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Öğe Bioinspired asymmetric-anisotropic (directional) fog harvesting based on the arid climate plant Eremopyrum orientale(ELSEVIER SCIENCE BV, 2017) Gursoy, M.; Harris, M. T.; Carletto, A.; Yaprak, A. E.; Karaman, M.; Badyal, J. P. S.Asymmetric-anisotropic (directional) fog collection behaviour is observed for leaves of the arid climate plant species Eremopyrum orientale. This is underpinned by a hierarchical surface structure comprising macroscale grooves, microscale tilted cones (in the direction of water flow), and nanoscale platelets. Soft lithography combined with either nanocoating deposition or functional nanoimprinting has been used to replicate this highly-efficient directional water collection mechanism.Öğe Bioinspired fog capture and channel mechanism based on the arid climate plant Salsola crassa(ELSEVIER SCIENCE BV, 2017) Gursoy, M.; Harris, M. T.; Downing, J. O.; Barrientos-Palomo, S. N.; Carletto, A.; Yaprak, A. E.; Karaman, M.Salsola crassa plant hairs collect fog in their natural arid climate habitat through the capture and growth of water droplets. These then, either drip onto the ground below due to gravity, or coalesce into larger attached water droplets, whilst concurrently rolling downwards along the curvature of the Salsola crassa leaf (fog collection and water channelling mechanism). Non-woven and cotton fibrous materials are shown to mimic the fog harvesting behaviour of Salsola crassa hairs, where the overall mist collection efficiency can be enhanced by over 300 percent through the incorporation of multiple length scale (hierarchical) channel structures in conjunction with hydrophobic surface functionalisation.Öğe Initiated Chemical Vapor Deposition of Ph Responsive Poly(2-diisopropylamino)ethyl Methacrylate Thin Films(Elsevier Science Sa, 2012) Karaman, M.; Cabuk, N.Poly(2-(diisopropylamino)ethyl methacrylate) (PDPAEMA) thin films were deposited on low temperature substrates by initiated chemical vapor deposition (iCVD) method using tertbutyl peroxide as an initiator. Very high deposition rates up to 38 nm/min were observed at low filament temperatures due to the use of the initiator. Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy show the formation of PDPAEMA films with high retention of tertiary amine functionality which is responsible for pH induced changes in the wetting behavior of the surfaces. As-deposited PDPAEMA thin films on flat Si surface showed a reversible switching of water contact angle values between 87 degrees and 28 degrees; after successive treatments of high and low pH water solutions, respectively. Conformal and non-damaging nature of iCVD allowed to functionalize fragile and rough electrospun poly(methyl methacrylate) fiber mat surfaces by PDPAEMA, which creates a surface with a switching behavior between superhydrophobic and approaching superhydrophilic with contact angle values of 155 +/- 3 degrees and 22 +/- 5 degrees, respectively. (C) 2012 Elsevier B.V. All rights reserved.Öğe Roll-to roll initiated chemical vapor deposition of super hydrophobic thin films on large-scale flexible substrates(Elsevier Ltd, 2020) Şakalak, H.; Yılmaz, K.; Gürsoy, M.; Karaman, M.In this study, a large-scale roll-to-roll initiated chemical vapor deposition (iCVD) system was developed to allow for coating superhydrophobic thin films on flexible substrates. Poly(hexafluorobutyl acrylate), which possesses a short fluorinated side-chain, was chosen as the hydrophobic finish material, while a commercial porous bamboo fabric was used as the flexible substrate. After iCVD coating, bamboo surface, which is superhydrophilic by its nature, transformed into a superhydrophobic with a water contact angle of 156° without changing its porous and flexible structure. Similar hydrophobic properties were observed against various daily liquids. Complete coverage of as-deposited films on both sides of bamboo surfaces was observed at very high roll speeds up to 225 mm/min, which allow coatings on 20 m2 flexible substrates in a single run. Large scale contact angle and chemical uniformity of coatings on fabric surfaces were evaluated using contact angle and XPS analyses. © 2019 Elsevier LtdÖğe Synthesis of Titania nanotubes/polyaniline via rotating bed-plasma enhanced chemical vapor deposition for enhanced visible light photodegradation(ELSEVIER SCIENCE BV, 2019) Subramaniam, M. N.; Goh, P. S.; Lau, W. J.; Ismail, A. F.; Gürsoy, M.; Karaman, M.This study employed rotating bed plasma enhanced chemical vapor deposition technique to coat a thin polymeric film of polyaniline (PANI) onto titania nanotubes (TNT). The effect of plasma power on the growth of thin film polymer on the photocatalyst surface was investigated. Transmission electron microscope micrographs evidenced the formation of thin polymeric layers on TNT surface. Fourier-transform infrared spectra confirmed the presence of functional groups associated with PANI. The band gap of coated photocatalyst reduced from 3.23 eV to 2.54 eV, implying the photosensitivity of TNT-PANI in visible light range, while photoluminescence spectra showed that PANI coated TNT exhibited lower recombination rates. The photocatalytic performance of the resultant TNT-PANI titania were evaluated under both UV and visible light irradiation using reactive black 5 (RB 5) as the model pollutant. Unlike TNT which could only be activated under UV light, TNT-PANI coated using a plasma power of 50 W exhibited superior photoactivity under both ultraviolet (UV) and visible light irradiation. The incorporation of PANI enhanced UV light photodegradation performance, where reaction rate improved to 0.615 ppm min(-1) and three times higher compared to uncoated TNT. The best sample TNT-PANI 50 W exhibited promising photodegradation efficiency of 56.4% within 240 min of visible light irradiation.
