Plasma-Based Chemical Modification of Epitaxial Graphene

2012 ◽  
Vol 717-720 ◽  
pp. 657-660 ◽  
Author(s):  
Scott G. Walton ◽  
Sandra C. Hernández ◽  
Mira Baraket ◽  
Virginia D. Wheeler ◽  
Luke O. Nyakiti ◽  
...  
Keyword(s):  
Electron Beam ◽  
Electrical Properties ◽  
Chemical Modification ◽  
Functional Groups ◽  
Surface Characterization ◽  
Epitaxial Graphene ◽  
Functionalized Graphene ◽  
Oxygen Functional Groups

In this work, the treatment of epitaxial graphene on SiC using electron beam generated plasmas produced in mixtures of argon and oxygen is demonstrated. The treatment imparts oxygen functional groups on the surface with concentrations ranging up to about 12 at.%, depending on treatment parameters. Surface characterization of the functionalized graphene shows incorporation of oxygen to the lattice by disruption of ∏-bonds, and an altering of bulk electrical properties.

Electrical Characterization of the Graphene-SiC Heterojunction

2012 ◽  
Vol 717-720 ◽  
pp. 641-644
Author(s):  
Travis J. Anderson ◽  
Karl D. Hobart ◽  
Luke O. Nyakiti ◽  
Virginia D. Wheeler ◽  
Rachael L. Myers-Ward ◽  
...  
Keyword(s):  
Electrical Properties ◽  
Charge Carrier ◽  
Graphene Sheet ◽  
Carrier Transport ◽  
Electrical Characterization ◽  
Epitaxial Graphene ◽  
Charge Carrier Transport ◽  
Semiconductor System ◽  
Significant Research

Graphene, a 2D material, has motivated significant research in the study of its in-plane charge carrier transport in order to understand and exploit its unique physical and electrical properties. The vertical graphene-semiconductor system, however, also presents opportunities for unique devices, yet there have been few attempts to understand the properties of carrier transport through the graphene sheet into an underlying substrate. In this work, we investigate the epitaxial graphene/4H-SiC system, studying both p and n-type SiC substrates with varying doping levels in order to better understand this vertical heterojunction.

scholarly journals Preparation and Characterization of Chemically-Modified Biomaterials and Their Application as Adsorbents of Penicillin G

2018 ◽  
Vol 1 (1) ◽  
pp. 114-124 ◽  
Author(s):  
Jesie Silva ◽  
Lizebel Morante ◽  
Tesfamichael Demeke ◽  
Jacqueline Baah-Twum ◽  
Abel Navarro
Keyword(s):  
Chemical Modification ◽  
Functional Groups ◽  
Negative Impact ◽  
Ph Dependence ◽  
Sem Analysis ◽  
Penicillin G ◽  
Tea Leaves ◽  
Reaction Conditions ◽  
Spent Tea Leaves

The prevalence of antibiotics in water creates microbial resistance and has a negative impact on the ecosystem. Biomaterials such as spent tea leaves are rich in functional groups and are suitable for chemical modification for diverse applications. This research proposes the use of spent tea leaves of chamomile (CM), green tea (GT), and peppermint (PM) as structural scaffolds for the incorporation of carboxyl, sulfonyl, and thiol groups to improve the adsorption of Penicillin G (Pe). Adsorbents characterization reported a higher number of acidic functional groups, mainly in thiolated products. Scanning electron microscopy (SEM) analysis showed changes on the surfaces of the adsorbents due to reaction conditions, with a stronger effect on thiolated and sulfonated adsorbents. Elemental analysis by Energy dispersive X-ray spectrophotometry (EDS) corroborated the chemical modification by the presence of sulfur atoms and the increase in oxygen/carbon ratios. Batch experiments at different pH shows a strong pH-dependence with a high adsorption at pH 8 for all the adsorbents. The adsorption follows the trend CMs > GTs > PMs. Thiolation and sulfonation reported higher adsorptions, which is most likely due to the sulfur bridge formation, reaching adsorption percentages of 25%. These results create a new mindset in the use of spent tea leaves and their chemical modifications for the bioremediation of antibiotics.

Surface characterization of carbon nanotubes irradiated by electron beam

2008 ◽  
Vol 79 (2) ◽  
pp. 02C510 ◽  
Author(s):  
Jeonggil Lee ◽  
Euikwon Kim ◽  
Jaekyun Jeon ◽  
Yoonman Lee ◽  
Jae-yong Kim
Keyword(s):  
Carbon Nanotubes ◽  
Electron Beam ◽  
Surface Characterization

scholarly journals DFT studies on the heterogeneous oxidation of SO2 by oxygen functional groups on graphene

2016 ◽  
Vol 18 (46) ◽  
pp. 31691-31697 ◽  
Author(s):  
Guangzhi He ◽  
Hong He
Keyword(s):  
Functional Groups ◽  
Functionalized Graphene ◽  
Dft Studies ◽  
Ambient Conditions ◽  
Heterogeneous Oxidation ◽  
Oxygen Functional Groups

Conversion of SO2 to SO3 on oxygen-functionalized graphene under ambient conditions.

An FTIR study of australian coals: Characterization of oxygen functional groups

1988 ◽  
Vol 19 (2) ◽  
pp. 123-140 ◽  
Author(s):  
S. Supaluknari ◽  
F.P. Larkins ◽  
P. Redlich ◽  
W.R. Jackson
Keyword(s):  
Functional Groups ◽  
Ftir Study ◽  
Oxygen Functional Groups

Optical, Electrical and Surface Characterization of Mercuric Iodide Platelets Grown in the HgI 2-HI-H2O System

1997 ◽  
Vol 487 ◽  
Author(s):  
L. Fornaro ◽  
H. Chen ◽  
K. Chattopadhyay ◽  
K.-T Chen ◽  
A. Burger
Keyword(s):  
Electrical Properties ◽  
Low Temperature ◽  
Apparent Resistivity ◽  
Surface Characterization ◽  
Vapor Transport ◽  
Physical Vapor Transport ◽  
Mercuric Iodide ◽  
Photoluminescence Properties ◽  
Low Temperature Photoluminescence

AbstractThe optical, electrical and surface properties of mercuric iodide platelets grown from solution in a HgI2-HI-H2O system were investigated by comparing them with Physical Vapor Transport (PVT) grown crystals. The absence of bulk imperfections and the uniformity of the as-grown surfaces and the KI solution etched surfaces were confirmed by optical microscopy. The as-grown surface uniformity is higher for solution grown crystals than that of PVT crystals, since the platelets do not have to be cleaved or polished. AFM studies show that the roughness for the cleaved, aged and etched surfaces were 0.06 nm, 0.48 nm and 0.3 nm respectively. Low temperature photoluminescence properties were measured for the two kind of crystals and will be discussed. However, I-V curves give higher current density and lower apparent resistivity values for the solution grown than for PVT grown crystals. Correlations between optical and surface quality as well as the electrical properties of the crystals grown from both solution and PVT methods are also discussed.

Characterization of oxygen functional groups on carbon surfaces with water and methanol adsorption

Carbon ◽  
2015 ◽  
Vol 81 ◽  
pp. 447-457 ◽  
Author(s):  
Yonghong Zeng ◽  
Luisa Prasetyo ◽  
Van T. Nguyen ◽  
Toshihide Horikawa ◽  
D.D. Do ◽  
...  
Keyword(s):  
Functional Groups ◽  
Methanol Adsorption ◽  
Oxygen Functional Groups ◽  
Carbon Surfaces

Growth and Characterization of Epitaxial GaAs on Ge/Si Substrates

1983 ◽  
Vol 25 ◽  
Author(s):  
Robert M. Fletcher ◽  
D. Ken Wagner ◽  
Joseph M. Ballantyne
Keyword(s):  
Electron Beam ◽  
Electrical Properties ◽  
Vapor Phase ◽  
Electron Beam Evaporation ◽  
Organometallic Vapor Phase Epitaxy ◽  
Si Substrate ◽  
Epitaxial Gaas ◽  
Si Substrates ◽  
Structural And Electrical Properties

ABSTRACTEpitaxial GaAs layers have been grown on Ge-coated Si substrates. Deposition of epitaxial Ge was performed by electron beam evaporation onto a <100> Si substrate. GaAs was then deposited by organometallic vapor-phase epitaxy. Films grown over large areas (∼1 cm2) and by selective epitaxy in stripe patterns (∼50 μm wide) have been evaluated by a number of techniques to determine structural and electrical properties. In addition, we report what we believe to be the first LEDs fabricated in GaAs/Ge/Si heterostructures.

scholarly journals The Influence of Compatibility on the Structure and Properties of PLA/Lignin Biocomposites by Chemical Modification

Polymers ◽  
2019 ◽  
Vol 12 (1) ◽  
pp. 56 ◽  
Author(s):  
Jianbing Guo ◽  
Xiaolang Chen ◽  
Jian Wang ◽  
Yong He ◽  
Haibo Xie ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Chemical Modification ◽  
Functional Groups ◽  
Three Dimensional ◽  
Mechanical Analysis ◽  
Poly Lactic Acid ◽  
Rheological Analysis ◽  
Oh Groups ◽  
Interfacial Compatibility

Lignin, a natural amorphous three-dimensional aromatic polymer, is investigated as an appropriate filler for biocomposites. The chemical modification of firsthand lignin is an effective pathway to accomplish acetoacetate functional groups replacing polar hydroxyl (–OH) groups, which capacitates lignin to possess better miscibility with poly(lactic acid) (PLA), compared with acidified lignin (Ac-lignin) and butyric lignin (By-lignin), for the sake of blending with poly(lactic acid) (PLA) to constitute a new biopolymer based composites. Generally speaking, the characterization of all PLA composites has been performed taking advantage of Fourier transform infrared (FTIR), scanning electron microscopy (SEM), dynamic Mechanical analysis (DMA), differential scanning calorimeter (DSC), thermogravimetric analysis (TGA), rheological analysis, and tensile test. Visibly, it is significant to highlight that the existence of acetoacetate functional groups enhances the miscibility, interfacial compatibility, and interface interaction between acetoacetate lignin (At-lignin) and PLA. Identical conclusions were obtained in this study where PLA/At-lignin biocomposites furthest maintain the tensile strength of pure PLA.

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