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Öğe A macrocyclic tetra-undecyl calix[4]resorcinarene thin film receptor for chemical vapour sensor applications(Springer, 2020) Sen, S.; Davis, F.; Capan, R.; Ozbek, Z.; Ozel, M. E.; Stanciu, G. A.This work demonstrates the fabrication of chemical vapour sensors using Langmuir-Blodgett (LB) thin films, describing the thin film properties of a tetra-undecyl calix[4]resorcinarene molecule along with a discussion of their sensing performance. Atomic Force Microscopy and Surface Plasma Resonance (SPR) methods were used for the characterization of the deposited thin films. As evidenced by these characterization methods, high quality and uniform Langmuir monolayers were formed on the water surface and can be transferred onto glass and gold-coated glass substrates with a transfer ratio of over 95%. The gas sensing properties towards the vapours of four volatile organic compounds were also examined by the SPR technique. Tetra-undecyl calix[4]resorcinarene LB thin film is sensitive to organic vapours (benzene, chloroform, ethanol and toluene) with rapid response and recovery times, demonstrating promise towards future vapour detection applications, especially for the rapid detection of leaks or spillage.Öğe Calix[4]amine Langmuir-Blodgett thin film sensing properties against volatile organic compounds(Iop Publishing Ltd, 2019) Sen, S.; Capan, R.; Ozbek, Z.; Ozel, M. E.; Stanciu, G. A.; Davis, F.Thin films of CBAMINE were deposited at air-water interface by the method of Langmuir-Blodgett (LB) technique onto a suitable substrate. Atomic force microscopy technique was used to characterize its thin film properties. The results indicate that a uniform LB film monolayer from the water surface to a glass or quartz crystal substrates deposited with a transfer ratio of over 96 %. Gas sensing properties and thickness of the LB thin films of CBAMINE were investigated using Surface plasmon resonance (SPR) technique. Its vapour sensing properties were investigated for different volatile organic compounds. Reversible changes in the optical behaviour were observed and thin films of this material are highly selective for chloroform vapour with fast response and recovery times.Öğe Langmuir-Blodgett film properties of based on calix[4]resorcinarene and the detection of those against volatile organic compounds(Springer Heidelberg, 2019) Sen, S.; Capan, R.; Ozbek, Z.; Ozel, M. E.; Stanciu, G. A.; Davis, F.To determine their inherent properties, thin films of calix[4]resorcinarene (C11AMINE) were deposited using the Langmuir-Blodgett (LB) technique onto a suitable substrate. Prior to the LB thin film preparation, this molecule was first studied at the air-water interface. For the characterization of the deposited film, UV-visible absorption spectroscopy and atomic force microscopy were used. Characterization results indicated that the Langmuir monolayer can be transferred from the water surface onto a glass or a quartz substrate with a transfer ratio of over 95%. This shows that this material is suitable for the preparation of high quality, uniform LB films. Later, gas sensing properties and thickness of these thin films were investigated using the surface plasmon resonance method. Thicknesses and the refractive index values of the C11AMINE films were obtained for differing number of layers. Then, the gas sensing properties towards vapours of four volatile organic compounds were examined: chloroform, benzene, toluene and ethanol. Reversible changes in the optical behaviour of thin films of C11AMINE were observed. It is found that thin films of this material are highly selective towards chloroform vapour, with rapid response and recovery times, making them suitable for practical chloroform-detection applications.Öğe Optical parameters of calix[4]arene films and their response to volatile organic vapors(Elsevier Science Sa, 2011) Ozbek, Z.; Capan, R.; Goktas, H.; Sen, S.; Ince, F. G.; Ozel, M. E.; Davis, F.The Langmuir-Blodgett (LB) technique was employed to produce thin LB films using an amphiphilic calix-4-resorcinarene onto different substrates such as quartz, gold coated glass and quartz crystals. The characteristics of the calix LB films are assessed by UV-visible, quartz crystal microbalance (QCM) and surface plasmon resonance (SPR) measurements. UV-vis and QCM measurements indicated that this material deposited very well onto the solid substrates with a transfer ratio of >0.95. Using SPR data, the thickness and refractive index of this LB film are determined to be 1.14 nm/deposited layer and 1.6 respectively. The sensing application of calixarene LB films towards volatile organic vapors such as chloroform, benzene, toluene and ethanol vapors is studied by the SPR technique. The response of this LB film to saturated chloroform vapor is much larger than for the other vapors. The response is fast and fully recoverable. It can be proposed that this sensing material deposited onto gold coated glass substrates has a good sensitivity and selectivity for chloroform vapor. This material may also find potential applications in the development of room temperature organic vapor sensing devices. (C) 2011 Elsevier B.V. All rights reserved.Öğe Plasma Polymerized Calixarene Thin Films and their Sensing Properties to Chloroform Vapors(Taylor & Francis Ltd, 2010) Ince, F. G.; Goktas, H.; Ozbek, Z.; Capan, R.; Davis, F.The production of calixarene thin films via double discharge plasma technique and their sensitivity towards chloroform vapor are presented here in. The calixarene thin film is fabricated for the first time by plasma polymerized technique. Each experiment carried out at room temperature, at 0.6 mbar operating pressure, 2.0 kV DC and 19 kV pulsed voltages. From the UV-vis spectra it is observed that the polyconjugated structure is established and the thin films highly possess the characteristic bands of the oligomer. The SPR results revealed that the films thickness is at the order of several nm and the refractive index range from 2.2 to 2.8. The QCM results show that the thin films are highly sensitive with a fast and reversible adsorption to chloroform. The typical response time was of a few seconds.
