Silicon and silicon oxide surface modification using thiamine-catalyzed benzoin condensations

2012 ◽  
Vol 90 (3) ◽  
pp. 262-270 ◽  
Author(s):  
Kelly A. Hoop ◽  
David C. Kennedy ◽  
Trevor Mishki ◽  
Gregory P. Lopinski ◽  
John Paul Pezacki
Keyword(s):  
Surface Modification ◽  
Ir Spectroscopy ◽  
Photoelectron Spectroscopy ◽  
Silicon Oxide ◽  
Oxide Surfaces ◽  
Oxide Surface ◽  
X Ray ◽  
Benzoin Condensation ◽  
Aldehyde Groups ◽  
Full Conversion

The benzoin condensation that involves the umpolung coupling of two aldehyde groups has been applied to the formation of functionalized silicon and silicon oxide surfaces using thiamine and other N-heterocyclic carbene (NHC) catalysis in water. This bioorthogonal conjugation of an aldehyde to a modified silicon or silicon oxide surface has been monitored and characterized using X-ray photoelectron spectroscopy and IR spectroscopy. NHC catalysis was found to be efficient in water mediating full conversion of the aldehyde functionalized silicon oxide surfaces at the interface.

Surface Chemical Structure of Sío2-TiO2 Sol-Gel Powders

1994 ◽  
Vol 346 ◽  
Author(s):  
G.M. Ingo ◽  
G. Padeletti ◽  
S. Dire' ◽  
F. Babonneau
Keyword(s):  
Photoelectron Spectroscopy ◽  
Chemical Structure ◽  
Silicon Oxide ◽  
Sol Gel ◽  
Treatment Temperature ◽  
Oxide Surface ◽  
Surface Chemical ◽  
Titanium Tetraisopropoxide ◽  
X Ray ◽  
Increasing Temperature

ABSTRACTAmorphous SiO2, TiO2 and x SiO2-(1-x) TiO2 powders, with nominal values of x=0.9, 0.7 and 0.5, have been prepared via sol-gel, using silicon tetrahoxysilane (TEOS) and titanium tetraisopropoxide Ti(OPri)4. X-ray photoelectron spectroscopy (XPS) and X-ray induced Auger electron spectroscopy (XAES) are used for studying the surface chemical structure of the powders as a function of the air thermal treatment temperature up to 1273 K. For the whole range of temperature, XPS and XAES signals indicate that silicon and titanium are present as Si4+ and Ti4+ oxides. From the line shape of the O 1s peak, it is possible to distinguish between the single O-Ti and O-Si bonds and to disclose also the presence of Si-O-Ti cross linking bonds that are supposed to act as bridges between SiO2 and TiO2 moieties. Starting from 873 K, the Si-O-Ti bonds are broken and formation of a low amount of new Ti-O and a higher amount of Si-O bonds takes place. Si/Ti atomic ratios obtained by curve fitting the O Is peaks and from Ti 2p3/2 and Si 2p peaks, confirm the silicon oxide surface enrichment. Furthermore, with increasing temperature, XAES data indicate the formation of crystalline phases.

scholarly journals Surface Analysis of Chamber Coating Materials Exposed to CF4/O2 Plasma

Coatings ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 105
Author(s):  
Seung Hyun Park ◽  
Kyung Eon Kim ◽  
Sang Jeen Hong
Keyword(s):  
Photoelectron Spectroscopy ◽  
Yttrium Aluminum Garnet ◽  
Silicon Oxide ◽  
Ceramic Materials ◽  
High Plasma ◽  
Coating Materials ◽  
Continuous Increase ◽  
X Ray ◽  
Bonding Structure ◽  
Manufacturing Environments

Coating the inner surfaces of high-powered plasma processing equipment has become crucial for reducing maintenance costs, process drift, and contaminants. The conventionally preferred alumina (Al2O3) coating has been replaced with yttria (Y2O3) due to the long-standing endurance achieved by fluorine-based etching; however, the continuous increase in radio frequency (RF) power necessitates the use of alternative coating materials to reduce process shift in a series of high-powered semiconductor manufacturing environments. In this study, we investigated the fluorine-based etching resistance of atmospheric pressure-sprayed alumina, yttria, yttrium aluminum garnet (YAG), and yttrium oxyfluoride (YOF). The prepared ceramic-coated samples were directly exposed to silicon oxide etching, and the surfaces of the plasma-exposed samples were characterized by scanning electron microscopy, energy-dispersive X-ray spectroscopy, and X-ray photoelectron spectroscopy. We found that an ideal coating material must demonstrate high plasma-induced structure distortion by the fluorine atom from the radical. For endurance to fluorine-based plasma exposure, the bonding structure with fluoride was shown to be more effective than oxide-based ceramics. Thus, fluoride-based ceramic materials can be promising candidates for chamber coating materials.

X-ray photoelectron spectroscopy study of the interaction of methanol with polycrystalline copper oxide surface

1996 ◽  
Vol 11 (7) ◽  
pp. 1605-1608 ◽  
Author(s):  
S. Badrinarayanan ◽  
A. B. Mandale ◽  
S. R. Sainkar
Keyword(s):  
Copper Oxide ◽  
Photoelectron Spectroscopy ◽  
Low Dose ◽  
Dissociative Adsorption ◽  
Methanol Decomposition ◽  
Oxide Surface ◽  
Polycrystalline Copper ◽  
Spectroscopy Study ◽  
Methanol Vapor ◽  
X Ray

Methanol decomposition on a clean polycrystalline copper oxide surface was studied by x-ray photoelectron spectroscopy (XPS). Methanol was adsorbed at 133 K and desorbed over a broad temperature range. When CuO was exposed to a very low dose of methanol vapor, dissociative adsorption takes place, leading to the formation of CH3O and H2O. This is attributed to the presence of preadsorbed oxygen on the CuO surface.

SiO2 films as heat resistant layers for protection of expandable polystyrene foam from flame torch–induced heat

2017 ◽  
Vol 31 (5) ◽  
pp. 657-667 ◽  
Author(s):  
S Varnagiris ◽  
S Tuckute ◽  
M Lelis ◽  
D Milcius
Keyword(s):  
Heat Resistance ◽  
Photoelectron Spectroscopy ◽  
Silicon Oxide ◽  
Plasma Generator ◽  
Expanded Polystyrene ◽  
Spectroscopy Analysis ◽  
X Ray ◽  
Heat Resistant ◽  
Pulsed Dc ◽  
Gas Atmosphere

Currently, polymeric insulation materials are widely used for energy saving in buildings. Despite of all benefits, these materials are generally sensitive to heat and highly flammable. This work discusses possibility to improve heat resistance of expanded polystyrene (EPS) foam using thin silicon dioxide (SiO2) films deposited by magnetron sputtering technique. In order to increase surface energy and adherence of SiO2 thin films to substrate EPS was plasma pretreated before films’ depositions using pulsed DC plasma generator for 40 s in argon gas. SiO2 formation was done in reactive argon and oxygen gas atmosphere. Laboratory made equipment was used for flame torch–induced heat resistance experiments. Results showed that silicon oxide films remains stable during heat resistance experiments up to 5 s and fully protects polystyrene (PS) substrate. Films are relatively stable for 30 s and 60 s and partially protect PS from melting and ignition. Scanning electron microscopy, energy-dispersive X-ray spectroscopy, and X-ray photoelectron spectroscopy analysis confirmed that SiO2 layer, which is distributed uniformly on the EPS surface, could work as a good heat resistant material.

Oxidation Behavior of Cu60Zr30Ti10 Bulk Metallic Glass

2005 ◽  
Vol 20 (6) ◽  
pp. 1396-1403 ◽  
Author(s):  
C.Y. Tam ◽  
C.H. Shek
Keyword(s):  
Metallic Glass ◽  
Oxide Layer ◽  
Bulk Metallic Glass ◽  
Photoelectron Spectroscopy ◽  
Oxidation Kinetics ◽  
Oxide Surface ◽  
X Ray ◽  
Rate Law ◽  
Cu Content ◽  
Surface Morphologies

The oxidation kinetics of Cu60Zr30Ti10 bulk metallic glass and its crystalline counterpart were studied in oxygen environment over the temperature range of 573–773 K. The oxidation kinetics, measured with thermogravimetric analysis, of the metallic glass follows a linear rate law between 573 and 653 K and a parabolic rate law between 673 and 733 K. It was also found that the oxidation activation energy of metallic glass is lower than that of its crystalline counterpart. The x-ray diffraction pattern showed that the oxide layer is composed of Cu2O, CuO, ZrO2, and metallic Cu. Cu enrichment on the topmost oxide layer of the metallic glass oxidized at 573 K was revealed by x-ray photoelectron spectroscopy while there was a decrease in Cu content in the innermost oxide layer. The oxide surface morphologies observed from scanning electron microscopy showed that ZrO2 granules formed at low temperatures while whiskerlike copper oxides formed at higher temperatures.

Surface Modification of Acrylonitrile Fibers and Membrane by Nitrilase from Escherichia Coli BL21 (DE3)/pET-Nit

2011 ◽  
Vol 175-176 ◽  
pp. 651-655 ◽  
Author(s):  
Li Li Feng ◽  
Jian Fei Zhang ◽  
Hui Luo ◽  
Zheng Li
Keyword(s):  
Escherichia Coli ◽  
Surface Modification ◽  
Photoelectron Spectroscopy ◽  
Membrane Surface ◽  
Atomic Ratio ◽  
X Ray ◽  
Escherichia Coli Bl21 ◽  
Treated Fiber ◽  
Acrylic Fibers ◽  
Pan Fibers

The surface of polyacrylonitrile fibers and membrane were modified by nitrilase from Escherichia coli BL21 (DE3)/pET-Nit. Escherichia coli BL21(DE3)/pET-Nit was able to convert nitrile groups on PAN fibers and membrane to corresponding carboxylic acid as indicated by X-ray photoelectron spectroscopy (XPS). An increase of O/C atomic ratio on the fiber and membrane surface showed an increase in hydrophilicity and fabric-dyeing efficiency. Strength of treated fiber decreased by only 1.17%, because only surfacial nitrile groups of acrylic fibers were hydrolyzed by E.coli BL21(DE3)/pET-Nit.

Photoinduced Selective Deposition of Aluminium Thin Film Using Dimethylaluminum Hydride

1991 ◽  
Vol 236 ◽  
Author(s):  
Mitsugu Hanabusa ◽  
Hideki Ouchi ◽  
Kenji Ishida ◽  
Masahiro Kawasaki ◽  
Satoshi Shogen
Keyword(s):  
Thin Film ◽  
Photoelectron Spectroscopy ◽  
Surface Reaction ◽  
Silicon Oxide ◽  
Film Growth ◽  
X Ray ◽  
Etched Silicon ◽  
Substrate Surfaces ◽  
Deuterium Lamp ◽  
Dimethylaluminum Hydride

AbstractAluminum thin film was deposited via a photochemical surface reaction of dimethylaluminum hydride (DMAH) using a deuterium lamp. The period required to initiate the film growth differed with substrate, and making use of this result the film could be grown preferentially on silicon nitride and silicon oxide layers rather than on wet-etched silicon. On the basis of an x-ray photoelectron spectroscopy the observed dependence of photodeposition on substrate surfaces can be attributed to how DMAH is chemisorbed initially.

X-ray photoelectron spectroscopy study of rapid thermal annealed silicon–silicon oxide systems

1997 ◽  
Vol 81 (11) ◽  
pp. 7386-7391 ◽  
Author(s):  
W. K. Choi ◽  
F. W. Poon ◽  
F. C. Loh ◽  
K. L. Tan
Keyword(s):  
Photoelectron Spectroscopy ◽  
Silicon Oxide ◽  
Spectroscopy Study ◽  
Oxide Systems ◽  
X Ray ◽  
Silicon Silicon
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