For grafting polypyrrole layers on oxidic substrates, the synthesis and characterization of a new adhesion promoter 11-(pyrrol-3-yl) undecyl trimethoxysilane (PyTMS) were described in this article. The oxidation potential of PyTMS was determined by cyclic voltammetry. The grafting behavior of such an adhesion promoter on oxidized surface and chemical deposition of polypyrrole over the modified oxidized surface were studied. The adsorbed layer on the oxidized substrates thus formed was determined by both contact angle measurements and X-ray photoelectron spectroscopy. Chemical polymerization of terminal pyrrole moieties on such substrates yielded adhesive polypyrrole films, and SEM image showed that the morphology of the polypyrrole films was influenced by the experimental conditions.

ω-(Pyrrol-1-ylalkyl)dimethylchlorosilanes with different chain lengths were adsorbed on silicon oxide surface, subsequently, the polypyrrole film was deposited on this modified substrate. The chemical deposition of polypyrrole on the modified surface was investigated by SEM and AFM. The thickness of deposited polypyrrole films on different chain adhesion promoter modified substrates has no big difference except that of the short chain length. The electric properties were investigated by current-potential characterization. The results show that the value of the electrical current does not monotonically depend on the length of the spacer of the adhesive monolayer. The electric property shows that the charge carrier mobility is 1.4×10⁻⁴ cm²·V⁻¹·s⁻¹.

The problem of delamination of electro-deposited polypyrrole (PPY) layers on several substrates can be avoided by using an adhesion promoting system. A new class of compounds–ω-(pyrrol-3-yl)alkylphosphonic acids have been designed to link polypyrrole layers covalently to metal oxide surfaces. Synthetic routes, which lead to the formation of 3-substituted pyrroles with surface active groups are described. The synthesis and characterization are shown in detail. 1-Phenylsulfonyl pyrrole was utilized as a precursor in the synthesis of 3-substituted pyrroles via Friedel-Crafts acylation reaction. Subsequently, two methods were used to synthesize ω-(pyrrol-3-yl)alkylpho- sphonic acid esters. One starts from the brominated oxoalkyl derivatives by removing the protecting group followed by reduction yielding ω-(pyrrol-3-yl)alkylphosphonic acid esters. This method is suitable for hexyl or longer chain derivatives. The other is the reduction of carbonyl group followed by de-protection, which is successful for short as well as long chain derivatives. Finally, ω-(pyrrol-3-yl)alkylphosphonic acids were obtained by hydrolysis of the ester derivatives.