Chemie an starren Grenzflächen, 7 [1] Ausgewählte Beispiele der chemischen Grenzflächenmodifizierung von Aerosil / Chemistry at Rigid Surfaces, 7 [1] Selected Examples of the Chemical Surface Modification of Aerosil

Abstract

Aminoaerosil containing primary amino end groups is obtained according (1) by reaction of aerosil with γ-triethoxysilylpropyl amine (Table II). The NH2-anchor groups are acylated in the usual manner: carbonic acid anhydrides, acid chlorides and acid azides and by application of the carbodiimide method (Table III). Optically active groups and phosphoric acid diestergroups are covalently linked with the surface of aerosil according (2) and (3). Aminoaerosil reacts with vinylsulfones as anchor groups of dyes (Remazol- Dyes) producing a covalent bond according (6). Functional groups linked to the surface of aerosil react “normal” (with respect to homogenous solutions) with group specific reagents. Examples: bromination, ozonization of C-C double bonds, hydrolysis of phosphoric acid esteramidates and surface bound chloroamine-T groups. "Interparticular" reactions of modified aerosil are not observed. But aerosil with electroactive groups are electroreduced using Hg- or Pb-electrodes. The optical induction of the catalytic hydrogenation of prochiral defines using palladium deposited on chiral modified aerosil surfaces is low (ca. 1%). Some analytical methods are presented, which are recommended for the determination of the amount of functional groups bound to the surface.