Influence of Oxygen Plasma Modification on Surface Free Energy of PMMA Films and Cell Attachment

2008 ◽  
Vol 269 (1) ◽  
pp. 128-137 ◽  
Author(s):  
Canturk Ozcan ◽  
Pınar Zorlutuna ◽  
Vasıf Hasirci ◽  
Nesrin Hasirci
Keyword(s):  
Free Energy ◽  
Surface Free Energy ◽  
Oxygen Plasma ◽  
Cell Attachment ◽  
Plasma Modification

Surface Free Energy Modification of Crude Rubber Using Oxygen Plasma and Uv Laser Treatment

2013 ◽  
Vol 21 (1) ◽  
pp. 51-54 ◽  
Author(s):  
Gorazd Golob ◽  
Marta Klanjšek Gunde ◽  
Marie Kaplanová ◽  
Mladen Lovreček ◽  
Miran Mozetič
Keyword(s):  
Free Energy ◽  
Laser Treatment ◽  
Surface Free Energy ◽  
Oxygen Plasma ◽  
Uv Laser

scholarly journals Surface characterization, hemo- and cytocompatibility of segmented poly(dimethylsiloxane)-based polyurethanes

2014 ◽  
Vol 68 (6) ◽  
pp. 731-741 ◽  
Author(s):  
Marija Pergal ◽  
Jelena Nestorov ◽  
Gordana Tovilovic-Kovacevic ◽  
Petar Jovancic ◽  
Lato Pezo ◽  
...  
Keyword(s):  
Free Energy ◽  
Endothelial Cell ◽  
Surface Properties ◽  
Surface Free Energy ◽  
Surface Characterization ◽  
Cell Attachment ◽  
Microphase Separation ◽  
Biomedical Application ◽  
Blood Protein ◽  
Endothelial Cell Attachment

Segmented polyurethanes based on poly(dimethylsiloxane), currently used for biomedical applications, have sub-optimal biocompatibility which reduces their efficacy. Improving the endothelial cell attachment and blood-contacting properties of PDMS-based copolymers would substantially improve their clinical applications. We have studied the surface properties and in vitro biocompatibility of two series of segmented poly(urethane-dimethylsiloxane)s (SPU-PDMS) based on hydroxypropyl- and hydroxyethoxypropyl- terminated PDMS with potential applications in blood-contacting medical devices. SPU-PDMS copolymers were characterized by contact angle measurements, surface free energy determination (calculated using the van Oss-Chaudhury-Good and Owens-Wendt methods), and atomic force microscopy. The biocompatibility of copolymers was evaluated using an endothelial EA.hy926 cell line by direct contact assay, before and after pre-treatment of copolymers with multicomponent protein mixture, as well as by a competitive blood-protein adsorption assay. The obtained results suggested good blood compatibility of synthesized copolymers. All copolymers exhibited good resistance to fibrinogen adsorption and all favored albumin adsorption. Copolymers based on hydroxyethoxypropyl-PDMS had lower hydrophobicity, higher surface free energy, and better microphase separation in comparison with hydroxypropyl-PDMS-based copolymers, which promoted better endothelial cell attachment and growth on the surface of these polymers as compared to hydroxypropyl-PDMS-based copolymers. The results showed that SPU-PDMS copolymers display good surface properties, depending on the type of soft PDMS segments, which can be tailored for biomedical application requirements such as biomedical devices for short- and long-term uses.

Surface modification of polyimide fibers by oxygen plasma treatment and interfacial adhesion behavior of a polyimide fiber/epoxy composite

2017 ◽  
Vol 24 (4) ◽  
pp. 477-484 ◽  
Author(s):  
Xuyang Sun ◽  
Junfeng Bu ◽  
Weiwei Liu ◽  
Hongqing Niu ◽  
Shengli Qi ◽  
...  
Keyword(s):  
Free Energy ◽  
Plasma Treatment ◽  
Surface Free Energy ◽  
Photoelectron Spectroscopy ◽  
Interfacial Adhesion ◽  
Oxygen Plasma ◽  
Dynamic Contact Angle ◽  
Epoxy Composites ◽  
Oxygen Plasma Treatment ◽  
Adhesion Properties

AbstractOxygen plasma was used to enhance the surface behavior of polyimide (PI) fibers and PI fiber-reinforced epoxy composites were prepared in our present work. The effects of plasma treating times on the surface properties of PI fiber and the interfacial adhesion of PI fiber/epoxy composites were investigated. Surface chemical composition, surface morphologies and surface free energy of the fibers were characterized by X-ray photoelectron spectroscopy, scanning electron microscopy and dynamic contact angle analysis, respectively. The results suggest that some oxygen functional groups were introduced onto PI fiber surfaces, and the surface roughness of fibers was enhanced. Resultantly, the surface free energy of fibers and the interfacial adhesion of composites were improved by the oxygen plasma treatment. The interlaminar shear strength of the composites increased to 70 MPa when the fibers were treated for 10 min, which proved good interfacial adhesion properties.

Surface modification of high-performance polyimide fibers by oxygen plasma treatment

2016 ◽  
Vol 29 (9) ◽  
pp. 1083-1089 ◽  
Author(s):  
You Wen ◽  
Xiangsheng Meng ◽  
Jingfeng Liu ◽  
Jingling Yan ◽  
Zhen Wang
Keyword(s):  
Tensile Strength ◽  
Free Energy ◽  
Surface Modification ◽  
Surface Free Energy ◽  
Oxygen Concentration ◽  
Epoxy Resins ◽  
Oxygen Plasma ◽  
Plasma Power ◽  
Single Filament ◽  
Untreated Fiber

In order to improve the interfacial compatibility between the fibers and epoxy resins, polyimide (PI) fibers were modified using oxygen plasma with various treatment powers. The properties of PI fibers before and after surface modification were comparatively characterized according to their chemical composition, surface morphology, surface free energy, single filament tensile strength, and interfacial shear strength (IFSS). Most of the fiber properties, including the ratio of oxygen to nitrogen, oxygen concentration, surface free energy, and IFSS firstly increased with the plasma power, and then decreased when the plasma power was higher than 120 W. With a plasma power of 120 W, the oxygen concentration and the ratio of oxygen to carbon atoms (O/C) was 26% (22% for untreated fiber) and 0.38 (0.28 for untreated fiber), respectively. Meanwhile, the values of surface free energy and IFSS were 89% and 30% higher than those for untreated fiber, respectively. Furthermore, the values of single filament tensile strength for modified fibers were only 2.3% lower than those for pristine one. These results indicated that the compatibility between PI fibers and epoxy resins was greatly improved without compromising mechanical properties.

Smectic A-Smectic B interface : faceting and surface free energy measurement

1989 ◽  
Vol 50 (24) ◽  
pp. 3527-3534 ◽  
Author(s):  
P. Oswald ◽  
F. Melo ◽  
C. Germain
Keyword(s):  
Free Energy ◽  
Surface Free Energy ◽  
Energy Measurement ◽  
Smectic A

Examination of the lubricant storing and releasing ability of thermally sprayed surfaces

2011 ◽  
Vol 2 (2) ◽  
pp. 101-105
Author(s):  
L. Fazekas ◽  
Z. S. Tiba ◽  
G. Kalácska
Keyword(s):  
Free Energy ◽  
Surface Energy ◽  
Surface Free Energy ◽  
Essential Role ◽  
Index Number ◽  
Adhesion Ability ◽  
Thermally Sprayed ◽  
Proper Operation

Abstract The lubricant storing and releasing ability of the thermally sprayed surfaces plays an essential role in the proper operation of the components. In the case of porous sprayed surfaces the lubricant storing and releasing ability depends mainly on porosity and the surface energy (adhesion susceptibility). The adhesion ability can also be expressed indirectly with an index number that is by determining the surface free energy.

Molecular orientation of liquid aliphatic hydrocarbons on the surface and at the interface with water

1989 ◽  
Vol 54 (12) ◽  
pp. 3171-3186 ◽  
Author(s):  
Jan Kloubek
Keyword(s):  
Free Energy ◽  
Surface Free Energy ◽  
Molecular Orientation ◽  
Phase Changes ◽  
Aliphatic Hydrocarbons ◽  
Water Molecules ◽  
Free Energies ◽  
Dispersion Component ◽  
System Water ◽  
Orientation Of Molecules

The validity of the Fowkes theory for the interaction of dispersion forces at interfaces was inspected for the system water-aliphatic hydrocarbons with 5 to 16 C atoms. The obtained results lead to the conclusion that the hydrocarbon molecules cannot lie in a parallel position or be randomly arranged on the surface but that orientation of molecules increases there the ration of CH3 to CH2 groups with respect to that in the bulk. This ratio is changed at the interface with water so that the surface free energy of the hydrocarbon, γH, rises to a higher value, γ’H, which is effective in the interaction with water molecules. Not only the orientation of molecules depends on the adjoining phase and on the temperature but also the density of hydrocarbons on the surface of the liquid phase changes. It is lower than in the bulk and at the interface with water. Moreover, the volume occupied by the CH3 group increases on the surface more than that of the CH2 group. The dispersion component of the surface free energy of water, γdW = 19.09 mJ/m2, the non-dispersion component, γnW = 53.66 mJ/m2, and the surface free energies of the CH2 and CH3 groups, γ(CH2) = 32.94 mJ/m2 and γ(CH3) = 15.87 mJ/m2, were determined at 20 °C. The dependence of these values on the temperature in the range 15-40 °C was also evaluated.

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