silanisaatio

Silaneisation (also silanization or silanisation) is a chemical surface modification process in which organosilane molecules are covalently bound to a solid substrate. It typically uses silanes that contain hydrolyzable alkoxy groups and a functional tail. On hydroxylated surfaces such as silica, glass, or silicon oxide, the alkoxy groups hydrolyze to silanols, which then condense with surface silanols or with other silanols to form Si–O–Si bonds. The result is a covalently attached layer that can range from a single molecular layer to a cross-linked network, depending on the silane structure and processing conditions.

The functionality of the silane tail determines the surface properties and reactivity. Common organosilanes include amino- or alkoxy-silanes (for example, aminopropylsilane), glycidoxy- or epoxy-functional silanes, vinyl- and mercapto-rich variants, and carboxyl- or alkyl-terminated silanes. These enable subsequent conjugation of biomolecules, catalysts, or polymers, and allow tuning of surface energy, adhesion, wettability, or biocompatibility. Silane layers are often used to anchor self-assembled monolayers (SAMs) on oxide supports, modify glassware, or couple organic compounds to silica, alumina, or silica-containing materials.

Practical considerations include sensitivity to moisture and oxygen, choice of solvent (commonly alcohols or glycol ethers), pH, and curing conditions. Incomplete hydrolysis or excessive condensation can cause multilayer growth or bridging between features, affecting film uniformity. Characterization methods include contact angle measurements, FTIR, XPS, and ellipsometry to assess coverage and functionality.

Silanisation is widely used in coatings, adhesion promotion, chromatographic supports, biosensors, and surface immobilization in biotechnology and materials science.