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.

Study of Surface Characteristics of T700 Carbon Fibers and Interfacial Properties of their Reinforced Epoxy Composites

2013 ◽  
Vol 364 ◽  
pp. 706-710
Author(s):  
Ling Cong Li ◽  
Li Li Wang ◽  
Hua Hao ◽  
Hui Ling ◽  
Hong Jie Sun ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Surface Energy ◽  
Carbon Fibers ◽  
Photoelectron Spectroscopy ◽  
Interfacial Adhesion ◽  
Dynamic Contact Angle ◽  
Surface Characteristics ◽  
Interfacial Properties ◽  
Epoxy Composites ◽  
Sem Images

The purpose of this paper is to comparatively study the surface characteristics of domestic and Toray T700 carbon fibers (T700-CFs) and the interfacial properties of their reinforced epoxy composites. The surface roughness and surface energy of the fibers were characterized by scanning electron microscope (SEM) and dynamic contact angle analysis (DCAA). The surface chemistry analysis of the fibers was carried out by using X-ray photoelectron spectroscopy (XPS). The interfacial properties of the T700-CF/epoxy composites were studied by testing the interlaminar shear strength (ILSS), observing SEM images of composites profiles and calculating the interfacial adhesion factors from dynamic mechanical thermal analysis (DMTA) data. The results show that domestic T700-CFs have a better interfacial adhesion to epoxy matrix due to its higher surface roughness, chemical activity and surface energy than Toray T700-CFs.

Protein Adsorption on Amorphous Metal Oxide Thin Films: An FTIR/ATR and Ellipsometry study

2010 ◽  
Vol 1277 ◽  
Author(s):  
Phaedra Silva-Bermudez ◽  
Sandra E. Rodil
Keyword(s):  
Thin Films ◽  
Protein Adsorption ◽  
Mass Density ◽  
Oxide Thin Films ◽  
Protein Layer ◽  
Metal Oxide Thin Films ◽  
Surface Mass ◽  
Adsorbed Protein ◽  
Surface Mass Density ◽  
Adsorbed Protein Layer

The adsorption of bovine serum albumin (BSA) and fibrinogen proteins dissolved on Phosphate buffer solution onto Ta, Nb and Ti oxide thin films was studied. The metal oxide thin films were deposited by magnetron sputtering on Si(100) wafers and characterized by contact angle measurements and profilometry. Spectroscopic ellipsometry was employed to characterize the kinetics of the protein adsorption process in-situ at the solid-liquid interface and the optical properties of the adsorbed protein layer formed after 45 minutes of immersion of the thin film in the protein solution. Infrared spectroscopy was used to study the proteins within the adsorbed layer. A trend indicating that the surface mass density of the adsorbed protein layer increases as the Rt (peak-to-valley height) surface roughness parameter increases was observed for fibrinogen and BSA. An increment in the surface mass density of the adsorbed protein layer was also observed onto surfaces with higher polar components of the surface energy. BSA and fibrinogen seemed to more readily adsorbed onto tantalum oxide than onto titanium oxide.

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.

scholarly journals Interaction of Surface Energy Components between Solid and Liquid on Wettability, and Its Application to Textile Anti-Wetting Finish

Polymers ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 498 ◽  
Author(s):  
Kwanwoo Song ◽  
Jinwook Lee ◽  
Seong-O Choi ◽  
Jooyoun Kim
Keyword(s):  
Surface Roughness ◽  
Surface Energy ◽  
Experimental Validation ◽  
Polar Component ◽  
Basic Information ◽  
Surface Energies ◽  
Energy Profiles ◽  
Silane Coating ◽  
Energy Components

With various options of anti-wetting finish methods, this study intends to provide basic information that can be applied in selecting a relevant anti-wetting chemical to grant protection from spreading of liquids with different surface energy profiles. With such an aim, the anti-wetting effectiveness of fluorinated coating and silane coating was investigated for liquids having different surface energy components, water (WA), methylene iodide (MI) and formamide (FA). The wetting thermodynamics was experimentally investigated by analyzing dispersive and polar component surface energies of solids and liquids. The role of surface roughness in wettability was examined for fibrous nonwoven substrates that have varied surface roughness. The presence of roughness enhanced the anti-wetting performance of the anti-wetting treated surfaces. While the effectiveness of different anti-wetting treatments was varied depending on the liquid polarities, the distinction of different treatments was less apparent for the roughened fibrous surfaces than the film surfaces. This study provides experimental validation of wetting thermodynamics and the practical interpretation of anti-wetting finishing.

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.

Study of Thermal Stability of Cvd Ta205/Si Interface

1999 ◽  
Vol 567 ◽  
Author(s):  
A. Y. Mao ◽  
K. A. Son ◽  
J. M. White ◽  
D. L. Kwong ◽  
D. A. Roberts ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Secondary Ion Mass Spectrometry ◽  
Interface Layer ◽  
Film Deposition ◽  
Ex Situ ◽  
Reduced Form ◽  
Si Substrates ◽  
Temperature Programmed ◽  
Major Chemical ◽  
Temperature Programmed Reaction

ABSTRACTThe effects of vacuum and inert gas annealing of ultra-thin (20Å) CVD Ta2O5 films deposited on Si substrates, with and without oxynitride interface layer, on the Ta2O5/Si interface stability were examined extensively by means of in-situ X-ray Photoelectron Spectroscopy (XPS), ex-situ Time-of-Flight Secondary Ion mass Spectrometry (ToF-SIMS), and Temperature Programmed Reaction (TPR). When annealed to 680 °C for up to 50 min, changes in ∼ 20Å Ta2O5 films formed on Si(100) are negligible, but annealing to 820 °C for 10 min in vacuum, Ar or N2 produces major chemical restructuring. SiO is formed at the Ta2O5 - Si(100) interfaces and becomes incorporated into the tantalum oxide. A reduced form of Ta, attributed to TaSix, forms at the buried interface. Extending the annealing time to 20 min produces no further changes. SiO desorbs during annealing at 1000 °C. Nitriding Si prior to forming the Ta2O5 film deposition inhibits these processes.

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.

Changes of Wettability and Surface Energy of Polymer by keV Ar+ Ion Irradiation

1995 ◽  
Vol 396 ◽  
Author(s):  
Jun-Sik Cho ◽  
Won-Kook Choi ◽  
Ki Hyun Yoon ◽  
Hyung-Jin Jung ◽  
Seok-Keun Koh
Keyword(s):  
Surface Roughness ◽  
Surface Energy ◽  
Photoelectron Spectroscopy ◽  
Ion Irradiation ◽  
Oxygen Flow Rate ◽  
Mean Square ◽  
X Ray ◽  
Atomic Force ◽  
Hydrophilic Group ◽  
Oxygen Gas

AbstractSurface modification of polycarbonate(PC) was performed to improve the wettability by Ar+ ion irradiation with 1 keV energy in oxygen environment. The ion dose ranged from 5 x 1014 to 5 x 1016 ions/cm2 and oxygen flow rate was also varied from 0 to 6 sccm(ml/min.). Contact angle was not much decreased from 78° to 48° for water and from 63° to 32° for formamide by Ar+ ion irradiation without oxygen gas, but largely reduced to 12° for water and to 8° for formamide as Ar+ ion irradiation with 4 seem oxygen gas. Surface energy of modified PC surface which was irradiated with oxygen gas was more increased than that of PC surface irradiated without oxygen gas. It is evident that the increase of surface energy for PC modified with oxygen gas is due to hydrophilic group which result from the chemical reaction between PC surface and oxygen gas. From X-ray photoelectron spectroscopy(XPS) analysis, the newly formed hydrophilic group is identified as hydrophilic C=0 bond, and atomic force microscope(AFM), it is found that the root mean square of surface roughness is changed from 14 Å to 22 ∼ 26 Å for Ar+ ion irradiation only and 26 ∼ 30 Å for Ar+ ion irradiation with 4 seem oxygen gas. Therefore wettability of PC surface is much more affected by newly formed hydrophilic group than surface roughness in keV energy Ar+ ion irradiation.

A new method for quantifying the blocking of coated paperboard

TAPPI Journal ◽  
2010 ◽  
Vol 9 (5) ◽  
pp. 29-35 ◽  
Author(s):  
PAULINE SKILLINGTON ◽  
YOLANDE R. SCHOEMAN ◽  
VALESKA CLOETE ◽  
PATRICE C. HARTMANN
Keyword(s):  
Surface Roughness ◽  
Fatty Acid ◽  
Surface Energy ◽  
Film Thickness ◽  
External Factors ◽  
Additive Concentration ◽  
Pressure Surface ◽  
Fatty Acid Amides ◽  
Coated Surfaces ◽  
Definite Period

Blocking is undesired adhesion between two surfaces when subjected to pressure and temperature constraints. Blocking between two coated paperboards in contact with each other may be caused by inter-diffusion, adsorption, or electrostatic forces occurring between the respective coating surfaces. These interactions are influenced by factors such as the temperature, pressure, surface roughness, and surface energy. Blocking potentially can be reduced by adjusting these factors, or by using antiblocking additives such as talc, amorphous silica, fatty acid amides, or polymeric waxes. We developed a method of quantifying blocking using a rheometer. Coated surfaces were put in contact with each other with controlled pressure and temperature for a definite period. We then measured the work necessary to pull the two surfaces apart. This was a reproducible way to accurately quantify blocking. The method was applied to determine the effect external factors have on the blocking tendency of coated paperboards, i.e., antiblocking additive concentration, film thickness, temperature, and humidity.

Sign in / Sign up

Export Citation Format

Share Document