• Title/Summary/Keyword: contact angle test

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Physicochemical properties, cytotoxicity and penetration into dentinal tubules of sodium hypochlorite with and without surfactants

  • Hernan Coaguila-Llerena;Isadora Barbieri ;Mario Tanomaru-Filho ;Renato de Toledo Leonardo;Ana Paula Ramos ;Gisele Faria
    • Restorative Dentistry and Endodontics
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    • v.45 no.4
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    • pp.47.1-47.11
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    • 2020
  • Objectives: The aim of this study was to assess the physicochemical properties, cytotoxicity and penetration into dentinal tubules of ChlorCidTM Surf (3% sodium hypochlorite [NaOCl] with surfactant) in comparison to ChlorCidTM (3% NaOCl without surfactant). Materials and Methods: The physicochemical properties evaluated were pH, surface tension, free available chlorine (FAC) and contact angle. Cytotoxicity was evaluated in L929 fibroblasts exposed to the solutions by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide and neutral red assays. Assessment of penetration into dentinal tubules was performed by staining single-rooted permanent human teeth with crystal violet (n = 9), which were irrigated with the solutions and analyzed in cervical, middle and apical segments. Data were analyzed by one-way analysis of variance (ANOVA) and Tukey's post-test, 2-way ANOVA and Bonferroni's post-test or t-test (α = 0.05). Results: ChlorCidTM Surf and ChlorCidTM FAC values were close to those indicated by the manufacturer. ChlorCidTM Surf showed lower surface tension and contact angle on dentin, and higher pH than ChlorCidTM (p < 0.05). The penetration of ChlorCidTM Surf was higher in cervical and middle segments, compared with ChlorCidTM (p < 0.05). There was no difference in irrigant cytotoxicity (p > 0.05). Conclusions: ChlorCidTM Surf showed lower surface tension, lower contact angle on root canal dentin, higher penetration into dentinal tubules and more alkaline pH, compared with ChlorCidTM. However, both solutions showed similar cytotoxicity and FAC content.

Validity of the Sessile Drop Test of the Molten Al-Mg Alloys on SiO2 under Various Atmospheres (분위기에서 Al-Mg합금의 SiO2에 대한 젖음실험의 타당성 고찰)

  • Jang, Hyung-Min;Lee, Chang-Myeon;Lee, Joon-Ho;Lee, Jae-Hoon;Lee, Jae-Chul
    • Korean Journal of Metals and Materials
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    • v.47 no.6
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    • pp.383-390
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    • 2009
  • The effects that processing atmospheres and alloy composition have on the wetting characteristics of Al-Mg alloys on the $SiO_{2}$ substrate were investigated by measuring the wetting angles. It was observed that the wetting behavior of the Al-Mg alloys on the $SiO_{2}$ substrate vary depending on the Mg content of the alloys and atmospheres. The results showed that the contact angle decreases with increasing Mg content, angle is generally larger in the $N_{2}$ atmosphere than in the Ar atmosphere. We discussed the validity of the results obtained from the wetting test on the basis of recent theories and the results observed from the actual penetration tests.

Evaluation of Material Durability by Identifying the Relationship between Contact Angle after Wear and Self-cleaning Effect Using Rolling Wear Tester (구름 마모시험 장비(Rolling wear tester)를 이용한 마모 후의 접촉각과 자가세정 효과와의 관계 규명을 통한 재료 내구성 평가)

  • Kyeongryeol Park;Yong Seok Choi;Seongmin Kang;Unseong Kim;Kyungeun Jeong;Young Jin Park;Kyungjun Lee
    • Tribology and Lubricants
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    • v.39 no.6
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    • pp.256-261
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    • 2023
  • This study is conducted to evaluate the durability of superhydrophobic surfaces, with a focus on two aspects: contact angle measurement and self-cleaning-performance analysis. Superhydrophobic copper and aluminum surfaces are fabricated using the immersion method and subjected to a rolling wear test, in which a 2 kg weight is placed on a rolling tester, under loaded conditions. To evaluate their durability, the contact angles of the specimens are measured for each cycle. In addition, the surface deformation of the specimens before and after the test is analyzed through SEM imaging and EDS mapping. The degradation of the self-cleaning performance is evaluated before and after the wear test. The results show that superhydrophobic aluminum is approximately 4.5 times more durable than superhydrophobic copper; the copper and aluminum specimens could endure 21,000 and 4,300 cycles of wear, respectively. The results of the self-cleaning test demonstrate that superhydrophobic aluminum is superior to superhydrophobic copper. After the wear test, the self-cleaning rates of the copper and aluminum specimens decrease to 72.7% and 83.4%, respectively. The relatively minor decrease in the self-cleaning rate of the aluminum specimen, despite the large number of wear cycles, confirms that the superhydrophobic aluminum specimen is more durable than its copper counterpart. This study is expected to aid in evaluating the durability of superhydrophobic surfaces in the future owing to the advantage of performing wear tests on superhydrophobic surfaces without damaging the surface coating.

Teflon coating of fabric filters for enhancement of high temperature durability (섬유상 여과필터의 고온 내구성 향상을 위한 테프론 코팅 연구)

  • Kim, Eun-Joo;Park, Young-Koo
    • Journal of the Korean Applied Science and Technology
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    • v.28 no.2
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    • pp.232-239
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    • 2011
  • Fabric fibrous filter has been used in various industrial applications owing to the low cost and wide generality. However, the basic properties of fabric materials often limit the practical utilization including hot gas cleaning. This study attempts to find new coatings of porous fibrous filter media in order to overcome its insufficient thermal resistance and durability. Teflon was one of the plausible chemicals to supplement the vulnerability against frequent external thermal impacts. A foaming agent composed of Teflon and some organic additives was tentatively coated on the glass fiber mat. The present test Teflon foam coated filter was fount to be useful for hot gas cleaning, up to $250^{\circ}C$-$300^{\circ}C$. Close examination using XPS(X-ray Photoelectron Spectroscopy) and Contact angle proved the binding interactions between carbon and fluorine, which implies coating stability. The PTFE/Glass foam coated filter consisted of more than 95% (C-F)n bond, and showed super-hydrophobic with good-oleophobic characteristics. The contact angle of liquid droplets on the filter surface enabled to find the filter wet-ability against liquid water or oil.

Surface Characteristics and Tracking Resistance of Epoxy Insulating Materials against Ultraviolet (자외선 열화에 의한 에폭시 절연재료의 표면특성과 내트래킹성)

  • Cho, Han-Goo;Yoo, Dae-Hoon;Kang, Hyung-Kyung
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2008.06a
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    • pp.495-496
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    • 2008
  • This paper describes the influence of Ultra-violet irradiation on time to tracking resistance of epoxy insulating materials by use of the inclined plane test. And, the influence of surface degradation was evaluated through several method such as measurement of contact angle, surface roughness, using a scanning electron microscopy. As the 1000 hours of the surface degradation with UV-CON, the flashover time decreases at different rates depending on epoxy resin and silicone rubber specimen. As the duration of the surface degradation with UV-CON is prolonged, the contact angle of epoxy resin decreases at the rate of degradation time, while that of silicone rubber was not exchanged. It is assumed that this phenomenon is related to the decrease in hydrophobicity of the surface of the materials. Also, as to epoxy resin, the decrease of hydrophobicity due to surface degradation with UV-CON is greater than that resulting from surface degradation with WOM. The UV radiation produced chalking and crazing on the surface of the insulating materials specimen.

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A Study on the Physical Properties of Addition Silicone Impression Materials (부가중합형실리콘인상재의 물리적 특성에 대한 연구)

  • Kim, Soo-Hwa
    • Journal of dental hygiene science
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    • v.6 no.4
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    • pp.231-235
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    • 2006
  • This study evaluated the properties of polyvinylsiloxane impression materials: Strain-in-compression, Elastic recovery, Consistency, and Wettability. Four polyvinylsiloxane impression materials(Examixfine, GC, Japan; Aquasilultra, Dentsply, USA; Extrude, Kerr, USA; Perfect-F, Handae, Korea) were used in this study. The measured data were analyzed with SPSSWIN 12.0 program. The results were as follows : 1. The strain-in-compression values showed that Extrude had the lowest value, 4.86% and Examixfine had the highest value, 6.78%. Significant difference between Examixfine and Perfect-F was not found but the other groups had significant differences(p = 0.000). 2. In the elastic recovery test, Extrude had the highest, 99.83% and Perfect-F had the lowest, 96.54%. There is no significant difference between Examixfine and Aquasilultra. The other impression material groups showed significant differences(p = 0.000). 3. The measurement of consistency results that the diameter of Examixfine was the largest, 45.12mm and one of Perfect-F was the smallest, 40.28 mm. No differences were shown between Examixfine and Aquasilultra and between Extrude and Perfect-F(p = 0.001). 4. Aquasilultra had a better hydrophilicity($47.85^{\circ}$) than other materials. Perfect-F had a larger contact angle($94.89^{\circ}$) and was hydrophobic. There were significant differences between groups(p = 0.000). 5. As for correlation among the test types, contact angle correlated with strain-in-compression, elstic recovery and consistency. The strain-in-compression had correlation to contact angle and elastic recovery. The elastic recovery correlated with contact angle and strain-in-compression. And the consistency had correlation to contact angle.

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Effect of modeling liquid on the shear-bond strength of zirconia core - porcelain veneer (도재 전용액이 지르코니아 코어-도재 비니어의 전단결합강도에 미치는 영향)

  • Choi, Byung-Hwan;Kim, Im-Sun
    • Journal of Technologic Dentistry
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    • v.36 no.2
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    • pp.83-89
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    • 2014
  • Purpose: This study is to evaluate the effect of modeling liquid on the shear-bond strength between zirconia core and veneering ceramic. Methods: Disk-shaped (diameter: 12.0mm; height: 3.0mm) zirconia were randomly divided into six groups according to the surface conditioning method and whether modeling liquid is used or not to be applied (N=60, n=10 per group): group 1-control group with distilled water(ZD); group 2-control group with modeling liquid(ZM); group 3-airborne particle abrasion with $110-{\mu}m$ $Al_2O_3$(AD) with distilled water; group 4-airborne particle abrasion with $110-{\mu}m$ $Al_2O_3$ with modeling liquid(AM); group 5-liner with distilled water(LD); group $6{\pounds}{\neq}liner$ with modeling liquid(LM). Contact angles were determined by the sessile drop method at room temperature using a contact angle measurement apparatus. The specimens were prepared using dentin veneering ceramics, veneered, 3mm high and 2.8mm in diameter, over the cores. The shear bond strength test was performed in a Shear bond test machine. Load was applied at a cross-head speed of 0.50mm/min until failure. The fractured zirconia surfaces were evaluated by using stereomicroscope (${\times}30$). Collected data were analyzed using SPSS(Statistical Package for Social Sciences) Win 12.0 statistics program. Results: ZD showed the highest contact angle($50.6{\pm}5.4^{\circ}$) and LD showed the lowest value($6.7{\pm}1.3^{\circ}$). Control groups and zirconia liner groups were significantly higher contact angle than liner groups(p<0.05). LD was the highest shear bond strength($43.9{\pm}3.8MPa$) and ZD was the lowest shear bond strength($24.8{\pm}4.9MPa$). Shear bond strengths of control groups and contact angle of liner groups were not significantly different((p>0.05). Liner groups presented adhesive failures. The others groups showed cohesive and adhesive failures. Conclusion: Modeling liquid groups showed lower contact angles and lower shear bond strength compared to those of distilled water groups.

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.

Compressive Strength and Water Contact Angle Properties of Cement Mortar by Type of Water Repellent (발수제종류별 잔골재 입도에 따른 시멘트 모르타르의 강도 및 발수특성)

  • Kang, Suk-Pyo;Kang, Hye-Ju;Kim, Sang-Jin;Suh, Jeong-In
    • Journal of the Korea Institute of Building Construction
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    • v.21 no.6
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    • pp.529-538
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    • 2021
  • In this study, the compressive strength and water contact angle were measured before and after surface abrasion of mortar specimens prepared by mixing two types of water repellents and two types of sands. In addition, the hydration products and chemical bonding of cement mortar by repellent were examined using X-ray diffraction(XRD), thermogravimetry-differential thermal analysis(TG-DTA), and Fourier-transform infrared spectroscopy(FT-IR) to evaluate the performance of these cement mortar mixtures as repair materials. We found that the compressive strength of the cement mortar with water repellent added was decreased compared to that of the plain cement mortar, and that of the oligomeric system was higher than that of the monomeric system. We further found that the contact angle of mortar with water repellent added was increased compared to that of the plain cement mortar, and that of the oligomeric system was increased compared to that of the monomer.

Surface characteristics and bonding performance of polymer restorative materials for dental CAD/CAM systems (치과 캐드캠 시스템에서 사용되는 고분자 수복재료들의 표면특성과 접착양상)

  • Kim, Jae-Hong;Kim, Ki-Baek
    • Journal of Technologic Dentistry
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    • v.41 no.3
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    • pp.203-209
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    • 2019
  • Purpose: The purpose of this study was to investigate the mechanical properties of polymer prosthetic and restorative materials for dental CAD/CAM using two test method; surface characteristics and shear bond strength. Methods: Commercialized CAD/CAM polymer blanks were investigated; One kinds of PMMA, and one PEKK blanks. A total of 20 PMMA and PEKK specimens were prepared, and each group was divided into 10 specimens. Average surface roughness was observed under surface profilometer. The contact angle was measured with a surface electrooptics. The bond strength was evaluated by a universal testing machine at a crosshead speed of 5mm/min. The data were statistically analyzed using independent t-test and Fisher's exact test(P<0.05). Results: The PMMA and PEKK group showed a significant difference in the shear bond strength with the composite resin(P<0.05). The surface roughness of the PEKK group was higher than that of the PMMA group. The fracture mode were observed in PEKK groups with 50% showing adhesive remnant index score. Conclusion: PEEK is used as substructure material and composite veneering material is applied. PEKK resins will contribute to the development of successful products that will provide structural and aesthetic satisfaction.