Surface treatments by silanization of metallic polycristalline titanium

In this work, we were interested in different ways of functionalizing polycristalline titanium surfaces. These functionalizations are based on the reaction between the outermost surface of the oxydized metal ("TiO2") and 'SiCl3 groups of the organic molecules in a way to create stable chemical bonds of the Ti-O-Si type. In a first step, we established pretreatment and silanisation conditions of the substrates. We showed, using appropriate analysis methods (XPS, contact angle measurements), that our silanization process led to the formation of dense, organized and strongly anchored monolayers to the titanium surface. We also set the synthesis of different functional organosilanes.

We then studied the grafting of a new bifunctional silanisation agent containing a terminal diazo group capable of initiating a radical polymerization from titanium samples. We established the polymerization conditions of styrene and applied these conditions to two others vinyl monomers such as methyl methacrylate and 4-chloromethylstyrene. In all cases, the so synthesized polymer films are thicker than 40Å. The methyl methacrylate and poly(4-chloromethyl)styrene films are particularly interesting because they allow subsequent functionalizations in order to attach biomolecules (peptides, proteins, ADN strands,...) through their ester and chloromethyl groups, respectively. We also approached the dilution of initiating agents on the surface and its influence on molecular masses of the polymers.

The electrodeposition of polypyrrole on pyrrole-functionalized self-assembled monolayers was also examined. We carried out a study on ITO glass substrates and applied these conditions for titanium substrates.

Finally we tested the interdigitation of functionalized alcanes into branched alkylsilane monolayers. We first studied the structure of self-assembled monolayers of different branched alkylsilanes and second we carried out some interdigitation experiments.