Study On Photophysics Of Temperature Response And Pressure Response Materials

Based on the oxygen or thermal luminescence quenching, optical temperature sensors or pressure sensors have the unique capability of providing non-contact, global temperature or pressure measurement visualization and tremendous information at various temperature range and different flow rate in the aerodynamic measurements.Temperature sensitive paint(TSP) and pressure sensitive paint(PSP) contain the polymer binder and the temperature or oxygen sensitive luminophores. The polymer binder in TSP or PSP is an important ingredient for the luminescent paint systems. It not only serves to adhesion the paint to the model surface, but also has significant influence on the TSP or PSP properties including the temperature or pressure sensitivity and the response time as well. In TSP, the interaction between probes and matrix results in the alteration of both the non-radiation decay rate and the activation energy of the non-radiative process for the thermal quenching process of TSP are significant, i.e. larger activation energy of the non-radiative process shows higher temperature sensitivity and less emission intensity for TSP. Moreover, the values of I0/I100 and Ksv for such materials increased with increasing the oxygen permeability of the polymer matrix in PSP.The thermal quenching behaviors of the temperature sensitivity paints(TSP)composed of europium(III) thenoyltrifluoroacetonate(EuTTA) and Eu-phenanthrene complex(Eu-2) in polystyrene(PS), polymethylmethacrylate(PMMA) and epoxy resin(EP) were investigated. It is found that both the emission intensity and temperature sensitivity were not only affected by the luminescence probes, but also by the polymer matrix. In the investigation of PSP, when silicone polymer, fluoro-containing siliconepolymer and copolymer were composed with pyrenebutyric acid(PYB) and tetrakis(p-tolyl)benzidine(TBD), respectively, it is found that the KSV and response time depended on oxygen permeability of the polymers for PYB, corresponding to diffusion controlled mechanism. Otherwise, the interaction of TBD with the polymers caused the emission shift, i.e. charger transfer takes place in the systems and then KSV depends on their electric state of the composites. Therefore, it means the oxygen quenching of the TBD/polymer materials follows charger –transfer controlled mechanism.The TSP and PSP studied in this work were applied to aerodynamic measurement for wind tunnels, the results of temperature or pressure distribution on model surface were significantly corresponded with that of the traditional measurement methods.