SilikatenNetzen

SilikatenNetzen are extended three-dimensional frameworks formed by silicate tetrahedra that share oxygen atoms. Each silicon atom is coordinated to four oxygen atoms, and neighboring tetrahedra connect at their corners to build a continuous Si–O–Si network. The degree of polymerization of the network, often described by the distribution of bridging and non-bridging oxygens, strongly influences the material’s properties.

In the structural taxonomy of silicates, network-forming frameworks are exemplified by tectosilicates, which include quartz and feldspars. These minerals feature nearly fully cross-linked SiO4 tetrahedra, producing rigid, high-melting, and chemically resistant solids. The presence of aluminum in the framework (aluminosilicates) introduces negative framework charges that are balanced by cations such as Na+, Ca2+, or K+. Zeolites are a notable subclass of aluminosilicate networks with well-defined porosity and ion-exchange capabilities.

SilikatenNetzen also encompass related network structures found in synthetic materials, including glassy silicates and geopolymers, where the network is formed through polymerization of SiO4 units under specific conditions. The network topology—bond angles, degree of cross-linking, and the presence of substitutions—controls properties such as hardness, melting point, chemical durability, and thermal stability.

Natural occurrence and industrial relevance are broad. Silicate networks make up the bulk of the Earth’s crust and underpin many ceramics, glass products, and catalyst supports. Their study integrates mineralogy, geochemistry, and materials science, as researchers explore how network connectivity governs structure–property relationships in both natural and engineered systems.