aminosilanen

Aminosilanes are a class of organosilicon compounds that contain an amino functional group and at least one hydrolysable silane substituent. They are typically described by structures such as (RO)3Si–(CH2)3–NH2, where RO are alkoxy groups (for example ethoxy or methoxy) and the amino group is connected to a propyl chain attached to silicon. Common examples include (3-aminopropyl)triethoxysilane (APTES) and (3-aminopropyl)trimethoxysilane (APTMS).

In the presence of moisture, these compounds hydrolyze their alkoxy groups to silanols, which can then condense to form siloxane networks. On hydroxylated inorganic surfaces such as silica, glass, or metal oxides, the silanol groups react to form covalent Si–O–Si or Si–O–M bonds, covalently attaching the organic moiety to the surface. The terminal amine group remains available for further chemical modification, such as linking biomolecules, polymers, or crosslinkers, making aminosilanes valuable as surface modifiers and coupling agents.

Applications include adhesion promotion in coatings and composites, surface functionalization of glass, silica, and metal-oxide substrates, and preparation of biosensors or microfluidic devices. They are used to introduce amine functionality for subsequent chemistries, including NHS-ester coupling, glutaraldehyde crosslinking, or direct amine-based reactions.

Handling and limitations: aminosilanes are moisture-sensitive and are typically used in anhydrous organic solvents or controlled humidity conditions. They can oligomerize or polymerize if not stored properly, which can affect coating uniformity. Safety considerations include irritation and exposure hazards; use appropriate PPE and ensure proper ventilation.