Yazar "Stanciu, G. A." seçeneğine göre listele

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    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.
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    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.
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    Characterization of Langmuir-Blodgett films of a calix[8]arene and sensing properties towards volatile organic vapors
    (Elsevier Science Sa, 2010) Capan, R.; Ozbek, Z.; Goktas, H.; Sen, S.; Ince, F. G.; Ozel, M. E.; Stanciu, G. A.
    Within this article, we report the characterization and organic vapor sensing properties of Langmuir-Blodgett (LB) thin films of calix[8]arenes. Surface pressure-area isotherms show that very stable monolayers are formed at the air-water interface. The LB film could be deposited onto different substrates which allowed the films to be characterized by UV, quartz crystal microbalance (QCM), surface plasmon resonance (SPR) and atomic force microscopy (AFM). The results indicate that good quality, uniform LB films can be prepared with transfer ratios of over 0.95. QCM results showed that the deposited mass of calix[8]arene monolayer onto a quartz crystal decreased from 693 to 204 ng as the number of layers is increased. AFM studies showed a smooth, and void free surface morphology with a rms value of 1.202 nm. The sensing abilities of this LB film towards the development of room temperature organic vapor sensing devices are also studied. Responses of the LB films to various vapors are fast, large, and reversible. It was found that the obtained LB film is significantly more sensitive to chloroform than other vapors. It can be concluded that this molecule could have a potential application in the research area of room temperature vapor sensing devices. (C) 2010 Elsevier B.V. All rights reserved.
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    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.