Sustainable Nanotechnology

10 Nanotechnology Applications in Natural Nanoclays Production and Application for Better Sustainability

Manjir Sarma Kataki, Bibhuti Bhusan Kakoti, Kangkan Deka, and Ananya Rajkumari

Department of Pharmaceutical Sciences, Dibrugarh University, Dibrugarh, Assam, India

10.1 Introduction

Nanoclays are fine‐grained crystalline materials composed of layered mineral silicates. Nanoclays are compounds based on silicon, oxygen, and other elements. A layer is the basic structural unit of nanoclays, and these layers are likely to position themselves over one another like pages of a book. Individual layers are composed of the tetrahedral and/or octahedral sheets, and this arrangement of sheets plays a crucial role in defining and differentiating these clay minerals. In tetrahedral sheet, the silicon–oxygen tetrahedra are linked to the neighboring tetrahedra by sharing three corners, while the fourth corner of each tetrahedron forms a part to the adjacent octahedral sheet. The octahedral sheet is typically composed of aluminum or magnesium in a sixfold coordination with oxygen from the tetrahedral sheet and with hydroxyl. Tetrahedral sheets consist of silicon–oxygen tetrahedra linked to the neighboring tetrahedra, sharing three corners, while the fourth corner of each tetrahedron sheet is linked to an adjacent octahedral sheet via a covalent bond. The arrangements of these sheets impact various defining and distinguishing aspects of nanoclays. Depending on their mineralogical composition, ...