Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection

Permanent URI for this collectionhttps://hdl.handle.net/11147/7148

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  • Article
    Citation - WoS: 10
    Citation - Scopus: 12
    Tuning Pendant Groups of Polythiophene on Carbon Nanotubes for Vapour Classification
    (Elsevier Ltd., 2017) Tu, Meng-Che; Svm, Hari Krishna; Thilini, Alahakoon; Wallace, Lim Tse Loong; Moochhala, Shabbir; Yıldız, Ümit Hakan; Palaniappan, Al.; Liedberg, Bo
    Poly(3-alkoxythiophene) (PT) with varying ratios of triethylamine and 1-methyl imidazole pendant groups and horizontally aligned single walled carbon nanotubes (SWCNT) are utilized in this study for volatile organic compounds (VOCs) classification. PTs with five different ratios of pendant groups are incorporated with SWCNT and are evaluated as chemiresistor arrays for analysis of VOCs such as ethanol, acetone, toluene, chloroform, isoprene and ethylene. Varying PT pendant groups yielded differential SWCNT current responses attributed to their chemical affinities for the VOCs tested. Principal component analysis (PCA) for vapour classification illustrated that the vapour responses are separable, thus, highlighting vapour discrimination ability of SWCNT with controlled ratios of PT pendant groups. The proposed methodology is a facile VOC classification approach for two main reasons; (i) PT could easily modified with various pendants groups containing appropriate chemical moieties for preferential interaction with various VOCs and (ii) increasing the number PTs with appropriate pendant group modifications would provide additional inputs to PCA thereby enabling capturing and assaying of a wide range of VOCs.
  • Article
    Citation - WoS: 41
    Citation - Scopus: 44
    Vapor Phase Solvatochromic Responses of Polydiacetylene Embedded Matrix Polymers
    (Royal Society of Chemistry, 2017) Tu, Meng-Che; Cheema, Jamal Ahmed; Yıldız, Ümit Hakan; Palaniappan, Alagappan; Liedberg, Bo
    The solvatochromic response of polydiacetylene (PDA) in the vapor phase is enabled upon incorporation with matrix polymers such as polyvinylpyrrolidone (PVP), polyethylene glycol (PEG), polyacrylic acid (PAA), and poly-4-vinylpyridine (P4VP). The matrix polymers provide a soft/gel-like framework for accommodating photopolymerized PDA, while facilitating its conformational alternations upon interaction with preconcentrated volatile organic compounds (VOCs). The matrix polymers enabled the differentiation of VOCs owing to their varying morphology, chemical affinity and solubility in VOCs. The ratios between PDA and the matrix polymers are optimized according to the obtained solvatochromic responses evaluated in varying temperature, humidity and storage conditions. As a proof of concept, a finger-print array for differentiation of 7 VOCs is demonstrated using matrix polymer-embedded PDA. The obtained results indicate that the response time and sensitivity of the proposed methodology supersedes previous reports on solvatochromic VOC assays. Furthermore, the proposed methodology would enable differentiation of a wide range of VOCs upon incorporation of additional matrix polymers with varying sorption properties.
  • Article
    Citation - WoS: 19
    Citation - Scopus: 19
    Visual Detection of Al3+ Ions Using Conjugated Copolymer-Atp Supramolecular Complex
    (Elsevier Ltd., 2016) Tu, Meng-Che; Rajwar, Deepa; Ammanath, Gopal; Alagappan, Palaniappan; Yıldız, Ümit Hakan; Liedberg, Bo
    A colorimetric Al3+ sensor based on fluorescence recovery of a conjugated copolymer-ATP complex is proposed. An optimized ratio of two polythiophene (PT) monomers is utilized to synthesize copolymer (CP) that yielded maximized colorimetric response for Al3+ in deionized (DI) and tap water. The electrostatic disassembly of CP-ATP upon addition of Al3+ led to an evident visual color change. The lowest concentration of Al3+ for naked eye observation is around 4 μM, which is below the threshold levels in drinking water according to European Economic Community (EEC) standard. Besides, the proposed assay showed a similar response to Al3+ in tap water. The proposed methodology showed selective and sensitive detection for Al3+ in analytically relevant concentration ranges without involving sophisticated instrumentation, illustrating the applicability for on-site drinking water monitoring.