Preparation and gas sensing properties of Langmuir-Blodgett thin films of calix[n]arenes: Investigation of cavity effect


ÖZMEN M., ÖZBEK Z. , Bayrakci M., ERTUL Ş., ERSÖZ M., ÇAPAN R.

SENSORS AND ACTUATORS B-CHEMICAL, cilt.195, ss.156-164, 2014 (SCI İndekslerine Giren Dergi) identifier identifier

  • Cilt numarası: 195
  • Basım Tarihi: 2014
  • Doi Numarası: 10.1016/j.snb.2014.01.041
  • Dergi Adı: SENSORS AND ACTUATORS B-CHEMICAL
  • Sayfa Sayıları: ss.156-164

Özet

Characterization and organic vapor sensing properties of Langmuir-Blodgett (LB) thin films of calix[n]arene (n=4, 6, 8) derivatives are reported in this work. Surface pressure-area isotherm graph shows that very stable monolayers are formed at the water surface. The results indicate that good quality, uniform LB films can be prepared with a transfer ratio of over 0.95. Calix[n]arene LB films have been characterized by contact angle measurements, quartz crystal microbalance (QCM), scanning electron microscopy (SEM) and atomic force microscopy (AFM). LB film of calix[8]arene which has the largest cavity yields a gradient with a mass value of 773 ng per layer according to the QCM results. AFM and SEM images showed a dense surface morphology obtained for all samples. QCM system was used for the measurement of sensor response against chloroform, benzene, toluene and ethanol vapors. These LB film samples yield a response to all vapors with a large, fast, and reproducible due to the adsorption of vapors into the LB film structures. Among them, calix[8]arene LB film has higher sensitivity toward the organic vapors because of a large cavity size. This study can be concluded that the cavity size of calix[n]arene molecule could have an important role in the research area of room temperature vapor sensing devices. (C) 2014 Elsevier B.V. All rights reserved.