Development of pressure sensitive molecular film composed of platinum porphyrin complex

The pressure-sensitive paint (PSP) has potential as a diagnostic tool for pressure measurement in the high Knudsen number regime because it works as a so-called "molecular sensor". However, there are few reports concerning application of the PSP to micro devices, because the conventional PSP is too thick owing to the use of polymer binder. In our previous work, we have adopted Langmuir-Blodgett (LB) technique to fabricate pressure sensitive molecular films (PSMFs) using Pd (II) Mesoporphyrin IX (PdMP). The PSMF based on PdMP has pressure sensitivity at low pressure range (below 130 Pa) only. In this study, we have constructed PSMF composed of Pt (II) Mesoporphyrin IX (PtMP) to apply pressure measurement near atmospheric pressure condition. The pressure sensitivity and temperature dependency of PSMF based on PtMP has tested, and it is clarified that the PSMF of PtMP has equivalent pressure sensitivity of polymer PSP and the temperature dependency of PSMF is dominated by non-radiative deactivation process of excited luminophore molecule. The pressure distribution on the solid surface interacting with supersonic free-jet can be measured with PSMF composed of PtMP.