Silicatesheet

Silicatesheet is a term used to describe a two-dimensional layer formed by silicate tetrahedra arranged in a planar network. In this arrangement, each silicon-centered tetrahedron shares three of its oxygen atoms with neighboring tetrahedra, creating a sheet that carries a negative charge balanced by interlayer cations or by adjacent octahedral sheets. These sheets can exist alone or be combined with octahedral layers to form layered silicate structures.

Two common motifs occur in silicate sheets: 1:1 and 2:1 layered silicates. In 1:1 structures, such as kaolinite, a tetrahedral sheet is bonded to a single octahedral sheet. In 2:1 structures, like illite and montmorillonite, two tetrahedral sheets sandwich one octahedral sheet. The octahedral layer and the tetrahedral sheets can be dioctahedral (dominant aluminum or magnesium in the octahedral layer) or trioctahedral (dominant magnesium or iron).

Natural and synthetic silicatesheets are widespread and functionally diverse. They are central to clay minerals used in soils, ceramics, drilling fluids, and as rheology modifiers and adsorbents. When exfoliated or organo-modified, silicatesheets are employed as reinforcement in polymer nanocomposites and as catalyst supports. In materials science, silicatesheets are studied as two-dimensional materials with high surface area and tunable chemistry.

Related concepts include phyllosilicates, clays, micas, and smectites, which describe specific arrangements, compositions, and behaviors of silicate sheets in natural and engineered systems.