【摘要】 光学-氧压敏感涂料(pressure sensitive paint,PSP)由氧敏感的发光探针和聚合物载体组成,涂料的氧压灵敏度既与发光探针有关,也与聚合物载体有关.以四(五氟苯基)卟啉铂(PtTFPP)为发光探针,将它分别与四种聚合物即聚二甲基硅氧烷(PDMS)、聚甲基苯基硅氧烷(PMPS)、聚甲基氟丙基硅氧烷(PFS)和三氟氯乙烯-醋酸乙烯酯共聚物(PFC)混合成膜.研究不同聚合物对PSP的氧压灵敏度的影响,在室温和氧浓度[O2]分别为0%、20%、40%、60%、80%和100%环境下,以λ=365 nm的光激发,测定其对荧光强度I的猝灭作用,从I0/I(I0为纯N2气氛下的荧光强度)对[O2]的关系可知:它们的氧猝灭灵敏度随聚合物的氧透过性而增加,即PDMS>PMPS>PFS>PFC,该结果表明上述体系的氧猝灭可从扩散控制机理得到解释.更多还原

【Abstract】 Based on luminescence quenching of chromophoric probes in oxygen permeable polymer matrix, pressure sensitive paint( PSP) and its devices have been developed as a kind of functional materials in recent years. The pressure sensitivity of PSP not only depends on the probe molecules,but also on the polymer matrix. In this work,tetrakis( pentafluorophenyl) porphyrin platinum( PtTFPP),as a luminescent probe,was composed with polydimethylsiloxane( PDMS),polymethylphenylsiloxane( PMPS),polymethyltrifluoropropylsiloxane( PFS) and trifluorochloroethylene-vinyl acetate copolymer( PFC) respectively,and then their luminescence quenching behaviors were measured at an excitation of λ = 365 nm with various oxygen concentrations from 0% to 100%. The ratio I0/ I100is used as oxygen sensitivity of PSP films,where I0and I100represent the fluorescence intensities from films exposed to 100% nitrogen and 100% oxygen,respectively. The I0/ I100values of the PtTFPP-based films are evaluated. It is found that the plots of I0/ I versus [O2]with identical Ksv are obtained and a two-site model fits the experiment data very well for the PtTFPP / polymer systems,except PtTFPP / PFC films. The values of I0/ I100and Ksvfor such materials increased with increasing the oxygen permeability of the polymer matrix,i. e. PDMS > PMPS > PFS > PFC,which is identical with theoretical reasoning. Therefore it could be concluded that the oxygen quenching for the PSP materials in this work showed a diffusion-controlled mechanism.更多还原