• Proceedings of the Korean Society For Composite Materials Conference
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• 1999.11a
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• pp.36-39
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• 1999

Steel tire cords were coated via RF Plasma Polymerization of acetylene in order to enhance adhesion to rubber compounds. Adhesion of tire cords was measured by TACT as a function of plasma polymerization and argon etching conditions such as power, treatment time and chamber pressure. Tested tire cords were analysed by SEM to elucidate the adhesion mechanism. The highest adhesion values were obtained with argon etching condition at 90W, 10min, 30mtorr followed by acetylene plasma polymerization condition at 10W, 30sec., 30mtorr. In SEM analysis, the plasma polymerized tire cord at the optimized condition showed 100% rubber coverage as observed from brass-plated steel tire cords.

• Journal of the Korean Wood Science and Technology
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• v.30 no.3
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• pp.1-11
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• 2002

This study was conducted to investigate the effects of reaction pH conditions and hardener types on the reactivity, chemical structure and adhesion performance of UF resins. Three different reaction pH conditions, such as traditional alkaline-acid (7.5 → 4.5), weak acid (4.5), and strong acid (1.0), were used to synthesize UF resins which were cured by adding three different hardeners (ammonium chloride, ammonium citrate, and zinc nitrate) to measure adhesion strength. Fourier transform infrared (FT-IR) and carbon-13 nuclear magnetic resonance (¹³C-NMR) spectroscopies were employed to study chemical structure of the resin prepared under three different reaction pH conditions. Adhesion strength of the resins cured with three different hardeners was determined with lap shear specimens in tension. The gel time of UF resins decreased with an increasing in the amount of both ammonium chloride and ammonium citrate added in the resins. However, the gel time increased for zinc nitrate. Both FT-IR and ¹³C-NMR spectroscopies showed that the strong reaction pH condition produce uronic structures in UF resin, while both alkaline-acid and weak acid conditions produce quite similar chemical species in the resins. The maximum adhesion strength was occurred with the resin prepared under strong acid pH condition. However, this study indicated that the weak acid reaction condition provide a balance between increasing resin reactivity and improving adhesion strength of UF resin. The measurement of formaldehyde emission from the panels bonded with the UF resins prepared is planned for future work.

• The Journal of the Korean dental association
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• v.50 no.7
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• pp.394-406
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• 2012

Objective: The adhesion capabilities of different types of self-ligating brackets were measured with respect to Streptococcus mutans and Streptococcus sobrinus. Methods: Five types of self-ligating brackets (Clippy-C; Mini Clippy; Clarity-SL; Speed; Damon 3) were used for the experiment group and composite resin brackets (Spirit-MB), metal brackets (Victory) and polycrystalline alumina brackets (Clarity) were used for the control group. In order to assess adhesion of bacteria to the brackets, the brackets were cultured for 3, 6 and 24 hours in media containing bacteria and 20% sucrose. Results: There was no statistic difference in adhesion amount of Streptococcus mutans and Streptococcus sobrinus according to the types of brackets. A total adhesion amount according to bracket type was different. An extended incubation time increased adhesion amount. Observation under scanning electron microscope showed that Streptococcus sobrinus adhered more to Clippy-C and Victory rather than to Clarity-SL. Conclusions: Clarity-SL, a self-ligating esthetic bracket was confirmed to show lower bacterial adhesion to cariogenic bacteria, Streptococcus mutans and Streptococcus sobrinus group than other self-ligating brackets or conventional brackets, which suggests that proper use of self-ligating esthetic brackets might even be better in preventing tooth surface decalcification.

• Journal of the Korean institute of surface engineering
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• v.51 no.6
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• pp.405-414
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• 2018

The present study investigated the adhesion and corrosion resistance of subsequent electrophoretic paint (E-paint) on "electroless" paint coated AZ31 Mg alloy, which was formed by immersion of AZ31 Mg alloy in E-painting solution. It was found that with increasing immersion time of AZ31 in E-painting solution, the amount of paint deposited by electroless process increased but it decreased the electrochemical equivalent of E-painting process and the adhesion of the subsequent E-paint layer. The E-paint on electroless paint coated AZ31 contained pores with the highest pore density and the largest pore size was obtained on the samples with electroless times of 2 and 5 minutes, respectively. Results of the salt-spray test showed an accelerated growth of blisters over the entire surface of the sample immersed for less than 5 minutes whereas blisters were observed only in the vicinity of the scratch in case of samples treated for 15 and 30 minutes. The E-paint on AZ31 with shorter electroless immersion time in E-painting solution was found to have good adhesion and better corrosion resistance.

• Journal of Adhesion and Interface
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• v.24 no.3
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• pp.86-94
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• 2023

To fabricate all-solution-processed flexible Organic Light-Emitting Diodes (OLEDs), we demonstrated a bonding technology using a polyethyleneimine (PEI) as an adhesion layer between the two substrates. As the adhesion layer requires not only a high adhesion strength, but also a high current density, we have tried to find out the optimum condition which meets the two requirements at the same time by changing experimental factors such as PEI concentration, thickness of the layer and by mixing some additives into the PEI. The adhesion strength and the electrical current density were investigated by tensile tests and electron only device (EOD) experiments, respectively. The results showed that at higher PEI concentration the adhesion strength showed higher value, but the electrical current through the PEI layer decreased rapidly due to the increased PEI layer thickness. We added Sorbitol and PolyEthyleneGlycohol (PEG) into the 0.1 wt% PEI solution to enhance the adhesion and electrical properties. With the addition of the 0.5 wt% PEG into the 0.1 wt% PEI solution, the device showed an electrical current density of 900 mA/cm² and a good adhesion characteristic also. These data demonstrated the possibility of fabricating all-solution-processed OLEDs using two-substrate bonding technology with the PEI layer as an adhesion layer.

• Journal of the Korean Wood Science and Technology
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• v.25 no.3
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• pp.16-23
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• 1997

This study was carried out to discuss feasibility of high density polyethylene(HDPE) as a new substitute for the conventional adhesives in plywood manufacture. Plywood was composed of radiata pine(Pinus radiata) and Malas(Homallium feotidium) veneers and bonded by HDPE. Adhesion characteristics and anatomical scanning has been examined through tensile-shear strength test and scanning electron microscopy(SEM). The results are as follows; 1. Optimum loading quantity was 15g/$(30.3{\times}30.3)cm^2$, and tensile-shear strength increased with the increase of loading quantity. 2. Even at the hot pressing time of 1 minute, tensile-shear strength met the value of KS(over the 7.5kgf/$cm^2$), and tensile-shear strength increased with the increase of hot pressing time. 3. Plywood composed of veneer at moisture content of 19.6% showed similar tensile-shear strength to that at air conditioned moisture content of 11.4%. 4. Under the same condition of hot pressing time, tensile-shear strength of plywood bonded by HDPE met the KS value of boil and wet test and proved the same group as phenol formaldehyde adhesive. 5. HDPE films showed mechanical adhesion through penetration into the lathe check and ray of veneer.

• Journal of environmental and Sanitary engineering
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• v.14 no.4
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• pp.1-8
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• 1999

This study was aimed ultimately to develop an adsorption process treating heavy metal wastewater by utilizing activated carbon using flyash. The affecting factors in adsorption process on heavy metal by flyash adhesion-activated carbon are s follows. Factors such as pH, and quality of activated carbon, and reaction time made batch adsorption isotherm described adsorption capacity was made use of the investigation to evaluate adsorptive possibility of heavy metal.As the results of this study, H ion has influence on adsorption of heavy metal if pH is low. As reaction time is transformed, factors such as optimum reaction time is taken into consideration an adsorptive process of heavy metal because an adsorption and a reduction process occur. Adsorption isotherm of adhesion-activated carbon was generally obeyed to Freundlich formular than Langmuir formular and Freundlich constant, l/n were obtained in the range of 0.1~0.5.

• Journal of Adhesion and Interface
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• v.10 no.3
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• pp.148-153
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• 2009

An atmospheric plasma pre-treatment method was applied to PU foam, Leather (Action), Rubber to improve its adhesion using solvent and water soluble type pressure sensitive adhesion in atmospheric plate type reactor. In order to investigate the optimum reaction condition of plasma treatment, type of reaction gas (nitrogen), rate of gas flow (30~100 mL/min), and reaction time (0~30 s) were examined in a plate plasma reactor. The result of the surface modification with respect to the treatment procedure was characterized by using SEM. Due to a de-crease of the contact angle of various materials, the greatest adhesion strength was achieved at optimum condition such as flow rate of 100 mL/min, reaction time of 10 second for an atmospheric plasma treatment of the PU foam, EVA foam, Leather (Action) and Rubber also resulted in the improvement of the adhesion.

• Tribology and Lubricants
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• v.24 no.2
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• pp.63-71
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• 2008

Friction and adhesion tests were conducted to investigate tribological characteristics of materials for MEMS/NEMS using atomic force microscope (AFM). AFM Si tips were chemically modified with a self-assembled monolayer (SAM) derived from trichlorosilane like octadecyltrichlorosilane (OTS) and (1H, 1H, 2H, 2H-perfluorooctyl) trichlorosilane (FOTS), and various materials, such as Si, Al, Au, Cu, Ti and PMMA films, were prepared for the tests. SAMs were coated on Si wafer by dipping method prior to AFM tip to determine a proper dipping time. The proper dipping time was determined from the measurements of contact angle, surface energy and thickness of the SAMs. AFM tips were then coated with SAMs by using the same coating condition. Friction and adhesion forces between the AFM Si tip modified with SAM and MEMS/NEMS materials were measured. These forces were compared to those when AFM tip was uncoated. According to the results, after coating OTS and FOTS, the friction and adhesion forces on all materials used in the tests decreased; however, the effect of SAM on the reduction of friction and adhesion forces could be changed according to counterpart materials. OTS was the most effective to reduce the friction and adhesion forces when counterpart material was Cu film. In case of FOTS, friction and adhesion forces decreased the most effectively on Au films.

• The korean journal of orthodontics
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• v.52 no.4
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• pp.278-286
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• 2022

Objective: To evaluate differences in the adhesion levels of the most common oral pathogens, Streptococcus mutans and Porphyromonas gingivalis, in human saliva-derived microcosm biofilms with respect to time and raw materials of orthodontic brackets. Methods: The samples were classified into three groups of bracket materials: 1) monocrystalline alumina ceramic (CR), 2) stainless steel metal (SS), and 3) polycarbonate plastic (PL), and a hydroxyapatite (HA) group was used to mimic the enamel surface. Saliva was collected from a healthy donor, and saliva-derived biofilms were grown on each sample. A real-time polymerase chain reaction was performed to quantitatively evaluate differences in the attachment levels of total bacteria, S. mutans and P. gingivalis at days 1 and 4. Results: Adhesion of S. mutans and P. gingivalis to CR and HA was higher than the other bracket materials (SS = PL < CR = HA). Total bacteria demonstrated higher adhesion to HA than to bracket materials, but no significant differences in adhesion were observed among the bracket materials (CR = SS = PL < HA). From days 1 to 4, the adhesion of P. gingivalis decreased, while that of S. mutans and total bacteria increased, regardless of material type. Conclusions: The higher adhesion of oral pathogens, such as S. mutans and P. gingivalis to CR suggests that the use of CR brackets possibly facilitates gingival inflammation and enamel decalcification during orthodontic treatment.