Preparation and characterization of 5,10,15,20-tetraphenylporphyrin Langmuir films for gas chemsensor applications

作者：Mansur Herman S^*; de Sales Nelicio F; Mansur Alexandra A P

来源：Surface and Interface Analysis, 2011, 43(11): 1423-1429.

DOI：10.1002/sia.3734

• spectroscopy
• porphyrin films
• Langmuir-Blodgett film
• Langmuir-Schaefer film
• gas sensor

In this work is reported the preparation and characterization of 5,10,15,20-tetraphenylporphyrin (H2TPP) films at the water-air interfaces. The surface pressure-area isotherms (pi-A) and UV-Vis spectroscopy were used to investigate the effect of the spreading methods and parameters on the porphyrin monolayer formation. Also, Langmuir-Blodgett (LB) and Langmuir-Schaefer (LS) films were deposited onto glass substrates in order to study the conformation changes in porphyrin molecular packing. Quartz crystal microbalance (QCM) was utilized as the active solid substrate for the development of the NO2 gas sensor based on the H2TPP molecular films. The results of pi-A curves have clearly shown the significant contribution of the preparation methods and processing parameters on the conformation of porphyrin molecular films. The UV-Vis spectroscopy results using polarized absorption dichroism have indicated different molecular packing for porphyrin films deposited by LB and LS methods, with relative tilted angles of 50 degrees +/- 5 degrees and 35 degrees +/- 5 degrees, respectively. Moreover, the QCM response has given strong evidence that H2TPP porphyrin molecular films have performed as NO2 chemsensor.

• 出版日期2011-11