Ion Assisted Reaction In Polymer And Ceramics

1997 ◽  
Vol 504 ◽  
Author(s):  
S. K. Koh ◽  
S. C. Choi ◽  
S. Han. ◽  
H-J Jung
Keyword(s):  
Surface Energy ◽  
Functional Group ◽  
Surface Modifications ◽  
Surface Damage ◽  
Surface Layers ◽  
Energetic Ions ◽  
Cu Films ◽  
Chain Mobility ◽  
Hydrophilic Surfaces ◽  
Polar Force

AbstracrIon assisted reaction (IAR), which was firstly presented in 1995 MRS Fall meeting, has been reviewed for the surface modifications of polymer and ceramics. The reaction is assisted by energetic ions from 0.5 to 1.5 keV, doses 1014 to 1017 ions/cm2, and blowing rate of oxygen 0 ∼ 8 ml/min. Hydrophilic surfaces of polymers (wetting angle < 20° and surface energy 60 ∼ 70 erg/cm2) have been accomplished by the reaction, and an improvement of wettability and an increment of the surface energy are mainly due to the polar force and hydrophilic functional groups such as C=O, (C=O)-O, C-O, etc., without surface damage. The IAR was also applied on aluminum nitride in an O2 environment and AMON on AIN is formed by the Ar+ irradiation. The improvement of bond strength of Cu films on the AIN surface resulted from the interface bonds between Cu and the surface layers. Comparisons between the conventional surface treatments and the IAR are described in terms of physical bombardment, surface damage, functional group, and chain mobility in polymer.

Surface Modification of Polymer by Ion Assisted Reaction in Reactive Gases Environment

1996 ◽  
Vol 438 ◽  
Author(s):  
S. K. Koh ◽  
S. C. Choi ◽  
W. K. Choi ◽  
H. J. Jung ◽  
H. H. Hu
Keyword(s):  
Surface Energy ◽  
Functional Group ◽  
Pure Water ◽  
Surface Damage ◽  
Energetic Ions ◽  
Chain Mobility ◽  
Oxygen Gas ◽  
Reactive Gases ◽  
Polar Force ◽  
Treatment Comparisons

AbstractWettable surface of polymers (advanced wetting angle ∼10° and surface energy ∼ 60 ∼ 70 erg/cm2) have been accomplished by the ion assisted reaction, in which energetic ions are irradiated on polymer with blowing oxygen gas. The energies of ions are varied from 0.5 to 1.5 keV, doses 1014 to 1017 ions/cm2, and blowing rate of oxygen 0 ∼ 8 ml/min. The wetting angles are increased when the wettable polymers were exposed in air, but are remained in pure water. Improvement of surface energy is mainly due to the polar force. Surface analysis shows hydrophilic functional groups such as C=O, (C=O)-O, C-O, etc., are formed without surface damage after the ion assisted reaction treatment. Comparisons between the conventional surface treatments and the ion assisted reaction are described in term of physical bombardment, surface damage, functional group, and chain mobility in polymer.

The Effect of the EHD Pressure Spike on Rolling Bearing Fatigue

1987 ◽  
Vol 109 (3) ◽  
pp. 444-450 ◽  
Author(s):  
L. Houpert ◽  
E. Ioannides ◽  
J. C. Kuypers ◽  
J. Tripp
Keyword(s):  
Pressure Distribution ◽  
High Stress ◽  
Surface Damage ◽  
Rolling Bearing ◽  
Shear Stresses ◽  
Stress Concentrations ◽  
Surface Layers ◽  
Rolling Bearings ◽  
Life Model ◽  
Pressure Spike

A recently proposed fatigue life model for rolling bearings has been applied to the study of lifetime reduction under conditions conducive to microspalling. The presence of a spike in the EHD pressure distribution produces large shear stresses localized very close to the surface which may account for early failure. This paper describes a parametric study of the effect of such spikes. Accurate stress fields in the volume are calculated for simulated pressure spikes of different height, width and position relative to a Hertzian pressure distribution, as well as for different lubricant traction coefficients and film thicknesses. Despite the high stress concentrations in the surface layers, reductions in life predicted by the model are modest. Typically, the pressure spike may halve the life, with the implication that subsurface fatigue still dominates. In corroboration of this prediction, preliminary experimental work designed to reproduce microspalling conditions shows that microindents due to overrolling particles are a much more common form of surface damage than microspalling.

The Percolation of Liquid Through a Compliant Seal—An Experimental and Theoretical Study

2018 ◽  
Vol 141 (3) ◽  
Author(s):  
Sorin-Cristian Vlădescu ◽  
Carmine Putignano ◽  
Nigel Marx ◽  
Tomas Keppens ◽  
Tom Reddyhoff ◽  
...  
Keyword(s):  
Surface Energy ◽  
Capillary Pressure ◽  
Contact Pressure ◽  
Roughness Length ◽  
Theoretical Study ◽  
Theoretical Explanation ◽  
Channel Section ◽  
Hydrophilic Surfaces ◽  
New Apparatus ◽  
The Impact

New apparatus is described to simulate a compliant seal interface, allowing the percolation of liquid to be viewed by a fluorescence microscope. A model, based on the boundary element (BE) methodology, is used to provide a theoretical explanation of the observed behavior. The impact of contact pressure, roughness, and surface energy on percolation rates are characterized. For hydrophilic surfaces, percolation will always occur provided a sufficient number of roughness length scales are considered. However, for hydrophobic surfaces, the inlet pressure must overcome the capillary pressure exerted at the minimum channel section before flow can occur.

A Study of Erosion Between Two Parallel Surfaces Oscillating at Close Proximity in Liquids

1967 ◽  
Vol 89 (3) ◽  
pp. 229-236 ◽  
Author(s):  
K. Endo ◽  
T. Okada ◽  
M. Nakashima
Keyword(s):  
Cavitation Erosion ◽  
Plane Surface ◽  
Surface Damage ◽  
Surface Layers ◽  
Fluid Films ◽  
Surface Shear ◽  
Close Proximity ◽  
Parallel Surfaces ◽  
Extent Of Damage ◽  
Bearing Alloy

A disk was vibrated in close proximity to a plane surface while submerged in either water or one of several oils. The specimens suffered surface damage either by subsurface fatigue or cavitation erosion. The type and extent of damage depends upon the thickness of the fluid films and the viscosity of the liquid. Specimens with bearing alloy surface layers showed cracks due to surface shear followed by flaking off of the bearing alloy.

Effect of Sequential Layer-by-Layer Surface Modifications on the Surface Energy of Plasma-Modified Poly(dimethylsiloxane)

Langmuir ◽  
2007 ◽  
Vol 23 (2) ◽  
pp. 667-672 ◽  
Author(s):  
Woo-Sung Bae ◽  
Anthony J. Convertine ◽  
Charles L. McCormick ◽  
Marek W. Urban
Keyword(s):  
Surface Energy ◽  
Surface Modifications ◽  
Layer By Layer ◽  
Layer Surface

Construction of Nonbiofouling Biofunctional Glass Surface by Self-Assembled Monolayer and Graft Hydrophilic Polymer

2008 ◽  
Vol 47-50 ◽  
pp. 1343-1346 ◽  
Author(s):  
Zong Bin Liu ◽  
Bei Zhang ◽  
Brian Yu Fung Pow ◽  
Mo Yang ◽  
Arthur Fuk Tak Mak
Keyword(s):  
Graft Polymerization ◽  
Functional Group ◽  
Substrate Surface ◽  
Surface Modifications ◽  
Activation Process ◽  
Self Assembled Monolayer ◽  
Functional Part ◽  
Reactive Functional Group ◽  
Self Assembled ◽  
Glass Surfaces

This paper introduces a new method of surface modification by self-assembled monolayer (SAM) and polymer monolayer grafting. Since most of the glass surfaces lack the reactive functional group, an activation process with 3-(trimethoxysilyl)propyl methacrylate(TPM) is used in our experiment to generate the vinyl reactive sites on the substrate surface for further graft polymerization. The TPM saline layer acts as the “anchor” part to link the functional part onto the surface of substrate. The paper summarizes the surface modifications by the polymerizations of PEGMA, AA(Acrylic acid) and NVP(Nitrogen-vinyl-2-pyrrolidone) respectively and their applications for protein adsorption and cell adhesion through a series of measurements. In previous research, AA and NVP had also been adopted for surface treatment and had achieved good results. The substrate can be glass, alumina, silicon, metals or stainless steel. We choose glass as our substrate during the experiment.

Crystal orientation and surface morphology of face-centered-cubic metal thin films deposited upon single-crystal ceramic substrates using pulsed laser deposition

2007 ◽  
Vol 22 (1) ◽  
pp. 89-102 ◽  
Author(s):  
Andrew J. Francis ◽  
Paul A. Salvador
Keyword(s):  
Surface Energy ◽  
Surface Diffusion ◽  
Structural Characteristics ◽  
Three Dimensional ◽  
Face Centered Cubic ◽  
Ceramic Substrates ◽  
Metal Thin Films ◽  
Cu Films ◽  
Wide Range ◽  
Face Centered

Cu, Pt, Ag, and Au were deposited on (100)-oriented ceramic substrates (SrTiO3, LaAlO3, and MgO). Over a wide range of temperatures (room temperature to 600 °C), Cu films were (100)-oriented and exhibited cube-on-cube epitaxy. Epitaxial Pt(100) films were obtained only at high temperature; oriented Pt(111) films were obtained at lower temperatures. Ag and Au were never obtained as purely (100)-oriented samples, although the amount of (100)-film increased with increasing temperature. Three-dimensional islands formed for all metals at higher temperatures, while flatter film surfaces developed at lower temperatures. At any given temperature, the surface roughness of films on SrTiO3(100) increased in the order Pt < Cu < Au < Ag. The variations in film structural characteristics are described well by considering the metals’ (i) surface/interfacial energies, (ii) surface energy anisotropies, and (iii) surface diffusion coefficients. Flat, epitaxial growth is promoted by low-energy interfaces, low surface energy anisotropies, and slow surface diffusion.

scholarly journals Tribological Performance and Application of Antigorite as Lubrication Materials

Lubricants ◽  
2020 ◽  
Vol 8 (10) ◽  
pp. 93
Author(s):  
Zhimin Bai ◽  
Guijin Li ◽  
Fuyan Zhao ◽  
Helong Yu
Keyword(s):  
Thermal Decomposition ◽  
Friction And Wear ◽  
Layered Silicate ◽  
Surface Modifications ◽  
Tribological Performance ◽  
Chemical Characteristics ◽  
Surface Layers ◽  
Silicate Mineral ◽  
Physico Chemical ◽  
Recent Advancement

Antigorite is a Mg-rich 1:1 trioctahedral-structured layered silicate mineral. In recent decades, many studies have been devoted to investigating the tribological performance and application of antigorite as lubrication materials. This article provides an overview of the mineralogy, thermal decomposition and surface modifications of antigorite powders, as well as the recent advancement that has been achieved in using antigorite to reduce friction and wear of friction pairs. The tribological performance of antigorite powders and its calcined product in different lubricating media, such as oil, grease and solid composites have been comprehensively reviewed. The physico-chemical characteristics of surface layers of the friction pairs are discussed. Applications and mechanisms of lubricity and anti-wear of antigorite are highlighted.

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