Porphyrins Color Sensor Sensitive Film Preparation And Performance

In this paper, two metalloporphyrin ZnTPP and CuTPP functional films were prepared by Langmuir-Blodgett (LB) technology. The LB films were characterized by UV-visible spectrum, BAM microscope and AFM method. The influenc of different preparation conditions on film's morphology and gas sensitivity were investigated. The color changing mechanism of LB films was investigated and the exploration of obtained LB films for colorimetric sensor array application was also included. The main works are as follows:1. The influence of surfactant stearic acid (SA) on improving film forming ability of metalloporphyrin Langmuir and LB film was characterized through BAM microscope andπ-A-isotherm.2. Different influnce of processing conditions on the metalloporphyrin LB films were studied through the AFM and UV-visible spectrum. It has been found that, comparing to great effect on ZnTPP LB film, the film layers and the surface pressure have no effect on the Soret absorption peak position of CuTPP LB film. However, the surface pressure showed great effection on the CuTPP LB film Q band than ZnTPP film's with the evidence that the film Q band absorption intensity versus its Soret band absorption intensity changed obviously, as it did not occur in the ZnTPP LB film.3. Based on the gas sensitivity of ZnTPP and CuTPP LB films in response to volatile organic compounds such as tetrahydrofuran, ethyl acetate and pyridine, it has been found that ZnTPP LB film was extremely active in the gas-sensing test, and its absorption spectrum was influenced not only by the type of the atmosphere, but also the surface pressure and the film layers. Moreover, the results revealed that the changing of electronic state in ZnTPP LB film affected by ligand molecules exhibited two different trends at different surface pressure, which indicated that both the type and method of liganding had influenc on changing of electronic state in ZnTPP LB film.4. The mixture of three kinds of volatile organic compound was sucessfully distinguished by obtained metalloporphyrin LB film covered gas sensor and these novel functional ultrathin film exhibites promising application for colorimetric sensor array.