Ideality of pressure-sensitive paint. III. Effect of the base-coat permeability on the luminescence behavior of the sensing layer

✍ Scribed by Sébastien Gouin; Martin Gouterman

• Publisher: John Wiley and Sons
• Year: 2000
• Tongue: English
• Weight: 144 KB
• Volume: 77
• Category: Article
• ISSN: 0021-8995
• DOI: 10.1002/1097-4628(20000923)77:13<2815::aid-app3>3.0.co;2-j

✦ Synopsis

The response time and temperature dependence of a pressure-sensitive paint (PSP) based on platinum tetra(pentafluorophenyl)porphine (PtTFPP) in the fluoroacrylic polymer FIB significantly increases for bilayer paint systems that include a base coat made of different polymers with solid TiO 2 added as scattering agent, compared to the single-layer sensor paint. The temperature dependencies at vacuum are the same in the various bilayer coatings (paint/base coat) as compared to monolayer paint, roughly Ϫ0.53%/ o C. With FIB base coat the percent of TiO 2 is adjusted to reduce photodegradation, in which case only a slight increase in response time (0.6 3 0.8 s) is caused by the base coat and there is almost no change in temperature dependence at 1 atm. However, in the cases of the less permeable polymers, poly(methylmethacrylate) (PMMA) and poly(vinyl acetate) (PVA), there is increased response time of the bilayer coating (rising, respectively, to 15 and 7 s) and significantly greater temperature dependence at 1 atm. The highly impermeable polyacrylonitrile (PAN) as base coat shows little effect on response time but a somewhat higher temperature dependence at 1 atm compared to vacuum. For the highly permeable polydimethylsiloxane (PDMS), adjustment of the TiO 2 concentration is needed to prevent an increase in temperature dependence but both PDMS base coats tested have response times Ͻ 2 s and lowtemperature dependence.