ARC Research Hub for Graphene Enabled Industry Transformation publications
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Browsing ARC Research Hub for Graphene Enabled Industry Transformation publications by Author "Alotaibi, F."
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Item Metadata only Engineering of highly conductive and ultra-thin nitrogen-doped graphene films by combined methods of microwave irradiation, ultrasonic spraying and thermal annealing(Elsevier BV, 2018) Tung, T.T.; Alotaibi, F.; Nine, M.J.; Silva, R.; Tran, D.N.H.; Janowska, I.; Losic, D.We report a new method for the fabrication of highly conductive and transparent ultrathin nitrogen (N) doped graphene films from graphene inks by combining a microwave treatment, ultrasonic nebulizer coating and thermal annealing. The starting graphene oxide (GO) solution was mixed with poly(ionic liquids) (PIL) and treated with microwave (Mw) irradiation to prepare Mw-rGO@PIL inks, which is a gentle reduction of PIL-attached reduced graphene oxide (rGO). In this non-contacting heating method, the PIL was used to not only mediate microwave irradiation and prevent disorder of the graphitic structure, but also repair the lattice defects and introduce nitrogen into the graphitic structure. The ultra-thin graphene films were prepared using the nebulizer for controlling the aerosol droplet distribution of the Mw-rGO@PIL inks coated onto quartz or glass substrates. The prepared films displayed a surface resistance of ∼1.45 × 107 Ω/sq at a transparency of ∼87%. A further thermal treatment was conducted to improve the conductivity of the prepared films by annealing at a high temperature (900 °C), which allowed complete reduction of oxygen containing groups, enhanced graphitization, and reordering of the basal graphene plane and N-doping of the carbon lattice (pyrolytic PIL). The resulting thin films significantly reduced the surface resistance in the range of 1.5 × 103 to 6.2 × 103 Ω/sq at a transparency ranging from 68 to 82%, respectively. The presented method involving in situ N-doping offers a promising environmentally-friendly, low-cost and scalable manufacture of high-quality conductive N-doped graphene films.Item Metadata only Facile adhesion-tuning of superhydrophobic surfaces between “lotus” and “petal” effect and their influence on icing and deicing properties(American Chemical Society, 2017) Nine, M.; Tung, T.; Alotaibi, F.; Tran, D.; Losic, D.Adhesion behavior of superhydrophobic (SH) surfaces is an active research field related to various engineering applications in controlled microdroplet transportation, self-cleaning, deicing, biochemical separation, tissue engineering, and water harvesting. Herein, we report a facile approach to control droplet adhesion, bouncing and rolling on properties of SH surfaces by tuning their air-gap and roughness-height by altering the concentrations of poly dimethyl-siloxane (PDMS). The optimal use of PDMS (4-16 wt %) in a dual-scale (nano- and microparticles) composite enables control of the specific surface area (SSA), pore volume, and roughness of matrices that result in a well-controlled adhesion between water droplets and SH surfaces. The sliding angles of these surfaces were tuned to be varied between 2 ± 1 and 87 ± 2°, which are attributed to the transformation of the contact type between droplet and surface from "point contact" to "area contact". We further explored the effectiveness of these low and high adhesive SH surfaces in icing and deicing actions, which provides a new insight into design highly efficient and low-cost ice-release surface for cold temperature applications. Low adhesion (lotus effect) surface with higher pore-volume exhibited relatively excellent ice-release properties with significant icing delay ability principally attributed to the large air gap in the coating matrix than SH matrix with high adhesion (petal effect).Item Metadata only Scanning atmospheric plasma for ultrafast reduction of graphene oxide and fabrication of highly conductive graphene films and patterns(Elsevier, 2018) Alotaibi, F.; Tung, T.; Nine, M.; Kabiri, S.; Moussa, M.; Tran, D.; Losic, D.Abstract not availableItem Metadata only Silver Nanowires with Pristine Graphene Oxidation Barriers for Stable and High Performance Transparent Conductive Films(American Chemical Society, 2018) Alotaibi, F.; Tung, T.T.; Nine, M.J.; Coghlan, C.J.; Losic, D.One-dimensional (1D) silver nanowires (AgNWs) have emerged as a leading candidate for the development of next-generation optoelectronic and wearable electronic devices. However, a key limitation of AgNW electrodes is that they are readily oxidized, resulting in a shift in properties leading to devices becoming erratic over time. To address this problem, we report a facile method to improve both the stability and performance of AgNW films. The AgNWs were combined with pristine graphene (pG) using an optimal (30/70 wt %) with the goals to prove that the pG sheets can provide a barrier shielding to protect against AgNW oxidation and have the additional benefit of improving the connections between wires and stability of the films. The fabrication of these films was demonstrated on wide range of substrates including glass, plastic, textile, and paper. A surface resistance of 18.23 Ω/sq and an optical transparency of 89% were obtained on the glass substrates, 50 Ω/sq and 88% transparency for poly(ethylene terephthalate) (PET), and 0.35 Ω/sq resistance on the textile substrate. Atmospheric pressure plasma jets (APPJ) treatment was further used to enhance the performance of the film (i.e., glass), resulting in a significant reduction of 30.6% in sheet resistance (15.20 Ω/sq) and an improvement of transparency to 91%. The stability of AgNW/pG film under environmental conditions and higher temperatures was significantly improved, showing only a minor increase in the sheet resistance after 30 days and at temperature increases up to 300 °C when compared with control (AgNW film) which shows a sharp increase after 8−10 days and is thermally stable until 150 °C as a result of Ag oxidation.