15,697 research outputs found
Solution-Processable Graphene Oxide as an Efficient Hole Injection Layer for High Luminance Organic Light-Emitting Diodes
The application of solution-processable graphene oxide (GO) as hole injection
layer in organic light-emitting diodes (OLEDs) is demonstrated. High luminance
of over 53,000 cd m-2 is obtained at only 10 V. The results will unlock a route
of applying GO in flexible OLEDs and other electrode applications.Comment: 14 pages, 3 figures, 1 tabl
Plasmon-free Surface-enhanced Raman Spectroscopy on TiO\u3csub\u3e2\u3c/sub\u3e-graphene Oxide Inverse Opal Substrates
TiO2-graphene oxide (GO) inverse opal materials were shown to be active plasmon-free surface-enhanced Raman spectroscopy (SERS) substrates. The SERS activity of the substrates was analyzed using three different probe molecules: phenethylamine (PEA), methylene blue (MB), and 4-mercaptobenzoic acid (4-MBA). The morphology of the substrates was investigated by SEM and AFM. Prepared TiO2-GO inverse opals substrates can be reused up to five times with minimal loss of signal, rendering them perfect candidates to be used as highly stable, low-cost, metal-free, recyclable SERS substrates
pH dependent isotropic to nematic phase transitions in graphene oxide dispersions reveal droplet liquid crystalline phases
Author Posting. © The Author(s), 2014. This is the author's version of the work. It is posted here by permission of Royal Society of Chemistry for personal use, not for redistribution. The definitive version was published in
Chemical Communications 50 (2014): 6668-6671, doi:10.1039/C4CC00970C.Size fractionation, amplified by the surface charge density of graphene oxide (GO) sheets, broadens the pH dependent isotropic (I) to nematic (N) phase transition in aqueous dispersions of graphene oxide (GO). In this biphasic region, a highly organized droplet nematic phase of uniform size (20 ± 2.8 μm diameter) with an isotropic interior is observed.Supports from the Australian Research Council (LP110100612 to MM), National Institute of Biomedical Imaging and Bioengineering (R01EB002045 to RO) and HFSP fellowship (to SM) are acknowledged.2015-05-0
Massive production of graphene oxide from expanded graphite
In a deviation from the conventional Hummers method, a spontaneous expansion
approach was introduced with expanded graphite as the precursors. The
intercalating agent (H2SO4) was able to penetrate into the expanded graphite;
this had further expanded the graphite and as a result, a foam-like
intermediate was produced. The foam-like graphite was more easily oxidized in
reaction with the oxidant (KMnO4) to form graphene oxide (GO). Fully exfoliated
GO was obtained with expanded graphite having the median diameter ~ 15 {\mu}m
as the precursors. This procedure was much safer and productive in scalable
applications than the conventional Hummers methods
Facile high-yield synthesis and purification of lysine-modified graphene oxide for enhanced drinking water purification
Lysine-covalently modified graphene oxide (GO-Lys) was prepared by an innovative procedure. Lysine brushes promote enhanced adsorption of bisphenol A, benzophenone-4 and carbamazepine contaminants from tap water, with a removal capacity beyond the state of the art
Paper Based Pressure Sensor for Green Electronics
This work reports a resistive paper-based disposable pressure sensor based on porous 3D conductive cellulose micro-fiber network. The conductivity in microfibers was achieved by subjecting the network to graphene oxide (GO) - poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT: PSS) solution. The modified cellulose matrix is sandwiched between graphite paper electrodes so that overall structure is flexible. The device tested in 32-386 Pa range detected a minimum of 34 Pa and exhibited fast dynamic response (in tenths of seconds) with excellent repeatability. The proposed approach for disposable sensors is a step towards green electronics and holds promise for wide range of wearable applications
Performance Evaluation of a Direct Absorption Collector for Solar Thermal Energy Conversion
The solar absorption efficiency of water as a base-fluid can be significantly improved by suspending nanoparticles of various materials in it. This experimental work presents the photo thermal performance of water-based nano-fluids of graphene oxide (GO), zinc oxide (ZnO), copper oxide (CuO), and their hybrids under natural solar flux for the first time. Nanofluid samples were prepared by the two-step method and the photothermal performance of these nanofluid samples was conducted under natural solar flux in a particle concentration range from 0.0004 wt % to 0.0012 wt %. The photothermal efficiency of water-based 0.0012 wt % GO nanofluid was 46.6% greater than that of the other nanofluids used. This increased photothermal performance of GO nanofluid was associated with its good stability, high absorptivity, and high thermal conductivity. Thus, pure graphene oxide (GO) based nanofluid is a potential candidate for direct absorption solar collection to be used in different solar thermal energy conversion applications
Tuning the Underwater Oleophobicity of Graphene Oxide Coatings via UV Irradiation
Ultraviolet (UV) irradiation was utilized to gradually modify the chemistry and structure of graphene oxide (GO) flakes, as confirmed by XPS and AFM. Ultrathin GO coatings/membranes, made of UV-irradiated flakes, showed tunable underwater oleophobicity. UV-treated, superoleophobic GO membranes exhibited excellent antifouling capability for oil/water separation
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