A novel pyrene-based binary pressure sensitive paint with low temperature coefficient and improved stability

Pyrene-based pressure sensitive paints (PSP) have certain advantages due to their high pressure sensitivity and low temperature coefficient but their major drawback is the paint degradation under wind tunnel conditions. This is due to the loss of pyrene as a result of diffusion and sublimation from the coating. We have developed a novel stable binary PSP formulation in which pyrene is covalently bonded to the polymer binder so that paint degradation is prevented. The coating thus obtained is a siloxane-based hybrid organic–inorganic material. The pressure sensitive paint also contains an additional reference luminophore, which is insensitive to pressure but sensitive to intensity variations on the model surface. The second luminophore is incorporated in the paint to correct for the excitation intensity variations during the wind tunnel experiment. The temperature coefficient of second luminophore exactly cancels the temperature coefficient of the pressure sensitive luminophore, thereby resulting in a binary paint with negligible temperature sensitivity.