• Title/Summary/Keyword: wettability property

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Interface and Surface Properties by Surface Treatment of Zirconia for All Ceramic Crown (전부도재관용 지르코니아의 표면처리에 따른 표면특성 및 계면특성 관찰)

  • Kim, Chi-Young;Chung, In-Sung;Choi, Sung-Min
    • Journal of Technologic Dentistry
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    • v.35 no.2
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    • pp.137-142
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    • 2013
  • Purpose: This study was to observe the surface and interfacial characteristic of Zirconia by surface treatment. And it was observed the roughness and contact angle according to processing, and the interfacial properties by surface treatment on zirconia. Methods: The oxide formation and ion diffusion between core and veneer ceramic were determined by the X-ray Dot Mapping of EPMA(Electron probe micro analyzer). The roughness was measured by 3D Digital microscope and the contact angle according to processing of zirconia was observed using distilled water on the surface. Results: The surface roughness of the specimens Z04, Z12, Z15 was measured $0.67({\pm}0.03){\mu}m$, $0.50({\pm}0.12){\mu}m$, $0.35({\pm}0.09){\mu}m$, respectively. As results of contact angle test, Z04, Z12, Z15 of specimen group without binder treatment was measured $46.79({\pm}3.17)^{\circ}$, $57.47({\pm}4.83)^{\circ}$, $56.19({\pm}2.66)^{\circ}$, respectively. but, L04, L12, L15 of specimen group without binder treatment was measured $63.84({\pm}2.20)^{\circ}$, $66.08({\pm}0.16)^{\circ}$, $65.10({\pm}1.01)^{\circ}$, respectively. Average contact angle of L15 was measured $65.10({\pm}1.01)^{\circ}$. In X-ray Dot Mapping results, thickness of binder including Al element was measured that each of L04, L12, L15 were $20{\mu}m$, $15{\mu}m$, $10{\mu}m$. Conclusion: The more rough surface increases the wettability, but the sintered exclusive binder decreases the wettability.

Characterization of Polyolefin Separator Support Membranes with Hydrophilic Coatings (폴리올레핀계 다공성 세퍼레이터 지지체 막의 친수 코팅에 따른 특성 평가)

  • Park, Yun Hwan;Nam, Sang Yong
    • Membrane Journal
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    • v.27 no.1
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    • pp.92-103
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    • 2017
  • In this study, electrochemical performance of the hydrophilized separator for the lithium ion battery is studied. The polyolefin based material used as the separator for the lithium ion battery is hydrophobic, and the electrolytic solution using a carbonate-based organic solvent is hydrophilic. Therefore, the polyolefin separator is hydrophilized using various hydrophilic polymers because lithium ion battery uses an aqueous electrolyte solution. In order to evaluate change of the coated separator, the performances of separator in terms of surface morphology, porosity and the wettability are investigated. Finally, the resistance and the ionic conductivity of separator coated with lithium ion are measured to evaluate the performance of lithium ion battery. Separator coated with PMVE shows good hydrophilicity and excellent ionic conductivity because the porosity of the separator is maintained. We can confirm that this property makes potential candidates for lithium ion battery.

Preparation of Gradient Polymer Surface and Their Pluripotent Biomedical Applications (고분자 구배표면 제조와 생체의료학적 응용)

  • Lee, Hai-Bang;Kim, Moon-Suk;Cho, Young-Ho;Khang, Gil-Son;Lee, Jin-Ho
    • Polymer(Korea)
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    • v.29 no.5
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    • pp.423-432
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    • 2005
  • Over last three decades, various biomaterials has been developed and applied in the biomedical market. The practical utilization of biomaterials depends on the study about an appropriate physical and biological response of biomaterials. The modification of biomaterials using various surface treatment methods has recently become an interesting topic in the field of surface engineering. A padient surface is the surface on which a gradually varying chemical composition exists along its length. A large number of research groups have been focused on the preparation of gradient surfaces. Such gradient surface is of particular interest for basic and applied studies of the interactions between biological species and surfaces since the effect of a selected property like wettability or chemical composition can be examined in a single experiment on one surface. The present review focuses on the preparation and characterization of various gradient surfaces, and their interactions with biological species.

Characteristics of Sn-1.7Bi-0.7Cu-0.6In Lead-free Solder (Sn-1.7Bi-0.7Cu-0.6In 솔더의 특성 연구)

  • Park, Ji-Ho;Lee, Hee-Yul;Jhun, Ji-Heon;Cheon, Chu-Seon;Jung, Jae-Pil
    • Journal of Welding and Joining
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    • v.26 no.5
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    • pp.43-48
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    • 2008
  • Characteristics of Sn-1.7%Bi-0.7%Cu-0.6%In (hereafter, SBIC) lead-free solder was investigated in this study. The results from SBIC were compared to other lead-free solders such as Sn-3.5%Ag-0.7%Cu (hereafter, SAC), Sn-0.7%Cu (hereafter, SC), and lead-bearing Sn-37%Pb (hereafter, SP) alloy. Tensile properties of bulk solder, wettability, spreading index, bridge and dross were evaluated. As experimental results, tensile strength and elongation of SBIC was 62.5MPa and 21.5%, respectively. The tensile strength was comparable to that of SP solder. The wetting time of SBIC was 1.2 sec at $250^{\circ}C$, and its wetting properties including wetting force were as good as the SAC alloy. However, wettability of the SC was not so good as the SBIC and SAC. The spreading index of SBIC at $250^{\circ}C$ was 71 %, and it was similar level to those of SAC and SC solders. Bridging was not found for all solders of SBIC, SAC and SC in the range from 240 to $260^{\circ}C$. In dross test at $250^{\circ}C$ for an hour, the amount of dross produced from SBIC was about 57% compared to that from SAC.

Bioinspired Nanoengineering of Multifunctional Superhydrophobic Surfaces

  • Choi, Chang-Hwan
    • Proceedings of the Korean Institute of Surface Engineering Conference
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    • 2015.11a
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    • pp.102-133
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    • 2015
  • Nature, such as plants, insects, and marine animals, uses micro/nano-textured surfaces in their components (e.g., leaves, wings, eyes, legs, and skins) for multiple purposes, such as water-repellency, anti-adhesiveness, and self-cleanness. Such multifunctional surface properties are attributed to three-dimensional surface structures with modulated surface wettability. Especially, hydrophobic surface structures create a composite interface with liquid by retaining air between the structures, minimizing the contact area with liquid. Such non-wetting surface property, so-called superhydrophobicity, can offer numerous application potentials, such as hydrodynamic drag reduction, anti-biofouling, anti-corrosion, anti-fogging, anti-frosting, and anti-icing. Over the last couple of decades, we have witnessed a significant advancement in the understanding of surface superhydrophobicity as well as the design, fabrication, and applications of superhydrophobic coatings/surfaces/materials. In this talk, the designs, fabrications, and applications of superhydrophobic surfaces for multifunctionalities will be presented, including hydrodynamic friction reduction, anti-biofouling, anti-corrosion, and anti-icing.

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Surface-Properties of Poly(Ethylene Terephthalate) Fabric by In-line Atmospheric Plasma Treatments (연속 대기압 플라즈마를 처리한 폴리에스테르 섬유의 표면 특성)

  • Kwon, Il-Jun;Park, Sung-Min;Koo, Kang;Song, Byung-Kab;Kim, Jong-Won
    • Textile Coloration and Finishing
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    • v.19 no.4
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    • pp.38-46
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    • 2007
  • Surface properties of the plasma treated fabric were changed while maintaining its bulk properties. Surface of plasma treated fabric take charge of enhanced adhesion by surface etching, surface activity. The water repellency coating Poly(Ethylene Terephthalate) fabric was treated with atmospheric pressure plasma using various parameters such as Argon gas, treatment time, processing power. Morphological changes by atmospheric pressure plasma treatment were observed using field emmission scanning electron microscopy(FE-SEM) and the zeta-potential measurement, contact angle measurement equipment. At the atmospheric pressure plasma treatment time of 150 sec, the power of 800W, the best wettability and peel strength were obtained. And we confirmed the possibility of industrial application by using atmospheric plasma system.

Catechol-mediated Functional Coatings of Polymer and Inorganic Nanostructures

  • Kim, Ji-Seon;Park, Jae-Yun;Son, Ho-Yeon;Lee, Hae-Sin;Nam, Yun-Seong
    • Proceedings of the Korean Institute of Surface Engineering Conference
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    • 2012.11a
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    • pp.66-67
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    • 2012
  • As polymer coatings of nano-structured surface become significant to obtain functionalized materials, catechol derived from a mussel protein has attracted increasing attention for its universal adhesiveness. In addition to the unique adhesion property, its reducing ability of metal ions during oxidative polymerization to polydopamine (pD) widely expands the application of catechol molecules in the field of surface modification. In this study, we present the catechol conjugated smart polymer coatings for regulating surface properties such as wettability and anti-fouling effects. In additino, the in situ silver coating of electrospun polymer nanofibers using a silver-catechol redox reaction is presented as a simple method to produce metal nanostructures.

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Effect of Various Factors on the Brazed Joint Properties in Al Brazing Technology

  • Sharma, Ashutosh;Lee, Seung Hyun;Ban, Hyung Oh;Shin, Young Sik;Jung, Jae-Pil
    • Journal of Welding and Joining
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    • v.34 no.2
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    • pp.30-35
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    • 2016
  • Last few decades have seen a rapid increase in the fabrication and characterization of Al alloys for automobiles, heat exchangers and aerospace industries. Aluminium alloys are popular because of their high specific strength, light weight, excellent wear and high oxidation resistance. The development of aluminium alloys in these applications makes their study and research of utmost importance. Brazing is applied to the aluminium alloys for joining various aluminium parts together in most of the industrial applications. Various parameters affect the joining process of these aluminium alloys. In this article, various types of processing parameters have been discussed, and special attention has been given to the category of aluminium brazing alloys. The article reviews on the various parameters that affect the brazing property in various scientific and technological applications.

The Analysis of surface free energy of RDX/EVA from contact angle measurements (접촉각 측정에 의한 RDX/EVA의 표면 에너지 해석)

  • 심정섭;김현수;이근득
    • Journal of the Korea Institute of Military Science and Technology
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    • v.3 no.2
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    • pp.219-230
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    • 2000
  • Plastic bonded explosive(PBX) is mainly composed of the nitramine explosives, RDX, HMX, and polymer binders. When the adhesion between nitramine crystals and binder is not particularly strong and can be failed under stress, dewetting occurs rather suddenly and this leads to a significant drop in tensile strength of explosives. Mechnical property of plastic bonded explosive depends on the surface characteristics of filler and binder. In order to design for better adhesion, an understanding of the surface properties of explosive and binder is essential. In this study, 2 kinds of RDX and 4 kinds of ethylene vinyl acetate copolymers are selected, since they are widely used in many plastic bonded explosives. The technical objective of this investigation is to calculate for the surface free energy of RDX and EVA using theory of Fowkes, van Oss, Neumann approaches and Kaelble equation and to predict the interaction between filler and binder from their surface free energies.

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Reflectivity of Sn Solder for LED Lead Frame

  • Xu, Zengfeng;Gi, Se-Ho;Park, Sang-Yun;Kim, Won-Jung;Jeong, Jae-Pil
    • Proceedings of the Korean Institute of Surface Engineering Conference
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    • 2011.05a
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    • pp.184-185
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    • 2011
  • In this study, in order to obtain a high reflectivity for the LED lead frame, tin dip coating and tin plating were conducted respectively, and wettability of LED lead frame with tin solder also was tested by wetting balance tester. A Cu sheet was plated in Cu brighten electroplating bath and followed by immersion in a Sn electro-less plating bath [1]. On the other hand, in the dip coating process, a Cu sheet was dipped into molten tin. In the progress of wetting test, besides wetting balance curve, the maximum measured force($F_m$), the maximum withdrawal force($F_w$) and zero-cross time($t_0$) were obtained in various temperatures. With the maximum withdrawal force, the surface tension was calculated at different temperatures. The Cu sheet plated with bright Cu and Sn show a silver bright property while that of Cu dipped with Sn possessed a high reflectance density of 1.34GAM at $270^{\circ}C$.

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