scholarly journals Effect of Cellulose Nanocrystals on the Coating of Chitosan Nanocomposite Film Using Plasma-Mediated Deposition of Amorphous Hydrogenated Carbon (a–C:H) Layers

2020 ◽  
Vol 6 (3) ◽  
pp. 51 ◽  
Author(s):  
Torben Schlebrowski ◽  
Zineb Kassab ◽  
Mounir El Achaby ◽  
Stefan Wehner ◽  
Christian B. Fischer
Keyword(s):  
Chemical Composition ◽  
Cellulose Nanocrystals ◽  
Photoelectron Spectroscopy ◽  
Nanocomposite Film ◽  
Chemical Vapor ◽  
Good Alternative ◽  
Ex Situ ◽  
X Ray ◽  
Wide Range ◽  
Amorphous Hydrogenated Carbon

The substitution of petroleum-based polymers with naturally derived biopolymers may be a good alternative for the conservation of natural fossil resources and the alleviation of pollution and waste disposal problems. However, in order to be used in a wide range of applications, some biopolymers’ properties should be enhanced. In this study, biocompatible, non-toxic, and biodegradable chitosan (CS) film and CS reinforced with 10 wt% of cellulose nanocrystals (CN–CS) were coated with amorphous hydrogenated carbon layers (a–C:H) of different thickness. To investigate the effect of the nano-reinforcement on the a–C:H layer applied, mild radio frequency plasma enhanced chemical vapor deposition (RF-PECVD) was used to coat the CS and its CN–CS bio-nanocomposite film. Both the surface characteristics and the chemical composition were analyzed. The surface morphology and wettability were examined by ex-situ atomic force microscopy (AFM) and contact angle measurements (CA), respectively. Hereby, the relationship between sp2/sp3 ratios on a macroscopic scale was also evaluated. For the investigation of the chemical composition, the surface sensitive synchrotron X-ray radiation techniques near edge X-ray absorption fine structure (NEXAFS) and X-ray photoelectron spectroscopy (XPS) as well as diffuse reflectance infrared Fourier transform spectroscopy (DRIFT) were used.

Atomic Hydrogen Effects on the Optical and Electrical Properties of Transparent Conducting Oxides For a-Si:H TFT-LCDs

1996 ◽  
Vol 424 ◽  
Author(s):  
Je-Hsiung Lan ◽  
Jerzy Kanicki
Keyword(s):  
Indium Tin Oxide ◽  
Photoelectron Spectroscopy ◽  
Atomic Hydrogen ◽  
Chemical Vapor ◽  
Optical Transmittance ◽  
Ex Situ ◽  
Hydrogen Treatment ◽  
X Ray ◽  
Conducting Oxides ◽  
Before And After

AbstractThe effects of the atomic hydrogen treatment (H-treatment) of indium-tin oxide (ITO) and aluminum-doped zinc oxide (AZO) films have been investigated. The atomic hydrogen was generated by hot-wire chemical vapor deposition (HW-CVD) technique. Experimental results have shown that AZO films are chemically very stable under the H-treatment; almost no variation in the optical transmittance and electrical resistivity was observed. On the contrary, ITO films, either prepared by sputtering with ex-situ or in-situ thermal-annealing, have shown severe optical and electrical degradation and surface whitening after the H-treatment. SEM studies of the H-treated ITO surfaces have revealed that the surface whitening was due to the increase in surface roughness and the formation of granule-like metallic balls. Auger electron spectroscopy has indicated that the balls were mainly composed of indium atoms and the areas between balls were rich in oxygen atoms. These results were confirmed by X-ray diffraction and X-ray photoelectron spectroscopy measurements done on ITO before and after the H-treatment. Finally, we have demonstrated that a-SiO, deposited by PECVD will completely suppress the chemical reaction between ITO surfaces and atomic hydrogen generated by HW-CVD technique.

scholarly journals Changing Contents of Carbon Hybridizations in Amorphous Hydrogenated Carbon Layers (a-C:H) on Sustainable Polyhydroxybutyrate (PHB) Exhibit a Significant Deterioration in Stability, Depending on Thickness

2019 ◽  
Vol 5 (3) ◽  
pp. 52 ◽  
Author(s):  
Torben Schlebrowski ◽  
Lucas Beucher ◽  
Hadi Bazzi ◽  
Barbara Hahn ◽  
Stefan Wehner ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Raw Materials ◽  
Chemical Vapor ◽  
Drift Spectroscopy ◽  
Significant Deterioration ◽  
X Ray ◽  
Diffuse Reflectance Infrared ◽  
X Ray Absorption ◽  
Amorphous Hydrogenated Carbon

PHB is a biodegradable polymer based on renewable raw materials that could replace synthetic polymers in many applications. A big advantage is the resulting reduction of the waste problem, as well as the conservation of fossil resources. To arrange it for various applications, the surface is arranged by plasma-enhanced chemical vapor deposition (PECVD) with amorphous hydrogenated carbon layers (a-C:H). Here, on a 50 µm thick PHB-foil, a-C:H layers of different thicknesses (0–500 nm) were deposited in 50 nm steps. Surface topography was investigated by scanning electron microscopy (SEM), chemical composition by diffuse reflectance infrared Fourier transform (DRIFT) spectroscopy and wettability checked by contact angle. In addition, layers were examined by synchrotron supported X-ray photoelectron spectroscopy (XPS) and near edge X-ray absorption fine structure (NEXAFS), which revealed thickness dependent changes of the sp2/sp3 ratio. With increasing thickness, even the topography changes show internal, stress-induced phenomena. The results obtained provide a more detailed understanding of the predominantly inorganic a-C:H coatings on (bio)polymers via in situ growth.

scholarly journals Characterization and Applications of Nanoparticles Modified in-Flight with Silica or Silica-Organic Coatings

Nanomaterials ◽  
2018 ◽  
Vol 8 (7) ◽  
pp. 530 ◽  
Author(s):  
Patrick Post ◽  
Lisa Wurlitzer ◽  
Wolfgang Maus-Friedrichs ◽  
Alfred Weber
Keyword(s):  
Chemical Composition ◽  
Photoelectron Spectroscopy ◽  
Elevated Temperatures ◽  
Chemical Vapor ◽  
Organic Coatings ◽  
Coated Particles ◽  
X Ray ◽  
Transmission Electron ◽  
Coating Composition ◽  
Modification Of The Surface

Nanoparticles are coated in-flight with a plasma-enhanced chemical vapor deposition (PECVD) process at ambient or elevated temperatures (up to 300 °C). Two silicon precursors, tetraethyl orthosilicate (TEOS) and hexamethyldisiloxane (HMDSO), are used to produce inorganic silica or silica-organic shells on Pt, Au and TiO2 particles. The morphology of the coated particles is examined with transmission electron microscopy (TEM) and the chemical composition is studied with Fourier-transform infrared spectroscopy (FTIR), Energy-dispersive X-ray spectroscopy (EDX) and X-ray photoelectron spectroscopy (XPS). It is found that both the precursor and certain core materials have an influence on the coating composition, while other parameters, such as the precursor concentration, aerosol residence time and temperature, influence the morphology, but hardly the chemical composition. The coated particles are used to demonstrate simple applications, such as the modification of the surface wettability of powders and the improvement or hampering of the photocatalytic activity of titania particles.

scholarly journals The Structure and Chemical Composition of the Cr and Fe Pyrolytic Coatings on the MWCNTs’ Surface According to NEXAFS and XPS Spectroscopy

Nanomaterials ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 374 ◽  
Author(s):  
Danil Sivkov ◽  
Olga Petrova ◽  
Alena Mingaleva ◽  
Anatoly Ob’edkov ◽  
Boris Kaverin ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Photoelectron Spectroscopy ◽  
Chemical Vapor ◽  
Diffraction Order ◽  
Charge Compensation ◽  
Organic Chemical ◽  
Total Electron ◽  
X Ray ◽  
Metal Atoms ◽  
Mwcnts Surface

The paper is devoted to the structure and properties of the composite material based on multi-walled carbon nanotubes (MWCNTs) covered with pyrolytic iron and chromium. Fe/MWCNTs and Cr/MWCNTs nanocomposites have been prepared by the metal organic chemical vapor deposition (MOCVD) growth technique using iron pentacarbonyl and bis(arene)chromium compounds, respectively. Composites structures and morphologies preliminary study were performed using X-ray diffraction, scanning and transmission electron microscopy and Raman scattering. The atomic and chemical composition of the MWCNTs’ surface, Fe-coating and Cr-coating and interface—(MWCNTs surface)/(metal coating) were studied by total electron yield method in the region of near-edge X-ray absorption fine structure (NEXAFS) C1s, Fe2p and Cr2p absorption edges using synchrotron radiation of the Russian-German dipole beamline (RGBL) at BESSY-II and the X-ray photoelectron spectroscopy (XPS) method using the ESCALAB 250 Xi spectrometer and charge compensation system. The absorption cross sections in the NEXAFS C1s edge of the nanocomposites and MWCNTs were measured using the developed approach of suppressing and estimating the contributions of the non-monochromatic background and multiple reflection orders radiation from the diffraction grating. The efficiency of the method was demonstrated by the example of the Cr/MWCNT nanocomposite, since its Cr2p NEXAFS spectra contain additional C1s NEXAFS in the second diffraction order. The study has shown that the MWCNTs’ top layers in composite have no significant destruction; the MWCNTs’ metal coatings are continuous and consist of Fe3O4 and Cr2O3. It is shown that the interface between the MWCNTs and pyrolytic Fe and Cr coatings has a multilayer structure: a layer in which carbon atoms along with epoxy –C–O–C– bonds form bonds with oxygen and metal atoms from the coating layer is formed on the outer surface of the MWCNT, a monolayer of metal carbide above it and an oxide layer on top. The iron oxide and chromium oxide adhesion is provided by single, double and epoxy chemical binding formation between carbon atoms of the MWCNT top layer and the oxygen atoms of the coating, as well as the formation of bonds with metal atoms.

scholarly journals Refinement of Sustainable Polybutylene Adipate Terephthalate (PBAT) with Amorphous Hydrogenated Carbon Films (a-C:H) Revealing Film Instabilities Influenced by a Thickness-Dependent Change of sp2/sp3 Ratio

Materials ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1077 ◽  
Author(s):  
Torben Schlebrowski ◽  
Halima Acharchi ◽  
Barbara Hahn ◽  
Stefan Wehner ◽  
Christian B. Fischer
Keyword(s):  
Photoelectron Spectroscopy ◽  
Chemical Vapor ◽  
Carbon Films ◽  
Organic Polymer ◽  
X Ray ◽  
Angle Measurements ◽  
Dependent Change ◽  
Contact Angle Measurements ◽  
Diffuse Reflectance Infrared ◽  
Amorphous Hydrogenated Carbon

The increasing use of polymers is related to a growing disposal problem. Switching to biodegradable polymers such as polybutylene adipate terephthalate (PBAT) is a feasible possibility, but after industrial production of commercially available material PBAT is not suitable for every application. Therefore, surface refinements with amorphous hydrogenated carbon films (a-C:H) produced by plasma-assisted chemical vapor deposition (PE-CVD) changing the top layer characteristics are used. Here, 50 µm-thick PBAT films are coated with a-C:H layers up to 500 nm in 50 nm steps. The top surface sp2/sp3 bonding ratios are analyzed by X-ray photoelectron spectroscopy (XPS) and near-edge X-ray absorption fine structure (NEXAFS) both synchrotron-based. In addition, measurements using diffuse reflectance infrared Fourier transform spectroscopy (DRIFT) were performed for detailed chemical composition. Surface topography was analyzed by scanning electron microscopy (SEM) and the surface wettability by contact angle measurements. With increasing a-C:H layer thickness not only does the topography change but also the sp2 to sp3 ratio, which in combination indicates internal stress-induced phenomena. The results obtained provide a more detailed understanding of the mostly inorganic a-C:H coatings on the biodegradable organic polymer PBAT via in situ growth and stepwise height-dependent analysis.

X-Ray Photoemission Study of Silicon Nitride-GaAs Interfaces in Relation with GaAs Mesfet Passivation

1987 ◽  
Vol 98 ◽  
Author(s):  
Patrick Alnot ◽  
J. Olivier ◽  
F. Wyczisk ◽  
J. F. Peray ◽  
R. Joubart
Keyword(s):  
Chemical Composition ◽  
Photoelectron Spectroscopy ◽  
Excitation Frequency ◽  
Chemical Vapor ◽  
Gaas Surface ◽  
Surface Pretreatment ◽  
X Ray ◽  
Chemical Vapor Deposited ◽  
Plasma Excitation ◽  
Photoemission Study

ABSTRACTWe have studied the influence of different GaAs surface treatments on the chemical composition and electrical behavior of the Si 3 N4 -GaAs interface, where Si 3 N4 was plasma enhanced chemical vapor deposited (PECVD) onto the treated GaAs(100) substrate. The chemistry of the resulting interface has been studied by X-ray photoelectron spectroscopy (XPS). It has been demonstrated that the chemical composition of the Si 3 N4-GaAs interface is drastically dependent on GaAs surface pretreatment and r.f. plasma excitation frequency. Output-input powers characteristics have been measured on chemically treated planar MESFET after Si3N4. passivation.

scholarly journals Plasma Supported Deposition of Amorphous Hydrogenated Carbon (a-C:H) on Polyamide 6: Determining Interlayer Completion and Dehydrogenation Effects during Layer Growth

Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1886
Author(s):  
Torben Schlebrowski ◽  
Henriette Lüber ◽  
Lucas Beucher ◽  
Melanie Fritz ◽  
Youssef Benjillali ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Chemical Vapor ◽  
Polyamide 6 ◽  
Carbon Layer ◽  
Layer Growth ◽  
Ex Situ ◽  
X Ray ◽  
Force Microscopy ◽  
Angle Measurements ◽  
Diffuse Reflectance Infrared

Polyamide 6 (PA6) is a commonly used material in many different sectors of modern industry. Herein, PA6 samples were coated with amorphous carbon layers (a-C:H) with increasing thickness up to 2 µm using radio frequency plasma enhanced chemical vapor deposition for surface adjustment. The morphology of the carbon coatings was inspected by ex situ atomic force microscopy and scanning electron microscopy. Surface wettability was checked by contact angle measurements. The chemical composition was analyzed using the surface sensitive synchrotron X-ray-based techniques near-edge X-ray absorption fine structure and X-ray photoelectron spectroscopy, supported by diffuse reflectance infrared Fourier transform spectroscopy. Particular attention was paid to the coating interval from 0 to 100 nm, to specify the interlayer thickness between the PA6 polymer and a-C:H coating, and the region between 1000 and 2000 nm, where dehydrogenation of the a-C:H layer occurs. The interlayer is decisive for the linkage of the deposited carbon layer on the polymer: the more pronounced it is, the better the adhesion. The thickness of the interlayer could be narrowed down to 40 nm in all used methods, and the dehydrogenation process takes place at a layer thickness of 1500 nm.

scholarly journals Investigations of Electron Properties of Carbon Nanotubes Decorated with Platinum Nanoparticles with Their Varying Fraction

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Anna Dobrzańska-Danikiewicz ◽  
Dariusz Łukowiec ◽  
Jerzy Kubacki
Keyword(s):  
Carbon Nanotubes ◽  
Chemical Composition ◽  
Platinum Nanoparticles ◽  
Photoelectron Spectroscopy ◽  
Qualitative And Quantitative Analysis ◽  
X Ray ◽  
Qualitative And Quantitative ◽  
The Core ◽  
Wide Range ◽  
Varying Mass

The paper presents the outcomes of investigations into electron properties and a qualitative and quantitative analysis of the chemical composition of unmodified carbon nanotubes with comparison to nanotubes decorated with platinum nanoparticles. The fabricated nanocomposite materials of the CNT-Pt type differed in a varying mass concentration of platinum nanoparticles (5, 10, and 20% of Pt). X-ray photoelectron spectroscopy (XPS) was employed to examine the structure and to analyse chemical composition. Survey spectra measurements within a wide range of the binding energy of 0–1400 eV were performed in the first phase of the investigations. The core lines of C1s carbon, Pt4f platinum, and O1s oxygen and a valence band were then measured. The chemical composition of the studied materials was determined based on the measured spectra of the core lines. The purpose of the investigations is to determine the effect of platinum nanoparticles on the structure and electron properties of the fabricated CNT-Pt nanocomposites.

scholarly journals Development of an Adsorbing System Made of DMS-1 Mesh Modified by Amino Groups to Remove Pb(II) Ions from Water

Materials ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 1914
Author(s):  
Viviana Palos-Barba ◽  
Cecilia Lugo-Nabor ◽  
Rodrigo R. Velázquez-Castillo ◽  
Dora Alicia Solís-Casados ◽  
Carmen L. Peza-Ledesma ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Low Cost ◽  
Sol Gel ◽  
Nitrogen Adsorption ◽  
Good Alternative ◽  
Ex Situ ◽  
Amino Groups ◽  
X Ray ◽  
Molar Ratios ◽  
Adsorption Processes

Water pollution by heavy metals represents several health risks. Conventional technologies employed to eliminate lead ions from residual or drinking water are expensive, therefore an efficient and low-cost technique is required and adsorption processes are a good alternative. In this work, the goal was to determine the adsorption capacity of a Disordered Mesoporous Silica 1 material (DMS-1) functionalized with amino groups, for Pb(II) ions removal. DMS-1 was prepared by sol-gel method and the incorporation of amino groups was performed by ex-situ method. As the source of amine groups, (3-Aminopropyl) triethoxysilane (APTES) was used and three different xNH2/DMS-1 molar ratios (0.2, 0.3, 0.4) were evaluated. In order to evaluate the incorporation of the amino group into the mesopore channels, thermal and structural analysis were made through Thermogravimetric Analysis (TGA), nitrogen adsorption–desorption at 77 K by Specific Brunauer–Emmett–Teller (SBET) method, Fourier Transfer Infrared spectroscopy (FTIR), Scanning Electron Microscopy (SEM), X-Ray Diffraction (XRD) and X-Ray Photoelectron Spectroscopy (XPS). The higher Pb(II) ions removal was achieved with the 0.3 molar proportion of xNH2/DMS-1 reaching 99.44% efficiency. This result suggests that the functionalized material can be used as an efficient adsorbent for Pb(II) ions from aqueous solution.

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