Low-Energy Ar+ Implantation of Uhmw-Pe Fibers: Effect on Surface Energy, Chemistry, and Adhesion Characteristics

1991 ◽  
Vol 236 ◽  
Author(s):  
R. Schalek ◽  
M. Hlavacek ◽  
D. S. Grummon
Keyword(s):  
Surface Energy ◽  
Photoelectron Spectroscopy ◽  
Polymer Matrix Composites ◽  
Ion Irradiation ◽  
High Surface ◽  
Surface Oxidation ◽  
Low Energy ◽  
Polar Component ◽  
Optimum Dose ◽  
Plasma Treatments

AbstractUltra-high molecular weight polyethylene (UHMW-PE) has a highly chain-extended and crystalline structure which is functionally inert and requires surface-modification before it can successfully operate as a reinforcement in polymer-matrix composites. Although plasma treatments are adequate for this purpose, recent work has shown that irradiation with low-energy inert gas ions can produce increases in interfacial shear strength (ISS), in epoxy matrices, which exceed those of commercial plasma treatments, and cause little degradation in tensile properties. Low energy ions are readily produced in high-current beams using gridded sources having moderate cost, and processing times may be a short as a few seconds. In this paper, we present results of recent experiments using argon ions accelerated to energies between 100 eV and 1 keV to irradiate 20-30 µm diameter UHMW-PE fibers to doses between 1×1016 and 1×1017 cm−2, and compare our findings with previous work at higher accelerating potentials. At the optimum dose (which increases with decreasing energy), greater than 9-fold improvements in ISS level, measured in epoxy-resin droplet pulloff tests, were found for ion irradiation at 0.25 keV. Scanning electron microscopy of fiber surfaces, of ion irradiated as well as commercial oxygen plasmatreated materials, revealed small crack-like pits in both cases, with the pits smaller and more uniformly distributed on the ion-irradiated fibers. Surface chemistry studies using X-ray photoelectron spectroscopy (XPS) and attenuated total reflectance Fourier-transform infrared spectroscopy (ATR-FTIR) indicate that irradiation resulted in high surface concentrations of polar functional groups, and extensive surface oxidation. This was accompanied by a substantial increase in the polar component of surface energy, which resulted in improved fiber wetting by the resin.

Low-Energy AR+ Implantation of Uhmw-Pe Fibers: Effect on Surface Energy, Chemistry, and Adhesion Characteristics

1991 ◽  
Vol 235 ◽  
Author(s):  
R. Schalek ◽  
M. Hlavacek ◽  
D. S. Grummon
Keyword(s):  
Surface Energy ◽  
Polymer Matrix Composites ◽  
Ion Irradiation ◽  
High Surface ◽  
Surface Oxidation ◽  
Low Energy ◽  
Polar Component ◽  
Optimum Dose ◽  
Plasma Treatments ◽  
Polar Functional Groups

ABSTRACTUltra-high molecular weight polyethylene (UHMW-PE) has a highly chain-extended and crystalline structure which is functionally inert and requires surface-modification before it can successfully operate as a reinforcement in polymer-matrix composites. Although plasma treatments are adequate for this purpose, recent work has shown that irradiation with low-energy inert gas ions can produce increases in interfacial shear strength (ISS), in epoxy matrices, which exceed those of commercial plasma treatments, and cause little degradation in tensile properties. Low energy ions are readily produced in high-current beams using gridded sources having moderate cost, and processing times may be a short as a few seconds. In this paper, we present results of recent experiments using argon ions accelerated to energies between 100 eV and 1 keV to irradiate 20–30 μm diameter UHMW-PE fibers to doses between 1×1016 and 1×1017 cm−2, and compare our findings with previous work at higher accelerating potentials. At the optimum dose (which increases with decreasing energy), greater than 9-fold improvements in ISS level, measured in epoxy-resin droplet pulloff tests, were found for ion irradiation at 0.25 keV. Scanning electron microscopy of fiber surfaces, of ion irradiated as well as commercial oxygen plasma-treated materials, revealed small crack-like pits in both cases, with the pits smaller and more uniformly distributed on the ion-irradiated fibers. Surface chemistry studies using X-ray photoelec-tron spectroscopy (XPS) and attenuated total reflectance Fourier-transform infrared spectroscopy (ATR-FTIR) indicate that irradiation resulted in high surface concentrations of polar functional groups, and extensive surface oxidation. This was accompanied by a substantial increase in the polar component of surface energy, which resulted in improved fiber wetting by the resin.

scholarly journals Non-Thermal Plasma-Modified Ru-Sn-Ti Catalyst for Chlorinated Volatile Organic Compound Degradation

Catalysts ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1456
Author(s):  
Yujie Fu ◽  
You Zhang ◽  
Qi Xin ◽  
Zhong Zheng ◽  
Yu Zhang ◽  
...  
Keyword(s):  
Plasma Treatment ◽  
Photoelectron Spectroscopy ◽  
High Surface ◽  
High Surface Area ◽  
Surface Oxidation ◽  
Treatment Method ◽  
X Ray ◽  
Chlorinated Volatile Organic Compounds ◽  
Volatile Organic ◽  
Doped Titania

Chlorinated volatile organic compounds (CVOCs) are vital environmental concerns due to their low biodegradability and long-term persistence. Catalytic combustion technology is one of the more commonly used technologies for the treatment of CVOCs. Catalysts with high low-temperature activity, superior selectivity of non-toxic products, and resistance to chlorine poisoning are desirable. Here we adopted a plasma treatment method to synthesize a tin-doped titania loaded with ruthenium dioxide (RuO2) catalyst, possessing enhanced activity (T90%, the temperature at which 90% of dichloromethane (DCM) is decomposed, is 262 °C) compared to the catalyst prepared by the conventional calcination method. As revealed by transmission electron microscopy, X-ray diffraction, N2 adsorption, X-ray photoelectron spectroscopy, and hydrogen temperature-programmed reduction, the high surface area of the tin-doped titania catalyst and the enhanced dispersion and surface oxidation of RuO2 induced by plasma treatment were found to be the main factors determining excellent catalytic activities.

A look into the interaction of metal oxide thin films with biological media: Albumin and Fibrinogen adsorption

2012 ◽  
Vol 1376 ◽  
Author(s):  
P. Silva-Bermudez ◽  
S. Muhl ◽  
M. Rivera ◽  
S. E. Rodil
Keyword(s):  
Surface Roughness ◽  
Surface Energy ◽  
Protein Adsorption ◽  
Photoelectron Spectroscopy ◽  
Ex Situ ◽  
Polar Component ◽  
Metal Oxide Thin Films ◽  
Adsorbed Protein ◽  
Major Chemical ◽  
Fibrinogen Adsorption

ABSTRACTIn the present work, the adsorption of albumin and fibrinogen on Ta, Nb, Ti and Zr oxidesthin films deposited on Si (100) wafers by magnetron sputtering was studied in order to get a better understanding of the correlation among the surface properties of these oxides and the protein adsorption phenomena on their surfaces. The surface energy, hydrophobicity, chemical composition, roughness and atomic order of the films were characterized. The films were immersedfor 45 minutes in single protein solutions; either albumin or fibrinogenand the adsorbed protein layer on the films was studied ex-situ in a dry ambient using bothX-ray photoelectron spectroscopy and atomic force microscopy.The adsorption of albumin and fibrinogen on the films modified the surface morphology and decreased the surface roughness for all the four different metal oxides. The XPS results confirmed the presence of the protein on the surface of the films and showed that the two proteins studied were adsorbed without undergoing a major chemical decomposition. A correlation between the surface roughness,the polar component of the surface energy of the films and the atomic percentage of nitrogen on the films after protein adsorption, an indirect signal of the amount of protein adsorbed, was found for albumin and fibrinogen adsorption on Ta, Nb and Ti oxides; the largest the roughness or the polar component the largest amount of adsorbed protein.

scholarly journals Extremely low-energy ARPES of quantum well states in cubic-GaN/AlN and GaAs/AlGaAs heterostructures

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Mahdi Hajlaoui ◽  
Stefano Ponzoni ◽  
Michael Deppe ◽  
Tobias Henksmeier ◽  
Donat Josef As ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Quantum Well ◽  
Photoelectron Spectroscopy ◽  
Momentum Space ◽  
High Surface ◽  
Sample Surface ◽  
Low Energy ◽  
Additional Information ◽  
Wide Range ◽  
Cubic Gan

AbstractQuantum well (QW) heterostructures have been extensively used for the realization of a wide range of optical and electronic devices. Exploiting their potential for further improvement and development requires a fundamental understanding of their electronic structure. So far, the most commonly used experimental techniques for this purpose have been all-optical spectroscopy methods that, however, are generally averaging in momentum space. Additional information can be gained by angle-resolved photoelectron spectroscopy (ARPES), which measures the electronic structure with momentum resolution. Here we report on the use of extremely low-energy ARPES (photon energy ~ 7 eV) to increase depth sensitivity and access buried QW states, located at 3 nm and 6 nm below the surface of cubic-GaN/AlN and GaAs/AlGaAs heterostructures, respectively. We find that the QW states in cubic-GaN/AlN can indeed be observed, but not their energy dispersion, because of the high surface roughness. The GaAs/AlGaAs QW states, on the other hand, are buried too deep to be detected by extremely low-energy ARPES. Since the sample surface is much flatter, the ARPES spectra of the GaAs/AlGaAs show distinct features in momentum space, which can be reconducted to the band structure of the topmost surface layer of the QW structure. Our results provide important information about the samples’ properties required to perform extremely low-energy ARPES experiments on electronic states buried in semiconductor heterostructures.

EFFECT OF SURFACE PROPERTIES ON THE WETTABILITY OF IRON CONTAINING AMORPHOUS CARBON FILMS

2002 ◽  
Vol 16 (06n07) ◽  
pp. 1031-1037 ◽  
Author(s):  
J. S. CHEN ◽  
S. P. LAU ◽  
Z. SUN ◽  
G. Y. CHEN ◽  
Y. J. LI ◽  
...  
Keyword(s):  
Contact Angle ◽  
Surface Energy ◽  
Amorphous Carbon ◽  
Photoelectron Spectroscopy ◽  
Contact Angle Measurement ◽  
Carbon Films ◽  
Angle Measurement ◽  
Vacuum Arc ◽  
Polar Component ◽  
Dispersive Component

Ta-C and iron containing amorphous carbon (a-C:Fe) films were deposited by filtered cathodic vacuum arc technique. The influences of Fe contents on the wettability of the films were investigated in terms of surface energy. The surface energy of a-C:Fe films was determined by the contact angle measurement. Atomic force microscopy (AFM), Raman spectroscopy and X-ray induced photoelectron spectroscopy (XPS) were employed to analyze the origin of the variation of surface energy with various Fe content. It is found that the contact angle for water increases significantly after incorporating Fe into the films and the films become hydrophobic. The roughness of these films has a little effect on the contact angle. The surface energy is reduced after incorporating Fe into the a-C film which is due to the reduction of both dispersive and polar component. The reduction in dispersive component is ascribed to the decrease of atomic density of the a-C:Fe films due to the increase in sp2 bonded carbon. The absorption of oxygen on the surface play an important role in the reduction of polar component for the a-C:Fe films. It is proposed that such network as (Ca-O-Fe)-O-(Fe-O-Ca) may be formed and responsible for the reduction of polar component.

PPS-Polymer-Composites for High Performance Rubber Components

2015 ◽  
Vol 825-826 ◽  
pp. 60-66
Author(s):  
Rico Hickmann ◽  
Olaf Diestel ◽  
Chokri Cherif ◽  
Thomas Götze ◽  
Gert Heinrich ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Surface Energy ◽  
Atmospheric Pressure ◽  
High Performance ◽  
Barrier Discharge ◽  
Atmospheric Pressure Plasma ◽  
Polar Component ◽  
Dielectric Barrier ◽  
Plasma Treatments ◽  
Reactive Gas

Based on their properties, PPS fibers are a promising material for reinforcing elastomeric components that are subjected to high mechanical and thermal loads. The use of this material is at present hindered because of the low adhesion between the fiber and matrix. Atmospheric pressure plasma treatments based on the dielectric barrier discharge were performed on PPS fibers using air as reactive gas for different treatment durations in order to improve the adhesion. The effects of these treatments have been characterized by determining the surface energy, and the residual tensile strength as well as by analyzing the surface chemistry. Required conditions for an improved wetting behavior and a significant increase in the polar component of the surface energy could then be identified.

Anti-Sticking Properties of PVD CrWNx, CrOx and ZrOx Coatings on Medical Electrode Application

2010 ◽  
Vol 297-301 ◽  
pp. 656-663
Author(s):  
Y.L. Hsu ◽  
C.H. Lee ◽  
S.M. Chiu ◽  
Y.C. Sung ◽  
K.Y. Yang ◽  
...  
Keyword(s):  
Contact Angle ◽  
Surface Energy ◽  
High Surface ◽  
Contact Angle Measurement ◽  
Angle Measurement ◽  
Polar Component ◽  
In Vitro Test ◽  
Unbalanced Magnetron Sputtering ◽  
Unbalanced Magnetron

The side effect of electrosurgery includes tissue charring, smoke generation and the adhesion of tissue to electrodes. These effects prolong surgery and interfere with effective coagulation. In this paper, CrWNx, CrOx and ZrOx coating were prepared by an unbalanced magnetron sputtering. The microstructure of films was characterized using XRD, XPS, TEM and AFM. The hydrophobicity and surface energy of coatings were calculated by contact angle measurement and Wu harmonic mean approach. Anti-sticking in vitro test was performed by monopolar electrosurgery using pork liver tissue. The hardness of CrWNx , ZrOx and CrOx coatings were 44 GPa, 26.3 GPa and 20.7 GPa, respectively. The CrOx coating had the lowest surface energy 33.5 mN/m and the highest contact angle of water as high as 103°. The high surface O-H bonds density of CrOx coating and N-H bonds density of CrWNx coating could explain about their lower polar component of surface energy. All the three PVD coatings remarkably reduced the quantity of tissue adhesion on the electrode from about 2 times (ZrOx and CrWNx coatings) to 4.88 times (CrOx coating) than uncoated SUS304 electrode.

On the Wettability of Nanocomposite Amorphous Carbon Films

2005 ◽  
Vol 23 ◽  
pp. 67-70
Author(s):  
P. Zhang ◽  
B.K. Tay ◽  
G.Q. Yu ◽  
S.P. Lau
Keyword(s):  
Contact Angle ◽  
Surface Energy ◽  
Amorphous Carbon ◽  
Photoelectron Spectroscopy ◽  
Contact Angles ◽  
Atomic Scale ◽  
Vacuum Arc ◽  
Polar Component ◽  
Metal Composite ◽  
Obvious Effect

Nanocomposite Si containing amorphous carbon (a-C:Si) and metal containing amorphous carbon (a-C:Me) films including a-C:Al, a-C:Ti, and a-C:Ni were prepared by the filtered cathodic vacuum arc (FCVA) technique The metal-carbon (5 at.% metal) composite targets were used. The VCA Optima system was used to measure the contact angle. Three types of liquid were used to study the changes in the surface energy. X-ray photoelectron spectroscopy (XPS) was employed to analyze the composition and chemical state of the films. The surface morphology and roughness of the films were determined by atomic force microscopy (AFM). The Al containing films show the highest contact angle with water, which reaches as high as 101.26°. The Si containing films show the lowest contact angle around 64°. The contact angles of Ni, and Ti containing films are around 83°, 96.5°, respectively. The absorption of oxygen on the surface play an important role on the polar component of the a-C:Me films. The formation of Al-O, and Ti-O bonds is responsible for the lower polar component. The metal state Ni results in higher polar component. The Si-O bond contributes to the high polar component of a-C:Si film. As all films are atomic scale smooth, the RMS roughness is below 0.5 nm, the roughness does not have obvious effect on the surface energy.

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