Abstract:Pressure-sensitive paint ( PSP), as a molecular-level oxygen sensor, has been widely used for high resolution full-field aerodynamics measurement of aircrafts. To apply PSP for the analysis and study of aerodynamic characteristics of aircrafts in near-vacuum environment, PSP with sufficiently high pressure sensitivity at low pressures needs to be prepared and studied to enable small pressure measurements in near-vacuum environments. In this article, two PSPs, namely PdTFPP / PTMSP and PtTFPP / PTMSP, with high-oxygenpermeability polymer PTMSP as the binder, PdTFPP and PtTFPP as luminescent molecules, are used to carry out the static calibration characteristics in near-vacuum environment. Experimental results show that the pressure sensitivity of PdTFPP / PTMSP is significantly higher than that of PtTFPP / PTMSP. While the temperature sensitivity and photostability of PdTFPP / PTMSP are comparable to those of PtTFPP / PTMSP, which is more suitable for measuring small pressure changes in near-vacuum environment. Further characterization of PdTFPP / PTMSP reveals that the pressure sensitivity of PdTFPP / PTMSP increases and then decreases with the increase of the concentration of luminescent molecule and polymer, and reaches the highest value of 68. 65 % / kPa at concentrations of luminescent molecule and polymer are 1. 2 and 8 mg / mL, respectively. The PdTFPP / PTMSP with toluene as solvent has the better pressure sensitivity than the formulation with dichloromethane or acetone as solvent, and has the optimum temperature sensitivity and photostability.