Oxygen Permeability of Sol-Gel Coatings

Sol-gel processes are applied to prepare organic-inorganic composite coatings. The purpose of this report is to evaluate the possibility of tuning the oxygen permeability of the resulting coatings. It is proposed that if the oxygen permeability is largely controlled by the hydrophobic character and the pore sizes of membranes, then the permeability of the solgel coatings could be tuned by adjusting the composition of the organosilane precursor. The oxygen permeability is measured by the selective oxygen quenching of phosphorescent probes, such as platinum octaethylporphine (PtOEP). The application of such sol-gel coatings for optical fiber oxygen sensors will also be discussed.