Characterization and Improvement of Heat Resistance of a Polymer-Ceramic Pressure-Sensitive Paint at High Temperatures

Abstract

Degradation of fast response pressure-sensitive paints (PSP) above room temperature is a serious problem for PSP measurements in high-temperature environments. A standard polymer-ceramic PSP (PC-PSP) composed of platinum(II)-5,10,15,20-tetrakis-(2,3,4,5,6-pentafluorphenyl)-porphyrin (PtTFPP), titania particles and poly(isobutyl methacrylate) (polyIBM) was characterized to elucidate the degradation mechanism. Applying a two-gate lifetime-based method, the PC-PSP has sufficient pressure and temperature sensitivities even at 100 °C, while the luminescence intensity significantly decreases during the test. Subsequent measurements on thermal and photostability as well as luminescence spectra reveal that the main cause of the degradation is the photodegradation of PtTFPP due to direct exposure of the dye molecules to the atmosphere. In order to suppress such degradation, a small amount of urethane resin is added to the dye solution as a simple additional step in the preparation of PC-PSP. The addition of the urethane resin significantly reduces the degradation of the PSP, although its time response is slightly slower than that of the standard PC-PSP.

Spray-On Colorimetric Sensors for Distinguishing the Presence of Lead Ions

“…Similarly, spray-fabrication of carbon nanotubes has been widely used to create conductive coatings, but these do not function as stand-alone sprayable sensors [9]. In contrast, purely sprayable materials for sensing, on which there is relatively little research, include: fluorescent nanocomposite inks for fingerprint detection [10], FITC-linked aminoethylcellulose particles for pH detection [11,12], porphyrin/coumarin based dyeembedded polymeric nanoparticles for oxygen detection [13], and porphyrin-embedded mesoporous fluorescent particles for pressure detection [14,15], among others. A common feature of such sprayable sensors is the ability of the optical properties to change in the presence of a given stimuli, whether that is a physical or chemical target response.…”