Formation of Si—C bonds at the surface of silica and glass fibres

Amorphous silica and glass fibres have been derivatised at the surface with fluorinated aromatic molecules. The resultant materials have been analysed by various techniques including thermogravimetry (TG), dynamic contact-angle analysis and, to a large extent, mass spectrometry. The last method was found to be particularly useful for the analysis of the surface of silica materials. Two different experimental routes were used to produce a -CH2C6F5 modified surface. Further modifications to these materials involved attempted nucleophilic replacement of fluorine of the pentafluorobenzyl group with phenolate and benzoate anions. The materials were relatively hydrophobic and have potential use in glass-fibre composites by prevention of water ingress along the interface of the material.