Optical and vapor sensing properties of calixarene langmuir-blodgett thin films with host-guest principles
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25,27-(Dipropylmorpholinoacetamido)-26,28-dihydroxycalixarene was used as a chemical sensor material in this work. The calixarene LB thin films were prepared onto a gold-coated glass and quartz glass substrates to fabricate a thin film chemical sensor element. Atomic Force Microscopy (AFM) and Surface Plasmon Resonance (SPR) techniques were used to characterize all the calixarene LB thin films. The film thickness and the refractive index of thin films can be evaluated with the fitted experimental SPR datas. The refractive index and the thickness per monolayer of LB films were determined as a 1.58 +/- 0.04 and 1.27 +/- 0.09nm, respectively. The calixarene LB thin film chemical sensor element was exposed to dichloromethane, chloroform, benzene and toluene vapors. The SPR kinetic measurements displayed that, the photodetector response change, I-rf for saturated dichloromethane vapor is much larger than the other vapors with the I-rf value of 48 au and the diffusion coefficient value of 5.1 x 10(-16) cm(2)s(-1). Swelling process was analyzed by well known Fick's Equations. In this approach diffusion coefficients for swelling were conformed to the square root of time and were correlated with the volatile organic compounds. Our results showed that calixarene thin film has a highly selective with a large response to dichloromethane vapor.