High-luminescence polymer/ceramic pressure-sensitive paint employing low-refractive-index silica nanoparticles

Abstract Pressure-sensitive paint (PSP) is an optical pressure-measurement technique that uses oxygen quenching. In unsteady PSP measurements, PSPs necessitate not only pressure sensitivity and response speed but also higher luminescence intensity. In this study, spherical silica nanoparticles are mixed into the paint to achieve a brighter luminescence. We prototype PSPs using particle size and mixing ratio as parameters and evaluate their performance. The results exhibit the luminescence intensity changes due to the low refractive index of silica; the smaller the particle size and the higher the particle ratio, the stronger the luminescence intensity. Silica-based PSPs are approximately 1.5 times brighter than titania-based PSP; which have frequently been used in previous studies. Additionally, a comprehensive performance investigation indicates that the silica-based PSP with the brightest formulation has a pressure sensitivity of 0.72 %/kPa with a response speed of 11.0 µs. These results prove that the higher luminescence is compatible with the high sensitivity and fast response using low-refractive index nanoparticles.