrated 7 Å-halloysite. Widely conducted research on modified kaolin group minerals, either intercalates or grafted compounds with selected organic molecules opened many possibilities for using this layered aluminosilicate in industry and environmental protection. One of the possible applications is the sorption of heavy metals. For the raw halloysite the sorption exclusively takes place on the particles surface. The interlayer space of the mineral is not accessible for cations. Thus the research goal was to provide the access of cations to the interlayer using organic modifications with selected aminoalcohols (Letaief & Detellier 2007). Moreover, the sorption properties of the new material towards selected cations were examined.