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

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).

2011 ◽  
Vol 1284 ◽  
Author(s):  
W. C. Mitchel ◽  
J. H. Park ◽  
Howard E. Smith ◽  
L. Grazulis ◽  
S. Mou ◽  
...  

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.


2011 ◽  
Vol 233-235 ◽  
pp. 2970-2974 ◽  
Author(s):  
Ruo Yu Chen ◽  
Jian Wu Wang ◽  
Hong Ning Wang ◽  
Wei Yao ◽  
Jing Zhong

The porous SiO2/TiO2bilayer antireflection coatings with self-cleaning capacity have been prepared by a sol-gel dip-coating method, the surfactant template, Pluronic F123 (PF123) was added to the sol as a pore generator. The performances of the coatings were analyzed with ultraviolet visible spectrophotometer (UV-Vis), scanning electron microscope (SEM) and atomic force microscopy (AFM). The self-cleaning function of coatings was evaluated by means of photocatalytic degradation of methyl orange in aqueous solution, and mechanical strength of the coatings has also been studied. The results indicate that the average transmittance of porous SiO2/TiO2coating increases by 6% as compared to uncoated glass, the coating has a small particle size, a porous structure and a low roughness. After illuminated by ultraviolet light for 3 h, the 5 mg/L methyl orange can be degraded by 56.5%. In addition, the coating has an excellent mechanical strength.


2013 ◽  
Vol 582 ◽  
pp. 149-152 ◽  
Author(s):  
Kenichi Mimura ◽  
Kazumi Kato

Single crystalline BaTiO3nanocubes, which were synthesized by hydrothermal reaction with organic surfactants and additives, were assembled in order and directly on the substrates by dip-coating method using the dispersed solution. After evaporation of solvent, the orderly assembly of the nanocubes was developed over the large region in about several tens of micrometers square. It can cover whole surface of the substrate. The microstructures of the nanocube assemblies were evaluated by scanning electron microscopy (SEM) and atomic force microscopy (AFM). Electrical property of the nanocube-assembled film was characterized by piezoresponse force microscopy (PFM). The d33-V curve showed ferroelectric hysteresis and saturation behaviors under high applied voltage.


Crystals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1544
Author(s):  
Yangyang Zhang ◽  
Na Liu ◽  
Haipeng Xie ◽  
Jia Liu ◽  
Pan Yuan ◽  
...  

The surface composition and morphology of FA0.85MA0.15Pb(I0.85Br0.15)3 films fabricated by the spin-coating method with different concentrations of NH2-POSS were investigated with atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), angle-resolved X-ray photoelectron spectroscopy (AR-XPS), and Fourier transform infrared spectroscopy (FTIR). It was found that the surface composition of the FA0.85MA0.15Pb(I0.85Br0.15)3 films was changed regularly through the interaction between NH2-POSS and the perovskite film. The corresponding surface morphological changes were also observed. When the concentration of NH2-POSS exceeded 10 mg/mL, a lot of cracks on the surface of the perovskite film were observed and the surface morphology was damaged. The surface composition and its distribution can be adjusted by changing the concentration of NH2-POSS and the proper concentration of NH2-POSS can substantially improve the quality of perovskite film.


2011 ◽  
Vol 299-300 ◽  
pp. 448-451
Author(s):  
Guo Chao Qi ◽  
Sam Zhang ◽  
Qiang Li ◽  
Feng Jun Shan ◽  
Jing Yuan Yu ◽  
...  

A series of the magnesium apatite coatings according to (Ca10-xMgx)(PO4)6(OH)2, where x = 0 to 2, was synthesized through a sol-gel dip-coating method. The roughness of the magnesium coatings increased as more magnesium incorporated into the coatings. The mechanical properties of the coatings were analyzed with Nanoindentor. The incorporation of magnesium decreased the hardness and the Young’s modulus of the coating. The X-ray Photoelectron Spectroscopy (XPS) analysis revealed that only part of magnesium was incorporated into the apatite structure while the rest existed in the form of MgO in the coating.


Coatings ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 326
Author(s):  
Xiaoli Liu ◽  
Youcai Gu ◽  
Tengfei Mi ◽  
Xiaomei Wang ◽  
Xu Zhang

The facile, simple, highly efficient, and fluorine-free fabrication of superhydrophobic surfaces on fabrics with high durability has attracted considerable attention because of its urgent practical application. The simple dip-coating method was adopted to make a stable and durable polydimethylsiloxane/stearic acid/silica (PDMS/STA/SiO2) superhydrophobic fabric. The fabric’s surface morphology, roughness, and composition were analyzed by scanning electron microscopy, atomic force microscopy, and Fourier transform infrared spectroscopy, respectively. The PDMS/STA/SiO2-coated fabric: demonstrated strong superhydrophobicity (a water contact angle (WCA) of around 163°), efficiently repelled different liquids (milk, coffee, orange juice, Coca-Cola, and 1 M of HCl and NaOH) with a contact angle above 155°, had excellent self-cleaning performance, and retained superhydrophobicity with a WCA greater than 150° after 72 h of ultraviolet irradiation and 700 cycles of mechanical abrasion. The PDMS/STA/SiO2 coating had few influences on the color fastness of the fabric. Superhydrophobic coatings are expected to be practically applied in the textile industry.


2011 ◽  
Vol 299-300 ◽  
pp. 508-511
Author(s):  
Guo Chao Qi ◽  
Feng Jun Shan ◽  
Qiang Li ◽  
Jing Yuan Yu ◽  
Qu Kai Zhang

Magnesium apatite (MA, (Ca9Mg)(PO4)6(OH)2) and Hydroxyapatite (HA) coatings were synthesized on Ti6Al4V substrates by a sol-gel dip coating method. Glucose and bovine serum albumin (BSA) were added to the standard simulated body fluid (SBF) separately to form organic-containing simulated body fluids. MA and HA coatings were immersed in standard and organic modified SBF for time periods of 4, 7, 14, 21 and 28 days at 37±1°C. The surface dissolution and deposition behavior of the coatings after soaking were examined with Scanning Electron Microscopy (SEM) and X-ray Photoelectron Spectroscopy (XPS). The results show that glucose in SBF has no apparent effect on the deposition of new apatite from the solution. BSA in SBF shows retardation effect on the deposition of apatite by forming a protein dominant globular layer. This layer inhibits the further deposition of apatite from SBF solution.


2010 ◽  
Vol 1246 ◽  
Author(s):  
W. C. Mitchel ◽  
J. H. Park ◽  
H. E. Smith ◽  
L. Grazulis

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.


Author(s):  
Alejandra Rendón-Patiño ◽  
Jinan Niu ◽  
Antonio Doménech-Carbó ◽  
Hermenegildo García ◽  
Ana Primo

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.


2003 ◽  
Vol 780 ◽  
Author(s):  
C. Essary ◽  
V. Craciun ◽  
J. M. Howard ◽  
R. K. Singh

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.


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