Development Of A Method For Vapour Phase Trimethylsilylation Of Surface Hydroxyl Groups

An efficient vapour phase routine for the conversion of surface OH groups into trimethylsilyl ether ones at room temperature was developed. A high reaction yield ranging between 90-100% could be achieved in a reasonable treatment time of 15 minutes for common trimethylsilylation agents such as N,O-bis(trimethylsilyl)acetamide and trimethylsilyl chloride after addition of pyridine acting as a catalyst. The presented trimethylsilylation method also exhibits a good selectivity to hydroxyl groups, as demonstrated on model polymers containing other moieties of amine (NH2), carbonyl (C=O) and carboxyl (COOH). Besides for tuning the wetting characteristics of material surfaces, i.e. from hydrophilic hydroxyl groups to hydrophobic trimethylsilyl ether ones, the developed method can find its application also in the surface chemical analysis by means of chemical derivatisation x-ray photoelectron spectroscopy.