scholarly journals Polystyrene as Graphene Film and 3D Graphene Sponge Precursor

2018 ◽  
Author(s):  
Alejandra Rendón-Patiño ◽  
Jinan Niu ◽  
Antonio Doménech-Carbó ◽  
Hermenegildo García ◽  
Ana Primo
Keyword(s):  
Thin Film ◽  
Photoelectron Spectroscopy ◽  
Graphene Film ◽  
Visible Absorption ◽  
X Ray ◽  
3D Graphene ◽  
Force Microscopy ◽  
Atomic Force ◽  
Graphene Films ◽  
Graphene Sponge

Polystyrene as a thin film on arbitrary substrates or pellets form defective graphene films or powders that can be dispersed in water and organic solvents. The materials were characterized by visible absorption, Raman and X-ray photoelectron spectroscopy, electron and atomic force microscopy and electrochemistry. Raman spectra of these materials show the presence of the expected 2D, G and D peaks at 2750, 1590 and 1350 cm-1, respectively. The relative intensity of the G vs. the D peak is taken as a quantitative indicator of the density of defects in the G layer.

scholarly journals Polystyrene as Graphene Film and 3D Graphene Sponge Precursor

Nanomaterials ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 101 ◽  
Author(s):  
Alejandra Rendón-Patiño ◽  
Jinan Niu ◽  
Antonio Doménech-Carbó ◽  
Hermenegildo García ◽  
Ana Primo
Keyword(s):  
Thin Film ◽  
Atomic Force Microscopy ◽  
Photoelectron Spectroscopy ◽  
Graphene Film ◽  
Visible Absorption ◽  
X Ray ◽  
3D Graphene ◽  
Force Microscopy ◽  
Atomic Force ◽  
Graphene Sponge

Polystyrene as a thin film on arbitrary substrates or pellets form defective graphene/graphitic films or powders that can be dispersed in water and organic solvents. The materials were characterized by visible absorption, Raman and X-ray photoelectron spectroscopy, electron and atomic force microscopy, and electrochemistry. Raman spectra of these materials showed the presence of the expected 2D, G, and D peaks at 2750, 1590, and 1350 cm−1, respectively. The relative intensity of the G versus the D peak was taken as a quantitative indicator of the density of defects in the G layer.

Graphene growth on SiC and other substrates using carbon sources

2011 ◽  
Vol 1284 ◽  
Author(s):  
W. C. Mitchel ◽  
J. H. Park ◽  
Howard E. Smith ◽  
L. Grazulis ◽  
S. Mou ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Carbon Flux ◽  
Carbon Sources ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
Graphene Films ◽  
Additional Control ◽  
P Type ◽  
Type Conduction

ABSTRACTDirect deposition of graphene from carbon sources on foreign substrates without the use of metal catalysts is shown to be an effective process with several advantages over other growth techniques. Carbon source molecular beam epitaxy (CMBE) in particular provides an additional control parameter in carbon flux and enables growth on substrates other than SiC, including oxidized Si and sapphire. CMBE using thermally evaporated C60 and a heated graphite filament on SiC is reported here. The graphene films were characterized by Raman spectroscopy, X-ray photoelectron spectroscopy, atomic force microscopy and Hall effect. Graphene films on Si-face SiC grown using the C60 source have Bernal-like stacking and n-type conduction while those grown using the graphite filament have turbostratic stacking and p-type conduction. The sheet concentration for both n- and p-type doping is linearly dependent on film thickness.

Fabrication of Uniformly Growing Graphene Films via the Dip-Coating Method

2013 ◽  
Vol 320 ◽  
pp. 185-189
Author(s):  
Juan Yang ◽  
Hong Bo Sun ◽  
Dan Li
Keyword(s):  
Sheet Resistance ◽  
Photoelectron Spectroscopy ◽  
Dip Coating ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
Graphene Films ◽  
Coating Method ◽  
Dip Coating Method ◽  
Dip Coating Technique

The graphene (GE) films were fabricated in this paper through the deposition of graphene oxide (GO) sheets onto the quartz slide by means of dip-coating technique, followed by thermal annealing. The growth process and transmittance of the film were monitored by ultraviolet and visible spectrophotometer (UV-Vis), the surface morphology and structure were investigated by Atomic force microscopy (AFM), Scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and Raman. The sheet resistance of the film was also tested and results showed that the sheet resistance is about 60 kΩ-1and the transmittance is as high as 81 % (at 550 nm).

scholarly journals Electronic and vibrational decoupling in chemically exfoliated bilayer 2D-V2O5

2021 ◽  
Author(s):  
Reshma P R ◽  
Anees Pazhedath ◽  
Ganesan Karuppiah ◽  
Arun Prasad ◽  
Sandip Dhara
Keyword(s):  
Transition Metal ◽  
Photoelectron Spectroscopy ◽  
Density Functional ◽  
Blue Shift ◽  
X Ray Diffraction ◽  
Phonon Modes ◽  
Visible Absorption ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force

Abstract Recently emerged transition metal oxide (TMO) based 2D nanostructures are gaining a foothold in advanced applications. Unlike, 2D transition metal dichalchogenides, it is strenuous to obtain high quality thin TMOs due to exotic surface reconstruction during synthesis. Herein, we report the synthesis of bilayer thin 2D-V2O5 nanosheets using chemical exfoliation. Synchrotron X-ray diffraction, X-ray photoelectron spectroscopy and atomic force microscopy substantiate the successful formation of bilayer thin 2D-V2O5. Ultraviolet-visible absorption spectra exhibit a thickness dependent blue shift in the optical band gap, signifying the emergence of electronic decoupling. Raman spectroscopy fingerprinting shows a thickness dependent vibrational decoupling of phonon modes. Further, it has been verified by computing the lattice vibrational modes using density functional perturbation theory. In this study, the manifestation of the electronic and vibrational decoupling is used as a novel probe to confirm the successful exfoliation of bilayer 2D-V2O5 from its bulk counterpart.

A Comparative Study of Structural and Optical Properties of ZnO Thin Film Prepared on Sapphire Substrate by PLD and Annealed

2011 ◽  
Vol 287-290 ◽  
pp. 2397-2400 ◽  
Author(s):  
Xian Qi Wei ◽  
Yong Jie Wang ◽  
Ming Yang Zhang ◽  
Zhong Zhang
Keyword(s):  
Thin Film ◽  
Optical Properties ◽  
Sapphire Substrate ◽  
Photoelectron Spectroscopy ◽  
Blue Emission ◽  
Annealing Treatment ◽  
Shallow Donor ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force

ZnO thin films are grown on sapphire substrate by employing a Nd:YAG (1064nm) laser ablation in 1.3 Pa oxygen ambient. X-ray diffraction (XRD) and atomic force microscopy (AFM) observation show that as-grown thin film possess (0002) textured feature and form columnar inclined grains with a small size. The as-grown films show a little oxygen vacancies and Zn interstitial by the analysis of X-ray photoelectron spectroscopy (XPS) and Raman. The annealing treatment in oxygen ambient causes obvious improvement on the structure, surface morphology, compositions and optical properties by the analysis of XRD, AFM, XPS, Raman and photoluminescence (PL) spectra. It can be concluded that the increase of UV emission is oriented to the improvement of structure and decrease of intrinsic defects. The blue emission (430 nm) is attributed to the electronic transition from shallow donor level of Zn interstitial to top level of valence band.

An approach to durable poly(vinylidene fluoride) thin film loudspeaker

2003 ◽  
Vol 18 (12) ◽  
pp. 2904-2911 ◽  
Author(s):  
C.S. Lee ◽  
J.Y. Kim ◽  
D.E. Lee ◽  
J. Joo ◽  
S. Han ◽  
...  
Keyword(s):  
Thin Film ◽  
Indium Tin Oxide ◽  
Photoelectron Spectroscopy ◽  
Vinylidene Fluoride ◽  
X Ray ◽  
Force Microscopy ◽  
Low Surface Energy ◽  
Oxide Electrodes ◽  
Atomic Force ◽  
Poly Vinylidene Fluoride

The piezoelectric poly(vinylidene fluoride) (PVDF) surface possessing low surface energy was modified by the ion-assisted-reaction (IAR) method for the application of thin film speaker. The IAR-treated hydrophilic PVDF surface was investigated using atomic force microscopy and x-ray photoelectron spectroscopy. The adhesion strength between various types of electrodes and the film was dramatically improved due to the hydrophilic functional groups, such as –C–O–, –(C=O)–, –(C=O)–O–, and so forth. A durable loudspeaker film was fabricated by enhancing the adhesion between the screen-printed poly(3,4-ethylenedioxythiophene)/poly(4-styrenesulfonate) (PEDOT/PSS) and the modified PVDF films. The PVDF speaker film with the PEDOT/PSS electrode showed higher durability, flatter sound pressure level characteristics, and easier processability compared to metals or indium tin oxide electrodes.

Graphene Growth on SiC and Metal Surfaces by Solid Source Carbon Deposition

2010 ◽  
Vol 1246 ◽  
Author(s):  
W. C. Mitchel ◽  
J. H. Park ◽  
H. E. Smith ◽  
L. Grazulis
Keyword(s):  
Thermal Decomposition ◽  
Raman Spectroscopy ◽  
Photoelectron Spectroscopy ◽  
Carbon Flux ◽  
Carbon Deposition ◽  
Carbon Sources ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
Graphene Films

AbstractGraphene has been grown by direct deposition of carbon from solid sources on both SiC and Ta films on SiC in an MBE environment. Carbon fluxes were obtained from thermally evaporated C60 and from a heated graphite filament. The graphene films were characterized by Raman spectroscopy, X-ray photoelectron spectroscopy and atomic force microscopy. Graphene films on Si-face SiC grown by carbon source MBE (CSMBE) were compared with graphene grown by the standard epitaxial graphene process using SiC thermal decomposition. CSMBE on SiC was found to grow at lower temperatures (1200°C) and to have fewer pits and a more uniform surface. Uniform graphene films were found to grow on Ta films after exposure to both carbon sources at 1200°C but Raman measurements showed no signs of graphene on films exposed to the same temperature without a carbon flux.

scholarly journals Properties of Zig-zag nickel nanostructures obtained by glad technique

2016 ◽  
Vol 48 (1) ◽  
pp. 51-56 ◽  
Author(s):  
Jelena Potocnik ◽  
Milos Nenadovic ◽  
Bojan Jokic ◽  
Maja Popovic ◽  
Zlatko Rakocevic
Keyword(s):  
Thin Film ◽  
Photoelectron Spectroscopy ◽  
Sessile Drop ◽  
Glancing Angle Deposition ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
Glancing Angle ◽  
Glad Technique ◽  
Angle Deposition

Zig-zag structure of the nickel thin film has been obtained using Glancing Angle Deposition (GLAD) technique. Glass substrate was positioned 75 degrees with respect to the substrate normal. The obtained nickel thin film was characterized by X-ray Photoelectron Spectroscopy, Scanning Electron Microscopy and Atomic Force Microscopy. Surface energy of the deposited thin film was determined by measuring the contact angle using the static sessile drop method.

Investigation of the Effect of Uv-Assisted Oxidation and Nitridation of Hafnium Metal Films

2003 ◽  
Vol 780 ◽  
Author(s):  
C. Essary ◽  
V. Craciun ◽  
J. M. Howard ◽  
R. K. Singh
Keyword(s):  
Uv Radiation ◽  
Photoelectron Spectroscopy ◽  
Grazing Angle ◽  
X Ray Diffraction ◽  
Metal Thin Films ◽  
X Ray ◽  
Force Microscopy ◽  
Si Substrates ◽  
Atomic Force ◽  
Silicon Interface

AbstractHf metal thin films were deposited on Si substrates using a pulsed laser deposition technique in vacuum and in ammonia ambients. The films were then oxidized at 400 °C in 300 Torr of O2. Half the samples were oxidized in the presence of ultraviolet (UV) radiation from a Hg lamp array. X-ray photoelectron spectroscopy, atomic force microscopy, and grazing angle X-ray diffraction were used to compare the crystallinity, roughness, and composition of the films. It has been found that UV radiation causes roughening of the films and also promotes crystallization at lower temperatures.Furthermore, increased silicon oxidation at the interface was noted with the UVirradiated samples and was shown to be in the form of a mixed layer using angle-resolved X-ray photoelectron spectroscopy. Incorporation of nitrogen into the film reduces the oxidation of the silicon interface.

Curcumin delivery by modified biosourced carbon-based nanoparticles

Nanomedicine ◽  
2022 ◽  
Author(s):  
Hossein Danafar ◽  
Marziyeh Salehiabar ◽  
Murat Barsbay ◽  
Hossein Rahimi ◽  
Mohammadreza Ghaffarlou ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Free System ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
Transmission Electron ◽  
Good Biocompatibility ◽  
Drug Free ◽  
Mcf 7 ◽  
Carbon Based

Aim: To prepare a novel hybrid system for the controlled release and delivery of curcumin (CUR). Methods: A method for the ultrasound-assisted fabrication of protein-modified nanosized graphene oxide-like carbon-based nanoparticles (CBNPs) was developed. After being modified with bovine serum albumin (BSA), CUR was loaded onto the synthesized hybrid (labeled CBNPs@BSA–CUR). The structure and properties of the synthesized nanoparticles were elucidated using transmission electron microscopy (TEM), atomic force microscopy (AFM), ultraviolet-visible spectroscopy (UV-Vis), Fourier-transform infrared spectroscopy (FTIR) and x-ray photoelectron spectroscopy (XPS) methods. Results: CBNPs@BSA–CUR showed pH sensitivity and were calculated as controlled CUR release behavior. The drug-free system exhibited good biocompatibility and was nontoxic. However, CBNPs@BSA–CUR showed acceptable antiproliferative ability against MCF-7 breast cancer cells. Conclusion: CBNPs@BSA–CUR could be considered a highly promising nontoxic nanocarrier for the delivery of CUR with good biosafety.

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