• Journal of the Korea Institute of Military Science and Technology
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• v.4 no.1
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• pp.207-215
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• 2001

Plastic bonded explosive(PBX) is mainly composed of the nitramine-ploymer compositions. PBX is characterized by high velocity and pressure of detonation, low vulnerability and good thermal stability. Many important applications of PBX require the good adhesion between nitramine crystals and the binder. For PBXs as well as propellants, where good mechanical properties are of great importance, dewetting therefore must be prevented by strong adhesion between filler-binder. Adhesion depends on surface characteristics of filler and binder. In order to design for better adhesion, an understanding of the surface properties of explosive and binder is required. The surface free energies are calculated from contact angle values by the method of Kaelble. Critical surface tension of solids are calculated by Zisman plot. Critical surface tension is a useful parameter for characterizing the wettability of solid surface. In this study, HMX and 3 kinds of copolymers are selected, since they are widely used in many plastic bonded explosives. The technical objective of this investigation is to predict the interaction between filler and binder from their surface free energies.

• Journal of the Korean institute of surface engineering
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• v.27 no.1
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• pp.19-28
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• 1994

A study on adhesion property of evaporated Al-Cr films was conducted on steel sheet by using two-source evaporator. Adhesion of Al-Cr coated steel was evaluated by tape test after $180^{\circ}$bending. Adhesion was decreased with increasing the Cr content in Al-Cr films. It was thought that the decrease in adhesion with increasing Cr content be related to insufficient wetting and diffusion of Cr atoms in the film. Best adhesion was achieved in the case of pure aluminum film..

• Journal of Adhesion and Interface
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• v.5 no.4
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• pp.9-16
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• 2004

Silk fibers were subjected to argon and ethylene plasma treatments in order to improve the interfacial adhesion with polylactic acid (PLA). After the plasma surface treatment, the surface morphology and surface adhesion of silk fibers to the PLA resin were largely changed. Various plasma treatment conditions were used in this work: 10, 25, 50, 100 and 150 W of electric power, 1, 3, 5, 7 and 10 minutes of treatment time, and 10 and 50 sccm of a gas flow rate. The interfacial shear strength of plasma-treated Silk/PLA biocomposites was measured by a single fiber micro-droplet debonding test method. The result provided an optimal plasma treatment condition to obtain the improved interfacial adhesion in the Silk/PLA biocomposites.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.07a
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• pp.78-81
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• 2004

In this paper, the effect of adhesion properties of semiconductive-insulating interface layer of silicone rubber on electrical properties was investigated. Surface structure and adhesion of semiconductive silicon rubber by surface asperity was obtained from SEM and T-peel test. In addition, ac breakdown test was carried out for elucidating the change of electrical property by roughness treatment. From the results, Adhesive strength of semiconductive-insulation interface was increased with surface asperity. Dielectric breakdown strength by surface asperity decreased than initial Specimen, but increased from Sand Paper #1200. According to the adhesional strength data unevenness and void formed on the silicone rubber interface expand the surface area and result in improvement of adhesion. Before treatment Sand Paper #1200, dielectric breakdown strength was decreased by unevenness and void which are causing to have electric field mitigation small. After the treatment, the effect of adhesion increased dielectric breakdown strength. It is found that ac dielectric breakdown strength was increased with improving the adhesion between the semiconductive and insulating interface.

• Electrical & Electronic Materials
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• v.8 no.3
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• pp.316-323
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• 1995

A vital step in magnetic tape manufacturing is the surface modification of polymer substrate prior to ink application. A critical element for good adhesion of magnetic ink on polymeric substrate is the ability to join ink in cost-effective manner. Corona discharging is one of the effective methods of modifying polymer surface to improve adhesion while maintaining the desirable properties of the film itself. Surface treatment by corona which is exposure of film surface to electron or ion bombardment, rather than mere exposure to active species, like atomic oxygen or ozone, can enhance adhesion by removing contaminant, electret, roughening surface, and/or introducing reactive chemical groups. Reactive neutrals, ions, electron and photons generated during the corona treatment interact simultaneously with polymers to alter surface chemical composition, wettability, and thus film adhesion. However, it is highly recommended that extensive chains scission be avoided because it can lead to side-effect by forming sticky matter, resulting in dropouts. This paper reviews principles of surface preparation of polymer substrate by corona discharging. In addition, the experimental section provides a description of parameter optimization on corona discharging treatment and its side-effect. Experimental results are discussed in terms of surface wetting as determined by contact angle measurements.

• KSTLE International Journal
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• v.9 no.1_2
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• pp.22-25
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• 2008

This paper investigated the wetting and adhesion property of undulated DLC film with surface morphology controlled for a reduced real area of contact. The undulated DLC Films were prepared by 13.56 MHZ radio frequency plasma enhanced chemical vapor deposition (r.f. PECVD) by using nanoscale Cu dots surface on a Si (100) substrate. FE-SEM, AFM analysis showed that the after repeated deposition and plasma induced damage with Ar ions, the surface was nanoscale undulated. This phenomenon changed the surface morphology of DLC surface. Raman spectra of film with changed morphology revealed that the plasma induced damage with Ar ions significantly suppressed the graphitization of DLC structure. Also, it was observed that while the untreated flat DLC surfaces had wetting angle starting ranged from $72^{\circ}$ and adhesion force of 333ni. Had wetting angle the undulated DLC surfaces, which resemble the surface morphology of a cylindrical shape, increased up to $104^{\circ}$ and adhesion force decreased down to 11 nN. The measurements agree with Hertz and JKR models. The surface undulation was affected mainly by several factors: the surface morphology affinity to cylindrical shape, reduction of the real area of contact and air pockets trapped in cylindrical asperities of the surface.

• Elastomers and Composites
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• v.37 no.3
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• pp.192-194
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• 2002

Polyester cord yarns have been treated in an atmospheric-pressure nitrogen plasma reactor in order to enhance their adhesion to rubber. A thin layer or the plasma was generated in the close vicinity of the yam surface using various types or surface discharge. To assess the effect of the plasma treatment on fiber surface properties, the cord thread/rubber matrix adhesion values measured using the untreated and threads cord threads were compared. The static and dynamic adhesion of the cord thread to rubber was characterized by using the standard Henley test. The dynamic adhesion values for the reference and plasma treated fiber were $7,3{\pm}1,2\;N$ and $83,5{\pm}3,5\;N$. The surface properties were investigated by scanning electron microscopy, infrared spectroscopy and electron spin resonance spectroscopy. It is concluded that both polar group interactions and increased surface area of the fibers are responsible for the improved adhesive strength.

• 한국전산유체공학회:학술대회논문집
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• 2011.05a
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• pp.2-5
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• 2011

This paper presents a numerical study on multiphase flows induced by wall adhesion The CSF(Continuum Surface Force} model is used for the calculation of the surface tension force and implemented in an in-house solution code(PowerCFD). The present method(code) employs an unstructured cell-centered method based on a conservative pressure-based finite-volume method with volume capturing method(CICSAM) in a volume of fluid(VOF) scheme for phase interface capturing As an application of the present method, the effects of wall adhesion are numerically simulated with the CSF model for a shallow pool of water located at the bottom of a cylindrical tank. Two different cases are computed, one in which the water wets the wall and one in which the water does not wet the wall. It is found that the present method simulates efficiently and accurately surface tension-dominant multiphase flows induced by wall adhesion.

• Journal of the Korean institute of surface engineering
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• v.32 no.3
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• pp.410-415
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• 1999

The adhesion strength of sputtered copper films to Inconel substrates has been studied using the scratch test. The effects of substrate treatments before deposition such as chemical or ion bombardment etching were investigated by means of a mean critical load derived from a Weibull-like statistical analysis. It was found that the mean critical load was very weak unless the amorphous layer produced by mechanical polishing on the substrate surface was eliminated. Chemical etching in a nitric-hydrochloric acid bath was shown to have practically no effect on the enhancement of the adhesion. In contrast, the addition in this bath of nickel and copper sulphates allowed removal of the amorphous layer and an increase in the values of the mean critical load. However, it was observed that excessive chemical etching could cancel out the mean critical load enhancement. The results obtained in the case of ion bombardment etching pretreatments could be far higher than those obtained with chemical etching. Moreover, for a sufficiently long period of ion bombardment etching, the adhesion strength was so high that it was impossible to observe evidence of an adhesion failure.

• Tribology and Lubricants
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• v.17 no.4
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• pp.276-282
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• 2001

Nano adhesion between SPM (scanning probe microscope) tips and 075 (octadecyltrichlorosilane) SAM (self-assembled monolayer) was experimentally studied. Tests were performed to measure the nano adhesion and friction in both AFM(atomic force microscope) and LFM(lateral force microscope) modes in various conditions of relative humidity. OTS SAM was formed on Si-wafer (100) surfaces, and Si$_3$N$_4$ tips of different radius of curvature were used. When the surface was hydrophobic, the adhesion and friction forces were found lower than those of bare Si-wafer. Results also showed that micro-adhesion force increased as the relative humidity and the tip radius of curvature increased. The main parameter for affecting the micro-adhesion was found absorbed humidity on the contact surface. These results were discussed with the JKR model and a capillary force caused by absorbed water.