WorldWideScience

Sample records for adhesive strength

  1. Adhesion Strength of Biomass Ash Deposits

    DEFF Research Database (Denmark)

    Laxminarayan, Yashasvi; Jensen, Peter Arendt; Wu, Hao;

    2016-01-01

    . Therefore, timely removal of ash deposits is essential for optimal boiler operation. In order to improve the qualitative and quantitative understanding of deposit shedding in boilers, this study investigates the shear adhesion strength of biomass ash deposits on superheater tubes. Artificial biomass ash...... deposits were prepared on superheater tubes and sintered in an oven at temperatures up to 1000 °C. Subsequently, the deposits were sheared off by an electrically controlled arm, and the corresponding adhesion strength was measured. The results reveal the effect of temperature, ash/deposit composition......, sintering duration, and steel type on the adhesion strength....

  2. Adhesion Strength of Biomass Ash Deposits

    DEFF Research Database (Denmark)

    Laxminarayan, Yashasvi; Jensen, Peter Arendt; Wu, Hao;

    2015-01-01

    This study investigates the shear adhesion strength of biomass ash deposits on superheater tubes. Artificial biomass ash deposits were prepared on superheater tubes and sintered in an oven at temperatures up to 1000°C. Subsequently, the deposits were sheared off with the help of an electrically...... controlled arm. Higher sintering temperatures resulted in greater adhesion strengths, with a sharp increase observed near the melting point of the ash. Repetition of experiments with fixed operation conditions revealed considerable variation in the obtained adhesion strengths, portraying the stochastic...

  3. Shear adhesion strength of aligned electrospun nanofibers.

    Science.gov (United States)

    Najem, Johnny F; Wong, Shing-Chung; Ji, Guang

    2014-09-01

    Inspiration from nature such as insects' foot hairs motivates scientists to fabricate nanoscale cylindrical solids that allow tens of millions of contact points per unit area with material substrates. In this paper, we present a simple yet robust method for fabricating directionally sensitive shear adhesive laminates. By using aligned electrospun nylon-6, we create dry adhesives, as a succession of our previous work on measuring adhesion energies between two single free-standing electrospun polymer fibers in cross-cylinder geometry, randomly oriented membranes and substrate, and peel forces between aligned fibers and substrate. The synthetic aligned cylindrical solids in this study are electrically insulating and show a maximal Mode II shear adhesion strength of 27 N/cm(2) on a glass slide. This measured value, for the purpose of comparison, is 270% of that reported from gecko feet. The Mode II shear adhesion strength, based on a commonly known "dead-weight" test, is 97-fold greater than the Mode I (normal) adhesion strength of the same. The data indicate a strong shear binding on and easy normal lifting off. Anisotropic adhesion (Mode II/Mode I) is pronounced. The size and surface boundary effects, crystallinity, and bending stiffness of fibers are used to understand these electrospun nanofibers, which vastly differ from otherwise known adhesive technologies. The anisotropic strength distribution is attributed to a decreasing fiber diameter and an optimized laminate thickness, which, in turn, influences the bending stiffness and solid-state "wettability" of points of contact between nanofibers and surface asperities.

  4. Shear adhesion strength of aligned electrospun nanofibers.

    Science.gov (United States)

    Najem, Johnny F; Wong, Shing-Chung; Ji, Guang

    2014-09-01

    Inspiration from nature such as insects' foot hairs motivates scientists to fabricate nanoscale cylindrical solids that allow tens of millions of contact points per unit area with material substrates. In this paper, we present a simple yet robust method for fabricating directionally sensitive shear adhesive laminates. By using aligned electrospun nylon-6, we create dry adhesives, as a succession of our previous work on measuring adhesion energies between two single free-standing electrospun polymer fibers in cross-cylinder geometry, randomly oriented membranes and substrate, and peel forces between aligned fibers and substrate. The synthetic aligned cylindrical solids in this study are electrically insulating and show a maximal Mode II shear adhesion strength of 27 N/cm(2) on a glass slide. This measured value, for the purpose of comparison, is 270% of that reported from gecko feet. The Mode II shear adhesion strength, based on a commonly known "dead-weight" test, is 97-fold greater than the Mode I (normal) adhesion strength of the same. The data indicate a strong shear binding on and easy normal lifting off. Anisotropic adhesion (Mode II/Mode I) is pronounced. The size and surface boundary effects, crystallinity, and bending stiffness of fibers are used to understand these electrospun nanofibers, which vastly differ from otherwise known adhesive technologies. The anisotropic strength distribution is attributed to a decreasing fiber diameter and an optimized laminate thickness, which, in turn, influences the bending stiffness and solid-state "wettability" of points of contact between nanofibers and surface asperities. PMID:25105533

  5. Influence of composition on the adhesive strength and initial viscosity of denture adhesives.

    Science.gov (United States)

    Han, Jian-min; Hong, Guang; Hayashida, Kentaro; Maeda, Takeshi; Murata, Hiroshi; Sasaki, Keiichi

    2014-01-01

    To investigate the effect of composition on the initial viscosity and adhesive strength between denture adhesives and the denture base. Two types of water-soluble polymers (methoxy ethylene maleic anhydride copolymer [PVM-MA] and sodium carboxymethyl cellulose [CMC]) were used. Samples were divided into three groups. Group 1 contained only PVM-MA; Group 2 contained only CMC; and Group 3 contained PVM-MA and CMC. The initial viscosity and adhesive strength were measured. For Group 1, the initial viscosity increased significantly as PVM-MA content increased. The adhesive strength of Group 1 lasted longer than Group 2. The adhesive strength of Group 3 varied greatly. The ratio of CMC and PVM-MA has a significant effect on the initial viscosity and adhesive strength of denture adhesives. Our results suggest that it is possible to improve the durability of a denture adhesive by combining different water-soluble polymers.

  6. Bond strength of adhesives to dentin contaminated with smoker's saliva.

    Science.gov (United States)

    Pinzon, Lilliam M; Oguri, Makoto; O'Keefe, Kathy; Dusevish, Vladimir; Spencer, Paulette; Powers, John M; Marshall, Grayson W

    2010-02-01

    The purpose of this study was to determine the effects of contamination with smoker's and non-smoker's saliva on the bond strength of resin composite to superficial dentin using different adhesive systems. The interfacial structure between the resin and dentin was evaluated for each treatment using environmental scanning electron microscopy (ESEM). Freshly extracted human molars were ground with 600-grit SiC paper to expose the superficial dentin. Adhesives [One-Up-Bond-F-Plus (OUFP) and Adper-Prompt-L-Pop (APLP)] and resin composite (TPHSpectrum) were bonded to the dentin (n = 8/group, 180 total specimens) under five surface conditions: control (adhesive applied following manufacturers' instructions); saliva, then 5-s air dry, then adhesive; adhesive, saliva, 5-s air dry; adhesive, saliva, 5-s water rinse, 5-s air dry (ASW group); and adhesive, saliva, 5-s water rinse, 5-s air dry, reapply adhesive (ASWA group). After storage in water at 37 degrees C for 24 h, the specimens were debonded under tension at a speed of 0.5 mm/min. ESEM photomicrographs of the dentin/adhesive interfaces were taken. Mean bond strength ranged from 8.1 to 24.1 MPa. Fisher's protected least significant difference (P = 0.05) intervals for critical adhesive, saliva, and surface condition differences were 1.3, 1.3, and 2.1 MPa, respectively. There were no significant differences in bond strength to dentin between contamination by smoker's and nonsmoker's saliva, but bond strengths were significantly different between adhesive systems, with OUFP twice as strong as APLP under almost all conditions. After adhesive application and contamination with either smoker's or nonsmoker's saliva followed by washing and reapplication of the adhesive (ASWA group), the bond strength of both adhesive systems was the same as that of the control group.

  7. Dynamic force spectroscopy to probe adhesion strength of living cells

    OpenAIRE

    Prechtel, K.; Bausch, A. R.; Marchi-Artzner, V.; Kantlehner, M.; Kessler, H; Merkel, R

    2002-01-01

    We studied the mechanical strength of the adhesion of living cells to model membranes. The latter contained a RGD lipopeptide which is a high affinity binding site for a cell adhesion molecule (integrin alpha(V)beta(3)). Cells adhered specifically to the vesicles. We used micropipette aspiration for breaking this adhesion with well defined forces. Systematic variation of the rate of force application revealed pronounced kinetic effects. The dependence of the detachment forces on the loading r...

  8. Adhesion strength improvement of epoxy resin reinforced with nanoelastomeric copolymer

    International Nuclear Information System (INIS)

    Research highlights: → Elastomeric nanoparticle (ENP) was prepared via miniemulsion polymerization. → ENP was added to epoxy resin (ER) with different amounts. → The lap shear strength (LSS) of different ENP/ER was measured. → The fractured surfaces were examined by scanning electron microscopy (SEM). - Abstract: Nano-sized copoly(styrene-butylacrylate-ethylenglycoldimethacrylate) (St-BA-EGDMA) particles were added at different contents to improve the toughness of diglycidyl ether of bisphenol A epoxy resin (ER) using piperidine as a curing agent. Transmission electron microscopy (TEM) proved that nanoelastomer was finely dispersed in the epoxy adhesive. To compare the adhesion strength of different adherents utilizing both modified and unmodified epoxy adhesive, the lap shear strength (LSS) test was measured as a function of elastomeric nanoparticles (ENP) amount. Scanning electron microscopy (SEM) and FTIR were used to investigate the interface morphology and chemical composition of adherent and epoxy adhesive. The result indicated that the adhesion strength was increased dramatically by addition of nanoparticles compared with that of pure epoxy adhesive. The highest adhesion strength was obtained with 20 wt% elastomeric nanoparticles. It was found that reinforcement with nanoparticles improved the fracture toughness.

  9. Adhesion strength improvement of epoxy resin reinforced with nanoelastomeric copolymer

    Energy Technology Data Exchange (ETDEWEB)

    Khoee, Sepideh, E-mail: Khoee@Khayam.ut.ac.ir [Polymer Laboratory, Chemistry Department, School of Science, University of Tehran, P.O. Box 14155-6455, Tehran (Iran, Islamic Republic of); Hassani, Narges [Polymer Laboratory, Chemistry Department, School of Science, University of Tehran, P.O. Box 14155-6455, Tehran (Iran, Islamic Republic of)

    2010-09-25

    Research highlights: {yields} Elastomeric nanoparticle (ENP) was prepared via miniemulsion polymerization. {yields} ENP was added to epoxy resin (ER) with different amounts. {yields} The lap shear strength (LSS) of different ENP/ER was measured. {yields} The fractured surfaces were examined by scanning electron microscopy (SEM). - Abstract: Nano-sized copoly(styrene-butylacrylate-ethylenglycoldimethacrylate) (St-BA-EGDMA) particles were added at different contents to improve the toughness of diglycidyl ether of bisphenol A epoxy resin (ER) using piperidine as a curing agent. Transmission electron microscopy (TEM) proved that nanoelastomer was finely dispersed in the epoxy adhesive. To compare the adhesion strength of different adherents utilizing both modified and unmodified epoxy adhesive, the lap shear strength (LSS) test was measured as a function of elastomeric nanoparticles (ENP) amount. Scanning electron microscopy (SEM) and FTIR were used to investigate the interface morphology and chemical composition of adherent and epoxy adhesive. The result indicated that the adhesion strength was increased dramatically by addition of nanoparticles compared with that of pure epoxy adhesive. The highest adhesion strength was obtained with 20 wt% elastomeric nanoparticles. It was found that reinforcement with nanoparticles improved the fracture toughness.

  10. Tangential adhesion strength of cement mortars in masonry

    Directory of Open Access Journals (Sweden)

    Derkach V.N.

    2012-05-01

    Full Text Available The initial shear strength (tangential adhesion and the angle of internal friction in the horizontal plane of mortar joints are among important characteristics, determining the masonry strength and stiffness qualities in case of share. These characteristics influence largely over the limit state approach of buildings and facilities during seismic activity and over wind, crane and other load, causing the panel frame distortion in frame buildings with masonry infill.In the paper the experimental studies results of tangential adhesion strength of cement mortars with solid and hollow ceramic bricks, porous stones, calcium silicate bricks and cellular concrete blocks are presented. This research gives experimental dependences of mortar adhesive strength with mentioned types of masonry units on compressive strength of cement mortar. There is also the comparison of the obtained results with Russian and foreign standards in this paper.

  11. ADHESION STRENGTH OF COATING SUBSTRATE AND SURFACE MORPHOLOGY OF PRETREATMENT

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Premature failure of coated tool often results from a poor adhesion of coating-substrate and shortens the lifetime of the tool.The results of increasing the adhesion strength of thin film coatings on cutting tool inserts by pretreating the inserts with sandblasting technique to obtain a desirable surface morphology of the inserts are presented.A geometric model representing the ideal surface morphology is established to enhance the nucleation density and adhesion strength of coating-substrate.Thin film coating experiment is conducted on the substrates of four different sample groups.Indentation and wear tests are performed on coated inserts to evaluate the effect of sandblasting on the adhesion strength of the coatings.A theoretical analysis is provided on the formation and growth of atom clusters in terms of the contact angle and the thermodynamic barrier of a substrate to predict thin film nucleation.

  12. Immediate Dentin Bond Strength of Self-etch Dentine Adhesives

    Directory of Open Access Journals (Sweden)

    David Lafuente

    2014-02-01

    Full Text Available Purpose: The purpose of this study was to evaluate the immediate bond strength of two sixth generation and two seventh generation dentin bonding agents to superficial dentin. Specimens were prepared to exposed superficial dentin and either Clearfil SE, Clearfil S3, Adper Prompt-l-pop of G-bond was applied over the dentin surface and light cured. Then composite resin was applied to the treated surface and light-cured in two increments. Specimens were tested 15 minutes after they were made for shear bond strength at 0.01 cm/min. Clearfil SE had statistically higher bond strength than the other three adhesives evaluated (42.9 MPa. There was no statistical difference among Clearfil S3, Adper Prompt-l-pop and G-Bond. The dentin adhesive with an application of an acidic primer before the application of the adhesive showed better immediate bond strength.

  13. Effects of surface roughness and energy on ice adhesion strength

    Energy Technology Data Exchange (ETDEWEB)

    Zou, M., E-mail: mzou@uark.edu [Department of Mechanical Engineering, University of Arkansas, Fayetteville, AR 72701 (United States); Beckford, S. [Department of Mechanical Engineering, University of Arkansas, Fayetteville, AR 72701 (United States); Wei, R.; Ellis, C. [Southwest Research Institute, 6220 Culebra Road, San Antonio, TX 78238 (United States); Hatton, G. [Shell Global Solutions, Inc., Houston, TX 77210 (United States); Miller, M.A. [Southwest Research Institute, 6220 Culebra Road, San Antonio, TX 78238 (United States)

    2011-02-01

    The aim of this study is to investigate the effects of surface roughness and surface energy on ice adhesion strength. Sandblasting technique was used to prepare samples with high roughness. Silicon-doped hydrocarbon and fluorinated-carbon thin films were employed to alter the surface energy of the samples. Silicon-doped hydrocarbon films were deposited by plasma-enhanced chemical vapor deposition, while fluorinated-carbon films were produced using deep reactive ion etching equipment by only activating the passivation step. Surface topographies were characterized using scanning electron microscopy and a stylus profilometer. The surface wetting properties were characterized by a video-based contact angle measurement system. The adhesion strength of ice formed from a water droplet on these surfaces was studied using a custom-built shear force test apparatus. It was found that the ice adhesion strength is correlated to the water contact angles of the samples only for surfaces with similar roughness: the ice adhesion strength decreases with the increase in water contact angle. The study also shows that smoother as-received sample surfaces have lower ice adhesion strength than the much rougher sandblasted surfaces.

  14. Failure strength prediction for adhesively bonded single lap joints

    Science.gov (United States)

    Rahman, Niat Mahmud

    For adhesively bonded joint, failure strength depends on many factors such as material properties (both adhesive and adherend), specimen geometries, test environments, surface preparation procedures, etc. Failure occurs inside constitutive materials or along joint interfaces. Based on location, adhesively bonded failure mode can be classified as adhesive failure mode, cohesive failure mode and adherend failure mode. Failure mode directly affects the failure strength of joint. For last eight decades, researchers have developed analytical, empirical or semi-empirical methods capable of predicting failure strength for adhesively bonded joints generating either cohesive failure or adherend failure. Applicability of most of the methods is limited to particular cases. In this research, different failure modes for single lap joints (SLJs) were generated experimentally using epoxy based paste adhesive. Based on experimental data and analytical study, simplified failure prediction methods were developed for each failure mode. For adhesive failure mode, it is observed that peel stress distributions concur along interface near crack initiation points. All SLJs for this test endured consistent surface treatments. Geometric parameters of the joints were varied to study their effect on failure strength. Peel stress distributions were calculated using finite analysis (FEA). Based on peel stress distribution near crack initiation point, a failure model is proposed. Numerous analytical, empirical and semi-empirical models are available for predicting failure strengths of SLJs generating cohesive failures. However, most of the methods in the literature failed to capture failure behavior of SLJs having thickness of adhesive layer as variable. Cohesive failure mode was generated experimentally using aluminum as adherend and epoxy adhesive considering thickness of adhesive layers as variable within SLJs. Comparative study was performed among various methods. It was observed that

  15. Temperature Effects on Adhesive Bond Strengths and Modulus for Commonly Used Spacecraft Structural Adhesives

    Science.gov (United States)

    Ojeda, Cassandra E.; Oakes, Eric J.; Hill, Jennifer R.; Aldi, Dominic; Forsberg, Gustaf A.

    2011-01-01

    A study was performed to observe how changes in temperature and substrate material affected the strength and modulus of an adhesive bondline. Seven different adhesives commonly used in aerospace bonded structures were tested. Aluminum, titanium and Invar adherends were cleaned and primed, then bonded using the manufacturer's recommendations. Following surface preparation, the coupons were bonded with the adhesives. The single lap shear coupons were then pull tested per ASTM D 1002 Standard Test Method for Apparent Shear Strength of Single- Lap-Joint over a temperature range from -150 deg C up to +150 deg C. The ultimate strength was calculated and the resulting data were converted into B-basis design allowables. Average and Bbasis results were compared. Results obtained using aluminum adherends are reported. The effects of using different adherend materials and temperature were also studied and will be reported in a subsequent paper. Dynamic Mechanical Analysis (DMA) was used to study variations in adhesive modulus with temperature. This work resulted in a highly useful database for comparing adhesive performance over a wide range of temperatures, and has facilitated selection of the appropriate adhesive for spacecraft structure applications.

  16. Enhancing the Adhesive Strength of a Plywood Adhesive Developed from Hydrolyzed Specified Risk Materials

    Directory of Open Access Journals (Sweden)

    Birendra B. Adhikari

    2016-08-01

    Full Text Available The current production of wood composites relies mostly on formaldehyde-based adhesives such as urea formaldehyde (UF and phenol formaldehyde (PF resins. As these resins are produced from non-renewable resources, and there are some ongoing issues with possible health hazard due to formaldehyde emission from such products, the purpose of this research was to develop a formaldehyde-free plywood adhesive utilizing waste protein as a renewable feedstock. The feedstock for this work was specified risk material (SRM, which is currently being disposed of either by incineration or by landfilling. In this report, we describe a technology for utilization of SRM for the development of an environmentally friendly plywood adhesive. SRM was thermally hydrolyzed using a Canadian government-approved protocol, and the peptides were recovered from the hydrolyzate. The recovered peptides were chemically crosslinked with polyamidoamine-epichlorohydrin (PAE resin to develop an adhesive system for bonding of plywood specimens. The effects of crosslinking time, peptides/crosslinking agent ratio, and temperature of hot pressing of plywood specimens on the strength of formulated adhesives were investigated. Formulations containing as much as 78% (wt/wt peptides met the ASTM (American Society for Testing and Materials specifications of minimum dry and soaked shear strength requirement for UF resin type adhesives. Under the optimum conditions tested, the peptides–PAE resin-based formulations resulted in plywood specimens having comparable dry as well as soaked shear strength to that of commercial PF resin.

  17. Evaluation of bond strength of different adhesive systems: Shear and Microtensile Bond Strength Test

    Science.gov (United States)

    GALLUSI, G.; GALEANO, P.; LIBONATI, A.; GIUCA, M.R.; CAMPANELLA, V.

    2010-01-01

    SUMMARY Objectives. Aim of this work is the in vitro bond strength evaluation of three bonding agents comparing the results of two kinds of test, Microtensile Bond Strength Test and a Shear Bond Strength Test. Bond strength tests have been used to test both direct and indirect restorative techniques to investigate if methods could give different results. Methods 72 human third molars have been collected and stored in physiological solution. Three kinds of test were conducted: 1- SB, 2- “Slice” preparation μTBS1, 3- “Stick” preparation μTBS2. We tested three different adhesive systems (Groups 1-2-3 n=24), two restorative techniques (subgroup A–B n=12). The tested adhesives were: Optibond FL (OFL) (Group 1), Optibond Solo Plus (OSP) (Group 2), Optibond Solo Plus Self-Etch (OSSE) (Group 3). For all tests was used a universal load machine Instron Machine. Results. Best values were found for Optibond FL with mean values of 45–50 MPa. Optibond Solo Plus resulted in values very similar and in some cases almost identical to FL. Optibond Solo Self Etch showed poorer adhesion in both direct and indirect restorative techniques. The parametric and non parametric statistical variance analysis pointed out the absence of significant differences between OFL and OSP, and demonstrated a significant difference for OSSE adhesive. Significance. The results confirm that a total etch two-step adhesive is the best compromise between easiness and effectiveness. PMID:23285371

  18. Improved Bond Strength of Cyanoacrylate Adhesives Through Nanostructured Chromium Adhesion Layers

    Science.gov (United States)

    Gobble, Kyle; Stark, Amelia; Stagon, Stephen P.

    2016-09-01

    The performance of many consumer products suffers due to weak and inconsistent bonds formed to low surface energy polymer materials, such as polyolefin-based high-density polyethylene (HDPE), with adhesives, such as cyanoacrylate. In this letter, we present an industrially relevant means of increasing bond shear strength and consistency through vacuum metallization of chromium thin films and nanorods, using HDPE as a prototype material and cyanoacrylate as a prototype adhesive. For the as received HDPE surfaces, unmodified bond shear strength is shown to be only 0.20 MPa with a standard deviation of 14 %. When Cr metallization layers are added onto the HDPE at thicknesses of 50 nm or less, nanorod-structured coatings outperform continuous films and have a maximum bond shear strength of 0.96 MPa with a standard deviation of 7 %. When the metallization layer is greater than 50 nm thick, continuous films demonstrate greater performance than nanorod coatings and have a maximum shear strength of 1.03 MPa with a standard deviation of 6 %. Further, when the combination of surface roughening with P400 grit sandpaper and metallization is used, 100-nm-thick nanorod coatings show a tenfold increase in shear strength over the baseline, reaching a maximum of 2.03 MPa with a standard deviation of only 3 %. The substantial increase in shear strength through metallization, and the combination of roughening with metallization, may have wide-reaching implications in consumer products which utilize low surface energy plastics.

  19. Evaluation for Adhesion Strength of Coating and Substrate by Burying Beforehand Specimen

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Adhesion strength is an important target in evaluating the quality of coating layers.The traditional way of adhesion strength test is bonding pull-off method for thick layers and scratch test for thin films.The drawbacks of these two methods are discussed in this paper,and an evaluating method for adhesion strength of coating by burying beforehand specimen is proposed.The adhesion strength of samples is measured with two methods.The dispersity of testing data is lower than that in the ASTM-C663-79 Standard.

  20. Application of tung oil to improve adhesion strength and water resistance of cottonseed meal and protein adhesives on maple veneer

    Science.gov (United States)

    Cottonseed meal-based products show promise in serving as environment-friendly wood adhesives. However, their practical utilization is currently limited due to low durability and water resistant properties. In this research, we tested the improvement of adhesion strength and water resistance of cott...

  1. Evaluation of a sugar based edible adhesive utilizing a tensile strength tester

    Science.gov (United States)

    A new method to evaluate adhesives has been developed and utilized to formulate a recently patented adhesive based on sugar and citric acid. Factors affecting adhesive performance were uncovered, such as reduced strength due to improper heating time, and an optimal curing temperature of 60oC was ac...

  2. Microtensile bond strength of different adhesive systems in dentin irradiated with Er:YAG laser

    International Nuclear Information System (INIS)

    The objective this study was to evaluate in vitro the bond strength of two etch-and-rise and one self-etching adhesive system after dentin irradiation with Er:YAG (erbium: yttrium aluminum garnet) laser using microtensile test. The results revealed that the groups treated with laser Er:YAG presented less tensile bond strength, independently to the adhesive system used. The prompt L-pop adhesive presented less microtensile bond strength compared to the other adhesives evaluated. There was no difference between single bond and excite groups. The adhesive failures were predominant in all the experimental groups. The Er:YAG laser influenced negatively bond strength values of adhesive systems tested in dental substrate

  3. Post-bleaching application of an antioxidant on dentin bond strength of three dental adhesives

    Directory of Open Access Journals (Sweden)

    Maryam Khoroushi

    2012-01-01

    Conclusions: The findings suggest that bond strength of resin to bleached dentin may be affected with the adhesive system. Reduced SBS to bleached dentin can be amended by the use of SA as an antioxidizing agent. However, the amount of reversed bond strength subsequent to applying antioxidant might be related to the kind of dental adhesive.

  4. Adhesive bonding of stainless steel : strength and durability

    OpenAIRE

    Boyes, Robert

    1998-01-01

    Adhesive bonding as an alternative method of joining materials together has many advantages over the more conventional joining methods such as fusion and spot welding, bolting and riveting. For example, adhesives can be used to bond dissimilar materials, adhesive joints have a high stiffness to weight ratio and the stress distribution within the joint is much improved. Stainless steels are commonly used in applications that would clearly benefit from adhesive bonding; architectural cladding, ...

  5. Adhesion strength of sputtered TiAlN-coated WC insert tool

    Energy Technology Data Exchange (ETDEWEB)

    Budi, Esmar [Department of Physics, Faculty of Science and Mathematics, Universitas Negeri Jakarta, Jl. Pemuda No. 10, Jakarta 13220 (Indonesia); Razali, M. Mohd.; Nizam, A. R. Md. [Faculty of Manufacturing Engineering, Universiti Teknikal Malaysia Melaka Karung Berkunci No 1752 Pejabat Pos Durian Tunggal 76109 Melaka (Malaysia)

    2013-09-09

    The adhesion strength of TiAlN coating that deposited by using DC magnetron sputtering on WC insert tool are studied. TiAlN coating are deposited on Tungsten Carbide (WC) insert tool by varying negatively substrate bias from 79 to 221 volt and nitrogen flow rate from 30 to 72 sccm. The adhesion strength are obtained by using Rockwell indentation test method with a Brale diamond at applied load of 60,100 and 150 kgf. The lateral diameter of indentation is plotted on three different applied loads and the adhesion strength of TiAlN coating was obtained from the curved slopes at 100 and 150 kgf. The lower curve slop indicated better adhesion strength. The results shows that the adhesion strength of sputterred TiAlN coating tend to increase as the negatively substrate bias and nitrogen flow rate are increased.

  6. Effect of Heartwood and Sapwood Ratio on Adhesion Strength of Finished Wood Species

    Directory of Open Access Journals (Sweden)

    Turgay Ozdemir

    2015-01-01

    Full Text Available The objective of this study was to determine adhesion strength of samples from wood species coated with cellulose varnish as function of heartwood and sapwood ratio. Roughness of the specimens from four different species was measured employing stylus type equipment before they were coated with varnish. Pull-off testing unit was employed to determine adhesion strength of the samples. Based on the findings in this work it seems that no significant difference was determined between adhesion strength values of the samples prepared from heartwood and sapwood portions. The highest adhesion strength value of 2.62 N/mm2 was found for the beech samples sanded with 80-grit sand paper. Overall rougher surfaces of the samples resulted in higher adhesion strength between finish and substrate.

  7. Effect of Molecular Flexibility upon Ice Adhesion Shear Strength

    Science.gov (United States)

    Wohl, Christopher J.; Kreeger, Richard E.; Smith, Joseph G.; Knuth, Taylor; Hadley, Kevin; Palacios, Jose

    2016-01-01

    Ice formation on aircraft surfaces effects aircraft performance by increasing weight and drag leading to loss of lift. Current active alleviation strategies involve pneumatic boots, heated surfaces, and usage of glycol based de-icing fluids. Mitigation or reduction of in-flight icing by means of a passive approach may enable retention of aircraft capabilities, i.e., no reduction in lift, while reducing the aircraft weight and mechanical complexity. Under a NASA Aeronautics Research Institute Seedling activity, the effect of end group functionality and chain length upon ice adhesion shear strength (IASS) was evaluated with the results indicating that chemical functionality and chain length (i.e. molecular flexibility) affected IASS. Based on experimental and modeling results, diamine monomers incorporating molecular flexibility as either a side chain or in between diamine functionalities were prepared, incorporated into epoxy resins that were subsequently used to fabricate coatings on aluminum substrates, and tested in a simulated icing environment. The IASS was found to be lower when molecular flexibility was incorporated in the polymer chain as opposed to a side chain.

  8. Bond strength of adhesives to dentin contaminated with smoker’s saliva

    Science.gov (United States)

    Oguri, Makoto; O’Keefe, Kathy; Dusevish, Vladimir; Spencer, Paulette; Powers, John M.; Marshall, Grayson W.

    2010-01-01

    The purpose of this study was to determine the effects of contamination with smoker’s and non-smoker’s saliva on the bond strength of resin composite to superficial dentin using different adhesive systems. The interfacial structure between the resin and dentin was evaluated for each treatment using environmental scanning electron microscopy (ESEM). Freshly extracted human molars were ground with 600-grit SiC paper to expose the superficial dentin. Adhesives [One-Up-Bond-F-Plus (OUFP) and Adper-Prompt-L-Pop (APLP)] and resin composite (TPH-Spectrum) were bonded to the dentin (n = 8/group, 180 total specimens) under five surface conditions: control (adhesive applied following manufacturers’ instructions); saliva, then 5-s air dry, then adhesive; adhesive, saliva, 5-s air dry; adhesive, saliva, 5-s water rinse, 5-s air dry (ASW group); and adhesive, saliva, 5-s water rinse, 5-s air dry, reapply adhesive (ASWA group). After storage in water at 37°C for 24 h, the specimens were debonded under tension at a speed of 0.5 mm/min. ESEM photomicrographs of the dentin/adhesive interfaces were taken. Mean bond strength ranged from 8.1 to 24.1 MPa. Fisher’s protected least significant difference (P = 0.05) intervals for critical adhesive, saliva, and surface condition differences were 1.3, 1.3, and 2.1 MPa, respectively. There were no significant differences in bond strength to dentin between contamination by smoker’s and non-smoker’s saliva, but bond strengths were significantly different between adhesive systems, with OUFP twice as strong as APLP under almost all conditions. After adhesive application and contamination with either smoker’s or nonsmoker’s saliva followed by washing and reapplication of the adhesive (ASWA group), the bond strength of both adhesive systems was the same as that of the control group. PMID:20155506

  9. Evaluation of the adhesion strength of diamond films brazed on K-10 type hard metal

    OpenAIRE

    Sérgio Ivan dos Santos; Carlos Alberto Medeiros Casanova; Cleiton Rodrigues Teixeira; Naira Maria Balzaretti; João Alziro Herz da Jornada

    2004-01-01

    The coating of cutting tools with diamond films considerably increases the tool performance due to the combination of the unique tribological properties of diamond with the bulk properties of the substrate (toughness). The tool performance, however, is strongly related to the adhesion strength between the film and the substrate. In this work our main goal was to propose and to test a procedure, based on a tensile strength test, to evaluate the adhesion strength of a diamond wafer brazed on a ...

  10. Lap shear strength and healing capability of self-healing adhesive containing epoxy/mercaptan microcapsules

    Science.gov (United States)

    Ghazali, Habibah; Ye, Lin; Zhang, Ming-Qiu

    2016-03-01

    The aim of this work is to develop a self-healing polymeric adhesive formulation with epoxy/mercaptan microcapsules. Epoxy/mercaptan microcapsules were dispersed into a commercialize two-part epoxy adhesive for developing self-healing epoxy adhesive. The influence of different content of microcapsules on the shear strength and healing capability of epoxy adhesive were investigated using single-lap-joints with average thickness of adhesive layer of about 180 µm. This self-healing adhesive was used in bonding of 5000 series aluminum alloys adherents after mechanical and alkaline cleaning surface treatment. The adhesion strength was measured and presented as function of microcapsules loading. The results indicated that the virgin lap shear strength was increased by about 26% with addition of 3 wt% of self-healing microcapsules. 12% to 28% recovery of the shear strength is achieved after self-healing depending on the microcapsules content. Scanning electron microscopy was used to study fracture surface of the joints. The self-healing adhesives exhibit recovery of both cohesion and adhesion properties with room temperature healing.

  11. The Effect of Diffusion Barrier and Bombardment on Adhesive Strength of CuCr Alloy Films

    Institute of Scientific and Technical Information of China (English)

    WANGJian-feng; SONGZhong-xiao; XUKe-wei; WANGYuan

    2004-01-01

    A novel co-sputtering method that combined magnetron sputtering (MS) with ion beam sputtering (IBS) was used to fabricate CuCr alloy films without breaking vacuum after depositing diffusion barrier with IBS. Different bombardment energies were used to improve the comprehensive properties of Cu alloy film. The results indicated that the effects of diffusion barriers and bombardment energy on adhesive strength could be evaluated by a rolling contact fatigue adhesion test. Diffusion barrier can enhance the adhesive strength, and the adhesion of CuCr/CrN was higher than that of CuCr/TiN. When bombarding energy was higher, the adhesive strength of CuCr/TiN films was higher due to the broader transition zone.

  12. Factors influencing the polymer-polymer adhesion- strength during two shot moulding

    DEFF Research Database (Denmark)

    Islam, Mohammad Aminul; Hansen, Hans Nørgaard; Tang, Peter Torben

    At the present state of two shot moulding, the adhesion strength of the two different polymers is an important issue. Many fascinating applications of two component or multi component polymer parts are restricted due to the weak interfacial adhesion of the polymers. A thorough understanding of the...

  13. Influence of Curing Condition on the Adhesive Strength of EVA Modified Mortar to Tile

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The reducing water effectiveness of EVA latex and powder was observed. Adhesive strength of EVA modified mortar to tile under different curing condition was studied. And the adhesive strengths of mortars modified by EVA latex and by EVA powder were compared. The results show that the reducing water effectiveness is improved by 36.12% and 21.55%, respectively, when the content of EVA latex and powder are 8% and 4%. EVA latex and powder can improve the adhesive strength of modified mortar to tile under the standard curing, high temperature curing, and freeze-thaw circle curing.EVA latex can improve the water resistance obviously, besides improve the adhesive strengths of standard curing and high temperature curing, comparing with EVA powder.

  14. Effect of Carbon Nanotube Reinforcement on Fracture Strength of Composite Adhesive Joints

    OpenAIRE

    Kwon, Young W.; Burkholder, Garrett L.; Pollak, Randall D.

    2016-01-01

    Research Project The objective of this research is to determine whether regular carbon nanotubes as well as functionalized carbon nanotubes can improve the joint strength of adhesives for composites and metals.

  15. Role of Powder Granulometry and Substrate Topography in Adhesion Strength of Thermal Spray Coatings

    Science.gov (United States)

    Kromer, R.; Cormier, J.; Costil, S.

    2016-06-01

    APS coating is deposited with different treated surfaces to understand the effects of surface topography and particle sizes on adhesion bond strength. Grit blasting and laser surface texturing have been used to create a controlled roughness and controlled surface topography, respectively. Coating adhesion is mainly controlled by a mechanical interlocking mechanism. Fully melted Ni-Al powder fills the respected target surface with high-speed radial flow. Pores around central flattening splat are usually seen due to splash effects. Laser surface texturing has been used to study near interface coating depending on the target shape and in-contact area. Pull-off test results have revealed predominant correlation with powder, surface topography, and adhesion bond strength. Adhesion bond strength is linked to the in-contact area. So, coating adhesion might be optimized with powder granulometry. Pores near the interface would be localized zones for crack initiations and propagations. A mixed-mode failure has been reported for sharp interface (interface and inter-splats cracks) due to crack kicking out phenomena. Coating toughness near the interface is a key issue to maximize adhesion bond strength. Volume particles and topography parameters have been proposed to enhance adhesion bond strength for thermal spray process for small and large in-contact area.

  16. Post-bleaching application of an antioxidant on dentin bond strength of three dental adhesives

    OpenAIRE

    Maryam Khoroushi; Tahereh Saneie

    2012-01-01

    Background: Antioxidizing agents have recently been suggested to compensate decreased bond strength of resin materials to bleached tooth tissues. This study compared the shear bond strength (SBS) of three different adhesives on bleached dentin immediately after bleaching, bleached/delayed for 1 week, and bleached/applied antioxidizing agent. Materials and Methods: The dentinal surfaces of 132 intact extracted molars were prepared and divided into 12 groups. The following adhesives were in...

  17. Comparative study to evaluate shear bond strength of RMGIC to composite resin using different adhesive systems

    Directory of Open Access Journals (Sweden)

    Manoj G Chandak

    2012-01-01

    Full Text Available Aim: The aim of the study is to compare and evaluate the role of new dental adhesives to bond composite to the resinmodified glass inomer cement (RMGIC. Materials and Methods: Thirty specimens were prepared on acrylic blocks, with wells prepared in it by drilling holes, to retain the RMGIC. The specimens were randomly divided into three groups of ten specimens each. In Group a thin layer of selfetch adhesive (3M ESPE was applied between the RMGIC and the composite resin FILTEK P60 (3M SPE. In Group II, total etch adhesive (Adeper Scotch bond 2, 3M ESPE was applied, and in Group III, there was no application of any adhesive between RMGIC and the composite resin. After curing all the specimens, the shear bond strength was measured using an Instron universal testing machine. Results: The results were drawn and tabulated using ANOVA-fishers and Dunnet D statistical tests.The maximum shear bond strength values were recorded in Group I specimens with self-etch adhesive showing a mean value of 2.74 when compared to the Group II adhesive (Total etch showing a mean shear strength of value 1.89, where no adhesive was used, showed a minimum mean shear bond strength of 1.42. There was a great and significant difference between Group I and Group II (P value 0.05 whereas, both Group I and Group II showed a vast and significant difference from Group III (P value = 0-001. Conclusion: Hence, this present study concludes that application of self-etch adhesive (3M ESPE, U.S.A in between RMGIC and composite resin increases the shear bond strength between RMGIC and the resin composites, as compared to the total-etch type adhesive (Adeper Scotch bond 2,3M ESPE, U.S.A as well as without application of the adhesive agent.

  18. Bond strength of different adhesives to normal and caries-affected dentins

    Institute of Scientific and Technical Information of China (English)

    XUAN Wei; HOU Ben-xiang; L(U) Yalin

    2010-01-01

    Background Currently, several systems of dentin substrate-reacting adhesives are available for use in the restorative treatment against caries. However, the bond effectiveness and property of different adhesive systems to caries-affected dentin are not fully understood. The objective of this study was to evaluate the bond strength of different adhesives to both normal dentin (ND) and caries-affected dentin (CAD) and to analyze the dentin/adhesive interracial characteristics.Methods Twenty eight extracted human molars with coronal medium carious lesions were randomly assigned to four groups according to adhesives used. ND and CAD were bonded with etch-and-rinse adhesive Adper~(TM) Single Bond 2 (SB2) or self-etching adhesives Clearfil SE Bond (CSE), Clearfil S~3 Bond (CS3), iBond GI (IB). Rectangular sticks of resin-dentin bonded interfaces 0.9 mm~2 were obtained. The specimens were subjected to microtensile bond strength (μTBS) testing at a crosshead speed of 1 mm/min. Mean μTBS was statistically analyzed with analysis of variance (ANOVA) and Student-Newman-Keuls tests. Interfacial morphologies were analyzed by Scanning Electron Microscopy (SEM).Results Etch-and-rinse adhesive Adper~(TM) Single Bond 2 yielded high bond strength when applied to both normal and caries-affected dentin. The two-step self-etching adhesive Clearfil SE Bond generated the highest bond strength to ND among all adhesives tested but a significantly reduced strength when applied to CAD. For the one-step self-etching adhesives, Clearfil S~3 Bond and iBond GI, the bond strength was relatively low regardless of the dentin type. SEM interfacial analysis revealed that hybrid layers were thicker with poorer resin tag formation and less resin-filled lateral branches in the CAD than in the ND for all the adhesives tested.Conclusion The etch-and-rinse adhesive performed more effectively to caries-affected dentin than the self-etching adhesives.

  19. Measurement of single-cell adhesion strength using a microfluidic assay.

    Science.gov (United States)

    Christ, Kevin V; Williamson, Kyle B; Masters, Kristyn S; Turner, Kevin T

    2010-06-01

    Despite the importance of cell adhesion in numerous physiological, pathological, and biomaterial-related responses, our understanding of adhesion strength at the cell-substrate interface and its relationship to cell function remains incomplete. One reason for this deficit is a lack of accessible experimental approaches that quantify adhesion strength at the single-cell level and facilitate large numbers of tests. The current work describes the design, fabrication, and use of a microfluidic-based method for single-cell adhesion strength measurements. By applying a monotonically increasing flow rate in a microfluidic channel in combination with video microscopy, the adhesion strength of individual NIH3T3 fibroblasts cultured for 24 h on various surfaces was measured. The small height of the channel allows high shear stresses to be generated under laminar conditions, allowing strength measurements on well-spread, strongly adhered cells that cannot be characterized in most conventional assays. This assay was used to quantify the relationship between morphological characteristics and adhesion strength for individual well-spread cells. Cell adhesion strength was found to be positively correlated with both cell area and circularity. Computational fluid dynamics (CFD) analysis was performed to examine the role of cell geometry in determining the actual stress applied to the cell. Use of this method to examine adhesion at the single-cell level allows the detachment of strongly-adhered cells under a highly-controllable, uniform loading to be directly observed and will enable the characterization of biological events and relationships that cannot currently be achieved using existing methods.

  20. Effect of indirect composite treatment microtensile bond strength of self-adhesive resin cements

    Science.gov (United States)

    Escribano, Nuria; Baracco, Bruno; Romero, Martin; Ceballos, Laura

    2016-01-01

    Background No specific indications about the pre-treatment of indirect composite restorations is provided by the manufacturers of most self-adhesive resin cements. The potential effect of silane treatment to the bond strength of the complete tooth/indirect restoration complex is not available.The aim of this study was to determine the contribution of different surface treatments on microtensile bond strength of composite overlays to dentin using several self-adhesive resin cements and a total-etch one. Material and Methods Composite overlays were fabricated and bonding surfaces were airborne-particle abraded and randomly assigned to two different surface treatments: no treatment or silane application (RelyX Ceramic Primer) followed by an adhesive (Adper Scotchbond 1 XT). Composite overlays were luted to flat dentin surfaces using the following self-adhesive resin cements: RelyX Unicem, G-Cem, Speedcem, Maxcem Elite or Smartcem2, and the total-etch resin cement RelyX ARC. After 24 h, bonded specimens were cut into sticks 1 mm thick and stressed in tension until failure. Two-way ANOVA and SNK tests were applied at α=0.05. Results Bond strength values were significantly influenced by the resin cement used (p0.05). All self-adhesive resin cements showed lower bond strength values than the total-etch RelyX ARC. Among self-adhesive resin cements, RelyX Unicem and G-Cem attained statistically higher bond strength values. Smartcem2 and Maxcem Elite exhibited 80-90% of pre-test failures. Conclusions The silane and adhesive application after indirect resin composite sandblasting did not improve the bond strength of dentin-composite overlay complex. Selection of the resin cement seems to be a more relevant factor when bonding indirect composites to dentin than its surface treatment. Key words:Bond strength, self-adhesive cement, silane, dentin, indirect composite. PMID:26855700

  1. Adhesion strategy and early bond strengths of glass-fiber posts luted into root canals

    Directory of Open Access Journals (Sweden)

    André Luis Faria-e-Silva

    2012-10-01

    Full Text Available This study investigated the effect of coinitiator solutions and self-adhesive resin cement on the early retention of glass-fiber posts. Cylindrical glass-fiber posts were luted into 40 incisor roots with different adhesion strategies (n = 10: SB2, Single Bond 2 + conventional resin cement (RelyX ARC; AP, Scotchbond Multipurpose Plus (SBMP activator + primer + ARC; APC, SBMP activator + primer + catalyst + ARC; and UNI, self-adhesive cement (RelyX Unicem. Pull-out bond strength results at 10 min after cementation showed APC > UNI > SB2 = AP (P < 0.05. The adhesion strategy significantly affected early bonding to root canals.

  2. Tensile Bond Strengths of Two Adhesives on Irradiated and Nonirradiated Human Dentin.

    Science.gov (United States)

    Bernard, Cécile; Villat, Cyril; Abouelleil, Hazem; Gustin, Marie-Paule; Grosgogeat, Brigitte

    2015-01-01

    The aim of this study was to assess the effect of radiotherapy on bond efficiency of two different adhesive systems using tensile bond strength test. Twenty extracted teeth after radiotherapy and twenty nonirradiated extracted teeth were used. The irradiation was applied in vivo to a minimal dose of 50 Gy. The specimens of each group were randomly assigned to two subgroups to test two different adhesive systems. A three-step/etch-and-rinse adhesive system (Optibond FL) and a two-steps/self-etch adhesive system (Optibond XTR) were used. Composite buildups were performed with a nanohybrid composite (Herculite XTR). All specimens were submitted to thermocycling ageing (10000 cycles). The specimens were sectioned in 1 mm(2) sticks. Microtensile bond strength tests were measured. Nonparametric statistical analyses were performed due to nonnormality of data. Optibond XTR on irradiated and nonirradiated teeth did not show any significant differences. However, Optibond FL bond strength was more effective on nonirradiated teeth than on irradiated teeth. Within the limitations of an in vitro study, it can be concluded that radiotherapy had a significant detrimental effect on bond strength to human dentin. However, it seems that adhesive choice could be adapted to the substrata. According to the present study, the two-steps/self-etch (Optibond XTR) adhesive system tested could be more effective on irradiated dentin compared to three-steps/etch-and-rinse adhesive system (Optibond FL). PMID:26783528

  3. Tensile Bond Strengths of Two Adhesives on Irradiated and Nonirradiated Human Dentin

    Directory of Open Access Journals (Sweden)

    Cécile Bernard

    2015-01-01

    Full Text Available The aim of this study was to assess the effect of radiotherapy on bond efficiency of two different adhesive systems using tensile bond strength test. Twenty extracted teeth after radiotherapy and twenty nonirradiated extracted teeth were used. The irradiation was applied in vivo to a minimal dose of 50 Gy. The specimens of each group were randomly assigned to two subgroups to test two different adhesive systems. A three-step/etch-and-rinse adhesive system (Optibond FL and a two-steps/self-etch adhesive system (Optibond XTR were used. Composite buildups were performed with a nanohybrid composite (Herculite XTR. All specimens were submitted to thermocycling ageing (10000 cycles. The specimens were sectioned in 1 mm2 sticks. Microtensile bond strength tests were measured. Nonparametric statistical analyses were performed due to nonnormality of data. Optibond XTR on irradiated and nonirradiated teeth did not show any significant differences. However, Optibond FL bond strength was more effective on nonirradiated teeth than on irradiated teeth. Within the limitations of an in vitro study, it can be concluded that radiotherapy had a significant detrimental effect on bond strength to human dentin. However, it seems that adhesive choice could be adapted to the substrata. According to the present study, the two-steps/self-etch (Optibond XTR adhesive system tested could be more effective on irradiated dentin compared to three-steps/etch-and-rinse adhesive system (Optibond FL.

  4. Fabrication and characterization of thermoplastic elastomer dry adhesives with high strength and low contamination.

    Science.gov (United States)

    Bin Khaled, Walid; Sameoto, Dan

    2014-05-14

    Polydimethylsiloxane (PDMS) and polyurethane elastomers have commonly been used to manufacture mushroom shaped gecko-inspired dry adhesives with high normal adhesion strength. However, the thermosetting nature of these two materials severely limits the commercial viability of their manufacturing due to long curing times and high material costs. In this work, we introduce poly(styrene-ethylene/butylene-styrene) (SEBS) thermoplastic elastomers as an alternative for the manufacture of mushroom shaped dry adhesives with both directional and nondirectional performance. These materials are attractive for their potential to be less contaminating via oligomer transfer than thermoset elastomers, as well as being more suited to mass manufacturing. Low material transfer properties are attractive for adhesives that could potentially be used in cleanroom environments for microscale assembly and handling in which device contamination is a serious concern. We characterized a thermoplastic elastomer in terms of oligomer transfer using X-ray photoelectron spectroscopy and found that the SEBS transfers negligible amounts of its own oligomers, during contact with a gold-coated silicon surface, which may be representative of the metallic bond pads found in micro-electro-mechanical systems devices. We also demonstrate the fabrication of mushroom shaped isotropic and anisotropic adhesive fibers with two different SEBS elastomer grades using thermocompression molding and characterize the adhesives in terms of their shear-enhanced normal adhesion strength. The overall adhesion of one of the thermoplastic elastomer adhesives was found to be stronger or comparable to their polyurethane counterparts with identical dimensions.

  5. Experimental study about the influence of adhesive stiffness to the bonding strengths of adhesives for ceramic/metal targets

    Institute of Scientific and Technical Information of China (English)

    W. SEIFERT; E. STRASSBURGER; S. GREFEN; S. SCHAARE

    2016-01-01

    The aim of the investigations presented here was to understand how the stiffness of the adhesive affects the failure of ceramic tiles adhered to metallic backings. The working hypothesis was that varying the adhesive stiffness could have the same effect on the ballistic performance as a variation of the adhesive thickness. Two different projectile/target combinations were utilized for ballistic tests in order to generate extremely different loading conditions. With targets consisting of 6 mm aluminum oxide ceramic and 6 mm aluminum backing, complete penetration occurred in each test with 7.62 mm tungsten carbide core AP ammunition at an impact velocity of 940 m/s. In contrast, with ceramic tiles of 20 mm thickness on 13 mm steel backing, no penetration of the ceramic occurred at the impact of a 7.62 mm ball round at 840 m/s. Four different types of adhesive (high-strength till high-flexible) were tested in both configurations. The elongation of the adhesive layer, the deformation of the metallic backing and the failure of the ceramics were observed by means of a high-speed camera during the projectile/target interaction. The results of the ballistic tests showed that a higher fracture strain caused a larger deformation of the backing compared to adhesives, which exhibit a high tensile strength and low fracture strains. The experimental results indicate that the damage behavior of the ceramic/metal composites depends on the absolute elongation of the adhesive layer. This can be controlled either by the thickness or the stiffness of the bonding layer.

  6. Relationships Between Process Parameters, Microstructure, and Adhesion Strength of HVOF Sprayed IN718 Coatings

    Science.gov (United States)

    Lyphout, Christophe; Nylén, Per; Östergren, Lars

    2011-01-01

    Fundamental understanding of relationships between process parameters, particle in-flight characteristics, and adhesion strength of HVOF sprayed coatings is important to achieve the high coating adhesion that is needed in aeronautic repair applications. In this study, statistical Design of Experiments (DoE) was used to identify the most important process parameters that influence adhesion strength of IN718 coatings sprayed on IN718 substrates. Special attention was given to the parameters combustion ratio, total gas mass flow, stand-off distance and external cooling, since these parameters were assumed to have a significant influence on particle temperature and velocity. Relationships between these parameters and coating microstructure were evaluated to fundamentally understand the relationships between process parameters and adhesion strength.

  7. Eroded dentin does not jeopardize the bond strength of adhesive restorative materials

    Directory of Open Access Journals (Sweden)

    Janaina Barros Cruz

    2012-08-01

    Full Text Available This in vitro study evaluated the bond strength of adhesive restorative materials to sound and eroded dentin. Thirty-six bovine incisors were embedded in acrylic resin and ground to obtain flat buccal dentin surfaces. Specimens were randomly allocated in 2 groups: sound dentin (immersion in artificial saliva and eroded dentin (pH cycling model - 3× / cola drink for 7 days. Specimens were then reassigned according to restorative material: glass ionomer cement (KetacTM Molar Easy Mix, resin-modified glass ionomer cement (VitremerTM or adhesive system with resin composite (Adper Single Bond 2 + Filtek Z250. Polyethylene tubes with an internal diameter of 0.76 mm were placed over the dentin and filled with the material. The microshear bond test was performed after 24 h of water storage at 37ºC. The failure mode was evaluated using a stereomicroscope (400×. Bond strength data were analyzed with two-way ANOVA and Tukey's post hoc tests (α = 0.05. Eroded dentin showed bond strength values similar to those for sound dentin for all materials. The adhesive system showed the highest bond strength values, regardless of the substrate (p < 0.0001. For all groups, the adhesive/mixed failure prevailed. In conclusion, adhesive materials may be used in eroded dentin without jeopardizing the bonding quality. It is preferable to use an etch-and-rinse adhesive system because it shows the highest bond strength values compared with the glass ionomer cements tested.

  8. Shear bond strength of three adhesive systems to enamel and dentin of permanent teeth

    Directory of Open Access Journals (Sweden)

    Niloofar Shadman

    2012-01-01

    Full Text Available Background and Aims: The purpose of this experimental study was to investigate the shear bond strength of three new adhesive systems to enamel and dentin of permanent human teeth using three new etch and rinse and self-etch adhesive systems.Materials and Methods: Sixty intact caries-free third molars were selected and randomly divided into 6 groups. Flat buccal and lingual enamel and dentin surfaces were prepared and mounted in the acrylic resin perpendicular to the plan of the horizon. Adhesives used in this study were Tetric N-Bond, AdheSE and AdheSE-One F (Ivoclar/Vivadent, Schaan, Liechtenstein. The adhesives were applied on the surfaces and cured with quartz tungsten halogen curing unit (600 mW/cm2 intensity for 20 s. After attaching composite to the surfaces and thermocycling (500 cycles, 5-55ºC, shear bond strength was measured using a universal testing machine at a crosshead speed of 0.5 mm/min. The failure modes were examined under a stereomicroscope. The data were statistically analyzed using T-test, one-way ANOVA, Tukey and Fisher's exact tests.Results: In enamel, Tetric N-Bond (28.57±4.58 MPa and AdheSE (21.97±7.6 MPa had significantly higher bond strength than AdheSE-One F (7.16±2.09 MPa (P0.05.Conclusion: Shear bond strength to dentin in Tetric N-Bond (etch and rinse system( was higher than self-etch adhesives (AdheSE and AdheSE-One F. The bond strength to enamel and dentin in two-step self-etch (AdheSE was higher than one-step self-etch (AdheSE-One F.

  9. Effect of thermal aging on the tensile bond strength at reduced areas of seven current adhesives.

    Science.gov (United States)

    Baracco, Bruno; Fuentes, M Victoria; Garrido, Miguel A; González-López, Santiago; Ceballos, Laura

    2013-07-01

    The purpose of this study was to determine the micro-tensile bond strength (MTBS) to dentin of seven adhesive systems (total and self-etch adhesives) after 24 h and 5,000 thermocycles. Dentin surfaces of human third molars were exposed and bonded with two total-etch adhesives (Adper Scotchbond 1 XT and XP Bond), two two-step self-etch adhesives (Adper Scotchbond SE and Filtek Silorane Adhesive System) and three one-step self-etch adhesives (G-Bond, Xeno V and Bond Force). All adhesive systems were applied following manufacturers' instructions. Composite buildups were constructed and the bonded teeth were then stored in water (24 h, 37 °C) or thermocycled (5,000 cycles) before being sectioned and submitted to MTBS test. Two-way ANOVA and subsequent comparison tests were applied at α = 0.05. Characteristic de-bonded specimens were analyzed using scanning electron microscopy (SEM). After 24 h water storage, MTBS values were highest with XP Bond, Adper Scotchbond 1 XT, Filtek Silorane Adhesive System and Adper Scotchbond SE and lowest with the one-step self-etch adhesives Bond Force, Xeno V and G-Bond. After thermocycling, MTBS values were highest with XP Bond, followed by Filtek Silorane Adhesive System, Adper Scotchbond SE and Adper Scotchbond 1 XT and lowest with the one-step self-etch adhesives Bond Force, Xeno V and G-Bond. Thermal aging induced a significant decrease in MTBS values with all adhesives tested. The resistance of resin-dentin bonds to thermal-aging degradation was material dependent. One-step self-etch adhesives obtained the lowest MTBS results after both aging treatments, and their adhesive capacity was significantly reduced after thermocycling.

  10. Determination of interfacial adhesion strength between oxide scale and substrate for metallic SOFC interconnects

    Science.gov (United States)

    Sun, X.; Liu, W. N.; Stephens, E.; Khaleel, M. A.

    The interfacial adhesion strength between the oxide scale and the substrate is crucial to the reliability and durability of metallic interconnects in solid oxide fuel cell (SOFC) operating environments. It is necessary, therefore, to establish a methodology to quantify the interfacial adhesion strength between the oxide scale and the metallic interconnect substrate, and furthermore to design and optimize the interconnect material as well as the coating materials to meet the design life of an SOFC system. In this paper, we present an integrated experimental/analytical methodology for quantifying the interfacial adhesion strength between the oxide scale and a ferritic stainless steel interconnect. Stair-stepping indentation tests are used in conjunction with subsequent finite element analyses to predict the interfacial strength between the oxide scale and Crofer 22 APU substrate.

  11. The influence of an adhesive system on shear bond strength of repaired high-copper amalgams.

    Science.gov (United States)

    Hadavi, F; Hey, J H; Ambrose, E R; elBadrawy, H E

    1991-01-01

    The shear bond strengths of intact high-copper spherical and admixed amalgams were compared with repaired high-copper spherical and admixed amalgam specimens with and without the use of an adhesive system (Amalgambond). In the spherical group the shear bond strength of the repaired specimens was found to be 55 and 53.2% of the intact specimens without and with the use of the adhesive system. After thermocycling those percentages were 48.5 and 43. In the admixed groups those percentages were 39, 36.5, 34.5, and 35.2 respectively. It was found that the application of Amalgambond did not significantly increase the strength of the repaired amalgam. Thermocycling only had a significantly adverse effect on the repair strength in the admixed group repaired without an adhesive system. PMID:1813872

  12. Comparative evaluation of tensile bond strengths of total-etch adhesives and self-etch adhesives with single and multiple consecutive applications: An in vitro study

    Directory of Open Access Journals (Sweden)

    Mandava Deepthi

    2009-01-01

    Full Text Available Aim: This study evaluates the effect of single and multiple consecutive applications of adhesives on the tensile bond strength. The currently available adhesives follow either the total-etch or the self-etch concept. However, in both techniques the uniformity and thickness of the adhesive layer plays a significant role in the development of a good bond. Materials and Methods: Sixty composite-dentin bonded specimens were prepared using a total-etch adhesive (Gluma and another 60 using a self-etch adhesive (AdheSE. Each group was further divided into six subgroups based on the number of applications, i.e., single application and multiple (2, 3, 4, 6, and 8 applications. The tensile bond strength was tested with the Instron universal testing machine. The values were analyzed with one-way ANOVA and multiple range tests by Tukey′s HSD procedure to identify those subgroups that had significantly higher bond strength. Results: The results indicate that with total-etch adhesive the bond strength increases significantly as the number of applications are increased from one to two or from two to three", for self-etch adhesive the bond strength obtained with two applications is significantly higher than that with one application. However, for both adhesive systems, there was a decrease in the tensile bond strength values with further applications. Conclusion: We conclude that, in the clinical setting, the application of multiple coats of total etch adhesive improves bonding.

  13. Influence of chlorhexidine digluconate on bond strength durability of a self-etching adhesive system

    Directory of Open Access Journals (Sweden)

    Synara Santos Herênio

    2011-10-01

    Full Text Available Introduction and objective: The aim of this study was to evaluate in vitro the effect of 2% chlorhexidine on bond strength durability of a self-etching adhesive system (ClearFill SE Bond. Material and methods: Forty bovine incisors’ crowns had their labial surfaces abraded to dentinexposure,inorderthatthestandardadhesion dentin exposure, inorderthatthestandardadhesion in order that the standard adhesion area reached 4 mm in diameter. Subsequently, they were divided into four groups, according to the treatments performed on the surfaces and storage time: G1 – adhesive system without chlorhexidine for 24 hours (control group; G2 – adhesive system without chlorhexidine for 6 months (control group; G3 – adhesive system with chlorhexidine for 24 hours (experimental group; G4 – adhesive system with chlorhexidine for 6 months (experimental group. After dentin surface treatments, cylinders of composite resin (Z350 were constructed. Then, the specimens were stored in distilled water according to each group design and storage time. Following, the four groups were subjected to shear bond strength test, at a crosshead speed of 0.5 mm / min. The obtained values were subjected to statistical analysis. Results: The results indicated a significant decrease of bond strength in the group treated with chlorhexidine followed by 24-hour storage when compared to control group. However, there was no significant difference in 6-month storage between the experimental and control groups (p>0.05. Conclusion: The application of 2% chlorhexidine was deleterious for bond strength after 24-hour storage.

  14. Shear adhesion strength of thermoplastic gecko-inspired synthetic adhesive exceeds material limits.

    Science.gov (United States)

    Gillies, Andrew G; Fearing, Ronald S

    2011-09-20

    Natural gecko array wearless dynamic friction has recently been reported for 30,000 cycles on a smooth substrate. Following these findings, stiff polymer gecko-inspired synthetic adhesives have been proposed for high-cycle applications such as robot feet. Here we examine the behavior of high-density polyethylene (HDPE) and polypropylene (PP) microfiber arrays during repeated cycles of engagement on a glass surface, with a normal preload of less than 40 kPa. We find that fiber arrays maintained 54% of the original shear stress of 300 kPa after 10,000 cycles, despite showing a marked plastic deformation of fiber tips. This deformation could be due to shear-induced plastic creep of the fiber tips from high adhesion forces, adhesive wear, or thermal effects. We hypothesize that a fundamental material limit has been reached for these fiber arrays and that future gecko synthetic adhesive designs must take into account the high adhesive forces generated to avoid damage. Although the synthetic material and natural gecko arrays have a similar elastic modulus, the synthetic material does not show the same wear-free dynamic friction as the gecko.

  15. Oxide film microstructure: the link between surface preparation processes and strength/durability of adhesively bonded aluminum. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Hsia, K. Jimmy; Pearlstein, Arne J.; Scheeline, Alexander; Shang, Jian Ku

    2000-11-30

    Strength and durability of adhesive bonding of aluminum alloys structures are intrinsically determined by the surface microstructures and interfacial failure micromechanisms. The current project presents a multidisciplinary approach to addressing critical issues controlling the strength and durability of adhesive bonds of aluminum alloys. Three main thrust areas have been pursued: surface treatment technology development to achieve desirable surface microstructures; relationship between surface structure and properties of adhesive bonds; and failure mechanisms of adhesively bonded components.

  16. Shear bond strength of different retainer wires and bonding adhesives in consideration of the pretreatment process

    OpenAIRE

    Reicheneder, C. (Claudia); Hofrichter, B. (Bernd); Faltermeier, A. (Andreas); P. Proff; Lippold, C. (Carsten); Kirschneck, C.J. (Christian)

    2015-01-01

    Introduction: We aimed to compare the shear bond strength (SBS) of three different retainer wires and three different bonding adhesives in consideration of the pretreatment process of enamel surface sandblasting. Methods: 400 extracted bovine incisors were divided into 10 groups of 20 paired specimens each. 10 specimens of each group were pretreated by enamel sandblasting. The retainer wires Bond-A-Braid™, GAC-Wildcat®-Twistflex and everStick®ORTHO were bonded to the teeth with the adhesives ...

  17. Effects of Different Hardeners on the Working Properties and Bonding Strength of Urea-formaldehyde Adhesives

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The addition of a hardener is necessary for the curing of urea-formaldehyde (UF) adhesives in the production of MDF and particleboard. The most commonly used hardener, ammonium chloride, however, is suspected to cause the formation of poisonous dioxin when waste boards are combusted and hence considered as a potential source of pollution. To assess the feasibility of substituting ammonium sulphate for ammonium chloride, working properties and bonding strength were measured for UF adhesives with the two ...

  18. Surface Physicochemistry and Ionic Strength Affects eDNA's Role in Bacterial Adhesion to Abiotic Surfaces

    DEFF Research Database (Denmark)

    Regina, Viduthalai R.; Lokanathan, Arcot R; Modrzynski, Jakub;

    2014-01-01

    with different chemistries resulting in variable hydrophobicity and charge. Cell adhesion experiments were carried out at three different ionic strengths. Removal of eDNA from S. xylosus cells by DNase treatment did not alter the zeta potential, but rendered the cells more hydrophilic. DNase treatment impaired......Extracellular DNA (eDNA) is an important structural component of biofilms formed by many bacteria, but few reports have focused on its role in initial cell adhesion. The aim of this study was to investigate the role of eDNA in bacterial adhesion to abiotic surfaces, and determine to which extent e......DNA-mediated adhesion depends on the physicochemical properties of the surface and surrounding liquid. We investigated eDNA alteration of cell surface hydrophobicity and zeta potential, and subsequently quantified the effect of eDNA on the adhesion of Staphylococcus xylosus to glass surfaces functionalised...

  19. High Fidelity Tape Transfer Printing Based On Chemically Induced Adhesive Strength Modulation

    Science.gov (United States)

    Sim, Kyoseung; Chen, Song; Li, Yuhang; Kammoun, Mejdi; Peng, Yun; Xu, Minwei; Gao, Yang; Song, Jizhou; Zhang, Yingchun; Ardebili, Haleh; Yu, Cunjiang

    2015-11-01

    Transfer printing, a two-step process (i.e. picking up and printing) for heterogeneous integration, has been widely exploited for the fabrication of functional electronics system. To ensure a reliable process, strong adhesion for picking up and weak or no adhesion for printing are required. However, it is challenging to meet the requirements of switchable stamp adhesion. Here we introduce a simple, high fidelity process, namely tape transfer printing(TTP), enabled by chemically induced dramatic modulation in tape adhesive strength. We describe the working mechanism of the adhesion modulation that governs this process and demonstrate the method by high fidelity tape transfer printing several types of materials and devices, including Si pellets arrays, photodetector arrays, and electromyography (EMG) sensors, from their preparation substrates to various alien substrates. High fidelity tape transfer printing of components onto curvilinear surfaces is also illustrated.

  20. Effect of Curing Direction on Microtensile Bond Strength of Fifth and Sixth Generation Dental Adhesives

    Directory of Open Access Journals (Sweden)

    Ali Nadaf

    2012-09-01

    Full Text Available Background and Aims: Composite restorative materials and dental adhesives are usually cured with light sources. The light direction may influence the bond strength of dental adhesives. The aim of this study was to evaluate the effect of light direction on the microtensile bond strength of fifth and sixth generation dental adhesives.Materials and Methods: Prime & Bond NT and Clearfil SE bond were used with different light directions.Sixty human incisor teeth were divided into 4 groups (n=15. In groups A and C, Clearfil SE bond with light curing direction from buccal was used for bonding a composite resin to dentin. In groups B and D, Prime & Bond NT with light curing direction from composite was used. After thermocycling the specimens were subjected to tensile force until debonding occurred and values for microtensile bond strength were recorded. The data were analyzed using two-way ANOVA and Tukey post hoc test.Results: The findings showed that the bond strength of Clearfil SE bond was significantly higher than that of Prime&Bond NT (P<0.001. There was no significant difference between light curing directions (P=0.132.Conclusion: Light curing direction did not have significant effect on the bond strength. Sixth generation adhesives was more successful than fifth generation in terms of bond strength to dentin.

  1. Tensile Bond Strengths of Two Adhesives on Irradiated and Nonirradiated Human Dentin

    OpenAIRE

    Cécile Bernard; Cyril Villat; Hazem Abouelleil; Marie-Paule Gustin; Brigitte Grosgogeat

    2015-01-01

    The aim of this study was to assess the effect of radiotherapy on bond efficiency of two different adhesive systems using tensile bond strength test. Twenty extracted teeth after radiotherapy and twenty nonirradiated extracted teeth were used. The irradiation was applied in vivo to a minimal dose of 50 Gy. The specimens of each group were randomly assigned to two subgroups to test two different adhesive systems. A three-step/etch-and-rinse adhesive system (Optibond FL) and a two-steps/self-et...

  2. Matching Forces Applied in Underwater Hull Cleaning with Adhesion Strength of Marine Organisms

    Directory of Open Access Journals (Sweden)

    Dinis Oliveira

    2016-10-01

    Full Text Available Biofouling is detrimental to the hydrodynamic performance of ships. In spite of advances in hull coating technology, a ship must usually undergo underwater hull cleaning to remove biofouling during her in-service time. However, some cleaning practices may also lead to decreased lifetime of the fouling-control coating. Therefore, cleaning forces should be minimized, according to the adhesion strength of marine organisms present on the hull. In this article, values of adhesion strength found in available literature are discussed in the light of current knowledge on hull cleaning technology. Finally, the following knowledge gaps are identified: (1 data on adhesion strength of naturally-occurring biofouling communities are practically absent; (2 shear forces imparted by current cleaning devices on low-form fouling (microfouling and corresponding effects on hull coatings are largely unknown. This knowledge would be valuable for both developers and users of cleaning technology.

  3. INITIAL MICROBIAL ADHESION IS A DETERMINANT FOR THE STRENGTH OF BIOFILM ADHESION

    NARCIS (Netherlands)

    BUSSCHER, HJ; VANDERMEI, HC; Bos, R.R.M.

    1995-01-01

    This paper presents a hypothesis on the importance of initial microbial adhesion in the overall process of biofilm formation. The hypothesis is based on the realization that dynamic shear conditions exist in many environments, such as in the oral cavity, or on rocks and ship hulls. Recognizing that

  4. Adhesive strength of hydroxyl apatite(HA) coating and biomechanics behavior of HA-coated prosthesis:an experimental study

    OpenAIRE

    Tian-yang ZHANG; Duan, Yong-hong; Zhu, Shu; Jin-yu ZHU; Zhu, Qing-sheng

    2011-01-01

    Objective To explore the influence of adhesive strength of hydroxyapatite(HA) coating on the post-implantation stability of HA-coated prosthesis.Methods The adhesive strength and biomechanics behavior of HA coating were studied by histopathological observation,material parameters and biomechanical testing,the titanium(Ti)-coated prosthesis was employed as control.Results Scratch test showed that the adhesive strength of HA coating was significantly lower than that of Ti coating(P < 0.01).Hist...

  5. Effect of glutaraldehyde and ferric sulfate on shear bond strength of adhesives to primary dentin

    Directory of Open Access Journals (Sweden)

    Prabhakar A

    2008-12-01

    Full Text Available Aim: The present study was undertaken to evaluate the effect of alternative pulpotomy agents such as glutaraldehyde and ferric sulfate on the shear bond strength of self-etch adhesive systems to dentin of primary teeth. Materials and Methods: Eighty human primary molar teeth were sectioned in a mesiodistal direction and divided into experimental and control groups. Lingual dentin specimens in experimental groups were treated with glutaraldehyde and ferric sulfate. Buccal surfaces soaked in water served as control group. Each group was then divided into two groups based on the adhesive system used: Clearfil SE Bond and Adper Prompt L-Pop. A teflon mold was used to build the composite (Filtek Z-250 cylinders on the dentinal surface of all the specimens. Shear bond strength was tested for all the specimens with an Instron Universal Testing Machine. The failure mode analysis was performed with a Scanning Electron Microscope (SEM. Results: The results revealed that glutaraldehyde and ferric sulfate significantly reduced the shear bond strength of the tested adhesive systems to primary dentin. Clearfil SE Bond showed much higher shear bond strength than Adper Prompt L Pop to primary dentin. SEM analysis revealed a predominant cohesive failure mode for both adhesive systems. Conclusion: This study revealed that the pulpotomy medicaments glutaraldehyde and ferric sulfate adversely affected the bonding of self-etch adhesive systems to primary dentin.

  6. Enhancing the adhesion strength of micro electroforming layer by ultrasonic agitation method and the application.

    Science.gov (United States)

    Zhao, Zhong; Du, Liqun; Tao, Yousheng; Li, Qingfeng; Luo, Lei

    2016-11-01

    Micro electroforming is widely used for fabricating micro metal devices in Micro Electro Mechanism System (MEMS). However, there is the problem of poor adhesion strength between micro electroforming layer and substrate. This dramatically influences the dimensional accuracy of the device. To solve this problem, ultrasonic agitation method is applied during the micro electroforming process. To explore the effect of the ultrasonic agitation on the adhesion strength, micro electroforming experiments were carried out under different ultrasonic power (0W, 100W, 150W, 200W, 250W) and different ultrasonic frequencies (0kHz, 40kHz, 80kHz, 120kHz, 200kHz). The effects of the ultrasonic power and the ultrasonic frequency on the micro electroforming process were investigated by polarization method and alternating current (a.c.) impedance method. The adhesion strength between the electroforming layer and the substrate was measured by scratch test. The compressive stress of the electroforming layer was measured by X-ray Diffraction (XRD) method. The crystallite size of the electroforming layer was measured by Transmission Electron Microscopy (TEM) method. The internal contact surface area of the electroforming layer was measured by cyclic voltammetry (CV) method. The experimental results indicate that the ultrasonic agitation can decrease the polarization overpotential and increase the charge transfer process. Generally, the internal contact surface area is increased and the compressive stress is reduced. And then the adhesion strength is enhanced. Due to the different depolarization effects of the ultrasonic power and the ultrasonic frequency, the effects on strengthening the adhesion strength are different. When the ultrasonic agitation is 200W and 40kHz, the effect on strengthening the adhesion strength is the best. In order to prove the effect which the ultrasonic agitation can improve the adhesion strength of the micro devices, micro pillar arrays were fabricated under

  7. Influence of superconductor film composition on adhesion strength of coated conductors

    Energy Technology Data Exchange (ETDEWEB)

    Kesgin, Ibrahim; Khatri, Narayan; Liu, Yuhao; Delgado, Louis; Galstyan, Eduard; Selvamanickam, Venkat

    2015-11-20

    The effect of high temperature superconductor (HTS) film composition on the adhesion strength of rare- earth barium copper oxide coated conductors (CCs) has been studied. It has been found that the mechanical integrity of the superconductor layer is very susceptible to the defects especially those along the ab plane, probably due to the weak interfaces between the defects and the matrix. Gd and Y in the standard composition were substituted with Sm and the number of in-plane defects was drastically reduced. Consequently, a four-fold increase in adhesion or peeling strength in Sm-based CCs was achieved compared to the standard GdYBCO samples.

  8. Effect of adhesive thickness and surface treatment on shear strength on single lap joint Al/CFRP using adhesive of epoxy/Al fine powder

    Science.gov (United States)

    Diharjo, Kuncoro; Anwar, Miftahul; Tarigan, Roy Aries P.; Rivai, Ahmad

    2016-02-01

    The objective of this study is to investigate the effect of adhesive thickness and surface treatment on the shear strength and failure type characteristic of single lap joint (SLJ) CFRP/Al using adhesive epoxy/Al-fine-powder. The CFRP was produced by using hand layup method for 30% of woven roving carbon fiber (w/w) and the resin used was bisphenolic. The adhesive was prepared using 12.5% of aluminum fine powder (w/w) in the epoxy adhesive. The powder was mixed by using a mixing machine at 60 rpm for 6 minutes, and then it was used to join the Al plate-2024 and CFRP. The start time to pressure for the joint process was 20 minutes after the application of adhesive on the both of adherends. The variables in this research are adhesive thickness (i.e. 0.2 mm, 0.4 mm, 0.6 mm, 0.8 mm and 1 mm) and surface treatment of adherends (i.e. acetone, chromate sulphuric acid, caustic etch and tucker's reagent). Before shear testing, all specimens were post-cured at 100 °C for 15 minutes. The result shows that the SLJ has the highest shear strength for 0.4 mm of adhesive thickness. When the adhesive thickness is more than 0.4 mm (0.6-1 mm), the shear strength decreases significantly. It might be caused by the property change of adhesive from ductile to brittle. The acetone surface treatment produces the best bonding between the adhesive and adherends (CFRP and Al-plate 2024), and the highest shear strength is 9.31 MPa. The surface treatment give the humidification effect of adherend surfaces by adhesive. The failure characteristic shows that the mixed failure of light-fiber-tear-failure and cohesive-failure are occurred on the high shear strength of SLJ, and the low shear strength commonly has the adhesive-failure type.

  9. Microtensile and tensile bond strength of single-bottle adhesives: a new test method.

    Science.gov (United States)

    Abdalla, A I

    2004-04-01

    To evaluate the tensile and microtensile bond strength of five single-bottle adhesives to dentine, extracted human molar teeth were used. For each tooth dentine was exposed on the occlusal surface by cutting with an isomet saw and the remaining part was mounted in a plastic ring using dental stone. The tested adhesive materials were: Scotchbond 1, Syntac SC, One-Step, Prime & Bond 2.1 and Clearfil SE Bond. The adhesive was applied to either 1 mm(2) of dentine or a circular area with a diameter of 3.9 mm. Composite resin Clearfil AP-X was placed to the adhesives using a Teflon split mould 3.9 mm in diameter and 2.5 mm in height. Tensile and microtensile bond strengths were measured using a universal testing machine at a crosshead speed of 0.5 mm min(-1). Under tensile mode, the bond strengths were 16.7 +/- 3.5, 15.2 +/- 2.5, 11.5 +/- 3.2, 13.7 +/- 2.6, 20.9 +/- 4.2 MPa for each material. Under microtensile mode, the bond strengths were 52.5 +/- 9.5, 55.3 +/- 8.3, 40.5 +/- 5.2, 37.5 +/- 8.7, 60 +/- 6.21 MPa. Fracture pattern of bonded specimens showed 66% cohesive dentine failure in samples tested for tensile bond strength. For the microtensile test, failures were mainly adhesive at the interface between adhesive and dentine (94%). PMID:15089946

  10. Coating of Carbon Nanotube Fibers: Variation of Tensile Properties, Failure Behavior, and Adhesion Strength

    OpenAIRE

    Mäder, Edith; Liu, Jianwen; Hiller, Janett; Lu, Weibang; Li, Qingwen; Zhandarov, Serge; Chou, Tsu-Wei

    2015-01-01

    An experimental study of the tensile properties of CNT fibers and their interphasial behavior in epoxy matrices is reported. One of the most promising applications of CNT fibers is their use as reinforcement in multifunctional composites. For this purpose, an increase of the tensile strength of the CNT fibers in unidirectional composites as well as strong interfacial adhesion strength is desirable. However, the mechanical performance of the CNT fiber composites manufactured so far is comparab...

  11. Effect of Curing Mode on Shear Bond Strength of Self-Adhesive Cement to Composite Blocks

    OpenAIRE

    Jin-Young Kim; Ga-Young Cho; Byoung-Duck Roh; Yooseok Shin

    2016-01-01

    To overcome the disadvantages of computer-aided design/computer-aided manufacturing (CAD/CAM) processed indirect restorations using glass-ceramics and other ceramics, resin nano ceramic, which has high strength and wear resistance with improved polish retention and optical properties, was introduced. The purpose of this study was to evaluate the shear bond strength and fracture pattern of indirect CAD/CAM composite blocks cemented with two self-etch adhesive cements with different curing mode...

  12. Shear bond strength between alumina substrate and prosthodontic resin composites with various adhesive resin systems

    OpenAIRE

    AlJehani, Yousef A.; Baskaradoss, Jagan K; Geevarghese, Amrita; AlShehry, Marey A; Pekka K. Vallittu

    2015-01-01

    Background With the increase in demand for cosmetics and esthetics, resin composite restorations and all-ceramic restorations have become an important treatment alternative. Taking into consideration the large number of prosthodontic and adhesive resins currently available, the strength and durability of these materials needs to be evaluated. This laboratory study presents the shear bond strengths of a range of veneering resin composites bonded to all-ceramic core material using different adh...

  13. Influence of saliva contamination on the shear bond strength of adhesives on enamel

    Directory of Open Access Journals (Sweden)

    Tatiana Feres Assad-Loss

    2012-04-01

    Full Text Available OBJECTIVE: To evaluate shear bond strength of 3 adhesive systems (Single Bond, TransbondTM MIP and TransbondTM XT applied on bovine enamel under saliva contamination condition. METHOD: One hundred and twenty enamel surfaces of bovine incisors were divided into 6 groups (n = 20 according to the adhesive system used (TransbondTM XT, TransbondTM MIP and Single Bond with or without saliva contamination. For each adhesive system, there were two groups defined as no contamination group (NC: 37% H3PO4 conditioning for 30 seconds and two layers of adhesive systems; saliva contamination group (SC: After the first adhesive layer application, the examined areas were contaminated with saliva. Samples were mounted appropriately for testing and stored in deionized water at 37 ºC for 7 days. Samples were then submitted to shear bond strength trials at a speed of 0.5 mm/min. The Adhesive Remnant Index (ARI was evaluated under stereomicroscopy. Two-way analysis of variance and the Tukey test were used to compare mean values (α = 0.05. RESULTS: Groups XT (NC = 26.29 ± 7.23; MIP (NC = 24.47 ± 7.52 and SB (NC = 32.36 ± 4.14 XT (SC = 19.59 ± 6.76; MIP (SC = 18.08 ± 6.39 and SB (SC = 18.18 ± 7.03 MPa. ARI 0 and 1 were the most prevalent scores in all study groups examined. CONCLUSION: Saliva contamination significantly decreased bond strength of the three adhesive systems examined (p <0.05. However, the comparison of groups with and without saliva contamination did not reveal any significant differences, and, therefore, the three systems may be considered equivalent.

  14. Does hybridized dentin affect bond strength of self-adhesive resin cement?

    Science.gov (United States)

    do Valle, Accácio-Lins; de Andrade, Gustavo-Henrique-Barbosa; Vidotti, Hugo-Alberto; Só, Marcus-Vinícius-Reis; Pereira, Jefferson-Ricardo

    2016-01-01

    Background Evaluate the influence of different hybridization bonding techniques of a self-adhesive resin cement. Material and Methods 30 human health molars were divided into six groups (n=10). The specimens received three longitudinal sections, allowing insertion of central cuts in PVC matrices. Each group received a different dentin pretreatment according to the manufacturer’s recommendations, except the control group (G1), as follows. G2 - a 3-step total-etch adhesive system (Optibond™ FL, Kerr); G3 - a 3-step total-etch adhesive system (Adper™ Scotchbond™ Multi-Purpose, 3M ESPE); G4 - a 2-step total-etch adhesive system (Adper™ Single Bond 2, 3M ESPE); G5 - a single-step self-etching system (Bond Force, Tokuyama); and G6 - universal bonding system (Single Bond Universal, 3M ESPE). Then, cylinders made of self-adhesive resin cement with polypropylene matrix was cemented in all groups (RelyX U200, 3M ESPE). Bond strength was assessed by submitting the specimens to micro-shear test and was characterized according to the fracture pattern observed through optical microscopy. Results The results were submitted to the Kruskal-Wallis test, which indicated a statistically significant difference between the groups (p=0.04), and Tukey’s multiple comparisons, which indicated a statistically significant difference between G1 and G3 (pcement, especially when used Adper™ Scotchbond™ Multi-Purpose system. Key words:Bonding, self-adhesive resin cement, adhesive systems, microshear. PMID:27703609

  15. Influence of chlorhexidine concentration on microtensile bond strength of contemporary adhesive systems

    Directory of Open Access Journals (Sweden)

    Edson Alves de Campos

    2009-09-01

    Full Text Available The purpose of this study was to investigate the influence of chlorhexidine (CHX concentration on the microtensile bond strength (μTBS of contemporary adhesive systems. Eighty bovine central incisors were used in this study. The facial enamel surface of the crowns was abraded with 600-grit silicon carbide paper to expose flat, mid-coronal dentin surfaces. The tested materials were Scotchbond Multipurpose (SMP, Single-Bond (SB, Clearfil SE Bond (CSEB and Clearfil Tri S Bond (CTSB. All the materials were applied according to manufacturer's instructions and followed by composite application (Z250. The teeth were randomly divided into 16 groups: for the etch-and-rinse adhesives (SMP and SB, 0.12% or 2% CHX was applied prior to or after the acid etching procedure. For the self-etch adhesives (CSEB and CTSB 0.12% or 2% CHX was applied prior to the primer. Control groups for each one of the adhesive systems were also set up. The specimens were immediately submitted to μTBS testing and the data were analyzed using Analysis of Variance and the Tukey post hoc test (alpha = .01. The failure patterns of the specimens were observed using scanning electron microscopy. The effects of 2% CHX were statistically significant (p < 0.01 for the self-etch adhesives but were not significant for the etch-and-rinse adhesive systems. Analysis of the data demonstrated no statistical difference between the etch-and-rinse adhesive systems. CHX-based cavity disinfectants in concentrations higher than 0.12% should be avoided prior to the self-etch adhesive systems evaluated in this study to diminish the possibilities of reduction in bond strength.

  16. Effect of caries infiltrant application on shear bond strength of different adhesive systems to sound and demineralized enamel

    OpenAIRE

    Jia, Liuhe; Stawarczyk, Bogna; Schmidlin, Patrick R; Attin, Thomas; Wiegand, Annette

    2012-01-01

    Purpose: To investigate the influence of caries infiltrant application on the shear bond strength of different adhesives on sound and demineralized enamel. Materials and Methods: Sound and artificially demineralized (14 days, acidic buffer, pH 5.0) bovine enamel specimens were treated with a caries infiltrant (Icon, DMG), three different commercial adhesives (unfilled etchand- rinse adhesive: Heliobond, Ivoclar Vivadent; filled etch-and-rinse adhesive: Optibond FL, Kerr; or self-etching adhes...

  17. Effect of cleaning methods on bond strength of self-etching adhesive to dentin

    Directory of Open Access Journals (Sweden)

    Juliana Delatorre Bronzato

    2016-01-01

    Full Text Available Aim: The aim of this study was to investigate the influence of cleaning methods to remove zinc oxide-eugenol-based root canal sealer (Endomethasone on the bond strength of the self-etching adhesive to dentin. Materials and Methods: Twenty crowns of bovine incisors were cut to expose the pulp chamber. A zinc oxide- and eugenol-based sealer was placed for 10 min in contact with the pulp chamber dentin. Specimens were divided into four groups according to the cleaning method of dentin used: G1, no root canal sealer (control; G2, 0.9% sodium chlorite (NaCl; G3, ethanol; and G4, followed by diamond drill. After cleaning, the teeth were restored with composite resin and Clearfil SE Bond. All specimens were sectioned to produce rectangular sticks and dentin/resin interface was submitted to microtensile bond testing. The mean bond strengths were analyzed using ANOVA/Tukey (α = 0.05. Results: G3 and G4 showed bond strengths similar to the G1 (P > 0.05. A significant decrease in the bond strength in the G2 was observed (P < 0.05. G1, G3, and G4, the predominant failure mode was the mixed type. The prevalence of adhesive failure mode was verified in the G2. Conclusion: The cleaning methods affected the bond strength of the self-etching adhesive to dentin differently.

  18. Enhancement of Adhesive Strength of Ultrahigh Molecular Weight Polyethylene Fibers Prepared by Polar Polymer Implantation

    Institute of Scientific and Technical Information of China (English)

    YU Jun-rong; YANG Xin-ge; HU Zu-ming; LIU Zhao-feng

    2007-01-01

    A new technique was proposed to enhance the adhesive strength of ultrahigh molecular weight polyethylene (UHMWPE) fibers. Polar polymer was implanted into UHMWPE gel fibers during extracting process and can then be trapped en the surface of the fibers after subsequent ultra-drawing. The physical and chemical changes in the fiber structure were examined with scanning electron microscopy (SEM) and Fourier transform infrared (FTIR) spectroscopy. The mechanical and interfacial adhesion properties of UHMWPE fibers were investigated with tensile testing. The results showed that there wee polar groups on the surface of pretreated UHMWPE fiber. The interracial shear strength of UHMWPE fibers with epoxy resin was greatly improved without socrificing the excellent mechanical properties of fibers. After pretreated with ethylene/vinyl acetate copolymer (EVA), the shear strength of the interface between fiber and epoxy resin increased from 1.06 to 2.49 MPa, while the integrated mechanical properties of the pretreated UHMWPE fibers ware still optimal.

  19. Evaluation of the adhesion strength of diamond films brazed on K-10 type hard metal

    Directory of Open Access Journals (Sweden)

    Sérgio Ivan dos Santos

    2004-06-01

    Full Text Available The coating of cutting tools with diamond films considerably increases the tool performance due to the combination of the unique tribological properties of diamond with the bulk properties of the substrate (toughness. The tool performance, however, is strongly related to the adhesion strength between the film and the substrate. In this work our main goal was to propose and to test a procedure, based on a tensile strength test, to evaluate the adhesion strength of a diamond wafer brazed on a hard metal substrate, taking into account the effect of the brazing temperature and time. The temperature range studied was from 800 to 980 °C and the brazing time ranged from 3 to 40 min. The obtained results could be used to optimize the costs and time required to the production of high performance cutting tools with brazed diamond wafers.

  20. A room temperature cured low dielectric hyperbranched epoxy adhesive with high mechanical strength

    Indian Academy of Sciences (India)

    Bibekananda De; Niranjan Karak

    2014-05-01

    A low dielectric constant hyperbranched epoxy thermoset with excellent adhesive and mechanical strength is the demand for advanced electronics and engineering applications. The present investigation provided a room temperature, curable hyperbranched epoxy, obtained by an A2 + B3 polycondensation reaction. The synthesized hyperbranched epoxy was cured by a combined hardener system consisting of a commercial poly(amido-amine) and a first generation aliphatic poly(amido-amine) dendrimer (PAD) prepared by Michael addition reaction of methyl acrylate and aliphatic amines. The thermoset exhibited high mechanical strength, excellent adhesive strength, low dielectric constant, good thermal stability and excellent weather resistance along with very good moisture resistance. The results showed the influence of the amount of PAD on the performance of the thermoset. Thus, the study revealed that the combined poly(amido-amine) cured hyperbranched epoxy has high potential in advanced electrical packaging and microelectronic devices.

  1. COMPOSITE RESIN BOND STRENGTH TO ETCHED DENTINWITH ONE SELF PRIMING ADHESIVE

    Directory of Open Access Journals (Sweden)

    P SAMIMI

    2002-09-01

    Full Text Available Introduction. The purpose of this study was to compare shear bond strength of composite resins to etched dentin in both dry and wet dentin surface with active and inactive application of a single-bottle adhesive resin (Single Bond, 3M Dental products. Methods. Fourthy four intact human extracted molars and premolars teeth were selected. The facial surfaces of the teeth were grounded with diamond bur to expose dentin. Then specimens were divided into four groups of 11 numbers (9 Molars and 2 Premolars. All the samples were etched with Phosphoric Acid Gel 35% and then rinsed for 10 seconds. The following stages were carried out for each group: Group I (Active-Dry: After rinsing, air drying of dentin surface for 15 seconds, active priming of adhesive resin for 15 seconds, air drying for 5 seconds, the adhesive resin layer was light cured for 10 seconds. Group III (Inactive-Dry:After rinsing, air drying of dentin surface for 15 seconds, adhesive resin was applied and air dryied for 5 seconds, the adhesive layer was light cured for 10 seconds. Group III (Active-Wet:After rinsing, removal of excess water of dentin surface with a cotton roll, active priming of adhesive resin for 15 seconds and air drying for 5 seconds, the adhesive layer was light cured for 10 seconds. Group IV (Inactive-Wet:After rinsing, removal of excess water of dentin surface with a cotton roll, the adhesive resin was applied and air dryied for 5 seconds and then cured for 10 seconds. After adhesive resin application, composite resin (Z250, 3M Dental products was applied on prepared surface with cylindrical molds (with internal diameter of 2.8mm, & height of 5mm and light-cured for 100 seconds (5x20s. The samples were then thermocycled. They were located in 6±3c water .temperature for 10 seconds and then 15 seconds in inviromental temperature, 10s in 55±3c water temperature and then were located at room temperature for 15s. This test was repeated for 100s. All of the specimens

  2. Effects of endodontic tri-antibiotic paste on bond strengths of dentin adhesives to coronal dentin

    OpenAIRE

    Mirzakoucheki, Parvin; Walter, Ricardo; Khalighinejad, Navid; Jahromi, Maryam Zare; Mirsattari, Sanaz; Akbarzadeh, Navid

    2015-01-01

    Objectives The aim of this study was to evaluate the effects of tri-antibiotic paste (TAP) on microtensile bond strengths (MTBS) of dental adhesives to dentin. Materials and Methods Sixty extracted molars had their occlusal surfaces flattened to expose dentin. They were divided into two groups, i.e., control group with no dentin treatment and experimental group with dentin treatment with TAP. After 10 days, specimens were bonded using self-etch (Filtek P90 adhesive) or etch-and-rinse (Adper S...

  3. Post-bleaching application of an antioxidant on dentin bond strength of three dental adhesives

    Science.gov (United States)

    Khoroushi, Maryam; Saneie, Tahereh

    2012-01-01

    Background: Antioxidizing agents have recently been suggested to compensate decreased bond strength of resin materials to bleached tooth tissues. This study compared the shear bond strength (SBS) of three different adhesives on bleached dentin immediately after bleaching, bleached/delayed for 1 week, and bleached/applied antioxidizing agent. Materials and Methods: The dentinal surfaces of 132 intact extracted molars were prepared and divided into 12 groups. The following adhesives were investigated: Optibond FL (OFL) (three-step etch-and-rinse), Optibond Solo Plus (two-step etch-and-rinse), and Optibond all-in-one (OA) (one-step self-etch) (Kerr, Orange, USA). Unbleached dentin groups (groups 1-3) were prepared as negative controls (NC). The remainder surfaces (groups 4-12) were bleached with 20% Opalescent PF (Ultradent, USA). Specimens were bonded immediately after bleaching (groups 4-6), after 1 week (groups 7-9), or after using 10% sodium ascorbate (SA) gel (groups 10-12). Subsequent to bonding of composite resin, the samples were tested for SBS and analyzed using Kruskal-Wallis and Mann-Whitney tests (α=0.05). Results: Regarding control groups, OA showed the highest SBS among the studied adhesives (P0.05) except the of delay bonding with OA. Conclusions: The findings suggest that bond strength of resin to bleached dentin may be affected with the adhesive system. Reduced SBS to bleached dentin can be amended by the use of SA as an antioxidizing agent. However, the amount of reversed bond strength subsequent to applying antioxidant might be related to the kind of dental adhesive. PMID:22363363

  4. Bond strength evaluation in adhesive joints using NDE and DIC methods

    Science.gov (United States)

    Poudel, Anish

    Adhesive bonding of graphite epoxy composite laminates to itself or traditional metal alloys in modern aerospace and aircraft structural applications offers an excellent opportunity to use the most efficient and intelligent combination of materials available thus providing an attractive package for efficient structural designs. However, one of the major issues of adhesive bonding is the occasional formation of interfacial defects such as kissing or weak bonds in the bondline interface. Also, there are shortcomings of existing non-destructive evaluation (NDE) methods to non-destructively detect/characterize these interfacial defects and reliably predicting the bond shear strength. As a result, adhesive bonding technology is still not solely implemented in primary structures of an aircraft. Therefore, there is a greater demand for a novel NDE tool that can meet the existing aerospace requirement for adhesive bondline characterization. This research implemented a novel Acoustography ultrasonic imaging and digital image correlation (DIC) technique to detect and characterize interfacial defects in the bondline and determine bond shear strength in adhesively bonded composite-metal joints. Adhesively bonded Carbon Fiber Reinforced Plastic (CFRP) laminate and 2024-T3 Aluminum single lap shear panels subjected to various implanted kissing/weak bond defects were the primary focus of this study. Kissing/weak bonds were prepared by controlled surface contamination in the composite bonding surface and also by improperly mixing the adhesive constituent. SEM analyses were also conducted to understand the surface morphology of substrates and their interaction with the contaminants. Morphological changes were observed in the microscopic scale and the chemical analysis confirmed the stability of the contaminant at or very close to the interface. In addition, it was also demonstrated that contaminants migrated during the curing of the adhesive from CFRP substrate which caused a

  5. Effect of Repeated Container Lid Opening on Dentin Shear Bond Strength of Two Dentin Adhesive Systems

    Directory of Open Access Journals (Sweden)

    H. Hassanzadeh

    2008-03-01

    Full Text Available Objective: Comparing the effect of repeated opening of the container lid of two dentin adhesive systems, Prime&Bond NT (P&B NT and iBond (iB, on shear bond strength.Materials and Methods: Intact bovine lower incisors (n=60, fixed in acrylic were ran-domly divided into six groups (n=10. Groups I and II were set as control groups. P&B NT and iB were applied on the samples after five days a week, three times a day for two weeks of use in groups III and VI; and after four weeks of use in groups V and VI. The samples were evaluated by a universal testing-machine (Instron, cross-head speed 1mm/min and stereomicroscope.Results: There was no significant difference between the bond strengths in any of the three P&B NT. The mean amount of the shear bond strength for iB after 60 times of use (15.31 MPa was significantly lowerthan that at the baseline (23.51 MPa. There was no significant difference between iB at the baseline and after 30 times of use (19.26 Mpa, and also between iB after 30 times of use and after 60 times of use. All P&B NT groups showed significantly highershear bond strengths when compared with their similar iB groups in iB.Conclusion: Repeated use (60 times of the all-in-one adhesive container seems to reduce dentin shear bond strength. Therefore, containers with a lower content of the same adhe-sive or a single-dose of the adhesive are preferred.

  6. Shear bond strength of amalgam to dentin using different dentin adhesive systems

    Directory of Open Access Journals (Sweden)

    Farimah Sardari

    2012-01-01

    Full Text Available Background and Aims: The aim of this in vitro study was to assess the shear bond strength of amalgam to dentin using four dentin adhesive systems.Materials and Methods: One hundred human molars were selected. After enamel removal, a dentin cylinder with 3 mm thickness was prepared. Eighty specimens were resorted with amalgam and four dentin adhesive systems as follows (n=20: group 1, Scotch Bond Multi-Purpose; group 2, One Coat Bond; group 3, PQ1; and group 4, Panavia-F. In group 5, 20 specimens were resorted with amalgam and varnish as control group. The specimens were incubated at 37°C for 24 h. The shear bond strengths were then measured by using push out method. The data were analyzed by one-way ANOVA and post hoc Duncan's tests.Results: Mean values for bond strengths of test groups were as follows: group 1=21.03±8.9, group 2=23.47±9, group 3=13.16±8.8, group 4=20.07±8.9 and group 5=14.15±8.7 MPa±SD. One-way ANOVA showed the statistically significant difference between the bond strengths of five groups (P=0.001. Post hoc Duncan's test showed significant difference between groups 1and 3 (P=0.008, groups 1 and 5 (P=0.019, groups 2 and 5 (P=0.0008, groups 4 and 5 (P=0.042, and groups 3 and 4 (P=0.018.Conclusion: Results of this study showed that the bond strength of amalgam to dentin using One Coat Bond as dentin adhesive system was higher than that observed in other dentin adhesive systems.

  7. Effect of new adhesion promoter and mechanical interlocking on bonding strength in metal-polymer composites

    Science.gov (United States)

    Schuberth, A.; Göring, M.; Lindner, T.; Töberling, G.; Puschmann, M.; Riedel, F.; Scharf, I.; Schreiter, K.; Spange, S.; Lampke, T.

    2016-03-01

    There are various opportunities to improve the adhesion between polymer and metal in metal-plastic composites. The addition of a bonding agent which reacts with both joining components at the interfaces of the composite can enhance the bonding strength. An alternative method for the adjustment of interfaces in metal-plastic composites is the specific surface structuring of the joining partners in order to exploit the mechanical interlock effect. In this study the potential of using an adhesion promoter based on twin polymerization for metal-plastic composites in combination with different methods of mechanical surface treatment is evaluated by using the tensile shear test. It is shown that the new adhesion promoter has a major effect when applied on smooth metal surfaces. A combination of both mechanical and chemical surface treatment of the metal part is mostly just as effective as the application of only one of these surface treatment methods.

  8. Effect of Self-etching Adhesives on the Bond Strength of Glass-Ionomer Cements.

    Directory of Open Access Journals (Sweden)

    Zahra Jaberi Ansari

    2014-12-01

    Full Text Available Adequate bond strength between glass ionomer cements and composite resin is necessary for the success of the sandwich technique.This study assessed the micro-shear bond strength of composite resin to glass-ionomer cements (GIC using self-etch adhesives with different pH values.One hundred specimens (6×4×2 mm were made using Fuji II and Fuji II LC GICs and treated with different adhesives as follows: Group 1:Fuji II+ Adper Prompt L-Pop, Group-2: Fuji II+SE bond, Group-3: Fuji II + AdheSE, Group-4:Fuji II+ Protect bond, Group-5: Fuji II + Single bond, Group-6:Fuji II LC+ Adper Prompt LPop, Group-7: Fuji II LC+SE bond, Group-8:Fuji II LC+ AdheSE, Group-9: Fuji II LC+ Protect bond, and Group-10: Fuji II LC+ Single bond. Each group consisted of 10 specimens. A cylinder of Z100 composite resin was placed on each sample and light cured. After 24 hours of water storage (37°C, the specimens were subjected to micro-shear bond strength tests (0.5 mm/min. Data were analyzed using two-way ANOVA and Tukey's test.The mean micro-shear bond strength of groups 1-10 was 11.66±1.79, 16.50±1.85, 18.47±1.77, 13.95±1.77, 15.27±1.49, 15.14±0.90, 20.03±1.19, 17.48±3.00, 16.24±1.98 and 16.03±1.49 MPa, respectively. There were significant differences between groups 1 and 7 (P0.05. Fuji II LC showed higher bond strength than Fuji II (P<0.05.Type of self-etch adhesive had no significant effect on micro-shear bond strength of glass-ionomer to composite resin. Resin modified glass ionomer cement (RMGIC exhibited higher bond strength than the conventional GIC.

  9. The effect of collagen removal on shear bond strength of four single bottle adhesive systems

    Directory of Open Access Journals (Sweden)

    Kasraie Sh

    2006-07-01

    Full Text Available Background and Aim: Achieving adhesion between restorative materials and dentin as a wet and dynamic surface is an important topic in restorative and especially in conservative dentistry. Adhesion of new dentin bonding systems depends on the formation of hybrid layer and micromechanical retention. Nevertheless, an ideal adhesive system has not yet been introduced .Recent studies reveal an increase in bonding stability when the collagen is removed from demineralized dentin surfaces. This study investigates the effect of collagen removal on the shear bond strength of four single bottle dentin bonding systems regarding their structural differences. Materials and Methods: This experimental study was performed on 56 intact human premolar teeth. Smooth surfaces of dentin were prepared on buccal & lingual aspects of teeth, providing 112 dentin surfaces. The dentin surfaces were etched with 37% phosphoric acid for 15 seconds and then rinsed. The specimens were divided into 8 groups. Single bottle adhesive systems [Single Bond (3M, One-Step (Bisco, Prime & Bond NT (Dentsply, and Excite (Vivadent] were then applied on the dentin surfaces of 4 groups using the wet bonding technique. In the other 4 groups, the demineralized dentin surfaces were treated with a 5.25% solution of sodium hypochlorite for one minute in order to remove the surface organic components. The adhesive systems mentioned before were applied to these 4 groups with the same wet bonding technique. A cylinder of Z100 (3M dental composite with a 3 mm diameter and 2 mm height was placed on the adhesive covered dentin surface of all groups and light-cured (400 mW/cm2 ,40 sec on each side. The specimens were kept in distilled water at room temperature for one week and then thermocycled for 3000 times (5-55 oc. Shear bond strength of specimens was measured using an Instron (1495 universal mechanical testing machine with cross-head speed of 0.5 mm/minute and chisel form shearing blade. Data were

  10. Microtensile Bond Strength of Self-Adhesive Luting Cements to Ceramics

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    Tomoko Abo

    2012-01-01

    Full Text Available The purpose of this paper was to compare the bond strengths of the self-adhesive luting cements between ceramics and resin cores and examine their relation to the cement thickness. Three self-adhesive luting cements (Smartcem, Maxcem, and G-CEM and a resin cement (Panavia F 2.0 for control were used in the paper. The thickness of the cements was controlled in approximately 25, 50, 100, or 200 μm. Each 10 specimens were made according to the manufacturers’ instructions and stored in water at 37°C. After 24 hours, microtensile bond strength (μTBS was measured. There were significant differences in cements. Three self-adhesive cements showed significantly lower μTBSs than control that required both etching and priming before cementation (Tukey, <0.05. The cement thickness of 50 or 100 μm tended to induce the highest μTBSs for each self-adhesive luting cements though no difference was found.

  11. A New Testing Method to Evaluate Adhesion Strength of Ceramic Top Coat in TBCs

    Science.gov (United States)

    Okazaki, Masakazu; Yamagishi, Satoshi; Osakabe, Masakazu; Fukanuma, Hirotaka

    A new testing method to evaluate adhesion strength of ceramic top coat has been proposed, employing a ring shape of TBC specimen specifically designed. It was shown by the experiments that a delamination behavior of the top coat was successfully reproduced in the proposed method, associating with a buckling mode; a similar mode frequently observed in actual gas turbine components. A method to quantitatively evaluate a resistance to delamination was also introduced, based on an energy release rate criterion. The experiments demonstrated that the testing method provided reasonable adhesion strength in terms of energy criterion, that almost agreed with the values measured by other researchers employing different type of testing method. It was also shown that the present method has many advantages, compared with the traditional methods.

  12. Shear Bond Strengths and Morphological Evaluation of Filled and Unfilled Adhesive Interfaces to Enamel and Dentine

    OpenAIRE

    Vajihesadat Mortazavi; Mohammadhosein Fathi; Ebrahim Ataei; Niloufar Khodaeian; Navid Askari

    2012-01-01

    In this laboratory study shear bond strengths of three filled and one unfilled adhesive systems to enamel and dentine were compared. Forty-eight extracted intact noncarious human mandibular molars were randomly assigned to two groups of 24 one for bonding to enamel and the other for bonding to dentine. Buccal and lingual surfaces of each tooth were randomly assigned for application of each one of filled (Prime & Bond NT (PBNT), Optibond Solo Plus (OBSP), and Clearfil SE Bond (CSEB)) and unfil...

  13. Effect of bromelain enzyme for dentin deproteinization on bond strength of adhesive system

    OpenAIRE

    Kirti Chauhan; Revaplar Siddaveerappa Basavanna; Vasundhara Shivanna

    2015-01-01

    Aims: To assess the deproteinizing effect of bromelain enzyme and compare it with 5% sodium hypochlorite (NaOCl) on shear bond strength before application of the adhesive system. Materials and Methods: A total of 30 extracted human premolars were divided into three groups, each one consisted of 10 teeth. The occlusal surface was wet ground to expose superficial dentin. In Group 1, teeth were etched; in Group 2, teeth were etched and deproteinized with bromelain enzyme; in Group 3, teeth w...

  14. [Comparative in vitro evaluation of modern glass ionomer cements for adhesion strength and fluoride release].

    Science.gov (United States)

    Zhitkov, M Yu; Rusanov, F S; Poyurovskaya, I Ya

    2016-01-01

    The study proved similar adhesion strength and fluoride release level in aqueous extracts of glass ionomer cements Cemion (VladMiVa, Russia), Glassin Rest (Omega-Dent, Russia), Cemfil 10 (StomaDent, Russia) and Fuji VIII (GC Corporation, Japan). Despite of close concentrations of fluoride in glasses, the rate of fluoride release in water from calcium and calcium-barium glasses is much higher than that of strontium glasses. PMID:27239999

  15. Effect of digluconate chlorhexidine on bond strength between dental adhesive systems and dentin: A systematic review

    OpenAIRE

    Dimitrios Dionysopoulos

    2016-01-01

    Aim: This study aimed to systematically review the literature for the effect of digluconate chlorhexidine (CHX) on bond strength between dental adhesive systems and dentin of composite restorations. Materials and Methods: The electronic databases that were searched to identify manuscripts for inclusion were Medline via PubMed and Google search engine. The search strategies were computer search of the database and review of reference lists of the related articles. Search words/terms were a...

  16. Thermal and tensile strength testing of thermally-conductive adhesives and carbon foam

    CERN Document Server

    Chertok, Maxwell; Irving, Michael; Neher, Christian; Shi, Mengyao; Tolfa, Kirk; Tripathi, Mani; Vinson, Yasmeen; Wang, Ruby; Zheng, Gayle

    2016-01-01

    Future collider detectors, including silicon tracking detectors planned for the High Luminosity LHC, will require components and mechanical structures providing unprecedented strength-to-mass ratios, thermal conductivity, and radiation tolerance. This paper studies carbon foam used in conjunction with thermally conductive epoxy and thermally conductive tape for such applications. Thermal conductivity and tensile strength measurements of aluminum-carbon foam-adhesive stacks are reported. Initial radiation damage tests are also presented. These results can inform bonding method choices for future tracking detectors.

  17. Casein Phosphopeptide-Amorphous Calcium Phosphate and Shear Bond Strength of Adhesives to Primary Teeth Enamel

    OpenAIRE

    Farokh Gisovar, Elham; Hedayati, Nassim; Shadman, Niloofar; Shafiee, Leila

    2015-01-01

    Background: CPP-ACP (Phosphopeptide-Amorphous Calcium Phosphate) has an important role in caries prevention in pediatric patients. This study was done, because of the great use of CPP-ACP and the need for restoration for teeth treated with CPP-ACP as well as the importance of shear bond strength of adhesives in the success of restorations. Objectives: This study aimed to evaluate the effect of casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) on shear bond strength of dental adhesiv...

  18. Influence of chlorhexidine application on longitudinal adhesive bond strength in deciduous teeth

    Directory of Open Access Journals (Sweden)

    Vicente Castelo Branco Leitune

    2011-10-01

    Full Text Available The aim of this study was to evaluate the influence of applying 2% chlorhexidine for 30 seconds after phosphoric acid conditioning of dentin on the immediate and long-term bond strengths in deciduous teeth. The occlusal enamel was removed from 40 human sound deciduous molars, which were exfoliated by natural means, and the dentin was conditioned with 37% phosphoric acid for 15 seconds and washed with running water. The specimens were divided into two groups of 20 teeth. The test group received an application of 2% chlorhexidine for 30 seconds prior to a three-step etch-and-rinse adhesive system, whereas the control group received only the adhesive system. Three cylindrical restorations were made with a composite resin for each tooth. Ten teeth in each group were submitted to a microshear bond strength test after 24 hours, while the remaining teeth were stored in distilled water at 37 °C for 6 months before testing the microshear bond strength. The test group had a higher bond strength than did the control group after 6 months of storage. No statistical differences were found when groups with the same dentin treatment were compared at different times. Short applications of chlorhexidine at low concentrations prevent hybrid layer degradation and positively affect bond strength over time.

  19. Effect of silorane-based adhesive system on bond strength between composite and dentin substrate

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    Jefferson Ricardo Pereira

    2015-01-01

    Full Text Available Context: The complexities of the oral environment, the dentin substrate, and the different bond and composite resin systems represent a challenge to the maintenance of reasonable bond between the composite resin and the tooth structure. Aims: To evaluate the effect of the adhesive system on bond strength between silorane-based composite resin and dentin. Materials and Methods: Fourteen human molars extracted were selected and vertically cut into 3 dentin fragments, randomly divided among the experimental groups and restored with Z250 and P90 composite resin using different adhesive protocols (Adper Single Bond 2, Silorano primer, Adper SE Plus, and Scotchbond Multiuse. Two composite resin cylinders were built up on each dentin surface (n = 10 and subjected to a micro-shear bond strength test. Statistical Analysis Used: Kruskal-Wallis one-way analysis of variance and Tukey test (P = 0.05. Results: According to the results, Kruskal-Wallis test evidenced at least one statistical significant difference (P = 0.001. The Tukey test showed statistically significant differences among the group (P < 0.05. Group PSM8 (P90 + SM showed statically significant higher results when compared with groups PSP4 (P90 + SP, PSB2 (P90 + SB, and ZSE5 (Z250 + SE. Conclusion: The results evidenced that the monomer of the adhesive system has an effect on bond strength between the composite resin and dentin.

  20. Adhesion Strength of Cellulosic Varnish Coated Wood Species as Function of Their Surface Roughness

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    Turgay Ozdemir

    2015-01-01

    Full Text Available The objective of this study was to evaluate adhesion strength of four wood species, namely, beech (Fagus orientalis Lipsky, alder (Alnus glutinosa subsp. barbata Yalt., spruce (Picea orientalis L. Link, and fir (Abies nordmanniana subsp. coated with cellulosic varnish. Samples were prepared in tangential and radial grain orientations from the above species. Surface quality of the specimens was also measured employing stylus type equipment after samples of all four types of species were sanded with 80- and 180-grit sandpaper prior to coating process. Surface roughness of the specimens sanded with 80-grit sandpaper resulted in significantly higher mean peak-to-valley height (Rz values based on the measurement employing stylus type profilometer. The highest adhesion strength values of 2.39 N/mm2 and 2.03 N/mm2 were found for beech and alder samples, respectively. It appears that overall higher roughness characteristics of the specimens exhibited enhanced adherence between substrate and varnish resulting in higher adhesion strength values.

  1. A study on the compatibility between one-bottle dentin adhesives and composite resins using micro-shear bond strength

    OpenAIRE

    Song, Minju; Shin, Yooseok; Park, Jeong-Won; Roh, Byoung-Duck

    2014-01-01

    Objectives This study was performed to determine whether the combined use of one-bottle self-etch adhesives and composite resins from same manufacturers have better bond strengths than combinations of adhesive and resins from different manufacturers. Materials and Methods 25 experimental micro-shear bond test groups were made from combinations of five dentin adhesives and five composite resins with extracted human molars stored in saline for 24 hr. Testing was performed using the wire-loop me...

  2. Comparative Shear-Bond Strength of Six Dental Self-Adhesive Resin Cements to Zirconia

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    Si-Eun Lee

    2015-06-01

    Full Text Available This study compared shear bond strength (SBS of six self-adhesive resin cements (SARC and one resin-modified glass ionomer cement (RMGIC to zirconia before and after thermocycling. The cylinder shape (Φ 2.35 mm × 3 mm of six SARCs (G-CEM LinkAce (GLA, Maxcem Elite (MAX, Clearfil SA Luting (CSL, PermaCem 2.0 (PM2, Rely-X U200 (RXU, Smartcem 2 (SC2 were bonded to the top surface of the zirconia specimens with light-curing. RMGIC (Fujicem (FJC was bonded to the specimens with self-curing. The shear bond strength of all cemented specimens was measured with universal testing machine. Half of the specimens were thermocycled 5000 times before shear bonding strength testing. Fractured surfaces were examined with a field-emission SEM (10,000× and analyzed by energy dispersive x-ray analysis. MAX, PM2, SC2 group without thermocycling and GLA, MAX, PM2 group with thermocycling showed adhesive failure, but GLA, CSL, RXU, FJC group without thermocycling and SLC, RXU, SC2, FJC group with thermocycling indicated cohesive failure. Within the limitation of this study, All of SARCs except MAX demonstrated higher bond strength than that of RMGIC regardless of thermocycling. Also, SARC containing MDP monomers (CSL retained better bonds than other cements.

  3. Effect of Multiple Coatings of One-step Self-etching Adhesive on Microtensile Bond Strength to Primary Dentin

    Institute of Scientific and Technical Information of China (English)

    Lin Ma; Jian-feng Zhou; Jian-guo Tan; Quan Jing; Ji-zhi Zhao; Kuo Wan

    2011-01-01

    Objective To investigate the effect of multiple coatings of the one-step self-etching adhesive on immediate microtensile bond strength to primary dentin.Methods Twelve caries-free human primary molars were randomly divided into 2 groups with 6 teeth each. In group 1,each tooth was hemisected into two halves. One half was assigned to control subgroup 1,which was bonded with a single-step self-etching adhesive according to the manufacturer's instructions; the other half was assigned to experimental subgroup 1 in which the adhesive was applied three times before light curing. In group 2, the teeth were also hemisected into two halves. One half was assigned to control subgroup 2, which was bonded with the single-step self-etching adhesive according to the manufacturer's instructions; the other half was assigned to experimental subgroup 2 in which three layers of adhesive were applied with light curing each successive layer. Microtensile bond strength was immediately tested after specimen preparation.Results When the adhesive was applied three times before light curing, the bond strength of the experimental subgroup 1 (n=33, 57.49±11.61 MPa) was higher than that of the control subgroup 1 (n=31,49.71±11.43 MPa, P0.05).Conclusion multiple coatings of one-step self-etching adhesive can increase the immediate bond strength to primary dentin when using the technique of light-curing after applying three layers of adhesive.

  4. Influence of fluoride-containing adhesives and bleaching agents on enamel bond strength

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    Vanessa Cavalli

    2012-12-01

    Full Text Available This study evaluated the influence of fluoride-containing carbamide peroxide (CP bleaching agents and adhesive systems on bonded enamel interfaces that are part of the dynamic pH cycling and thermal cycling models. The buccal surfaces of 60 bovine incisors were restored with a composite resin and bonded with three- and two-step, etch-and-rinse, fluoride-containing adhesives, Optibond FL (FL and Optibond Solo Plus (SP, respectively. Restored teeth were subjected to thermal cycling to age the interface. Both SP and FL adhesive-restored teeth were bleached (n = 10 with 10% CP (CP and 10% CP + fluoride (CPF or were left unbleached (control. Bleaching was performed for 14 days simultaneously with pH cycling, which comprised of 14 h of remineralization, 2 h of demineralization and 8 h of bleaching. The control groups (FL and SP were stored in remineralizing solution during their bleaching periods and were also subjected to carious lesion formation. Parallelepiped-shaped samples were obtained from the bonded interface for microtensile bond strength (∝TBS testing. The enamel ∝TBS of the FL and SP groups (control, not bleached were higher (p FL + CPF = FL + CP and SP > SP + CPF = SP + CP. The groups subjected to treatment with the fluoride-containing bleaching agents exhibited similar ∝TBS compared to regular bleaching agents. Bleaching agents, regardless of whether they contained fluoride, decreased enamel bond strength.

  5. Influence of fluoride-containing adhesives and bleaching agents on enamel bond strength.

    Science.gov (United States)

    Cavalli, Vanessa; Liporoni, Priscila Cristiane Suzy; Rego, Marcos Augusto do; Berger, Sandrine Bittencourt; Giannini, Marcelo

    2012-01-01

    This study evaluated the influence of fluoride-containing carbamide peroxide (CP) bleaching agents and adhesive systems on bonded enamel interfaces that are part of the dynamic pH cycling and thermal cycling models. The buccal surfaces of 60 bovine incisors were restored with a composite resin and bonded with three- and two-step, etch-and-rinse, fluoride-containing adhesives, Optibond FL (FL) and Optibond Solo Plus (SP), respectively. Restored teeth were subjected to thermal cycling to age the interface. Both SP and FL adhesive-restored teeth were bleached (n = 10) with 10% CP (CP) and 10% CP + fluoride (CPF) or were left unbleached (control). Bleaching was performed for 14 days simultaneously with pH cycling, which comprised of 14 h of remineralization, 2 h of demineralization and 8 h of bleaching. The control groups (FL and SP) were stored in remineralizing solution during their bleaching periods and were also subjected to carious lesion formation. Parallelepiped-shaped samples were obtained from the bonded interface for microtensile bond strength (μTBS) testing. The enamel μTBS of the FL and SP groups (control, not bleached) were higher (p FL > FL + CPF = FL + CP and SP > SP + CPF = SP + CP). The groups subjected to treatment with the fluoride-containing bleaching agents exhibited similar μTBS compared to regular bleaching agents. Bleaching agents, regardless of whether they contained fluoride, decreased enamel bond strength. PMID:23184165

  6. Influence of previous acid etching on interface morphology and bond strength of self-etching adhesive to cavosurface enamel

    OpenAIRE

    Lima, Adriano Fonseca; da Silva, Vinícius Brito; Soares, Giulliana Panfiglio; Marchi, Giselle Maria; Baggio Aguiar, Flávio Henrique; Lovadino, José Roberto

    2012-01-01

    Objectives: The aim of this study was to evaluate the (1) bond strength of a etch-and-rinse and self-etching adhesive systems to cavosurface enamel, (2) influence of the previous acid etching with phosphoric acid 35% to the self-etching adhesive application on bond strength values, and (3) analysis of the cavosurface enamel morphology submitted to different types of conditioning, with the use of a scanning electronic microscope (SEM). Methods: Twenty four human third molars were sectioned on ...

  7. Effect of Nanofiller Addition to an Experimental Dentin Adhesive on Microtensile Bond Strength to Human Dentin

    Directory of Open Access Journals (Sweden)

    SH. Kasraei

    2009-06-01

    Full Text Available Objective: The purpose of the study was to evaluate the influence of adding nanofiller particles to a dentin bonding agent on resin-dentin bond strength.Materials and Methods: Fifty-four human intact premolar teeth were divided in to 6 groups of nine. The teeth were ground on occlusal surfaces and polished with 320 and then 600 grit silicon carbide papers. An experimental bonding system based on acetone/alcoholsolvent was provided with filler contents of 0.0, 0.5, 1.0, 2.5, 5.0, and 10.0 weight percent fumed silica nanofiller. After dentin surface etching, rinsing and blot drying, the experimentalbonding agents were applied to dentin surface. A composite resin was, then,bonded to the dentin on the bonding agent. The specimens were thermocycled for 500 cycles and sectioned in stick form. After two week of storage in distilled water, resin-dentin microtensile bond strength of the specimens was measured. Data were analyzed by one way ANOVA and DunnettT3 tests.Results: Bond strength to dentin was significantly affected by the filler level. Minimum and maximum resin-microtensile bond strength was in the experimental bonding agent with no filler (5.88 MPa and with filler level of 1.0 weight percent (15.15 MPa, respectively,and decreased with the increase of filler content down to 8.95 MPa for the filler level of 10.0 weight percent.Conclusion: Filler content seems to be one of the important factors influencing the bond strength of dental adhesives. Maximum dentin bond strength was obtained with 1% silanized nanofiller silica added to experimental adhesive system.

  8. SHEAR STRENGTH OF HEAT-TREATED TALI (ERYTHROPHLEUM IVORENSE AND IROKO (CHLOROPHORA EXCELSA WOODS, BONDED WITH VARIOUS ADHESIVES

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    Hamiyet Sahin Kol

    2009-11-01

    Full Text Available The aim of this study was to evaluate the effect of heat treatment on the shear strength of tali (Erythrophleum ivorense and iroko (Chlorophora excelsa woods, bonded with some structural adhesives. Shear strength of untreated and heat-treated woods bonded with phenol-formaldehyde (PF, melamine-urea-formaldehyde (MUF, melamine-formaldehyde (MF, and polyurethane (PUR adhesives was studied. An industrial heat treatment method (ThermoWood was used. The timbers were thermally modified for 2 hours at 180 ºC. Laminated samples having two sample sets were prepared from untreated and heat-treated wood for the shear strength test. The results of the tests showed that the heat treatment affected shear strength of laminated wood negatively. Although there was a considerable difference in adhesive bond shear strength between untreated and treated wood, both wood species bonded with the adhesives fulfilled the required value for shear strength of the adhesive bonds. PF, MUF, MF, and PUR adhesives performed in a rather similar way for both wood species.

  9. Composite shear bond strength to dry and wet enamel with three self-etch adhesives

    Directory of Open Access Journals (Sweden)

    Shafiee F

    2006-01-01

    Full Text Available Background and Aim: The bonding mechanisms of self etching primers, based upon the simultaneous etching and priming of dentin, simplifies the bonding technique, but the efficiency of these systems is still controversial. This study compared the shear bond strength of three self etch adhesive systems in dry and wet conditions. Materials and Method: In this experimental study, 77 intact bovine lower incisors with flat 600 grit sanded enamel surface were fixed in acrylic molds and divided into 7 groups, of 11 teeth. The enamel surfaces were treated according to a special procedure as follows: Group 1: Prompt L-Pop (PLP in dry condition, Group 2: Prompt L-Pop in wet condition, Group 3: Clearfield SE Bond (CSEB in dry condition, Group 4: Clearfield SE Bond in wet condition, Group 5: iBond (iB in dry condition, Group 6: iBond in wet condition, Group 7: Margin Bond (Control in dry condition. Surfaces were air dried for ten seconds, or blot dried in wet condition. Composite resin was bonded on the enamel and built up by applying a cylindric teflon split mold (4 mm height 2mm diameter. After 24 hours storage in dionized water at room temperature, all specimens were thermocycled and shear bond test was employed by a universal testing machine (Instron with a cross-head speed of 1mm/min. The shear bond strength was recorded in MPa and data were analyzed with ANOVA and Scheffe statistical tests. P<0.05 was considered as statistically significant. The mode of failure was examined under a stereomicroscope. Results: 1- Shear bond strength of CSEB in dry condition (21.5 ± 4.8 MPa was significantly higher than PLP and iB groups (p<0.0001. 2- Shear bond strength of iB and PLP groups in dry condition (9.60 ± 2.2, 9.49 ± 3 MPa were significantly lower than CSEB and control (2.99 ± 5.1 MPa (P<0.0001. 3- There was no significant difference between PLP and iB groups in dry condition (P=1. 4- Shear bond strength of CSEB in wet condition (21.8 ± 3 MPa was

  10. Direct molding of dry adhesives with anisotropic peel strength using an offset lift-off photoresist mold

    Science.gov (United States)

    Sameoto, D.; Menon, C.

    2009-11-01

    We demonstrate for the first time a wafer scale, directly molded anisotropic dry adhesive made of silicone that can be produced in a two-mask process. We demonstrate that the peel strength of this adhesive is dependent on the amount of overhang of a thin flexible cap on the top of each fiber. By precisely placing the center of this cap offset to the center of the supporting post, the peel strength of the adhesive can be altered when pulled off in different directions.

  11. Influence of dentin contamination by temporary cements on the bond strength of adhesive systems

    Directory of Open Access Journals (Sweden)

    Josimeri Hebling

    2009-01-01

    Full Text Available Objective: The aim of this study was to assess the bond strength of adhesive systems to dentin contaminated by temporary cements with or without eugenol. Method: Flat dentin surfaces were obtained from twenty-four human third molars. With exception of the control group (n=8, the surfaces were covered with Interim Restorative Material (Caulk Dentsplay, Milford, DE, USA or Cavit (3M ESPE, St. Paul, MN, USA and kept in an oven at 37oC for seven days. After removing the cements, the adhesive systems Adper Single Bond (3M ESPE, St. Paul, MN, USA or Clearfil SE Bond (Kuraray Co. Ltd., Osaka, Japan were applied in accordance with the manufacturers’ recommendations, and then the crowns were constructed in of resin composite. The teeth were sectioned into specimens with a cross-sectional bond area of 0.81mm2, which were sub mitted to microtensile testing in a mechanical test machine at an actuator speed of 0.5mm/min. The data were analyzed by t- and ANOVA tests, complemented by Tukey tests (α=0.05. Results: For Adper Single Bond (3M ESPE, St. Paul, MN, USA, bond strength did not differ statistically (p>0.05 for all the experimental conditions. For Clearfil SE Bond (Kuraray Co. Ltd., Osaka, Japan, only the Interim Restorative Material (Caulk Dentsplay, Milford, DE, USA Group showed significantly lower bond strength (30.1±13.8 MPa in comparison with the other groups; control (38.9±13.5 MPa and Cavit (3M ESPE, St. Paul, MN, USA (42.1±11.0 MPa, which showed no significant difference between them.Conclusion: It was concluded that the previous covering of dentin with temporary cement containing eugenol had a deleterious effect on the adhesive performance of the self-etching system only.

  12. Comparative Shear-Bond Strength of Six Dental Self-Adhesive Resin Cements to Zirconia

    OpenAIRE

    Si-Eun Lee; Ji-Hyeon Bae; Jae-Won Choi; Yong-Chan Jeon; Chang-Mo Jeong; Mi-Jung Yoon; Jung-Bo Huh

    2015-01-01

    This study compared shear bond strength (SBS) of six self-adhesive resin cements (SARC) and one resin-modified glass ionomer cement (RMGIC) to zirconia before and after thermocycling. The cylinder shape (Φ 2.35 mm × 3 mm) of six SARCs (G-CEM LinkAce (GLA), Maxcem Elite (MAX), Clearfil SA Luting (CSL), PermaCem 2.0 (PM2), Rely-X U200 (RXU), Smartcem 2 (SC2)) were bonded to the top surface of the zirconia specimens with light-curing. RMGIC (Fujicem (FJC)) was bonded to the specimens with self-c...

  13. Effect of water storage on microshear bond strength of four dental adhesive systems to dentin

    OpenAIRE

    Montenegro, Robinson Viegas; Carlo, Hugo Lemes; Batista, André Ulisses Dantas; Montenegro, Sheyla Christinne Lira; Farias, Ohana Rodrigues

    2015-01-01

    AIM: To evaluate the microshear bond strength of 4 dental adhesive systems after 1 year-water storage. MATERIAL AND METHODS: The sample consisted of 120 cylinders of composite, obtained from 24 bovine incisors, which were divided into four experimental groups: G1-Scotchbond Multi-Purpose, G2-Single Bond 2, G3-Clearfil SE Bond, G4-Adper Easy One and two storage times in distilled water: T0 - 24h and T1 - 1 year. A bivariate analysis was performed using the ANOVA and Tukey test (α=0.05). Result...

  14. An Average Failure Index Method for the Tensile Strength Prediction of Composite Adhesive-bondedJoints

    Institute of Scientific and Technical Information of China (English)

    ZHANG Jianyu; SHAN Meijuan; ZHAO Libin; FEI Binjun

    2015-01-01

    An average failure index method based on accurate FEA was proposed for the tensile strength prediction of composite out-of-plane adhesive-bondedπjoints. Based on the simple and independent maximum stress failure criterion, the failure index was introduced to characterize the degree of stress components close to their corresponding material strength. With a brief load transfer analysis, the weak fillers were prominent and further detailed discussion was performed. The maximum value among the average failure indices which were related with different stress components was filtrated to represent the failure strength of the critical surface, which is either the two curved upside surfaces or the bottom plane of the fillers for compositeπjoints. The tensile strength of three kinds ofπjoints with different material systems, configurations and lay-ups was predicted by the proposed method and corresponding experiments were conducted. Good agreements between the numerical and experimental results give evidence of the effectiveness of the proposed method. In contrast to the existed time-consuming strength prediction methods, the proposed method provides a capability of quickly assessing the failure of complex out-of-plane joints and is easy and convenient to be widely utilized in engineering.

  15. Effect of saliva and blood contamination on the bond strength of self-etching adhesive system- An in vitro study

    Science.gov (United States)

    Koppolu, Madhusudhana; Gogala, Dorasani; Mathew, Vinod B; Thangala, Venugopal; Deepthi, Mandava; Sasidhar, Nalluru

    2012-01-01

    Aim: The aims of this study were to determine the effect of saliva and blood contamination on the shear bond strength of self-etching adhesive to enamel and dentin; and, to compare the difference in bond strength due to contamination beforeand after application of the self-etch adhesive. Materials and Methods: 40 human mandibular molars were wet ground on both buccal and lingual surfaces to prepare flat superficial enamel and dentin surfaces. They were randomly divided into two groups (n = 40) based on the substrate (enamel and dentin). Each group was further divided into five subgroups (n = 8) based on the type of contamination it was subjected to, and the step in the bonding sequence when the contamination occurred (before or after adhesive application). Fresh saliva and fresh human blood were applied either before or after the application of Xeno III® self-etching adhesive system (SES). Composite resin was applied as inverted, truncated cured cones that were subjected to shear bond strength test. Statistical Analysis: One-way analysis of variance (ANOVA) and Tukey's Honestly Significant Difference (HSD) test were used. Results: Statistically significant reduction in the bond strength was shown after both saliva and blood contamination before and after Xeno III® application (Pcontamination with blood as compared to saliva. Conclusions: When self-etching adhesive systems are used, saliva and blood contamination significantly decrease the bond strength of the adhesive to enamel and dentin of the tooth. PMID:22876017

  16. The effect of antimicrobial agents on bond strength of orthodontic adhesives: a meta-analysis of in vitro studies.

    Science.gov (United States)

    Altmann, A S P; Collares, F M; Leitune, V C B; Samuel, S M W

    2016-02-01

    Antimicrobial orthodontic adhesives aim to reduce white spot lesions' incidence in orthodontic patients, but they should not jeopardizing its properties. Systematic review and meta-analysis were performed to answer the question whether the association of antimicrobial agents with orthodontic adhesives compromises its mechanical properties and whether there is a superior antimicrobial agent. PubMed and Scopus databases. In vitro studies comparing shear bond strength of conventional photo-activated orthodontic adhesives to antimicrobial photo-activated orthodontic adhesives were considered eligible. Search terms included the following: orthodontics, orthodontic, antimicrobial, antibacterial, bactericidal, adhesive, resin, resin composite, bonding agent, bonding system, and bond strength. The searches yielded 494 citations, which turned into 467 after duplicates were discarded. Titles and abstracts were read and 13 publications were selected for full-text reading. Twelve studies were included in the meta-analysis. The global analysis showed no statistically significant difference between control and experimental groups. In the subgroup analysis, only the chlorhexidine subgroup showed a statistically significant difference, where the control groups had higher bond strength than the experimental groups. Many studies on in vitro orthodontic bond strength fail to report test conditions that could affect their outcomes. The pooled in vitro data suggest that adding an antimicrobial agent to an orthodontic adhesive system does not influence bond strength to enamel. It is not possible to state which antimicrobial agent is better to be associated.

  17. Tamarindus indica pectin blend film composition for coating tablets with enhanced adhesive force strength.

    Science.gov (United States)

    Khurana, Rajneet; Singh, Kuldeep; Sapra, Bharti; Tiwary, A K; Rana, Vikas

    2014-02-15

    Tablet coating is the most useful method to improve tablet texture, odour and mask taste. Thus, the present investigation was aimed at developing an industrially acceptable aqueous tablet coating material. The physico-chemical, electrical and SEM investigations ensures that blending of Tamarindus indica (Linn.) pectin (TP) with chitosan gives water resistant film texture. Therefore, CH-TP (60:40) spray coated tablets were prepared. The evaluation of CH-TP coated tablets showed enhanced adhesive force strength (between tablet surface to coat) and negligible cohesive force strength (between two tablets) both evaluated using texture analyzer. The comparison of CH-TP coated tablets with Eudragit coated tablets further supported superiority of the former material. Thus, the findings pointed towards the potential of CH-TP for use as a tablet coating material in food as well as pharmaceutical industry.

  18. Mechanical Strength of Particleboard Produced from Fonio Husk with Gum Arabic Resin Adhesive as Binder

    Directory of Open Access Journals (Sweden)

    Ndububa E. E

    2015-04-01

    Full Text Available Fonio (“Acha” husk passing through a maximum 4mm sieve aperture was blended with an adhesive liquid resin of gum Arabic to form Fonio Husk Particleboard (FHP samples. The resin binder was a product of crushed balls of gum Arabic that was mixed with water at ratio 4:3 by weight. The resin was introduced at percentage levels of 20%, 25%, 30%, 35%, 40% and 45% by weight. After pressing, heat treatments and curing, the particleboard samples were tested for mechanical strengths. The compressive strength ranged from 0.057N/mm2 at 20% level to 0.369N/mm2 at 45% level. Tensile strength increased steadily with increase in resin levels peaking at 0.792 N/mm2 for 45% level. The flexural strength followed the same trend peaking at 45% level with 3.697 N/mm2 . Some of the values met the minimum values prescribed by British, American and European Standards. The boards may not be used as load bearing materials but will be better suited as internal wall partitions and ceiling materials.

  19. Effects of Nanosilver-Impregnation and Heat Treatment on Coating Pulloff Adhesion Strength on Solid Wood

    Directory of Open Access Journals (Sweden)

    Hamid Reza Taghiyari

    2016-01-01

    Full Text Available Effects of impregnation with a silver nano-suspension, as well as of heat-treatment, on pull-off adhesion strengths of the coating system on three commercial solid wood species were studied. The wood species included beech, poplar, and fi r. The size range of silver nanoparticles was 30 – 80 nm. The specimens were coated with an un-pigmented sealer and a clear fi nish on the basis of an organic solvent. The results showed that the highest and the lowest pull-off strengths were found in beech specimens heat-treated at 145 °C (5.7 MPa and in nanosilver-impregnated poplar specimens heat-treated at 185 °C (2.5 MPa, respectively. Impregnation with nanosilver decreased pull-off strength in the case of all species as a result of formation of micro checks in the cell walls caused by the impregnation under high pressure in vessel. Heat-treatment at the temperature lower than 145 °C increased pull-off strength as to the irreversible hydrogen bonding in the course of water movements within the pore system of the cell walls, resulting in extra bonds among cell wall components and higher mechanical properties. However, heat treatment at the temperature higher than 185 °C significantly decreased the strength as the degradation of hemicellulose and cell wall wood components caused signifi cant decrease in mechanical strength and cell wall thinning. High thermal conductivity coefficient of silver intensified the impact of heat-treatment by rapid absorption of heat on the surface of the specimens.

  20. Shear bond strengths and microleakage of four types of dentin adhesive materials.

    Science.gov (United States)

    Ateyah, Nasrien Z; Elhejazi, Ahmed A

    2004-02-15

    The aim of this investigation was to compare the microleakage of composite resin (Z-100) and shear bond strength to bovine dentin using different types of adhesive systems (Scotch Bond Multi-Purpose, All-Bond 2, One-Step, and Perma Quick) to compare and correlate microleakage to shear bond strength. For the microleakage aspect of the study, 20 class V were prepared (bovine incisors) with 90-degree cavosurface margins and were located at the cemento-enamel junction using a template. Each dentin bonding system was applied to five cavities following the manufacturer's instructions and restored with Z-100 composite resin. After 24 hours of storage in distilled water at 37 degrees C, the teeth were immersed in 2% basic fuchsin dye. All teeth were sectioned in a mesiodistal direction using a diamond saw, and each section was then inspected under a stereomacroscope. For the shear bond strength aspect of the study, 20 bovine incisors were centrally horizontally mounted in Teflon mold with cold cure acrylic resin. Flat labial dentin surfaces were prepared using different grit silicon carbide abrasive wheels. Five specimens were used for each of the bonding agent systems. Each specimen was bonded with restorative composite resin (Z-100) and applied to the treated dentinal surface through a split Teflon mold. All specimens were stored in distilled water at 37 degrees C for 24 hours. The bonds were stressed using shear forces at a crosshead speed of 0.5mm/min using an Instron Universal testing machine. Findings indicate none of the systems tested in this study were free from microleakage. Scotch bond multi-purpose achieved the best seal, with One-Step being second best, while All-Bond 2 and Perma Quick had the poorest seal. However, there were significant differences among the shear bond strengths of the four bonding systems tested. Scotch Bond Multi-Purpose has a higher bond strength to composite resin when compared to the other dentin adhesives. The study also concluded

  1. Adhesion

    Science.gov (United States)

    As the body moves, tissues or organs inside are normally able to shift around each other. This is because these tissues have ... occur if the adhesions cause an organ or body part to: Twist Pull ... unable to move normally The risk of forming adhesions is high ...

  2. Effect of delayed insertion of composite resin on the bond strength of etch-and-rinse adhesive systems

    OpenAIRE

    Edson Alves de CAMPOS; SAAD, José Roberto Cury; Sizenando Toledo PORTO NETO; Campos, Lucas Arrais; de Andrade, Marcelo Ferrarezi

    2009-01-01

    Introduction: Etch-and-rinse adhesive systems are characterized bythe dental acid etching previously to the monomer application. Thesematerials can be classified as 3-step (when primer and bond are applied separately) or 2-step (when the primer and bond functions are carried out by a single component). Objective: To determine the influence of immediate or delayed insertion of restorative material on the values of bond strength of 2-step and 3-step etch-and-rinse adhesive systems using the mic...

  3. Influence of warm air-drying on enamel bond strength and surface free-energy of self-etch adhesives.

    Science.gov (United States)

    Shiratsuchi, Koji; Tsujimoto, Akimasa; Takamizawa, Toshiki; Furuichi, Tetsuya; Tsubota, Keishi; Kurokawa, Hiroyasu; Miyazaki, Masashi

    2013-08-01

    We examined the effect of warm air-drying on the enamel bond strengths and the surface free-energy of three single-step self-etch adhesives. Bovine mandibular incisors were mounted in self-curing resin and then wet ground with #600 silicon carbide (SiC) paper. The adhesives were applied according to the instructions of the respective manufacturers and then dried in a stream of normal (23°C) or warm (37°C) air for 5, 10, and 20 s. After visible-light irradiation of the adhesives, resin composites were condensed into a mold and polymerized. Ten samples per test group were stored in distilled water at 37°C for 24 h and then the bond strengths were measured. The surface free-energies were determined by measuring the contact angles of three test liquids placed on the cured adhesives. The enamel bond strengths varied according to the air-drying time and ranged from 15.8 to 19.1 MPa. The trends for the bond strengths were different among the materials. The value of the γS⁺ component increased slightly when drying was performed with a stream of warm air, whereas that of the γS⁻ component decreased significantly. These data suggest that warm air-drying is essential to obtain adequate enamel bond strengths, although increasing the drying time did not significantly influence the bond strength.

  4. Tensile bond strength of indirect composites luted with three new self-adhesive resin cements to dentin

    Directory of Open Access Journals (Sweden)

    Cafer Türkmen

    2011-08-01

    Full Text Available OBJECTIVE: The aims of this study were to evaluate the tensile bond strengths between indirect composites and dentin of 3 recently developed self-adhesive resin cements and to determine mode of failure by SEM. MATERIAL AND METHODS: Exposed dentin surfaces of 70 mandibular third molars were used. Teeth were randomly divided into 7 groups: Group 1 (control group: direct composite resin restoration (Alert with etch-and-rinse adhesive system (Bond 1 primer/adhesive, Group 2: indirect composite restoration (Estenia luted with a resin cement (Cement-It combined with the same etch-and-rinse adhesive, Group 3: direct composite resin restoration with self-etch adhesive system (Nano-Bond, Group 4: indirect composite restoration luted with the resin cement combined with the same self-etch adhesive, Groups 5-7: indirect composite restoration luted with self-adhesive resin cements (RelyX Unicem, Maxcem, and Embrace WetBond, respectively onto the non-pretreated dentin surfaces. Tensile bond strengths of groups were tested with a universal testing machine at a constant speed of 1 mm/min using a 50 kgf load cell. Results were statistically analyzed by the Student's t-test. The failure modes of all groups were also evaluated. RESULTS: The indirect composite restorations luted with the self-adhesive resin cements (groups 5-7 showed better results compared to the other groups (p0.05. The surfaces of all debonded specimens showed evidence of both adhesive and cohesive failure. CONCLUSION: The new universal self-adhesive resins may be considered an alternative for luting indirect composite restorations onto non-pretreated dentin surfaces.

  5. Tensile bond strength of indirect composites luted with three new self-adhesive resin cements to dentin

    Science.gov (United States)

    TÜRKMEN, Cafer; DURKAN, Meral; CİMİLLİ, Hale; ÖKSÜZ, Mustafa

    2011-01-01

    Objective The aims of this study were to evaluate the tensile bond strengths between indirect composites and dentin of 3 recently developed self-adhesive resin cements and to determine mode of failure by SEM. Material and Methods Exposed dentin surfaces of 70 mandibular third molars were used. Teeth were randomly divided into 7 groups: Group 1 (control group): direct composite resin restoration (Alert) with etch-and-rinse adhesive system (Bond 1 primer/adhesive), Group 2: indirect composite restoration (Estenia) luted with a resin cement (Cement-It) combined with the same etch-and-rinse adhesive, Group 3: direct composite resin restoration with self-etch adhesive system (Nano-Bond), Group 4: indirect composite restoration luted with the resin cement combined with the same self-etch adhesive, Groups 5-7: indirect composite restoration luted with self-adhesive resin cements (RelyX Unicem, Maxcem, and Embrace WetBond, respectively) onto the non-pretreated dentin surfaces. Tensile bond strengths of groups were tested with a universal testing machine at a constant speed of 1 mm/min using a 50 kgf load cell. Results were statistically analyzed by the Student's t-test. The failure modes of all groups were also evaluated. Results The indirect composite restorations luted with the self-adhesive resin cements (groups 5-7) showed better results compared to the other groups (p0.05). The surfaces of all debonded specimens showed evidence of both adhesive and cohesive failure. Conclusion The new universal self-adhesive resins may be considered an alternative for luting indirect composite restorations onto non-pretreated dentin surfaces. PMID:21710095

  6. Effect of wettability and surface roughness on ice-adhesion strength of hydrophilic, hydrophobic and superhydrophobic surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Bharathidasan, T. [Surface Engineering Division, CSIR- National Aerospace Laboratories, Bangalore 560017 (India); Kumar, S. Vijay; Bobji, M.S. [Department of Mechanical Engineering, Indian Institute of Science, Bangalore 560003 (India); Chakradhar, R.P.S. [Surface Engineering Division, CSIR- National Aerospace Laboratories, Bangalore 560017 (India); Basu, Bharathibai J., E-mail: bharathijbasu@gmail.com [Surface Engineering Division, CSIR- National Aerospace Laboratories, Bangalore 560017 (India)

    2014-09-30

    Highlights: • Anti-icing property is related to wettability and surface roughness. • Silicone based hydrophobic coating showed excellent ice-adhesion strength. • Superhydrophobic surfaces displayed poor anti-icing property. - Abstract: The anti-icing properties of hydrophilic, hydrophobic and superhydrophobic surfaces/coatings were evaluated using a custom-built apparatus based on zero-degree cone test method. The ice-adhesion reduction factor (ARF) of these coatings has been evaluated using bare aluminium alloy as a reference. The wettability of the surfaces was evaluated by measuring water contact angle (WCA) and sliding angle. It was found that the ice-adhesion strength (τ) on silicone based hydrophobic surfaces was ∼ 43 times lower than compared to bare polished aluminium alloy indicating excellent anti-icing property of these coatings. Superhydrophobic coatings displayed poor anti-icing property in spite of their high water repellence. Field Emission Scanning Electron Microscope reveal that Silicone based hydrophobic coatings exhibited smooth surface whereas the superhydrophobic coatings had a rough surface consisting of microscale bumps and protrusions superimposed with nanospheres. Both surface roughness and surface energy play a major role on the ice-adhesion strength of the coatings. The 3D surface roughness profiles of the coatings also indicated the same trend of roughness. An attempt is made to correlate the observed ice-adhesion strength of different surfaces with their wettability and surface roughness.

  7. Effect of wettability and surface roughness on ice-adhesion strength of hydrophilic, hydrophobic and superhydrophobic surfaces

    International Nuclear Information System (INIS)

    Highlights: • Anti-icing property is related to wettability and surface roughness. • Silicone based hydrophobic coating showed excellent ice-adhesion strength. • Superhydrophobic surfaces displayed poor anti-icing property. - Abstract: The anti-icing properties of hydrophilic, hydrophobic and superhydrophobic surfaces/coatings were evaluated using a custom-built apparatus based on zero-degree cone test method. The ice-adhesion reduction factor (ARF) of these coatings has been evaluated using bare aluminium alloy as a reference. The wettability of the surfaces was evaluated by measuring water contact angle (WCA) and sliding angle. It was found that the ice-adhesion strength (τ) on silicone based hydrophobic surfaces was ∼ 43 times lower than compared to bare polished aluminium alloy indicating excellent anti-icing property of these coatings. Superhydrophobic coatings displayed poor anti-icing property in spite of their high water repellence. Field Emission Scanning Electron Microscope reveal that Silicone based hydrophobic coatings exhibited smooth surface whereas the superhydrophobic coatings had a rough surface consisting of microscale bumps and protrusions superimposed with nanospheres. Both surface roughness and surface energy play a major role on the ice-adhesion strength of the coatings. The 3D surface roughness profiles of the coatings also indicated the same trend of roughness. An attempt is made to correlate the observed ice-adhesion strength of different surfaces with their wettability and surface roughness

  8. Influence of oxygen inhibition on the surface free-energy and dentin bond strength of self-etch adhesives.

    Science.gov (United States)

    Koga, Kensaku; Tsujimoto, Akimasa; Ishii, Ryo; Iino, Masayoshi; Kotaku, Mayumi; Takamizawa, Toshiki; Tsubota, Keishi; Miyazaki, Masashi

    2011-10-01

    We compared the surface free-energies and dentin bond strengths of single-step self-etch adhesives with and without an oxygen-inhibited layer. The labial dentin surfaces of bovine mandibular incisors were wet ground with #600-grit silicon carbide paper. The adhesives were applied to the ground dentin, light-irradiated, and the oxygen-inhibited layer was either retained or removed with ethanol. The surface free-energies were determined by measuring the contact angles of three test liquids placed on the cured adhesives. The dentin bond strengths of specimens with and without the oxygen-inhibited layer were measured. For all surfaces, the value of the estimated surface tension component was relatively constant at 35.5-39.8 mJ m(-2) . The value of the , Lewis acid component increased slightly when the oxygen-inhibited layer was removed, whereas that of the , Lewis base component decreased significantly. The bond strengths of the self-etch adhesives were significantly lower in specimens without an oxygen-inhibited layer (13.2-13.6 MPa) than in those with an oxygen-inhibited layer (17.5-18.4 MPa). These results indicate that the presence of an oxygen-inhibited layer in single-step self-etch adhesives with advanced photoinitiators promotes higher dentin bond strength. PMID:21896057

  9. Shear Bond Strengths of Methacrylate- and Silorane-based Composite Resins to Feldspathic Porcelain using Different Adhesive Systems.

    Science.gov (United States)

    Mohammadi, Narmin; Shakur Shahabi, Maryam; Kimyai, Soodabeh; Pournagi Azar, Fatemeh; Ebrahimi Chaharom, Mohammad Esmaeel

    2015-01-01

    Background and aims. Use of porcelain as inlays, laminates and metal-ceramic and all-ceramic crowns is common in modern dentistry. The high cost of ceramic restorations, time limitations and difficulty of removing these restorations result in delays in replacing fractured restorations; therefore, their repair is indicated. The aim of the present study was to compare the shear bond strengths of two types of composite resins (methacrylate-based and silorane-based) to porcelain, using three adhesive types. Materials and methods. A total of 156 samples of feldspathic porcelain surfaces were prepared with air-abrasion and randomly divided into 6 groups (n=26). In groups 1-3, Z250 composite resin was used to repair porcelain samples with Ad-per Single Bond 2 (ASB), Clearfil SE Bond (CSB) and Silorane Adhesive (SA) as the bonding systems, afterapplication of silane, respectively. In groups 4-6, the same adhesives were used in the same manner with Filtek Silorane composite resin. Finally, the shear bond strengths of the samples were measured. Two-way ANOVA and post hoc Tukey tests were used to compare bond strengths between the groups with different adhesives at P<0.05. Results. There were significant differences in the mean bond strength values in terms of the adhesive type (P<0.001). In addition, the interactive effect of the adhesive type and composite resin type had no significant effect on bond strength (P=0.602). Conclusion. The results of the present study showed the highest repair bond strength values to porcelain with both composite resin types with the application of SA and ASB. PMID:26697151

  10. Shear Bond Strengths of Methacrylate- and Silorane-based Composite Resins to Feldspathic Porcelain using Different Adhesive Systems

    Science.gov (United States)

    Mohammadi, Narmin; Shakur Shahabi, Maryam; Kimyai, Soodabeh; Pournagi Azar, Fatemeh; Ebrahimi Chaharom, Mohammad Esmaeel

    2015-01-01

    Background and aims. Use of porcelain as inlays, laminates and metal-ceramic and all-ceramic crowns is common in modern dentistry. The high cost of ceramic restorations, time limitations and difficulty of removing these restorations result in delays in replacing fractured restorations; therefore, their repair is indicated. The aim of the present study was to compare the shear bond strengths of two types of composite resins (methacrylate-based and silorane-based) to porcelain, using three adhesive types. Materials and methods. A total of 156 samples of feldspathic porcelain surfaces were prepared with air-abrasion and randomly divided into 6 groups (n=26). In groups 1-3, Z250 composite resin was used to repair porcelain samples with Ad-per Single Bond 2 (ASB), Clearfil SE Bond (CSB) and Silorane Adhesive (SA) as the bonding systems, afterapplication of silane, respectively. In groups 4-6, the same adhesives were used in the same manner with Filtek Silorane composite resin. Finally, the shear bond strengths of the samples were measured. Two-way ANOVA and post hoc Tukey tests were used to compare bond strengths between the groups with different adhesives at P<0.05. Results. There were significant differences in the mean bond strength values in terms of the adhesive type (P<0.001). In addition, the interactive effect of the adhesive type and composite resin type had no significant effect on bond strength (P=0.602). Conclusion. The results of the present study showed the highest repair bond strength values to porcelain with both composite resin types with the application of SA and ASB. PMID:26697151

  11. Insulin-like Growth Factor I Controls Adhesion Strength Mediated by α5β1 Integrins in Motile Carcinoma Cells

    OpenAIRE

    Lynch, Laura; Vodyanik, Pavel I.; Boettiger, David; Guvakova, Marina A

    2005-01-01

    One of the intriguing questions regarding cell motility concerns the mechanism that makes stationary cells move. Here, we provide the first physical evidence that the onset of breast cancer cell motility in response to insulin-like growth factor I (IGF-I) correlates with lowering of adhesion strength from 2.52 ± 0.20 to 1.52 ± 0.13 μdynes/μm2 in cells attached to fibronectin via α5β1 integrin. The adhesion strength depends on the dose of IGF-I and time of IGF-I treatment. Weakening of cell-ma...

  12. Lap shear strength of selected adhesives (epoxy, varnish, B-stage glass cloth) in liquid nitrogen and at room temperature

    International Nuclear Information System (INIS)

    The adhesives included several epoxy resins, a varnish, and a B-stage glass cloth (a partially cured resin in a fiberglass cloth matrix). Several parameters critical to bond strength were varied: adhesive and adherend differences, surface preparation, coupling agents, glass cloth, epoxy thickness, fillers, and bonding pressure and temperature. The highest lap shear strengths were obtained with the B-shear glass cloth at both liquid nitrogen and room temperatures with values of approximately 20 MPa (3000 psi) and approximately 25.5 MPa (3700 psi) respectively

  13. Using scratch testing to measure the adhesion strength of calcium phosphate coatings applied to poly(carbonate urethane) substrates.

    Science.gov (United States)

    Barnes, Dunstan; Johnson, Scott; Snell, Robert; Best, Serena

    2012-02-01

    Bioactive coatings are applied to components of modern orthopædic implants to improve the host tissue response to the implants. Such coatings cannot be applied to polymeric implants by high-temperature techniques, because the use of high temperatures may critically degrade the polymer substrate. Regardless of the coating technique that is used, the coating must be sufficiently well adhered to the underlying substrate to provide any practical benefit. This paper investigates the use of scratch testing to measure the adhesion strength of calcium phosphate (CaP) coatings that were applied to a poly(carbonate urethane) (PCU) substrate by an aqueous process at temperatures of 19, 28, 37, and 50 °C. This work represents the first time that scratch testing analysis has been used to study CaP coatings deposited by an aqueous, low-temperature process on to a polymer substrate. Scratch testing was shown to be a useful technique for obtaining comparative, rather than absolute, values of adhesion strength for hard coatings formed on a compliant substrate. Generally, the coating temperature was not found to influence the CaP-PCU adhesion strength. Although CaP coatings formed at 19 °C exhibited considerably lower adhesion strengths than CaP coatings formed at 28, 37, and 50 °C, this finding was attributable to the inconsistency of CaP coatings formed on the PCU substrates at 19 °C. The coating-substrate adhesion strength was measured for CaP coatings of four different coating ages (0, 1, 2, and 3 years). CaP coatings that were aged for 0, 1, or 2 years exhibited similar coating-substrate adhesion strengths to each other. In contrast, CaP coatings that were aged for 3 years demonstrated considerably lower coating-substrate adhesion strengths. The observed reduction in adhesion strength with age was thought to be attributable to suspected "drying out" of the CaP coatings. PMID:22301182

  14. ADHESION STRENGTH OF TiN COATINGS AT VARIOUS ION ETCHING DEPOSITED ON TOOL STEELS USING CATHODIC ARC PVD TECHNIQUE

    OpenAIRE

    MUBARAK ALI; ESAH HAMZAH; NOUMAN ALI

    2009-01-01

    Titanium nitride (TiN) widely used as hard coating material was coated on tool steels, namely on high-speed steel (HSS) and D2 tool steel by physical vapor deposition method. The goal of this study was to examine the effect of ion etching with and without titanium (Ti) and chromium (Cr) on the adhesion strength of TiN coatings deposited on tool steels. From the scratch tester, it was observed that by increasing Ti ion etching showed an increase in adhesion strength of the deposited coatings. ...

  15. Bond strength comparison of color-change adhesives for orthodontic bonding using a self-etching primer

    OpenAIRE

    Frey GN; Bussa HI; Powers JM; Ontiveros JC; English JD; Ekhlassi S; Colville CD; Ellis RK

    2011-01-01

    Sara Ekhlassi, Jeryl D English, Joe C Ontiveros, John M Powers, Harry I Bussa, Gary N Frey, Clark D Colville, Randy K EllisHouston Department of Orthodontics, The University of Texas Dental Branch, Houston, TX, USABackground: The purpose of this study was to compare the shear bond strengths of two color-change adhesives with a commonly used conventional light-cure adhesive while using a self-etching primer, and to compare any changes in shear bond strengths over time.Methods: One hundred and ...

  16. Experimental study about the influence of adhesive stiffness to the bonding strengths of adhesives for ceramic/metal targets

    Directory of Open Access Journals (Sweden)

    W. Seifert

    2016-04-01

    The experimental results indicate that the damage behavior of the ceramic/metal composites depends on the absolute elongation of the adhesive layer. This can be controlled either by the thickness or the stiffness of the bonding layer.

  17. Coating of carbon nanotube fibers: variation of tensile properties, failure behavior and adhesion strength

    Directory of Open Access Journals (Sweden)

    Edith eMäder

    2015-07-01

    Full Text Available An experimental study of the tensile properties of CNT fibers and their interphasial behavior in epoxy matrices is reported. One of the most promising applications of CNT fibers is their use as reinforcement in multifunctional composites. For this purpose, an increase of the tensile strength of the CNT fibers in unidirectional composites as well as strong interfacial adhesion strength is desirable. However, the mechanical performance of the CNT fiber composites manufactured so far is comparable to that of commercial fiber composites. The interfacial properties of CNT fiber/polymer composites have rarely been investigated and provided CNT fiber/epoxy interfacial shear strength of 14.4 MPa studied by the microbond test.In order to improve the mechanical performance of the CNT fibers, an epoxy compatible coating with nano-dispersed aqueous based polymeric film formers and low viscous epoxy resin, respectively, was applied. For impregnation of high homogeneity, low molecular weight epoxy film formers and polyurethane film formers were used. The aqueous based epoxy film formers were not crosslinked and able to interdiffuse with the matrix resin after impregnation. Due to good wetting of the individual CNT fibers by the film formers, the degree of activation of the fibers was improved leading to increased tensile strength and Young’s modulus. Cyclic tensile loading and simultaneous determination of electric resistance enabled to characterize the fiber’s durability in terms of elastic recovery and hysteresis.The pull-out tests and SEM study reveal different interfacial failure mechanisms in CNT fiber/epoxy systems for untreated and film former treated fibers, on the one hand, and epoxy resin treated ones, on the other hand. The epoxy resin penetrated between the CNT bundles in the reference or film former coated fiber, forming a relatively thick CNT/epoxy composite layer and thus shifting the fracture zone within the fiber. In contrast to this

  18. Coating of carbon nanotube fibers: variation of tensile properties, failure behavior and adhesion strength

    Science.gov (United States)

    Mäder, Edith; Liu, Jian-Wen; Hiller, Janett; Lu, Weibang; Li, Qingwen; Zhandarov, Serge; Chou, Tsu-Wei

    2015-07-01

    An experimental study of the tensile properties of CNT fibers and their interphasial behavior in epoxy matrices is reported. One of the most promising applications of CNT fibers is their use as reinforcement in multifunctional composites. For this purpose, an increase of the tensile strength of the CNT fibers in unidirectional composites as well as strong interfacial adhesion strength is desirable. However, the mechanical performance of the CNT fiber composites manufactured so far is comparable to that of commercial fiber composites. The interfacial properties of CNT fiber/polymer composites have rarely been investigated and provided CNT fiber/epoxy interfacial shear strength of 14.4 MPa studied by the microbond test. In order to improve the mechanical performance of the CNT fibers, an epoxy compatible coating with nano-dispersed aqueous based polymeric film formers and low viscous epoxy resin, respectively, was applied. For impregnation of high homogeneity, low molecular weight epoxy film formers and polyurethane film formers were used. The aqueous based epoxy film formers were not crosslinked and able to interdiffuse with the matrix resin after impregnation. Due to good wetting of the individual CNT fibers by the film formers, the degree of activation of the fibers was improved leading to increased tensile strength and Young’s modulus. Cyclic tensile loading and simultaneous determination of electric resistance enabled to characterize the fiber’s durability in terms of elastic recovery and hysteresis. The pull-out tests and SEM study reveal different interfacial failure mechanisms in CNT fiber/epoxy systems for untreated and film former treated fibers, on the one hand, and epoxy resin treated ones, on the other hand. The epoxy resin penetrated between the CNT bundles in the reference or film former coated fiber, forming a relatively thick CNT/epoxy composite layer and thus shifting the fracture zone within the fiber. In contrast to this, shear sliding along

  19. Effect of delayed insertion of composite resin on the bond strength of etch-and-rinse adhesive systems

    Directory of Open Access Journals (Sweden)

    Edson Alves CAMPOS

    2009-12-01

    Full Text Available Introduction: Etch-and-rinse adhesive systems are characterized bythe dental acid etching previously to the monomer application. Thesematerials can be classified as 3-step (when primer and bond are applied separately or 2-step (when the primer and bond functions are carried out by a single component. Objective: To determine the influence of immediate or delayed insertion of restorative material on the values of bond strength of 2-step and 3-step etch-and-rinse adhesive systems using the microtensile test. Material and methods: Bovine incisors were used, which had its vestibular surface abraded to obtain a flat dentin surface. 3-step (Scotchbond Multi-Purpose – SMP; Optibond FL – OFL; Bond-It – BIT and 2-step (Single-Bond – SB; Optibond Solo Plus – OSP; Bond-1 – B1 etch-and-rinse adhesive systems were used, and composite resin (Z-350 was adhered to this substrate at two different times: immediately and later (after 24 hours. Procedures were performed with simulated physiological pulpal pressure. Results were submitted to statistical analysis through Anova and Tukey’s test (p < 0.05. Results: When the composite resin was immediately inserted all the adhesive systems showed similar results. 3-step adhesive systems did not show reduction in bond strength values related to delayed insertion of composite. On the other hand, 2-step adhesive systems showed significant reduction in the values of bond strength. Reduction was around 30.24% to SB, 27.19% to OSP and 28.21% to B1. Conclusion: 2-step etch-and-rinse adhesive systems should be used very carefully. It is advisable to insert and polymerize the composite resin immediately after the conclusion of adhesive procedure.

  20. Effect of saliva contamination on the shear bond strength of a new self-etch adhesive system to dentin

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    Swapna Munaga

    2014-01-01

    Full Text Available Aims and Objectives: To evaluate the effect of saliva contamination on the shear bond strength of a new two-step self-etch adhesive (P90 system adhesive to dentin and to determine the effect of contaminant removing treatments on the recovery of bond strengths. Materials and Methods: The buccal surfaces of 40 human premolars were ground to expose dentin. The specimens were randomly divided into four groups. Group 1 is uncontaminated and serves as the control group. Further groups were divided based on the step in the bonding sequence when the contamination had occurred as follows: Group 2 (primer, saliva contamination, rinse and dry, group 3 (after procedure of group 2, reapplication of primer, and group 4 (after procedure like in control group, saliva contamination, rinse and dry. Filtek P90 composite resin cylinders of 3 mm diameter and 3 mm length were fabricated on the surfaces. Shear bond strength testing was done in an Instron Universal Testing Machine and the data were subjected to one-way analysis of variance (ANOVA and Student′s t-test. Results: With P90 system adhesive, group 2 and group 4 showed lower shear bond strength than group 1 (control and group 3 (P < 0.05. Conclusion: Saliva contamination significantly decreased the shear bond strength of the adhesive to dentin.

  1. Bond strength durability of self-etching adhesives and resin cements to dentin

    Directory of Open Access Journals (Sweden)

    Carolina de Andrade Lima Chaves

    2009-06-01

    Full Text Available OBJECTIVES: To evaluate the microtensile bond strength (µTBS of one- (Xeno III, Dentsply and two-step (Tyrian-One Step Plus, Bisco self-etching adhesive systems bonded to dentin and cemented to chemically cured (C&B Metabond or light-cured paste of a dual-cure resin cement (Variolink II, Ivoclar within a short (24 h and long period of evaluation (90 days. MATERIAL AND METHODS: Forty recently extracted human molars had their roots removed and their occlusal dentin exposed and ground wet with 600-grit SiC paper. After application of one of the adhesives, the resin cement was applied to the bonded surface and a composite resin block was incrementally built up to a height of 5 mm (n=10. The restored teeth were stored in distilled water at 37ºC for 7 days. The teeth were then cut along two axes (x and y, producing beam-shaped specimens with 0.8 mm² cross-sectional area, which were subjected to µTBS testing at a crosshead speed of 0.05 mm/min and stressed to failure after 24 h or 90 days of storage in water. The µTBS data in MPa were subjected to three-way analysis of variance and Tukey's test (α= 0.05. RESULTS: The interaction effect for all three factors was statistically significant (three-way ANOVA, p<0.001. All eight experimental means (MPa were compared by the Tukey's test (p<0.05 and the following results were obtained: Tyrian-One Step Plus /C&B/24 h (22.4±7.3; Tyrian-One Step Plus /Variolink II/24 h (39.4±11.6; Xeno III/C&B/24 h (40.3±12.9; Xeno III/Variolink II/24 h (25.8±10.5; Tyrian-One Step Plus /C&B/90 d (22.1±12.8 Tyrian-One Step Plus/VariolinkII/90 d (24.2±14.2; Xeno III/C&B/90 d (27.0±13.5; Xeno III/Variolink II/90 d (33.0±8.9. CONCLUSIONS: Xeno III/Variolink II was the luting agent/adhesive combination that provided the most promising bond strength after 90 days of storage in water.

  2. [Bonding strength of metal frameworks and adhesive agents in the resin-bonded bridge technic. 3. Comparative research on various retention mechanisms and adhesive systems].

    Science.gov (United States)

    Wirz, J; Besimo, C; Schmidli, F

    1989-01-01

    In fixed denture prosthetics, macro- and micromechanical as well as chemical adhesive mechanisms may be used between metal and bonding agent. The in vitro research presented here determines the adhesive strength of six different bonding agents and five different retention mechanisms on twelve precious and nonprecious metal alloys using shearing stress. The evaluation of the results should help to assess the suitability of the various combinations of materials and anchoring methods for the fixation of adhesive bridges. On the basis of the adhesive strengths and the examination of the various clinical advantages and disadvantages of the different methods that were analyzed, the electrolytic etching of nonprecious metal alloys appears to be particularly suitable for fixed denture prostheses. An efficient combination between alloy and bonding agent is of particular importance in this area. Macromechanical mesh and negative retentions can only be used to a limited clinical extent due to their high space requirements. Very good results were produced by the preconditioning of inner anchor surfaces with silanes. Sandblasting, however, provided unsatisfactory shear-stress results over a broad front independently of the type of alloy.

  3. Influence of 10-MDP Adhesive System on Shear Bond Strength of Zirconia-Composite Interfaces

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    Philipp Cornelius Pott

    2015-09-01

    Full Text Available Introduction: This in-vitro study investigated the initial 24h bond strength between different composites and zirconia after application of four different adhesive systems. Methods: A total of 120 specimens of zirconia (InCoris, Sirona, Germany, Bernsheim were ground with a 165 µm grit rotating diamond disc. Thirty specimens were each additionally treated with Cimara Zircon “CZ” (VOCO GmbH, Germany, Cuxhaven, Futurabond U “FBU” (VOCO GmbH, Futurabond M+ “FBM” (VOCO GmbH or Futurabond M+ in combination with the DCA activator “FBMD” (VOCO GmbH. One of three different types of composites – BifixSE (“BS”, BifixQM (“BQ” or GrandioSO (“G” (VOCO GmbH – was bonded to ten specimens each in every group. Shear bond strength (SBS was determined in a universal testing machine. Statistical analysis was performed with ANOVA and the Tukey test. Results: FBM and FBMD gave higher SBS than CZ and FBU in combination with all tested composites. In comparison to FBU, FBM gave statistically significant increases in SBS with BifixSE (19.4±5.7 MPa (P

  4. Can previous acid etching increase the bond strength of a self-etching primer adhesive to enamel?

    Directory of Open Access Journals (Sweden)

    Ana Paula Morales Cobra Carvalho

    2009-06-01

    Full Text Available Because a greater research effort has been directed to analyzing the adhesive effectiveness of self etch primers to dentin, the aim of this study was to evaluate, by microtensile testing, the bond strength to enamel of a composite resin combined with a conventional adhesive system or with a self-etching primer adhesive, used according to its original prescription or used with previous acid etching. Thirty bovine teeth were divided into 3 groups with 10 teeth each (n= 10. In one of the groups, a self-etching primer (Clearfil SE Bond - Kuraray was applied in accordance with the manufacturer's instructions and, in the other, it was applied after previous acid etching. In the third group, a conventional adhesive system (Scotchbond Multipurpose Plus - 3M-ESPE was applied in accordance with the manufacturer's instructions. The results obtained by analysis of variance revealed significant differences between the adhesive systems (F = 22.31. The self-etching primer (Clearfil SE Bond presented lower enamel bond strength values than the conventional adhesive system (Scotchbond Multipurpose Plus (m = 39.70 ± 7.07 MPa both when used according to the original prescription (m = 27.81 ± 2.64 MPa and with previous acid etching (m = 25.08 ± 4.92 MPa.

  5. Effect of reactive adhesives on the tensile bond strength of polyvinyl siloxane impression materials to methyl methacrylate tray material.

    Science.gov (United States)

    Ona, Masahiro; Takahashi, Hidekazu; Sato, Masayuki; Igarashi, Yoshimasa; Wakabayashi, Noriyuki

    2010-05-01

    The effect of new adhesives on the bond strength of elastomeric impression materials to acrylic trays was evaluated. Two polyvinyl siloxane impression materials (Fusion and Imprinsis) with reactive adhesives and one (Examix) with a conventional adhesive were tested. Flat, double-sided plates of auto-polymerizing methyl methacrylate (10 x 10 x 2.5 mm) were prepared with one of the adhesives. Five specimens were prepared by injecting each impression material into a 2-mm gap between the two plates. Tensile tests were conducted until separation failure occurred. The mean bond strengths of Fusion (1.0 MPa) and Imprinsis (0.8 MPa) were significantly greater than that of Examix (0.2 MPa). On the contrary, one of five Fusion showed adhesive failure mode while all the Imprinsis exhibited mixed failure. The conflicting results were presumably attributed to the mean tear strength of Fusion (0.8 N/mm) being higher than that of Imprinsis (0.5 N/mm).

  6. Nanospherical arabinogalactan proteins are a key component of the high-strength adhesive secreted by English ivy

    Science.gov (United States)

    Huang, Yujian; Wang, Yongzhong; Tan, Li; Sun, Leming; Petrosino, Jennifer; Cui, Mei-Zhen; Hao, Feng; Zhang, Mingjun

    2016-06-01

    Over 130 y have passed since Charles Darwin first discovered that the adventitious roots of English ivy (Hedera helix) exude a yellowish mucilage that promotes the capacity of this plant to climb vertical surfaces. Unfortunately, little progress has been made in elucidating the adhesion mechanisms underlying this high-strength adhesive. In the previous studies, spherical nanoparticles were observed in the viscous exudate. Here we show that these nanoparticles are predominantly composed of arabinogalactan proteins (AGPs), a superfamily of hydroxyproline-rich glycoproteins present in the extracellular spaces of plant cells. The spheroidal shape of the AGP-rich ivy nanoparticles results in a low viscosity of the ivy adhesive, and thus a favorable wetting behavior on the surface of substrates. Meanwhile, calcium-driven electrostatic interactions among carboxyl groups of the AGPs and the pectic acids give rise to the cross-linking of the exuded adhesive substances, favor subsequent curing (hardening) via formation of an adhesive film, and eventually promote the generation of mechanical interlocking between the adventitious roots of English ivy and the surface of substrates. Inspired by these molecular events, a reconstructed ivy-mimetic adhesive composite was developed by integrating purified AGP-rich ivy nanoparticles with pectic polysaccharides and calcium ions. Information gained from the subsequent tensile tests, in turn, substantiated the proposed adhesion mechanisms underlying the ivy-derived adhesive. Given that AGPs and pectic polysaccharides are also observed in bioadhesives exuded by other climbing plants, the adhesion mechanisms revealed by English ivy may forward the progress toward understanding the general principles underlying diverse botanic adhesives.

  7. An in vitro comparison of adhesive techniques and rotary instrumentation on shear bond strength of nanocomposite with simulated pulpal pressure

    Directory of Open Access Journals (Sweden)

    Jayshree Hegde

    2011-01-01

    Full Text Available Aim: The aim of this study is to evaluate the shear bond strength of composite to tooth using different adhesive techniques and rotary instruments under simulated pulpal pressure. Materials and Methods: Sixty extracted human molars were randomly divided into two groups of 30 samples each (group I and II, according to the adhesive technique followed (i.e. total etch and self etch groups. Each group was further divided into two sub-groups (Sub-groups A and B of 15 samples each according to the cutting instrument (diamond abrasive or carbide burs used. Class II cavities were made with diamond abrasive or carbide burs, and restored with nano-composite under positive intra-pulpal pressure. Shear bond strength of the specimens were recorded simultaneously. Results: After statistical evaluation using two-way ANOVA and t-test, the mean shear bond strength values of the groups are as follows: Group IA- 4.69 MPa, Group IB-6.15 MPa, Group IIA-4.3 MPa, and Group IIB-6.24 MPa. It was seen that group IIB showed highest bond strength followed by group IB. Group II A showed the least bond strength. Conclusions: Within the limitations of the study, diamond abrasive gave better bond strength than carbide bur with both the adhesive techniques.

  8. A statistical approach to estimating the strength of cell-cell interactions under the differential adhesion hypothesis

    Directory of Open Access Journals (Sweden)

    Emily Mathieu

    2007-09-01

    Full Text Available Abstract Background The Differential Adhesion Hypothesis (DAH is a theory of the organization of cells within a tissue which has been validated by several biological experiments and tested against several alternative computational models. Results In this study, a statistical approach was developed for the estimation of the strength of adhesion, incorporating earlier discrete lattice models into a continuous marked point process framework. This framework allows to describe an ergodic Markov Chain Monte Carlo algorithm that can simulate the model and reproduce empirical biological patterns. The estimation procedure, based on a pseudo-likelihood approximation, is validated with simulations, and a brief application to medulloblastoma stained by beta-catenin markers is given. Conclusion Our model includes the strength of cell-cell adhesion as a statistical parameter. The estimation procedure for this parameter is consistent with experimental data and would be useful for high-throughput cancer studies.

  9. Shear Bond Strength of Saliva Contaminated and Re-etched All-in-One Adhesive to Enamel

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    M. Khoroushi

    2008-12-01

    Full Text Available Objective: The aim of this study was to investigate the effect of phosphoric acid re-etching of an enamel surface treated via a one-bottle adhesive system on shear bond strength between resin composite and the enamelsurface in different stages of adhesive application.Materials and Methods: Extracted intact premolars (n=84 were divided into sevengroups (n=12. In the control group 1, the adhesive i-Bond was used according to the manufacturer's instructions, with nocontamination. In groups 2 to 4, the conditioned and saliva, contaminated enamel was blot dried only, rinsed,and blot dried, rinsed blot dried and re-etched, respectively. In groups 5, 6and 7 cured adhesive was contaminated with saliva and then rinsed and blot-dried, blot dried only and rinsed, blot-dried and re-etched respectively. In groups 3, 4, 6 and 7 the adhesive was reapplied. Afterward, Z100 compos-ite cylinders were bonded to the enamel surfaces. The samples were thermocycled (5°C and 55°C, 30 s, dwelling time: 10 s, 500 cycles. Finally, the samples were sheared using Dartec testing machine and shear bond strength data were subjected to one-way ANOVA analysis and Tukey's HSD test.Results: There were statistically significant differences among groups 1 and 5-7. The samples in groups 1 and 4 demonstrated higher bond strengths than those in the other groups.Conclusion: Using phosphoric acid etching may be effective, only where contamination occurs prior to curing of the adhesive. After curing of the adhesive, none of the methods in this study would be preferred.

  10. Effect of pretreating technologies on the adhesive strength and anticorrosion property of Zn coated NdFeB specimens

    Science.gov (United States)

    Zhang, Pengjie; Xu, Guangqing; Liu, Jiaqin; Yi, Xiaofei; Wu, Yucheng; Chen, JingWu

    2016-02-01

    Zinc coated NdFeB specimens were prepared with different pretreating technologies, such as polishing, pickling (50 s), sandblasting and combined technology of sandblasting and pickling (5 s). Morphologies of the NdFeB substrates pretreated with different technologies were observed with a scanning electron microscope equipped with an energy dispersive spectrometer and an atomic force microscope. The tensile test was performed to measure the adhesive strength between Zn coating and NdFeB substrate. The self-corrosion behavior of the NdFeB specimen was characterized by potentiodynamic polarization curve. The anticorrosion properties of Zn coated NdFeB specimens were characterized by neutral salt spray tests. The pretreating technologies possess obvious impact on the adhesive strength and anticorrosion property of Zn coated NdFeB specimens. Combined pretreating technology of sandblasting and pickling (5 s) achieves the highest adhesive strength (25.56 MPa) and excellent anticorrosion property (average corrosion current density of 21 μA/cm2) in the four pretreating technologies. The impacting mechanisms of the pretreating technology on the adhesive strength and anticorrosion properties are deeply discussed.

  11. Effect of desensitizing agents on the microtensile bond strength of two-step etch-and-rinse adhesives to dentin.

    Science.gov (United States)

    Cortiano, Fernanda M; Rached, Rodrigo N; Mazur, Rui F; Vieira, Sergio; Freire, Andrea; de Souza, Evelise M

    2016-06-01

    Desensitizers can be used to control postoperative sensitivity in adhesive restorations. The aim of this study was to evaluate the effect of desensitizing agents on the bond strength of two-step etch-and-rinse adhesive systems to dentin. Forty-two human molars were sectioned to obtain 3-mm-thick dentin discs. The discs were divided into three groups (n = 14 in each) - no-treatment control group (CT), and oxalic acid [BisBlock (BB)] and calcium phosphate [Desensibilize Nano-P (NP)] desensitizers - before the application of two adhesive systems [Adper Single Bond Plus (SB) and One-Step Plus (OSP)]. A nanoparticle composite resin was used to create a 3-mm-thick build-up. The specimens were stored in distilled water for 24 h before a microtensile bond-strength test was performed. The failure modes were determined using a stereomicroscope at 100 × magnification. Specimens were sectioned perpendicular to the interface for scanning electron microscopy analyses. The CT-SB group exhibited the highest bond strength, differing significantly from BB-SB and BB-OSP groups. Mixed failures were prevalent for all groups. Scanning electron microscopy revealed a continuous hybrid layer and resin tags in all groups. Dentin bond strength of etch-and-rinse adhesive systems was reduced by an oxalic acid desensitizer but was not affected by a calcium phosphate-containing desensitizer. PMID:27038226

  12. Efficacy of microtensile versus microshear bond testing for evaluation of bond strength of dental adhesive systems to enamel

    NARCIS (Netherlands)

    A.A. El Zohairy; M.H. Saber; A.I. Abdalla; A.J. Feilzer

    2010-01-01

    Objective The aim of the study was to evaluate the efficacy of the microtensile bond test (μTBS) and the microshear bond test (μSBS) in ranking four dental adhesives according to bond strength to enamel and identify the modes of failure involved. Materials and methods Forty-four caries-free human mo

  13. Bond strength of an adhesive system irradiated with Nd:YAG laser in dentin treated with Er:YAG laser

    International Nuclear Information System (INIS)

    The purpose of this in vitro study was to verify through micro tensile bond test the bond strength of an adhesive system irradiated with Nd:YAG laser in dentine previously treated with Er:YAG laser. Twenty caries free extracted human third molars were used. The teeth were divided in four experimental groups (n = 5): (G1) control group; (G2) irradiation of the adhesive system with the Nd:YAG laser; (G3) dentin treatment with Er:YAG laser; (G4) dentin treatment with Er:YAG laser followed by the irradiation of the adhesive system with Nd:YAG laser. The Er:YAG laser fluency parameter for the dentin treatment was of 60 J/cm2. The adhesive system was irradiated with the Nd:YAG laser with fluency of 100 J/cm2. Dental restorations were performed with Adper Single Bond 2/Z250. One tooth from each group was prepared for the evaluation of the adhesive interface under SEM and bond failure tests were also performed and evaluated. The statistical analysis showed statistical significant difference between the groups G1 and G3, G1 and G4, G2 and G3, and G2 and G4; and similarity between the groups G1 and G2, and G3 and G4. The adhesive failures were predominant in all the experimental groups. The SEM analysis showed an adhesive interface with features confirming the results of the mechanical tests. The Nd:YAG laser on the adhesive system did not influence the bond strength in dentin treated or not with the Er:YAG laser

  14. Dentin Bond Strength of Two One-Bottle Adhesives after Delayed Activation of Light-Cured Resin Composites

    Directory of Open Access Journals (Sweden)

    F. Shafiei

    2007-12-01

    Full Text Available Objective: Adverse surface interactions between one-bottle adhesives and chemical-cured composites may occur with delayed light activation of light-cured composites. The purpose of this study was to assess the Effects of delayed activation of light-cured compositeson shear bond strength of two one-bottle adhesives with different acidity to bovine dentin.Materials and Methods: Flat dentin surface was prepared on sixty-six bovine incisors using 600 grit carbide papers. Prime&Bond NT, and One-Step adhesives and resin composite were applied in six groups: 1 immediate curing of the composite, 2 the composite was left 2.5 minutes over the cured adhesive before light activation, 3 prior to delayed activation of the composite, the cured adhesive was covered with a layer of nonacidic hydrophobic porcelain bonding resin (Choice 2 and cured immediately. After thermocycling,shear bond strength (SBS test was performed using a universal testing machine at 1 mm/min crosshead speed. Data were analyzed with Friedmans two-way Non-parametric ANOVA.Results: The SBS of delayed activation of Prime&Bond was significantly lower than immediate activated (P<0.05. Decrease in the SBS of One-Step was not statistically significant after delayed activation. The SBS of delayed activation of Prime&Bond and One-Step with an additional resin layer was significantly higher than delayed activation (P<0.001.Conclusion: The bond strength of Prime&Bond might be compromised by the higher acidity of this adhesive during the 2.5 minutes delayed activation of light-cured composite.Addition of a layer of hydrophobic resin compensated the effect of delayed activation andimproved the bond strength.

  15. Investigating the Effect of Different Light Sources on the Microtensile Bond Strength of Two Types of Adhesives to Dentin

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    M Momeni Sarvestani

    2013-08-01

    Full Text Available Introduction: Different light sources influence restoration bond strength. Therefore the purpose of this study was evaluation of the microtensile bond strength of two types of sixth generation adhesives in different light sources. Methods: some sound human molars were collected. 10 sample in each group was prepared that totally 60 samples were investigated. In each tooth some dentinal specimen was prepared in buccal surface using diamond bur after abrading the enamel. Composite resin (Z250 was inserted in form of a layer using a Clearfil SE bond and Adper prompt L-POP adhesives. Both adhesives were polymerized using different light curing units including QTH at 600mW/cm2, LED at 400mW/cm2, PAC at1200mW/cm2, G1-Adper /LED, G2-Adper /Plasma, G3-Adper /QTH, G4-SE/LED, G5-SE /Plasma, G6-SE /QTH. The restorations were sectioned with 1mm thickness per teeth. All specimens were then subjected to microtensile testing machines. Then, data were analyzed using SPSS software, ANOVA and T-test. Results: Clearfil SE /Plasma arc group had the highest bond strength. The bond strength of Adper prompt L-POP significantly varied in different light sources (p<0.05. Significant difference was observed between Adper and SE (p<0.05 while using LED. Conclusion: This study showed that various light sources have different influence on bond strength.

  16. RESEARCH OF ADHESIVE STRENGTH OF NEW CONCRETE LAYER WITH A SURFACE OF OLD CONCRETE

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    Bulgakov Boris Igorevich

    2016-04-01

    Full Text Available Concrete is a material very commonly used in modern construction, each year over 4 billion m3 of concrete is used around the world. In the recent years high-quality fine grain and other types of concrete allow giving the modern creation city buildings new architectural expressivity, meeting the requirements of the XXI century. The trend of using of these new types of concrete is also applied in the construction of tunnel systems and the subway. The fine-grained high performance concrete obtained by using a mixture of organo-mineral additives and fiber reinforcement, compares fovourably with ordinary fine-grained concrete, namely its bending and tensile strength is higher, it has good resistance to shock impacts and fatigue, as well as crack resistance, water resistance and resistance to erosion. So this type of fine-grained high performance concrete is suitable for the construction of subway tunnels and other special objects. When evaluating the concrete performance in underground rock layers subjected to complex mechanical forces, it is important to take into account the stress of metro upon departure and stopping at the stations. The article presents a new experimental method of determining the adhesion strength of fine-grained high performance concrete layer freshly poured on the surface of old concrete in the process of construction and repair of underground. The result of this method application showed that fine-grained high performance concrete is capable of skid resistance higher than 55 % compared to regular fine-grained concrete without additives.

  17. Bond strength comparison of color-change adhesives for orthodontic bonding using a self-etching primer

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    Frey GN

    2011-06-01

    Full Text Available Sara Ekhlassi, Jeryl D English, Joe C Ontiveros, John M Powers, Harry I Bussa, Gary N Frey, Clark D Colville, Randy K EllisHouston Department of Orthodontics, The University of Texas Dental Branch, Houston, TX, USABackground: The purpose of this study was to compare the shear bond strengths of two color-change adhesives with a commonly used conventional light-cure adhesive while using a self-etching primer, and to compare any changes in shear bond strengths over time.Methods: One hundred and eighty extracted bovine incisors were randomly divided into nine groups of 20 teeth each. The teeth were prepared with a self-etching primer (Transbond™ Plus Metal lower incisor brackets were bonded directly to each tooth with two different color-change adhesives (TransbondPlus and Grengloo™ and a control (Transbond XT. The teeth were debonded at three different time points (15 minutes, 24 hours, 1 week using an Instron at 1.0 mm/min. The teeth that were to be debonded at 24 hours and 1 week were stored in distilled water at 37°C to simulate the oral environment. The data were analyzed by two-way analysis of variance and with Fisher's protected least-significant difference multiple comparisons test at the P < 0.05 level of significance. Adhesive remnant index (ARI scores were calculated for each debonded tooth.Results: Transbond Plus at 1 week had the highest mean shear bond strength (14.7 mPa. Grengloo tested at 24 hours had the lowest mean shear bond strength (11.3 mPa. The mean shear bond strengths for the remaining seven groups had a range of 12–14.5 mPa. Grengloo had >80% samples presenting with an ARI score of 1 at all times. Interestingly, both Transbond groups had ARI scores of 3 in more than 50% of their samples.Conclusion: Time had no significant effect on the mean shear bond strength of Transbond XT, Grengloo, or Transbond Plus adhesive.Keywords: bond strength, color-change adhesives, self-etching primer, orthodontic bonding 

  18. The Influence of No-Primer Adhesives and Anchor Pylons Bracket Bases on Shear Bond Strength of Orthodontic Brackets

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    Andrea Scribante

    2013-01-01

    Full Text Available Objective. The aim of this study was to compare the shear bond strength (SBS and adhesive remnant index (ARI scores of no-primer adhesives tested with two different bracket bases. Materials and Methods. 120 bovine permanent mandibular incisors were divided into 6 groups of 20 specimens. Two brackets (ODP with different bracket bases (anchor pylons and 80-gauge mesh were bonded to the teeth using a conventional adhesive (Transbond XT and two different no-primer adhesive (Ortho Cem; Heliosit systems. Groups were tested using an instron universal testing machine. SBS values were recorded. ARI scores were measured. SEM microphotographs were taken to evaluate the pattern of bracket bases. Statistical analysis was performed. ANOVA and Tukey tests were carried out for SBS values, whereas a chi-squared test was applied for ARI scores. Results. Highest bond strength values were reported with Transbond XT (with both pad designs, Ortho Cem bonded on anchor pylons and Heliosit on 80-gauge mesh. A higher frequency of ARI score of “3” was reported for Transbond XT groups. Other groups showed a higher frequency of ARI score “2” and “1.” Conclusion. Transbond XT showed the highest shear bond strength values with both pad designs.

  19. Structure, Substructure, Hardness and Adhesion Strength of Multiperiod Composite Coatings MoN / CrN

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    S.S. Grankin

    2015-12-01

    Full Text Available A comprehensive study of the influence of the thickness of the layers, Us and PN on the structural engineering to obtain high mechanical properties in multilayer composite MoN / CrN vacuum-arc coatings has been conducted by means of scanning electron microscopy with energy analysis, X-ray diffraction studies microindentation and scratch testing methods. It has been determined that in the studied PN = (2-30 × 10 – 4 Torr, the content of nitrogen in the coatings varies from 6.3 to 33 at. %, which leads even at the greatest nitrogen content to the formation of lower phase by nitrogen, γ-Mo2N and isostructural CrN with the vacant sites in the nitrogen sublattice. The increase of thickness of the layers applied on the substrate in a stationary state promotes the increase of nitrogen content. Along with this, the lowest microdeformation and the average size of crystallites are formed at Ub = – 300 V, which defines the achievement of greater hardness of 35 GPa and high adhesion strength, which resists the destruction, Lc5 = 187.6 N.

  20. The Investigation of the Effect of Micro-Arc Oxidation Modes on the Adhesion Strength of Coatings

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    N.Yu. Dudareva

    2014-07-01

    Full Text Available The paper presents the results of studies of the properties of hardened surface layers formed by micro-arc oxidation on the workpiece surfaces of aluminum alloy Al-12Si-Mg-Cu-Ni. The authors attempted to determine the influence of micro-arc oxidation modes on the properties of the modified layers. Investigation of the adhesion strength of the surface layers formed at different concentrations of electrolyte components and analysis of the change in coatings adhesion characteristics after thermal cycling were presented.

  1. Adhesion strength of nickel and zinc coatings with copper base electroplated in conditions of external stimulation by laser irradiance

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    V. V. Dudkina

    2013-04-01

    Full Text Available Purpose. The investigation of laser irradiance influence on the adhesion strength of nickel and zinc coatings with copper base and the research of initial stages of crystallization for nickel and zinc films. Methodology. Electrodeposition of nickel and zinc films from the standard sulphate electrolyte solutions was carried out on the laser-electrolytic installations, built on the basis of gas discharge CO2-laser and solid ruby laser KVANT-12. The adhesion strength of metal coatings with copper base are defined not only qualitatively using the method of meshing and by means of multiple bending, but also quantitatively by means of indention of diamond pyramid into the border line between coating and base of the side section. Spectrum microanalysis of the element composition of the border line “film and base” is carried out using the electronic microscope REMMA-102-02. Findings. Laser irradiance application of the cathode region in the process of electroplating of metal coatings enables the adhesion strength improvement of coating with the base. Experimental results of adhesive strength of the films and the spectrum analysis of the element composition for the border line between film and base showed that during laser-assisted electroplating the diffusion interaction between coating elements and the base metal surface takes place. As a result of this interaction the coating metal diffuses into the base metal, forming transition diffused layer, which enhances the improvement of adhesion strength of the coatings with the base. Originality. It is found out that ion energy increase in the double electric layer during interaction with laser irradiance affects cathode supersaturation at the stage of crystallization. Hence, it also affects the penetration depth of electroplated material ions into the base metal, which leads to the adhesion strength enhancement. Practical value. On the basis of research results obtained during the laser

  2. Adhesive strength of hydroxyl apatite(HA coating and biomechanics behavior of HA-coated prosthesis:an experimental study

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    Tian-yang ZHANG

    2011-05-01

    Full Text Available Objective To explore the influence of adhesive strength of hydroxyapatite(HA coating on the post-implantation stability of HA-coated prosthesis.Methods The adhesive strength and biomechanics behavior of HA coating were studied by histopathological observation,material parameters and biomechanical testing,the titanium(Ti-coated prosthesis was employed as control.Results Scratch test showed that the adhesive strength of HA coating was significantly lower than that of Ti coating(P < 0.01.Histopathological examination and bone morphometry showed that,at the early stage of prosthesis implantation,the bony growth around HA-coated prosthesis was significantly higher than that around Ti-coated prosthesis(P < 0.01,but the ultimate shear strength of HA-coated prosthesis was much lower than that of Ti-coated prosthesis(P < 0.01.After the push-out test with prosthesis,histopathological observation showed that there were accumulations of clump-and strip-like granular residues on the surface of bones that newly grew around the HA-coated prosthesis,and surface energy-dispersive X-ray spectroscopy(EDX analysis also confirmed that the shear stress induced HA decohesion from the substrate of prosthesis.Conclusions Although HA coating showed a satisfactory effect on early bone formation and prosthetic stability,due to the deficiencies of adhesive strength,the early stability of prosthesis may be gradually destroyed by the shear loads of human body and coating degradation.

  3. Effect of Bioactive Glass air Abrasion on Shear Bond Strength of Two Adhesive Resins to Decalcified Enamel.

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    Alireza Eshghi

    2014-12-01

    Full Text Available Bioactive glass air abrasion is a conservative technique to remove initial decalcified tissue and caries. This study examined the shear bond strength of composite resin to sound and decalcified enamel air-abraded by bioactive glass (BAG or alumina using etch-and-rinse and self-etch adhesives.Forty-eight permanent molars were root-amputated and sectioned mesiodistally. The obtained 96 specimens were mounted in acrylic resin; the buccal and lingual surfaces remained exposed. A demineralizing solution was used to decalcify half the specimens. Both sound and decalcified specimens were divided into two groups of alumina and bioactive glass air abrasion. In each group, the specimens were subdivided into two subgroups of Clearfil SE Bond or OptiBond FL adhesives (n=12. Composite resin cylinders were bonded on enamel surfaces cured and underwent thermocycling. The specimens were tested for shear bond strength. Data were analyzed using SPSS 16.0 and three-way ANOVA (α=0.05. Similar to the experimental groups, the enamel surface of one specimen underwent SEM evaluation.No significant differences were observed in composite resin bond strength subsequent to alumina or bioactive glass air abrasion preparation techniques (P=0.987. There were no statistically significant differences between the bond strength of etch-and-rinse and self-etch adhesive groups (P=1. Also, decalcified or intact enamel groups had no significant difference (P=0.918. However, SEM analysis showed much less enamel irregularities with BAG air abrasion compared to alumina air abrasion.Under the limitations of this study, preparation of both intact and decalcified enamel surfaces with bioactive glass air abrasion results in similar bond strength of composite resin in comparison with alumina air abrasion using etch-&-rinse or self-etch adhesives.

  4. Influence of Temporary Cements on the Bond Strength of Self-Adhesive Cement to the Metal Coronal Substrate.

    Science.gov (United States)

    Peixoto, Raniel Fernandes; De Aguiar, Caio Rocha; Jacob, Eduardo Santana; Macedo, Ana Paula; De Mattos, Maria da Gloria Chiarello; Antunes, Rossana Pereira de Almeida

    2015-01-01

    This research evaluated the influence of temporary cements (eugenol-containing [EC] or eugenol-free [EF]) on the tensile strength of Ni-Cr copings fixed with self-adhesive resin cement to the metal coronal substrate. Thirty-six temporary crowns were divided into 4 groups (n=9) according to the temporary cements: Provy, Dentsply (eugenol-containing), Temp Cem, Vigodent (eugenol-containing), RelyX Temp NE, 3M ESPE (eugenol-free) and Temp Bond NE, Kerr Corp (eugenol-free). After 24 h of temporary cementation, tensile strength tests were performed in a universal testing machine at a crosshead speed of 0.5 mm/min and 1 kN (100 kgf) load cell. Afterwards, the cast metal cores were cleaned by scraping with curettes and air jet. Thirty-six Ni-Cr copings were cemented to the cast metal cores with self-adhesive resin cement (RelyX U200, 3M ESPE). Tensile strength tests were performed again. In the temporary cementation, Temp Bond NE (12.91 ± 2.54) and Temp Cem (12.22 ± 2.96) presented the highest values of tensile strength and were statistically similar to each other (p>0.05). Statistically significant difference (pcementation of Ni-Cr copings with self-adhesive resin cement. In addition, Temp Cem (120.68 ± 48.27) and RelyX Temp NE (103.04 ± 26.09) showed intermediate tensile strength values. In conclusion, the Provy eugenol-containing temporary cement was associated with the highest bond strength among the resin cements when Ni-Cr copings were cemented to cast metal cores. However, the eugenol cannot be considered a determining factor in increased bond strength, since the other tested cements (1 eugenol-containing and 2 eugenol-free) were similar. PMID:26963209

  5. Microtensile bond strength of current adhesive systems when compared to cohesive strength of sound dentin and a resin-based composite

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    Paulo Eduardo Capel Cardoso

    2004-12-01

    Full Text Available Purpose: To evaluate the microtensile bond strength (µTBS to dentin of 4 adhesive systems, the micromorphology of the adhesive/dentin interface and to compare the results to the µTS (cohesive strength of sound dentin and resin composite. Occlusal surfaces of 24 extracted caries-free human molars were cut flat to expose the dentin surface. They were randomly assigned to 4 groups (n = 6: Adper Scotchbond Multi Purpose Plus (MP, Adper Single Bond (SB, Clearfil Protect Bond (CP and Adper Prompt (AP. Adhesive systems were applied and "crowns" were built using Z100. Other 5 human molars were sectioned to obtain square-shaped dentin blocks and 5 resin blocks were built using a composite resin, Z100. After storage in distilled water at 37 °C for 24 h, stick-shaped specimens were obtained for all groups (n = 5 with 0.8 mm² and subjected to µTBS or µTS test. Results were analyzed using One-Way ANOVA and Tukey's test at p 0.05. The lowest result was found for AP (27.4 + 4.7 MPa, although not statistically different from MP. Most specimens (89.4% showed predominant adhesive failure. None of the systems tested reached the µTS values of dentin (108.5 + 9.4 MPa and Z100 (86.5 + 3.6 MPa. Bonded interfaces showed lower µTBS than those µTS of dentin and resin composite blocks. The all-in-one self-etching adhesive had the lowest µTBS.

  6. Tests of Experimental Tissue Adhesive Sealants: Analysis of Strength Effects in Relation to Tissue Adhesive Sealant Standards

    OpenAIRE

    Browdie, David A.; Cox, David ,

    2007-01-01

    The sealing efficiencies (SE% = surfaces sealed/surfaces tested) of 2 experimental tissue adhesive sealants (TASs), L.C. TAS and glutaraldehyde TAS (GA TAS), were determined by applications in 12 mixed-breed pigs (weight range, 40–60 kg) that had been anticoagulated with heparin and divided into groups of 6: Group I, L.C. TAS; and Group II, GA TAS. Leaking tissue surfaces used were 5-mm aortic punch holes and lacerated splenic, hepatic, and lung surfaces (2 of each, in each pig). First-applic...

  7. Comparison of the retention strengths of three complete denture adhesives: An in vivo study

    OpenAIRE

    Selva-Otaolaurruchi, Eduardo José; Barutell, A. de; Bouazza Juanes, Kheira; Mañes-Ferrer, José Félix

    2011-01-01

    One of the main problems posed by complete dentures is retention and stability. In order to solve this problem, dentists and the dental industry for a long time have attempted to improve denture adhesion by developing a range of "glues" of highly varied composition and efficacy. The present in vivo clinical study evaluates whether the adhesives used to improve complete denture retention are truly effective and able to increase denture adhesion to the mucosa covering the edentulous alveolar ri...

  8. Influence of caries infiltrant contamination on shear bond strength of different adhesives to dentin

    OpenAIRE

    Jia, Liuhe; Stawarczyk, Bogna; Schmidlin, Patrick R; Attin, Thomas; Wiegand, Annette

    2013-01-01

    OBJECTIVES: To analyze whether the contamination with a caries infiltrant system impairs the adhesive performance of etch-and-rinse and self-etching adhesives on dentin. MATERIALS AND METHODS: Dentin contamination with the caries infiltrant system (Icon, DMG) was simulated by applying either hydrochloric acid (15 % HCl, Icon Etch, 15 s), the resin infiltrant (Icon infiltrant, 4 min), or both prior to the application of the respective adhesives (each group n = 10). In the control groups, th...

  9. Lap shear strength and fatigue behavior of friction stir spot welded dissimilar magnesium-to-aluminum joints with adhesive

    Energy Technology Data Exchange (ETDEWEB)

    Chowdhury, S.H. [Department of Mechanical and Industrial Engineering, Ryerson University, 350 Victoria Street, Toronto, Ontario M5B 2K3 (Canada); Chen, D.L., E-mail: dchen@ryerson.ca [Department of Mechanical and Industrial Engineering, Ryerson University, 350 Victoria Street, Toronto, Ontario M5B 2K3 (Canada); Bhole, S.D. [Department of Mechanical and Industrial Engineering, Ryerson University, 350 Victoria Street, Toronto, Ontario M5B 2K3 (Canada); Cao, X.; Wanjara, P. [National Research Council Canada Aerospace, 5145 Decelles Avenue, Montreal, Quebec H3T 2B2 (Canada)

    2013-02-01

    Lightweighting is currently considered as an effective way in improving fuel efficiency and reducing anthropogenic greenhouse gas emissions. The structural applications of lightweight magnesium and aluminum alloys in the aerospace and automotive sectors unavoidably involve welding and joining while guaranteeing the safety and durability of motor vehicles. The objective of this study was to evaluate the lap shear strength and fatigue properties of friction stir spot welded (FSSWed) dissimilar AZ31B-H24 Mg alloy and Al alloy (AA) 5754-O in three combinations, i.e., (top) Al/Mg (bottom), Al/Mg with an adhesive interlayer, and Mg/Al with an adhesive interlayer. For all the dissimilar Mg-to-Al weld combinations, FSSW induced an interfacial layer in the stir zone (SZ) that was composed of intermetallic compounds of Al{sub 3}Mg{sub 2} and Al{sub 12}Mg{sub 17}, which led to an increase in hardness. Both Mg/Al and Al/Mg dissimilar adhesive welds had significantly higher lap shear strength, failure energy and fatigue life than the Al/Mg dissimilar weld without adhesive. Two different types of fatigue failure modes were observed. In the Al/Mg adhesive weld, at high cyclic loads nugget pull-out failure occurred due to fatigue crack propagation circumferentially around the nugget. At low cyclic loads, fatigue failure occurred in the bottom Mg sheet due to the stress concentration of the keyhole leading to crack initiation followed by propagation perpendicular to the loading direction. In the Mg/Al adhesive weld, nugget pull-out failure mode was primarily observed at both high and low cyclic loads.

  10. Effect of repeated use on dentin bond strength of two adhesive systems: All-in-one and one-bottle

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    Shafiei Fershteh

    2009-01-01

    Full Text Available Aims: To compare the effects of repeated use of two one-bottle adhesives with that of two all- in- one adhesives (with acetone solvent on bond strength to dentin. Materials and Methods: A flat dentin surface was prepared on 120 bovine incisors using 600- grit abrasive pape. The teeth were randomly assigned into 12 equal groups. The four adhesive systems [Prime and Bond NT (P&B NT, One-Step Plus (OS, iBond (iB, and G-Bond (GB] were used at baseline, after the lid of the container had been opened 30 times, and after it had been opened 60 times. Before each use of the adhesives, the lids of the containers were left open for 1 min. The resin composites were applied on the dentin in a cylindrical split mold. After thermocycling, shear bond strength test was performed with a universal testing machine at 1 mm/min. We used Kruskal-Wallis and Dunn tests for statistical analysis. Results: There was no statistically significant difference among bond strength (MPa of the groups of P&B NT (31.9 ± 4.6, 31.8 ± 6.5, 26.1 ± 6.7 and OS (33.2 ± 5.1, 30.9 ± 7, 29.3 ± 5.9, respectively (P > 0.05. The mean of the bond strength of iB and GB after 60 times (15.3 ± 4.1 and 12.2 ± 3.9, respectively was significantly lower than that of iB and GB at baseline (23.5 ± 4.8 and 22.2 ± 4.5, respectively (P < 0.05. Conclusions: Repeated use (60 times of the all-in-one adhesive led to a decline in the dentin bond strength. To avoid this problem it would be advisable to have containers with smaller amounts of adhesive or perhaps those with only a singe dose.

  11. A Fracture-Based Criterion for Debonding Strength of Adhesive-Bonded Double-Strap Steel Joints

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    Prawit Santisukpotha

    2012-01-01

    Full Text Available This paper addresses the debonding strength of adhesive-bonded double-strap steel joints. A fracture-based criterion was formulated in terms of a stress singularity parameter, i.e., the stress intensity factor, which governs the magnitude of a singular stress field near the joint ends. No existing crack was assumed. A total of 24 steel joint specimens were tested under constant amplitude fatigue loadings at stress ratio of 0.2 and frequency of 2 Hz. The joint stiffness ratio was slightly less than one to control the maximum adhesive stresses at the joint ends. To detect the debonding, a simple and practical technique was developed. The test results showed that the interfacial failure near the steel/adhesive corner was a dominant failure mode. The failure was brittle and the debonding life was governed by the crack initiation stage. The finite element analysis was employed to calculate the stress intensity factors and investigate the effects of the adhesive layer thickness, lap length and joint stiffness ratio on the debonding strength.

  12. Resin-dentin bond strength of 10 contemporary etch-and-rinse adhesive systems after one year of water storage.

    Science.gov (United States)

    Fontes, Silvia Terra; Cubas, Gloria Beatriz de Azevedo; Flores, Josiane Barcelos; Montemezzo, Murieli Leonor; Pinto, Marcia Bueno; Piva, Evandro

    2010-01-01

    To compare the resin-dentin bond degradation of 10 contemporary etch-and-rinse adhesive systems after one year of water storage, 100 bovine incisors were randomly separated into 10 groups and their superficial coronal dentin was exposed. According to manufacturers' instructions, dentin surfaces were bonded with one of seven two-step etch-and-rinse adhesives or one of three three-step etch-and-rinse adhesives. Composite buildups were constructed incrementally. Restored teeth were sectioned to obtain sticks (0.5 mm²). The specimens were subjected to a microtensile bond strength test after storage in distilled water (at 37°C) for one year. Data (MPa) were analyzed using Kruskal-Wallis and Tukey's tests at α = 0.05. Of the adhesives tested, One Step, All Bond 2, and Optibond FL attained the highest bond strength to dentin after one year in water storage, while Magic Bond DE and Master Bond presented a high number of premature debonded flaws. PMID:21062710

  13. Bond Strength of a Bisphenol-A-Free Fissure Sealant With and Without Adhesive Layer under Conditions of Saliva Contamination.

    Science.gov (United States)

    Mesquita-Guimarães, Késsia Suênia Fidelis de; Sabbatini, Iliana Ferraz; Almeida, Cintia Guimarães de; Galo, Rodrigo; Nelson-Filho, Paulo; Borsatto, Maria Cristina

    2016-01-01

    Dental sealants are important for prevention of carious lesions, if they have good shear strength. The aim of this study was to evaluate the shear bond strength (SBS) of two sealants to saliva-contaminated and non-contaminated enamel with and without an intermediate adhesive layer underneath the sealant. Ninety flat enamel surfaces from human third molars were randomly assigned to 6 groups (n=15): F (control): Fluroshield(tm) sealant; EWB (control): Embrace(tm) WetBond(tm); SB/F: Single Bond adhesive system + F; SB/EWB, s-SB/F and s-SB/EWB. In the s-SB/F and s-SB/EWB groups, the acid-etched enamel was contaminated with 0.01 mL of fresh human saliva for 20 s. Sealant cylinders were bonded to enamel surface with and without an intermediate adhesive system layer. The shear tests were performed using a universal testing machine (0.5 mm/min). Data were analyzed statistically by Kruskal-Wallis and Mann-Whitney tests (α=0.05). F presented higher mean SBS than EWB in all experimental conditions. The lowest SBS mean was obtained for EWB on contaminated enamel (padhesive system layer should be used prior to sealant placement, in both dry and saliva-contaminated enamel. F had the best performance in all experimental conditions. EWB sealant showed very low results, but an adhesive layer underneath the sealant increased its SBS even after salivary contamination. PMID:27224565

  14. Influence of nitrogen implantation into HSS substrate on internal stress and adhesion strength of c-BN films

    Institute of Scientific and Technical Information of China (English)

    ZHANG Ping; CAI Zhi-hai; TAN Jun; XIONG Wan-quan

    2004-01-01

    Cubic boron nitride(c-BN) films were deposited on HSS substrate implanted with nitrogen ion by RF-magnetron sputtering. The films were analyzed by bending beam method, scratch test, XRD and AFM. The results show that the implantation of N ion can reduce the internal stress and improve the adhesion strength of the films.The critical load comes to 16.92N, compared to 1.75N of c-BN film on the unimplanted HSS. AFM shows that the surface of the c-BN film on the implanted HSS is low in roughness and small in grain size. The phase structure of the nitrogen implanted layer was analyzed by XRD. The influence of nitrogen implanted layer on the internal stress and adhesion strength of c-BN films were also investigated.

  15. Optimization of the Adhesion Strength of Arc Ion Plating TiAlN Films by the Taguchi Method

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    Tong-Yul Cho

    2009-06-01

    Full Text Available A three-level six-factor (arc power, substrate temperature, pre-treatment bias voltage, working pressure, deposition bias voltage and pretreatment time orthogonal experimental array (L18 to optimize the adhesion strength of arc ion plating (AIP TiAlN films was designed using the Taguchi method. An optimized film process, namely substrate temperature 220 °C, arc power 60 A, negative bias voltage -800 V, nitrogen pressure 10-2 Torr, pretreated voltage -450 V and pretreated time 15 minutes was obtained by the Taguchi program for the purpose of obtaining a larger critical load. The critical load of the optimized TiAlN film (53 N was increased by 43% compared to the film with the highest critical load before optimization. The improvement in the adhesion strength of the films was attributed to the enhancement of hardness and the competitive growth of the (111, (200 and (220 orientations in the film.

  16. Adhesive strength of atherosclerotic plaque in a mouse model depends on local collagen content and elastin fragmentation.

    Science.gov (United States)

    Wang, Ying; Johnson, John A; Fulp, Abigail; Sutton, Michael A; Lessner, Susan M

    2013-02-22

    Atherosclerotic plaque rupture is a major cause of myocardial infarction and ischemic stroke. The adhesive strength of the bond between a plaque and the vascular wall, measured as local energy release rate, G, is used for quantitative plaque stability estimation. We tested the hypothesis that adhesive strength varies with plaque composition. Matrix metalloproteinase-12 (MMP12) deficiency was previously reported to alter lesion composition. To estimate G values, peeling experiments are performed on aortic plaques from apolipoprotein E knockout (apoE KO) and apoE MMP12 double knockout (DKO) male mice after 8 months on high-fat diet. For plaques in apoE KO and apoE MMP12 DKO mice, experimental values for G differ significantly (paveraging 19.2J/m(2) and 12.1J/m(2), respectively. Histology confirms that plaques delaminate along their interface with the underlying internal elastic lamina (IEL) in both genotypes. Quantitative image analysis of stained tissue sections demonstrates a significant positive correlation (p<0.05) between local collagen content of lesions and G values in both genotypes, indicating that adhesive strength of plaques depends on local collagen content. Surprisingly, macrophage content of aortic plaques is neither significantly correlated with G values nor significantly different between genotypes. The IEL underlying plaques in apoE KO mice is significantly more fragmented (number of breaks and length of breaks) than in apoE MMP12 DKO mice, suggesting that elastin fragmentation also influences adhesion strength of plaques. Overall, our results suggest that plaques adhere more strongly to the underlying IEL in apoE KO mice than in apoE MMP12 DKO mice. PMID:23261250

  17. Effect of Bioactive Glass air Abrasion on Shear Bond Strength of Two Adhesive Resins to Decalcified Enamel

    OpenAIRE

    Alireza Eshghi; Maryam Khoroushi; Alireza Rezvani

    2014-01-01

    Objective: Bioactive glass air abrasion is a conservative technique to remove initial decalcified tissue and caries. This study examined the shear bond strength of composite resin to sound and decalcified enamel air-abraded by bioactive glass (BAG) or alumina using etch-and-rinse and self-etch adhesives. Materials and Methods: Forty-eight permanent molars were root-amputated and sectioned mesiodistally. The obtained 96 specimens were mounted in acrylic resin; the buccal and lingual surfaces r...

  18. Influence of ionic strength and substratum hydrophobicity on the co-adhesion of oral microbial pairs

    NARCIS (Netherlands)

    vanderMei, HC; Busscher, HJ; Bos, R.R.M.

    1996-01-01

    Co-adhesion between oral microbial pairs (i.e. adhesion of a planktonic micro-organism, University of organism to a sessile organism adhering to a substratum surface) has been described as a highly specific interaction, mediated by stereochemical groups on the interacting microbial cell surfaces, an

  19. Adhesion strength and nucleation thermodynamics of four metals (Al, Cu, Ti, Zr) on AlN substrates

    Science.gov (United States)

    Tao, Yuan; Ke, Genshui; Xie, Yan; Chen, Yigang; Shi, Siqi; Guo, Haibo

    2015-12-01

    Devices based on AlN generally require adherent and strong interfaces between AlN and other materials, whereas most metals are known to be nonwetting to AlN and form relatively weak interfaces with AlN. In this study, we selected four representative metals (Al, Cu, Ti, and Zr) to study the adhesion strength of the AlN/metal interfaces. Mathematical models were constructed between the adhesion strength and enthalpy of formation of Al-metal solid solutions, the surface energies of the metals, and the lattice mismatch between the metals and AlN, based on thermodynamic parameters calculated using density functional theory. It appears that the adhesion strength is mainly determined by the lattice mismatch, and is in no linear correlation with either the Al-metal solution's formation enthalpies or the metals' surface energies. We also investigated the nucleation thermodynamics of the four metals on AlN substrates. It was found that Ti forms the strongest interface with AlN, and has the largest driving force for nucleation on AlN substrates among the four metals.

  20. Microstructure and adhesion strength of Sn-9Zn-xAg lead-free solders wetted on Cu substrate

    Energy Technology Data Exchange (ETDEWEB)

    Chang, T.-C. [Department of Materials Science and Engineering, National Cheng Kung University, 1 Ta-Huseh Road, Tainan 70101, Taiwan (China); Chou, S.-M. [Department of Materials Science and Engineering, National Cheng Kung University, 1 Ta-Huseh Road, Tainan 70101, Taiwan (China); Hon, M.-H. [Department of Materials Science and Engineering, National Cheng Kung University, 1 Ta-Huseh Road, Tainan 70101, Taiwan (China); Dayeh University, 112 Shan-Jiau Road, Da-Tsuen, Changhua 515, Taiwan (China); Wang, M.-C. [Department of Materials Science and Engineering, National United University, 1 Lien-Da Road, Kung-Ching Li, Miaoli 360, Taiwan (China) and Faculty of Fragrance and Cosmetics, Kaohsiung Medical University, 100 Shi-Chuan 1st Road, Kaohsiung 807, Taiwan (China)]. E-mail: chsi@nuu.edu.tw

    2006-08-15

    The microstructure and adhesion strength of the Sn-9Zn-xAg lead-free solders wetted on Cu substrates have been investigated by differential scanning calorimetry, optical microscopy, scanning electron microscopy, energy dispersive spectrometry and pull-off testing. The liquidus temperatures of the Sn-9Zn-xAg solder alloys are 222.1, 226.7, 231.4 and 232.9 deg. C for x = 2.5, 3.5, 5.0 and 7.5 wt%, respectively. A flat interface can be obtained as wetted at 350 deg. C at a rate of 11.8 mm/s. The adhesion strength of the Sn-9Zn-xAg/Cu interfaces decreases from 23.09 {+-} 0.31 to 12.32 {+-} 1.40 MPa with increasing Ag content from 2.5 to 7.5 wt% at 400 deg. C. After heat treatment at 150 deg. C, the adhesion strength of the Sn-9Zn-xAg/Cu interface decreases with increasing aging time.

  1. Microstructure and adhesion strength of Sn-9Zn-xAg lead-free solders wetted on Cu substrate

    International Nuclear Information System (INIS)

    The microstructure and adhesion strength of the Sn-9Zn-xAg lead-free solders wetted on Cu substrates have been investigated by differential scanning calorimetry, optical microscopy, scanning electron microscopy, energy dispersive spectrometry and pull-off testing. The liquidus temperatures of the Sn-9Zn-xAg solder alloys are 222.1, 226.7, 231.4 and 232.9 deg. C for x = 2.5, 3.5, 5.0 and 7.5 wt%, respectively. A flat interface can be obtained as wetted at 350 deg. C at a rate of 11.8 mm/s. The adhesion strength of the Sn-9Zn-xAg/Cu interfaces decreases from 23.09 ± 0.31 to 12.32 ± 1.40 MPa with increasing Ag content from 2.5 to 7.5 wt% at 400 deg. C. After heat treatment at 150 deg. C, the adhesion strength of the Sn-9Zn-xAg/Cu interface decreases with increasing aging time

  2. Quantification of the Existence Ratio of Non-Adhesion Grain Boundaries and Factors Governing the Strength of Coke Containing Low-Quality Coal

    Science.gov (United States)

    Kanai, Tetsuya; Yamazaki, Yoshiaki; Zhang, Xiaoqing; Uchida, Ataru; Saito, Yasuhiro; Shoji, Masakazu; Aoki, Hideyuki; Nomura, Seiji; Kubota, Yukihiro; Hayashizaki, Hideyuki; Miyashita, Shigeto

    “Non-adhesion grain boundaries” are formed when low-quality coal grains do not adhere to other grains in the carbonization process because of the low dilation of coke. To better understand the effects of non-adhesion grain boundaries on coke strength, the relationship between the existence ratio of non-adhesion grain boundaries and coke strength was investigated quantitatively. The existence ratio of non-adhesion grain boundaries were measured quantitatively by observing the fracture cross-section of coke using scanning electron microscopy (SEM). Coke strength was measured with a diametral-compression test and an I-shape drum index test. As a result, non-adhesion grain boundaries increased with an increase in the blending ratio of low-quality coal. In particular, non-adhesion grain boundaries increased rapidly when the blending ratio of low-quality coal was over 50%. When the ratio was less than 50%, low-quality coals adhered to other caking coal. However, not many low-quality coals adhered to other caking coals when the ratio was over 50%. The tensile strength of coke was not affected by the porosity of coke. However, the tensile strength and the drum index were affected by the existence ratio of non-adhesion grain boundaries. Tensile strength decreased rapidly even for a few non-adhesion grain boundaries because significant defects caused a fracture in the diametral-compression test. However, the I-shape drum index decreased linearly with the existence ratio of the non-adhesion grain boundaries because many fractures occurred during 600 rotations in the drum. The strength of coke containing low-quality coal is governed by the existence ratio of non-adhesion grain boundaries rather than mean values such as the porosity of coke.

  3. Effects of etching and adhesive applications on the bond strength between composite resin and glass-ionomer cements

    Directory of Open Access Journals (Sweden)

    Tijen Pamir

    2012-12-01

    Full Text Available OBJECTIVE: This study determined the effects of various surface treatment modalities on the bond strength of composite resins to glass-ionomer cements. MATERIAL AND METHODS: Conventional (KetacTM Molar Quick ApplicapTM or resin-modified (PhotacTM Fil Quick AplicapTM glass-ionomer cements were prepared. Two-step etch-rinse & bond adhesive (AdperTM Single Bond 2 or single-step self-etching adhesive (AdperTM PromptTM L-PopTM was applied to the set cements. In the etch-rinse & bond group, the sample surfaces were pre-treated as follows: (1 no etching, (2 15 s of etching with 35% phosphoric acid, (3 30 s of etching, and (4 60 s of etching. Following the placement of the composite resin (FiltekTM Z250, the bond strength was measured in a universal testing machine and the data obtained were analyzed with the two-way analysis of variance (ANOVA followed by the Tukey's HSD post hoc analysis (p=0.05. Then, the fractured surfaces were examined by scanning electron microscopy. RESULTS: The bond strength of the composite resin to the conventional glass-ionomer cement was significantly lower than that to the resin-modified glass-ionomer cement (p0.05. However, a greater bond strength was obtained with 30 s of phosphoric acid application. CONCLUSIONS: The resin-modified glass-ionomer cement improved the bond strength of the composite resin to the glass-ionomer cement. Both etch-rinse & bond and self-etching adhesives may be used effectively in the lamination of glass-ionomer cements. However, an etching time of at least 30 s appears to be optimal.

  4. An Ultrasonic Technique to Determine the Residual Strength of Adhesive Bonds

    Science.gov (United States)

    Achenbach, J. D.; Tang, Z.

    1999-01-01

    In this work, ultrasonic techniques to nondestructively evaluate adhesive bond degradation have been studied. The key to the present approach is the introduction of an external factor which pulls the adhesive bond in the nonlinear range, simultaneously with the application of an ultrasonic technique. With the aid of an external static tensile loading, a superimposed longitudinal wave has.been used to obtain the slopes of the stress-strain curve of an adhesive bond at a series of load levels. The critical load, at which a reduction of the slope is detected by the superimposed longitudinal wave, is an indication of the onset of nonlinear behavior of the adhesive bond, and therefore of bond degradation. This approach has been applied to the detection of adhesive bond degradation induced by cyclic fatigue loading. Analogously to the longitudinal wave case, a superimposed shear wave has been used to obtain the effective shear modulus of adhesive layers at different shear load levels. The onset of the nonlinear behavior of an adhesive bond under shear loading has been detected by the use of a superimposed shear wave. Experiments show that a longitudinal wave can also detect the nonlinear behavior when an adhesive bond is subjected to shear loading. An optimal combination of ultrasonic testing and mechanical loading methods for the detection of degradation related nonlinear behavior of adhesive bonds has been discussed. For the purpose of a practical application, an ultrasonic technique that uses a temperature increase as an alternative to static loading has also been investigated. A general strain-temperature correspondence principle that relates a mechanical strain to a temperature has been presented. Explicit strain-temperature correspondence relations for both the tension and shear cases have been derived. An important parameter which quantifies the relation between the wave velocity and temperature has been defined. This parameter, which is indicative of adhesive

  5. Effect of collagen fibrils removal on shear bond strength of total etch and self etch adhesive systems

    Directory of Open Access Journals (Sweden)

    Pishevar L.

    2009-12-01

    Full Text Available "nBackground and Aim: Sodium hypochlorite can remove the organic phase of the demineralized dentin and it produces direct resin bonding with hydroxyapatite crystals. Therefore, the hydrolytic degradation of collagen fibrils which might affect the bonding durability is removed. The aim of this study was to evaluate the effect of collagen fibrils removal by 10% NaOCl on dentin shear bond strength of two total etch and self etch adhesive systems."nMaterials and Methods: Sixty extracted human premolar teeth were used in this study. Buccal surface of teeth were grounded until dentin was exposed. Then teeth were divided into four groups. According to dentin surface treatment, experimental groups were as follows: Group I: Single Bond (3M according to manufacture instruction, Group II: 10% NaOCl+Single bond (3M, Group III: Clearfil SE Bond (Kuraray according to manufacture instruction, and Group IV: Clearfil SE Bond primer. After that, the specimens were immersed in 50% acetone solution for removing extra monomer. Then the specimens were rinsed and dried. 10% NaOCl was applied and finally adhesive was used. Then composite was bonded to the treated surfaces using a 4 2 mm cylindrical plastic mold. Specimens were thermocycled for 500 cycles (5-55ºC. A shear load was employed by a universal testing machine with a cross head speed of 1mm/min. The data were analyzed for statistical significance with One-way ANOVA, Two-way ANOVA and Tukey HSD post-hoc tests."nResults: The mean shear bond strengths of groups were as follows: Single Bond=16.8±4.2, Clearfil SE Bond=23.7±4.07, Single Bond+NaOCl=10.5±4.34, Clearfil SE Bond+NaOCl=23.3±3.65 MPa. Statistical analysis revealed that using 10% NaOCl significantly decreased the shear bond strength in Single Bond group (P=0.00, but caused no significant difference in the shear bond strength in Clearfil SE Bond group (P=0.99."nConclusion: Based on the results of this study, NaOCl treatment did not improve the bond

  6. On the effect of roughness and degree of cold working on adhesion strength of plasma coatings

    International Nuclear Information System (INIS)

    The effect of surface roughness and coldhardening on the adhesion properties of the chromium-nickel spinel thermal control plasma spray-coating on the base D16AT alloy and steel Kh18N10T substrates is considered. The formula which shows the relationship between the height of the substrate surface miero irregularities, parameters of shot blasting, and hardness of the material. The optimum parameters which insure maximum adhesion between the plating and the substrate are determined

  7. Nondestructive strength evaluation of adhesive-bonded single-lap joints by signal processing method

    International Nuclear Information System (INIS)

    Application of bonding by adhesives can be found in many industries, particularly in advanced technological domains such as the aeronautical and space industries, automobile manufacture, and electronics. Periodic inspection with conventional ultrasonic NDE techniques is capable of indicating the presence and possible location of crack. Continuous ultrasonic attenuation monitoring has potential to supply information. This study used adhesive-bonded single-lap joints specimen to evaluate such possibility by ultrasonic signal processing method

  8. Influence of fluoride-containing adhesives and bleaching agents on enamel bond strength

    OpenAIRE

    Vanessa Cavalli; Priscila Cristiane Suzy Liporoni; Marcos Augusto do Rego; Sandrine Bittencourt Berger; Marcelo Giannini

    2012-01-01

    This study evaluated the influence of fluoride-containing carbamide peroxide (CP) bleaching agents and adhesive systems on bonded enamel interfaces that are part of the dynamic pH cycling and thermal cycling models. The buccal surfaces of 60 bovine incisors were restored with a composite resin and bonded with three- and two-step, etch-and-rinse, fluoride-containing adhesives, Optibond FL (FL) and Optibond Solo Plus (SP), respectively. Restored teeth were subjected to thermal cycling to age th...

  9. Effect of dentin dehydration and composite resin polymerization mode on bond strength of two self-etch adhesives

    Directory of Open Access Journals (Sweden)

    Pooran Samimi

    2016-01-01

    Full Text Available Background: Dual-cured composite resins are similar to self-cured composite resins in some of their clinical applications due to inadequate irradiation, lack of irradiation, or delayed irradiation. Therefore, incompatibility with self-etch adhesives (SEAs should be taken into account with their use. On the other, the extent of dentin dehydration has a great role in the quality of adhesion of these resin materials to dentin. The aim of this study was to investigate the effect of dentin dehydration and composite resin polymerization mode on bond strength of two SEAs. Materials and Methods: A total of 120 dentinal specimens were prepared from extracted intact third molars. Half of the samples were dehydrated in ethanol with increasing concentrations. Then Clearfil SE Bond (CSEB and Prompt L-Pop (PLP adhesives were applied in the two groups. Cylindrical composite resin specimens were cured using three polymerization modes: (1 Immediate light-curing, (2 delayed light-curing after 20 min, and (3 self-curing. Bond strength was measured using universal testing machine at a crosshead speed of 1 mm/min. Data were analyzed with two-way ANOVA and Duncan post hoc tests. Statistical significance was defined at P 0.05. PLP showed significant differences between subgroups with the lowest bond strength in hydrated dentin with delayed light-curing and self-cured mode of polymerization. Conclusion: Within the limitations of this study, a delay in composite resin light-curing or using chemically cured composite resin had a deleterious effect on dentin bond strength of single-step SEAs used in the study.

  10. A scaffold-enhanced light-activated surgical adhesive technique: surface selection for enhanced tensile strength in wound repair

    Science.gov (United States)

    Soller, Eric C.; Hoffman, Grant T.; Heintzelman, Douglas L.; Duffy, Mark T.; Bloom, Jeffrey N.; McNally-Heintzelman, Karen M.

    2004-07-01

    An ex vivo study was conducted to determine the effect of the irregularity of the scaffold surface on the tensile strength of repairs formed using our Scaffold-Enhanced Biological Adhesive (SEBA). Two different scaffold materials were investigated: (i) a synthetic biodegradable material fabricated from poly(L-lactic-co-glycolic acid); and (ii) a biological material, small intestinal submucosa, manufactured by Cook BioTech. The scaffolds were doped with protein solder composed of 50%(w/v) bovine serum albumin solder and 0.5mg/ml indocyanine green dye mixed in deionized water, and activated with an 808-nm diode laser. The tensile strength of repairs performed on bovine thoracic aorta, liver, spleen, small intestine and lung, using the smooth and irregular surfaces of the above scaffold-enhanced materials were measured and the time-to-failure was recorded. The tensile strength of repairs formed using the irregular surfaces of the scaffolds were consistently higher than those formed using the smooth surfaces of the scaffolds. The largest difference was observed on repairs formed on the aorta and small intestine, where the repairs were, on average, 50% stronger using the irregular versus the smooth scaffold surfaces. In addition, the time-to-failure of repairs formed using the irregular surfaces of the scaffolds were between 50% and 100% longer than that achieved using the smooth surfaces of the scaffolds. It has previously been shown that distributing or dispersing the adhesive forces over the increased surface area of the scaffold, either smooth or irregular, produces stronger repairs than albumin solder alone. The increase in the absolute strength and longevity of repairs seen in this new study when the irregular surfaces of the scaffolds are used is thought to be due to the distribution of forces between the many independent micro-adhesions provided by the irregular surfaces.

  11. The Effects of Surface Roughness on Adhesion Strength of Coated Ash (Fraxinus excelsior L. and Birch (Betula L. Wood

    Directory of Open Access Journals (Sweden)

    Justina VITOSYTĖ

    2012-12-01

    Full Text Available For the evaluation of surface roughness impact on adhesion properties, the samples of dried ash (Fraxinus excelsior L. and birch (Betula L. wood were used. Before wood finishing, the surfaces of the samples were sanded. In order to get different surface roughness the abrasive material of P80, P120, P150, P180, P220 and P240 grit was used. The parameters of surface roughness Ra, Rz and Rmax were measured in three directions: along the wood grain, across the grain and in the angle of 45º. Comparison of the results showed the non-linear dependency of roughness parameters. Afterwards the wood surface was coated with three different acrylic-polyurethane coating systems (1 layer of varnish without primer, 1 layer of primer and 1 layer of varnish, and 1 layer of primer and 2 layers of varnish. The adhesion strength was assessed using the pull-off method. Also the nature of the fracture was evaluated. It was determined that the peculiarities of surface roughness, coating system type and wood species signally results the values of the adhesion strength.DOI: http://dx.doi.org/10.5755/j01.ms.18.4.3094

  12. Effects of residual water on microtensile bond strength of one-bottle dentin adhesive systems with different solvent bases

    Institute of Scientific and Technical Information of China (English)

    ZHANG Zhi-xing; HUANG Cui; ZHENG Tie-li; WANG Sa; CHENG Xiang-rong

    2005-01-01

    Background The wet-bonding technique is recommended for the one-bottle dentin adhesive systems, but the moisture concept varies widely among the instructions of manufacturers as well as among investigators. The aim of this study was to evaluate the effects of different dentin surface moisture on the microtensile bond strength(s) of an ethanol/water-based adhesive system and an acetone-based system to dentin. Methods Forty intact human premolars extracted for orthodontic reasons were used. Superficial occlusal flat dentin surfaces of these premolars were exposed, finished with wet 600-grit silicon carbide paper. Under four wet and dry conditions (overwet, blot dry, one-second dry and desiccated), resin composite was bonded to dentin by using Single Bond (SB) or Prime & Bond NT (PB) according to the manufacturers' instructions. The teeth were longitudinally sectioned in the "x" and "y" directions to obtain bonded beams with a cross-sectional area of 0.81 mm2 with a slow-speed diamond saw. The bonded specimens were tested in tension at a crosshead speed of 1 mm/min until failure of the bonds. Failure modes were observed with a scanning electron microscope. The mean bond strengths were analyzed by one-way ANOVA and Turkey's test. Results The bond strength of the overwet/SB, blot dry/SB, one-second dry/SB and desiccated/SB groups was 10.87 Mpa, 22.47 Mpa, 24.91 Mpa and 12.99 Mpa, respectively. The bond strength of the overwet/PB, blot dry/PB, one-second dry/PB and desiccated/PB groups was 10.02 Mpa, 20.67 Mpa, 21.82 Mpa and 10.09 Mpa, respectively. For both SB and PB, the blot dry group and one-second dry group revealed significantly higher bond strengths than the overwet and desiccated groups (P<0.05). Conclusions In order to achieve the highest bond strength to dentin, keeping the dentin surface in an appropriately moist condition is critical for the one-bottle dentin adhesive systems with ethanol/water or acetone solvent.

  13. Analysis of Self-Adhesive Resin Cement Microshear Bond Strength on Leucite-Reinforced Glass-Ceramic with/without Pure Silane Primer or Universal Adhesive Surface Treatment

    Directory of Open Access Journals (Sweden)

    Yoon Lee

    2015-01-01

    Full Text Available Objective. To evaluate the microshear bond strength (μSBS of self-adhesive resin (SA cement on leucite-reinforced glass-ceramic using silane or universal adhesive. Materials and Methods. Ceramic blocks were etched with 9.5% hydrofluoric acid and divided into three groups (n=16: (1 negative control (NC without treatment; (2 Single Bond Universal (SBU; (3 RelyX Ceramic Primer as positive control (PC. RelyX Unicem resin cement was light-cured, and μSBS was evaluated with/without thermocycling. The μSBS was analyzed using one-way analysis of variance. The fractured surfaces were examined using stereomicroscopy and scanning electron microscopy (SEM. Results. Without thermocycling, μSBS was highest for PC (30.50 MPa ± 3.40, followed by SBU (27.33 MPa ± 2.81 and NC (20.18 MPa ± 2.01 (P0.05. PC and NC predominantly fractured by cohesive failure within the ceramic and mixed failure, respectively. Conclusion. SBU treatment improves μSBS between SA cement and glass ceramics, but to a lower value than PC, and the improvement is eradicated by thermocycling. NC exhibited the lowest μSBS, which remained unchanged after thermocycling.

  14. Analysis of Self-Adhesive Resin Cement Microshear Bond Strength on Leucite-Reinforced Glass-Ceramic with/without Pure Silane Primer or Universal Adhesive Surface Treatment

    Science.gov (United States)

    Lee, Yoon; Kim, Jae-Hoon; Woo, Jung-Soo; Yi, Young-Ah; Hwang, Ji-Yun; Seo, Deog-Gyu

    2015-01-01

    Objective. To evaluate the microshear bond strength (μSBS) of self-adhesive resin (SA) cement on leucite-reinforced glass-ceramic using silane or universal adhesive. Materials and Methods. Ceramic blocks were etched with 9.5% hydrofluoric acid and divided into three groups (n = 16): (1) negative control (NC) without treatment; (2) Single Bond Universal (SBU); (3) RelyX Ceramic Primer as positive control (PC). RelyX Unicem resin cement was light-cured, and μSBS was evaluated with/without thermocycling. The μSBS was analyzed using one-way analysis of variance. The fractured surfaces were examined using stereomicroscopy and scanning electron microscopy (SEM). Results. Without thermocycling, μSBS was highest for PC (30.50 MPa ± 3.40), followed by SBU (27.33 MPa ± 2.81) and NC (20.18 MPa ± 2.01) (P 0.05). PC and NC predominantly fractured by cohesive failure within the ceramic and mixed failure, respectively. Conclusion. SBU treatment improves μSBS between SA cement and glass ceramics, but to a lower value than PC, and the improvement is eradicated by thermocycling. NC exhibited the lowest μSBS, which remained unchanged after thermocycling. PMID:26557660

  15. Shear bond strength and SEM morphology evaluation of different dental adhesives to enamel prepared with ER:YAG laser

    Directory of Open Access Journals (Sweden)

    Patrícia T Pires

    2013-01-01

    Full Text Available Context: Early observations of enamel surfaces prepared by erbium lasers motivated clinicians to use laser as an alternative to chemical etching. Aims: Evaluate shear bond strength (SBS values of different dental adhesives on Erbium:Yttrium Aluminum Garnet (Er:YAG laser prepared enamel and to evaluate possible etching patterns correlations between dental adhesives and SBS values. Subjects and Methods: One hundred bovine incisors were randomly assigned to SBS tests on enamel (n = 15 and to enamel morphology analysis ( n = 5 after Er:YAG laser preparation as follows: Group I - 37% phosphoric acid (PA+ ExciTE® ; Group II - ExciTE® ; Group III - AdheSE® self-etching; Group IV - FuturaBond® no-rinse. NR; Group V - Xeno® V. Teeth were treated with the adhesive systems and subjected to thermal cycling. SBS were performed in a universal testing machine at 5 mm/min. Statistical Analysis Used: One-way ANOVA and post-hoc tests (p < 0.05. For the morphology evaluation, specimens were immersed in Ethylenediamine tetraacetic acid (EDTA and the etching pattern analyzed under Scanning Electron Microscope (SEM. Results: Mean bond strengths were Group I - 47.17 ± 1.61 MPa (type I etching pattern; Group II - 32.56 ± 1.64 MPa, Group III - 29.10 ± 1.34 MPa, Group IV - 23.32 ± 1.53 MPa (type III etching pattern; Group V - 24.43 MPa ± 1.55 (type II etching pattern. Conclusions: Different adhesive systems yielded significantly different SBSs. Acid etching significantly increased the adhesion in laser treated enamel. No differences in SBS values were obtained between AdheSE® and ExciTE® without condition with PA. FuturaBond® NR and Xeno® V showed similar SBS, which was lower in comparison to the others adhesives. No correlation between enamel surface morphology and SBS values was observed, except when PA was used.

  16. Comparative study of the bond strength of self-etch adhesive systems with different pHs applied to enamel and dentine

    Directory of Open Access Journals (Sweden)

    Rubens Côrte Real de Carvalho

    2008-01-01

    Full Text Available Objective: To evaluate whether the pH of the primer is capable of influencing the bond strength of three self-etching adhesive systems to enamel and dentin. Methods: Forty enamel surfaces and 40 dentin surfaces were used, divided into eight groups (n=10 according to the adhesive system (Single Bond, ClearfilSE, AdheSE, Adper Prompt L-Pop. A 3 mm matrix was used to delimit the area restored with composite resin Z250. The test specimens were stored in distilled water at 37ºC for 24 hours and submitted to mechanical shear testing.Results: The ANOVA and Tukey statistical tests showed that there was no statistical difference among the groups in which the adhesivesystems Single Bond (control and Clearfil SE Bond were used and among the groups in which the AdheSE and Adper Prompt L-Pop systemswere used, both with statistical difference when compared with the Single Bond and Clearfil SE Bond groups. There was no statisticallysignificant difference between the bond strength values obtained, when the same adhesive systems were compared with regard to thesubstrates (enamel and dentin. The increased acidity of the self-etch adhesive systems was not capable of increasing the bond strengthvalues. Conclusion: The increasing of self-etch acidity of adhesive systems was not capable to increase the band strenght values. In the comparison between the same adhesive system in enamel or dentin, all adhesive presented similar performance, irrespective of the substrate used.

  17. Streptococcus mutans and Streptococcus intermedius adhesion to fibronectin films are oppositely influenced by ionic strength

    NARCIS (Netherlands)

    Busscher, H.J.; Belt-Gritter, van de B.; Dijkstra, R.J.B.; Norde, W.; Mei, van der H.C.

    2008-01-01

    Bacterial adhesion to protein-coated surfaces is mediated by an interplay of specific and nonspecific interactions. Although nonspecific interactions are ubiquitously present, little is known about the physicochemical mechanisms of specific interactions. The aim of this paper is to determine the inf

  18. Impact of cold temperatures on the shear strength of Norway spruce joints glued with different adhesives

    DEFF Research Database (Denmark)

    Wang, Xiaodong; Hagman, Olle; Sundqvist, Bror;

    2015-01-01

    × 20 mm × 10 mm) were bonded with seven commercially available adhesives: polyurethane (PUR), polyvinyl acetate (PVAc), emulsion-polymer-isocyanate (EPI), melamine-formaldehyde (MF), phenol-resorcinol-formaldehyde (PRF), melamine-urea-formaldehyde1 (MUF1), and melamine-urea-formaldehyde2 (MUF2). Each...

  19. Effect of Numbers of Load Cycling on the Micro Tensile Bond Strength of Total Etch Adhesives to Dentin

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    AR Daneshkazemi

    2013-06-01

    Full Text Available Introduction: Today load cycling is used for similarity of invitro and invivo studies, though different results were reported in different studies. Therefore, this study aimed to investigate the effect of load cycling on micro tensile bond strength of two total etch adhesives to dentin. Methods: Enamel of 48 molar teeth were removed to expose the superficial dentin. The teeth were randomly divided into two equal groups, and were restored with Single bond (SB, ExciTE and Synergy composite. Then the teeth of each group were divided to 4 equal sub groups. Moreover, load cycling of 0, 50, 100, 200 k load cycle with 50 newton load was used. In each sub group, 12 hour glass slabs with 1mm2 thickness were made. Then the samples were loaded by Dartec testing machine (Model HC/10 with 1 mm/min cross head speed to make the fracture occur. Data were analyzed by ANOVA, t-test, Bonferroni tests. Results: The most micro tensile bond strength belonged to ExciTE without load cycling and lowest refered to SB with 200 k. There was a significant difference between the groups (p ExciTE= 0.0001, p SB = 0.001. Micro tensile bond strength in SB group was significantly lower than ExciTE (p= 0.001. Moreover, load cycling had negative effect on micro tensile bond strength. Conclusion: By increasing load cycling, micro tensile bond strength of both bondings decreased significantly

  20. Effect of Re-Application of Microbrush on Micro Tensile Bond Strength of an Adhesive to Dentin

    Directory of Open Access Journals (Sweden)

    Seied Majid Mosavi Nasab

    2013-02-01

    Full Text Available Background and Aims: Re-application of microbrush may affect the micro tensile bond strength of adhesives to dentin. The aim of this study was to evaluate the effect of re-application of microbrushes on the micro tensile bond strength of an adhesive to dentin.Materials and Methods: Thirty freshly extracted molars teeth were collected and enamel of occlusal surface were removed to expose superficial dentin. Then superficial dentin was etched, washed and partially air dried.According to the times of application of microbrush, teeth were divided into two test groups. In group 1, newmicrobrushs were used, but in group 2, the ones that were already used for twice were included. Ambar dentin bonding agent (FGM/Brazil was applied to the etched dentin with microbrushes according to the manufacturer’s instructions. Then the crown of teeth was built up with LLiss (FGM/Brazil composite resin. The teeth were sectioned in buccolingual direction to obtain 1mm slabs. Then 50 hourglass- shape samples were made from 30 teeth (25 Specimens per group. The microtensile bond strength of the specimens was tested using MTD500 (SD Mechatronik, Germany. The data were statistically analyzed by T-test.Results: The mean values for the microtensile bond strength were 30.49±7.18 and 23.61±9.06 MPa±SD for the first and second groups, respectively. There was significant difference between the groups (P=0.005.Conclusion: Microbrushes should not be used for more than one cavity preparation.

  1. Biomechanics of shear-sensitive adhesion in climbing animals: peeling, pre-tension and sliding-induced changes in interface strength.

    Science.gov (United States)

    Labonte, David; Federle, Walter

    2016-09-01

    Many arthropods and small vertebrates use adhesive pads for climbing. These biological adhesives have to meet conflicting demands: attachment must be strong and reliable, yet detachment should be fast and effortless. Climbing animals can rapidly and reversibly control their pads' adhesive strength by shear forces, but the mechanisms underlying this coupling have remained unclear. Here, we show that adhesive forces of stick insect pads closely followed the predictions from tape peeling models when shear forces were small, but strongly exceeded them when shear forces were large, resulting in an approximately linear increase of adhesion with friction. Adhesion sharply increased at peel angles less than ca 30°, allowing a rapid switch between attachment and detachment. The departure from classic peeling theory coincided with the appearance of pad sliding, which dramatically increased the peel force via a combination of two mechanisms. First, partial sliding pre-stretched the pads, so that they were effectively stiffer upon detachment and peeled increasingly like inextensible tape. Second, pad sliding reduces the thickness of the fluid layer in the contact zone, thereby increasing the stress levels required for peeling. In combination, these effects can explain the coupling between adhesion and friction that is fundamental to adhesion control across all climbing animals. Our results highlight that control of adhesion is not solely achieved by direction-dependence and morphological anisotropy, suggesting promising new routes for the development of controllable bio-inspired adhesives. PMID:27605165

  2. Adhesive strength and structure of micro-arc oxidation ceramic coatings grown in-situ on LY12 aluminum alloy

    Institute of Scientific and Technical Information of China (English)

    WU Zhen-dong; JIANG Zhao-hua; YAO Zhong-ping

    2006-01-01

    The ceramic coatings containing zirconium dioxide were grown in-situ on LY12 aluminium alloy by micro-arc oxidation in mixed zirconate and phosphate solution. The phase composition and morphology of the coatings were studied by XRD and SEM.The adhesive strength of ceramic coatings was assessed by thermal shock test and tensile test. The results show that the coating is composed of m-ZrO2, t-ZrO2, and a little γ-Al2O3. Along the section of the coating, t-ZrO2 is more onboth sides than that in the middle, while m-ZrO2 is more in the middle than that on both sides. Meantime the coating is also composed of a dense layer and a loose layer. The coating has excellent thermal shock resistance under 550 ℃ and 600 ℃. And tensile tests show the adhesive strength of the dense layer of the coating with the substrate is more than 17.5 MPa.

  3. Acid Neutralizing Ability and Shear Bond Strength Using Orthodontic Adhesives Containing Three Different Types of Bioactive Glass

    Directory of Open Access Journals (Sweden)

    Song-Yi Yang

    2016-02-01

    Full Text Available The objective of the study was to compare the acid neutralizing ability and shear bond strength (SBS of three different types of orthodontic adhesives containing bioactive glasses (BAGs. 45S5, 45S5F and S53P4 BAGs were prepared using the melting technique and ground to fine particles. Orthodontic adhesives containing three types of BAGs were prepared as follows: 52.5% 45S5 BAG + 17.5% glass (45S5_A; 61.25% 45S5 BAG + 8.75% glass (45S5_B; 52.5% 45S5F BAG + 17.5% glass (45S5F_A; 61.25% 45S5F BAG + 8.75% glass (45S5F_B; 52.5% S53P4 BAG + 17.5% glass (S53P4_A; 61.25% S53P4 BAG + 8.75% glass (S53P4_B; and 70.0% glass (BAG_0. To evaluate the acid neutralizing properties, specimens were immersed in lactic acid solution, and pH changes were measured. SBS was measured with a universal testing machine. For all of the BAG-containing adhesives, the one with 61.25% of BAG showed a significantly greater increase of pH than the one with 52.5% of BAG (p < 0.05. Groups with 61.25% of BAG showed lower SBS than samples with 52.5% of BAG. 45S5F_A showed no significant difference of SBS compared to BAG_0 (p > 0.05. The adhesive containing 61.25% of 45S5F BAG exhibited clinically acceptable SBS and acid neutralizing properties. Therefore, this composition is a suitable candidate to prevent white spot lesions during orthodontic treatment.

  4. In vitro evaluation of casein phosphopeptide-amorphous calcium phosphate effect on the shear bond strength of dental adhesives to enamel

    Directory of Open Access Journals (Sweden)

    Niloofar Shadman

    2015-01-01

    Full Text Available Background: Casein phosphopeptide-amorphous calcium phosphate (CPP-ACP is applied for remineralization of early caries lesions or tooth sensitivity conditions and may affect subsequent resin bonding. This in vitro study investigated the effect of CPP-ACP on the shear bond strength of dental adhesives to enamel. Materials and Methods: Sixty extracted human molar teeth were selected and randomly divided into three groups and six subgroups. Buccal or lingual surfaces of teeth were prepared to create a flat enamel surface. Adhesives used were Tetric N-Bond, AdheSE and AdheSE One F. In three subgroups, before applying adhesives, enamel surfaces were treated with Tooth Mousse CPP-ACP for one hour, rinsed and stored in 37°C temperature with 100% humidity. This procedure was repeated for 5 days and then adhesives were applied and Tetric N-Ceram composite was adhered to the enamel. This procedure was also fulfilled for the other three subgroups without CPP-ACP treatment. After 24 hour water storage, samples were tested for shear bond strength test in a universal testing machine. Failure modes were determined by stereomicroscope. Data were analyzed by t-test and one-way analysis of variance with P 0.05. In non-applied CPP-ACP subgroups, there were statistically significant differences among all subgroups. Tetric N-Bond had the highest and AdheSE One F had the lowest shear bond strength. Conclusion: CPP-ACP application reduces the shear bond strength of AdheSE and AdheSE One F to enamel but not Tetric N-Bond.

  5. Evaluation of the effect of surface moisture on dentinal tensile bond strength to dentine adhesive: An in vitro study

    Directory of Open Access Journals (Sweden)

    Jayaprakash Thumu

    2010-01-01

    Full Text Available Aim : To evaluate the effect of surface moisture on dentinal tensile bond strength. Materials and Methods : Forty freshly extracted caries free, unrestored human mandibular molars were selected. The occlusal surfaces of each tooth were ground to prepare flat dentin surfaces at a depth of 1.5 mm. Following acid etching with 37% phosphoric acid for 15 sec, they were randomly grouped, with ten specimens in each: Group I - Over wet, Group II - Blot dry, Group III- One second dry, Group IV- Over dry. Each group was treated with a single bond adhesive system (3M ESPE as per manufacturer′s instructions. Blocks or cylinders of composite resin were built up using Teflon mould and cured. Tensile bond strengths were tested using Instron universal testing machine. The results were statistically analyzed. Results : The mean tensile bond strength values of group II, Blot dry was highest and statistically significant (P<0.001. Conclusion : After acid etching and rinsing blot drying provided consistently better bond strength.

  6. In vitro evaluation of influence of salivary contamination on the dentin bond strength of one-bottle adhesive systems

    Directory of Open Access Journals (Sweden)

    Nujella B.P Suryakumari

    2011-01-01

    Full Text Available Aim: To evaluate the effect of salivary contamination on the bond strength of one-bottle adhesive systems - (the V generation at various stages during the bonding procedure and to investigate the effect of the contaminant removing treatments on the recovery of bond strengths. Materials and Methods: In this study the V generation one-bottle system - (Adper Single Bond was tested. Fifty caries-free human molars with flat dentin surfaces were randomly divided into five groups of ten teeth each: Group I had 15 second etching with 35% Ortho Phosphoric acid, 15 second rinse and blot dried (Uncontaminated; Group II contaminated and blot dried; Group III contaminated and completely dried; Group IV contaminated, washed, blot dried; Group V contaminated, retched washed, and blot dried. The bonding agent was applied and resin composite (Z-100 3M ESPE was bonded to the treated surfaces using the Teflon mold. The specimens in each group were then subjected to shear bond strength testing in an Instron Universal testing machine at a crosshead speed of 1 mm / minute and the data were subjected to one way ANOVA for comparison among the groups (P<0.05. Results: There was a significant difference between the group that was dried with strong oil-free air after contamination (Group III and the other groups. When the etched surface was contaminated by saliva, there was no statistical difference between the just blot dry, wash, or the re-etching groups (Groups II, IV, V if the dentin surface was kept wet before priming. When the etched dentin surface was dried (Group III the shear bond strength decreased considerably. Conclusion: The bond strengths to the tooth structure of the recent dentin bonding agents are less sensitive to common forms of contamination than assumed. Re-etching without additional mechanical preparation is sufficient to provide or achieve the expected bond strength.

  7. Effects of Reinforcement Geometry on Strength and Stiffness in Adhesively Bonded Steel-Timber Flexural Beams

    OpenAIRE

    Dave Smedley; Martin Ansell; Parvez Alam

    2012-01-01

    A finite element model is developed to analyse, as a function of volume fraction, the effects of reinforcement geometry and arrangement within a timber beam. The model is directly validated against experimental equivalents and found to never be mismatched by more than 8% in respect to yield strength predictions. Yield strength increases linearly as a function of increasing reinforcement volume fraction, while the flexural modulus follows more closely a power law regression fit. Reinforcement ...

  8. Between Amyloids and Aggregation Lies a Connection with Strength and Adhesion

    Directory of Open Access Journals (Sweden)

    Peter N. Lipke

    2014-01-01

    Full Text Available We tell of a journey that led to discovery of amyloids formed by yeast cell adhesins and their importance in biofilms and host immunity. We begin with the identification of the adhesin functional amyloid-forming sequences that mediate fiber formation in vitro. Atomic force microscopy and confocal microscopy show 2-dimensional amyloid “nanodomains” on the surface of cells that are activated for adhesion. These nanodomains are arrays of adhesin molecules that bind multivalent ligands with high avidity. Nanodomains form when adhesin molecules are stretched in the AFM or under laminar flow. Treatment with anti-amyloid perturbants or mutation of the amyloid sequence prevents adhesion nanodomain formation and activation. We are now discovering biological consequences. Adhesin nanodomains promote formation and maintenance of biofilms, which are microbial communities. Also, in abscesses within candidiasis patients, we find adhesin amyloids on the surface of the fungi. In both human infection and a Caenorhabditis elegans infection model, the presence of fungal surface amyloids elicits anti-inflammatory responses. Thus, this is a story of how fungal adhesins respond to extension forces through formation of cell surface amyloid nanodomains, with key consequences for biofilm formation and host responses.

  9. Effects of two soft drinks on shear bond strength and adhesive remnant index of orthodontic metal brackets.

    Directory of Open Access Journals (Sweden)

    Soodabeh Sadat Sajadi

    2014-08-01

    Full Text Available Bond failure of brackets during orthodontic treatment is a common problem; which results in treatment interference, increased treatment time and prolonged clinical time for rebonding of failed brackets. The purpose of this study was to evaluate the effects of Coca-Cola and a non-alcoholic beer on the shear bond strength and adhesive remnant index (ARI of orthodontic metal brackets in vitro.Eighty intact human premolars were divided into two experimental groups of Coca-Cola and non-alcoholic beer (Istak, and a control group of artificial saliva. Over a period of thirty days, the test groups were immersed in the respective soft drinks for 5 minutes, twice a day. For the remainder of the time, they were kept in artificial saliva at 37°C. The control group was stored in artificial saliva during the experiment. All samples were subjected to shearing forces using Universal Testing Machine. ARI was determined with a stereomicroscope at ×12 magnification. The data of shear bond strength were statistically analyzed by one-way ANOVA and Tukey's Post-Hoc test and the data of ARI scores were analyzed by Kruskal-Wallis test.No significant difference was observed in ARIs of the three groups (P≤ 0.552. The shear bond strength of Coke group was significantly lower than that of the two other groups (P≤ 0.035; but there was no significant difference between the shear bond strength of Istak and the control group (P≤ 0.999.Coca-Cola decreased the shear bond strength of orthodontic brackets.

  10. Effects of Reinforcement Geometry on Strength and Stiffness in Adhesively Bonded Steel-Timber Flexural Beams

    Directory of Open Access Journals (Sweden)

    Dave Smedley

    2012-07-01

    Full Text Available A finite element model is developed to analyse, as a function of volume fraction, the effects of reinforcement geometry and arrangement within a timber beam. The model is directly validated against experimental equivalents and found to never be mismatched by more than 8% in respect to yield strength predictions. Yield strength increases linearly as a function of increasing reinforcement volume fraction, while the flexural modulus follows more closely a power law regression fit. Reinforcement geometry and location of reinforcement are found to impact both the flexural properties of timber-steel composite beams and the changes due to an increase in volume fraction.

  11. Effect of salivary contamination during different bonding stages on shear dentin bond strength of one-step self-etch and total etch adhesive

    Directory of Open Access Journals (Sweden)

    H. Kermanshah

    2010-09-01

    Full Text Available Objective: This study evaluated the effect of saliva contamination during bonding procedures without removing saliva on shear dentin bond strength of three adhesive generations when rubber dam isolation is not feasible.Materials and Methods: Flat superficial dentin surfaces of seventy-two extracted human molars were randomly divided into three groups (A: Scotch Bond MP Plus (SBMP, B: Single Bond (SB, C: Prompt L-Pop according to the applied adhesives and twelve subgroups (n=6according to the following saliva contamination applied in different bonding steps. The specimens were contaminated with saliva after etching (A1 and B1, after primer application (A2, after adhesive application before polymerization (A3, B2 and C1, and after adhesivepolymerization (A4, B3 and C2. Three subgroups were not contaminated as controls (A5, B4 and C3. Resin composite was placed on dentin subsequently followed by thermocycling.Shear test was performed by Universal testing machine at 0.5 mm/min crosshead speed. The collected data were statically analyzed using one and two-way ANOVA and Tukey HSD.Results: In contrast to SBMP and SB, the mean shear bond strength of Promote L-Pop was not significantly different between contaminated and uncontaminated subgroups. Mean shear bond strengths of SBMP subgroups contaminated after adhesive polymerization or uncontaminated were significantly higher compared to the other two groups (p<0.05.Conclusion: Unlike Promote L-Pop, saliva contamination could reduce shear bond strength of the total-etch adhesives. Furthermore, the step of bonding procedures and the type of adhesive seems to be effective on the bond strength of adhesive contaminated with saliva.

  12. Effect of Adhesive Type on the Shear Bond Strength of Metal Brackets to Two Ceramic Substrates

    Directory of Open Access Journals (Sweden)

    Mohammad Sadegh Ahmad Akhoundi

    2014-04-01

    Full Text Available Increased number of adult patients requesting orthodontic treatment result in bonding bracket to ceramic restorations more than before. The aim of this study was to evaluate and compare the shear bond strength of orthodontic brackets bonded to two types of ceramic bases with conventional orthodontic bonding resin and a new nano-filled composite resin.Twenty four feldespathic porcelain and 24 lithium disilicate ceramic disks were fabricated. All of the samples were conditioned by sandblasting, hydrofluoric acid and silane. Maxillary incisor metal brackets were bonded to half of the disks in each group by conventional orthodontic bonding resin and the other half bonded with a nano-filled composite. The samples then were thermocycled for 2000 cycle between 5-55° C. Shear bond strength was measured and the mode of failure was examined. Randomly selected samples were also evaluated by SEM.The lowest bond strength value was found infeldespathic ceramic bonded by nano-filled composite (p<0.05. There was not any statistically significant difference between other groups regarding bond strength. The mode of failure in the all groups except group 1 was cohesive and porcelain damages were detected.Since less damages to feldspathic porcelain was observed when the nano-filled composite was used to bond brackets, the use of nano-filled composite resins can be suggested for bonding brackets to feldspathic porcelain restorations.

  13. A novel coating strategy towards improving interfacial adhesion strength of Cu–Sn alloy coated steel with vulcanized rubber

    International Nuclear Information System (INIS)

    Highlights: • We propose a double layer Cu–Sn alloy coating strategy on steel to improve adhesion. • Uniform coating with adequate penetration inside micro-roughness was observed. • XPS and GDOES study revealed improved substrate surface coverage by coating. • TEM investigation confirmed compact, uniform and micro-porosity free interface. • Peel test with vulcanized rubber confirmed improved adhesion with cohesive fracture. - Abstract: A comparative assessment in terms of uniformity, coating coverage and coating deposition mechanism has been carried out for two different types of Cu–Sn coatings on steel substrate with varying Sn composition (2–6.5 wt%) deposited via immersion technique, viz. (i) single layer Cu–Sn coating and (ii) double layer coating consisting of a thin Cu strike layer followed by a Cu–Sn layer. Coating morphology, surface coverage, coating-substrate interface, and coating composition at surface and along the depth were studied using laser confocal microscope (OLS), scanning electron microscope (SEM) coupled with energy dispersive spectroscope (EDS), glow discharge optical emission spectroscopy (GDOES), X-ray photoelectron spectroscopy (XPS) and cross-sectional transmission electron microscopy (TEM). Quantitative depth profiling using GDOES and surface compositional analysis via XPS suggested improvement in surface coverage in the case of double layer coatings. SEM-EDS and TEM analysis confirmed that the coating deposition was more uniform with sufficient coating penetration inside the deep roughness troughs resulting in compact and micro-porosity free interface for this type of coatings. Better adhesion strength with less variation in peel force and cohesive mode of fracture within the rubber was observed for the double layer coated samples during the peel test carried out on coated steel samples vulcanized with rubber. On the other hand, the single layer coated samples showed large variation in peel force with adhesive

  14. Surface modification of cotton fabrics by gas plasmas for color strength and adhesion by inkjet ink printing

    Science.gov (United States)

    Pransilp, Porntapin; Pruettiphap, Meshaya; Bhanthumnavin, Worawan; Paosawatyanyong, Boonchoat; Kiatkamjornwong, Suda

    2016-02-01

    Surface properties of cotton fabric were modified by three types of gas plasma pretreatment, namely, oxygen (O2), nitrogen (N2) and sulfur hexafluoride (SF6), to improve ink absorption of water-based pigmented inkjet inks and color reproduction of the treated surfaces. Effects of gas plasma exposure parameters of power, exposure time and gas pressure on surface physical and chemical properties of the treated fabrics were investigated. XPS (X-ray photoelectron spectroscopy) was used to identify changes in functional groups on the fabric surface while AFM (atomic force microscopy) and SEM (scanning electron microscopy) were used to reveal surface topography of the fabric. Color spectroscopic technique was used to investigate changes in color strength caused by different absorptions of the printed fabrics. The O2 plasma treatments produced new functional groups, sbnd Osbnd Csbnd O/Cdbnd O and Osbnd Cdbnd O while N2 plasma treatments produced additionally new functional groups, Csbnd N and Odbnd Csbnd NH, onto the fabric surface which increased hydrophilic properties and surface energy of the fabric. For cotton fabric treated with SF6 plasma, the fluorine functionalization was additionally found on the surface. Color strength values (K/S) increased when compared with those of the untreated fabrics. SF6 plasma-treated fabrics were hydrophobic and caused less ink absorption. Fabric surface roughness caused by plasma etching increased fabric surface areas, captured more ink, and enhanced a larger ink color gamut and ink adhesion. Cotton fabrics exhibited higher ink adhesion and wider color gamut after the O2 plasma treatment comparing with those after N2 plasma treatment.

  15. Plasma surface oxidation of 316L stainless steel for improving adhesion strength of silicone rubber coating to metal substrate

    Energy Technology Data Exchange (ETDEWEB)

    Latifi, Afrooz, E-mail: afroozlatifi@yahoo.com [Department of Biomaterials, Biomedical Engineering Faculty, Science and Research Branch, Islamic Azad University, Tehran (Iran, Islamic Republic of); Imani, Mohammad [Novel Drug Delivery Systems Dept., Iran Polymer and Petrochemical Institute, P.O. Box 14965/115, Tehran (Iran, Islamic Republic of); Khorasani, Mohammad Taghi [Biomaterials Dept., Iran Polymer and Petrochemical Institute, P.O. Box 14965/159, Tehran (Iran, Islamic Republic of); Daliri Joupari, Morteza [Animal and Marine Biotechnology Dept., National Institute of Genetic Engineering and Biotechnology, P.O. Box 14965/161, Tehran (Iran, Islamic Republic of)

    2014-11-30

    Highlights: • Stainless steel 316L was surface modified by plasma surface oxidation (PSO) and silicone rubber (SR) coating. • On the PSO substrates, concentration of oxide species was increased ca. 2.5 times comparing to non-PSO substrates. • The surface wettability was improved to 12.5°, in terms of water contact angle, after PSO. • Adhesion strength of SR coating on the PSO substrates was improved by more than two times comparing to non-PSO ones. • After pull-off test, the fractured area patterns for SR coating were dependent on the type of surface modifications received. - Abstract: Stainless steel 316L is one of the most widely used materials for fabricating of biomedical devices hence, improving its surface properties is still of great interest and challenging in biomaterial sciences. Plasma oxidation, in comparison to the conventional chemical or mechanical methods, is one of the most efficient methods recently used for surface treatment of biomaterials. Here, stainless steel specimens were surface oxidized by radio-frequency plasma irradiation operating at 34 MHz under pure oxygen atmosphere. Surface chemical composition of the samples was significantly changed after plasma oxidation by appearance of the chromium and iron oxides on the plasma-oxidized surface. A wettable surface, possessing high surface energy (83.19 mN m{sup −1}), was observed after plasma oxidation. Upon completion of the surface modification process, silicone rubber was spray coated on the plasma-treated stainless steel surface. Morphology of the silicone rubber coating was investigated by scanning electron microscopy (SEM). A uniform coating was formed on the oxidized surface with no delamination at polymer–metal interface. Pull-off tests showed the lowest adhesion strength of coating to substrate (0.12 MPa) for untreated specimens and the highest (0.89 MPa) for plasma-oxidized ones.

  16. In vitro analysis of shear bond strength and adhesive remnant index comparing light curing and self-curing composites

    Directory of Open Access Journals (Sweden)

    Murilo Gaby Neves

    2013-06-01

    Full Text Available OBJECTIVE: To evaluate, in vitro, the shear bond strength of self-curing (ConciseTM - 3M and Alpha Plast - DFL and light-curing composites (TransbondTM XT - 3M and Natural Ortho - DFL used in orthodontics bonding, associated to Morelli metal brackets, with further analysis of adhesive remnant index (ARI and enamel condition in scanning electron microscopy (SEM. METHODS: Forty human premolars, just extracted and stored in physiologic solution 0.9 % were used. Randomly, these samples were divided in four groups: G1 group, the brackets were bonded with ConciseTM - 3M composite; in G2 group, Alpha Plast - DFL composite was used; in G3 group, TransbondTM XT - 3M was used; in G4 group, Natural Ortho - DFL composite was used. These groups were submitted to shear strength tests in universal testing machine, at 0.5 mm per minute speed. RESULTS: Statistical difference between G3 and G4 groups was recorded, as G4 showing higher strength resistance than G3. In the other hand, there were no statistical differences between G1, G2 and G3 and G1, G2 and G4 groups. ARI analysis showed that there was no statistical difference between the groups, and low scores were recorded among then. The scanning electron microscopy (SEM analysis revealed the debonding spots and the enamel surface integrity. CONCLUSIONS: Shear bond strength was satisfactory and similar between the composites, however Natural Ortho - DFL revealed best comparing to TransbondTM XT - 3M.

  17. Stability of Secondary and Tertiary Structures of Virus-Like Particles Representing Noroviruses: Effects of pH, Ionic Strength, and Temperature and Implications for Adhesion to Surfaces.

    Science.gov (United States)

    Samandoulgou, Idrissa; Hammami, Riadh; Morales Rayas, Rocio; Fliss, Ismail; Jean, Julie

    2015-11-01

    Loss of ordered molecular structure in proteins is known to increase their adhesion to surfaces. The aim of this work was to study the stability of norovirus secondary and tertiary structures and its implications for viral adhesion to fresh foods and agrifood surfaces. The pH, ionic strength, and temperature conditions studied correspond to those prevalent in the principal vehicles of viral transmission (vomit and feces) and in the food processing and handling environment (pasteurization and refrigeration). The structures of virus-like particles representing GI.1, GII.4, and feline calicivirus (FCV) were studied using circular dichroism and intrinsic UV fluorescence. The particles were remarkably stable under most of the conditions. However, heating to 65°C caused losses of β-strand structure, notably in GI.1 and FCV, while at 75°C the α-helix content of GII.4 and FCV decreased and tertiary structures unfolded in all three cases. Combining temperature with pH or ionic strength caused variable losses of structure depending on the particle type. Regardless of pH, heating to pasteurization temperatures or higher would be required to increase GII.4 and FCV adhesion, while either low or high temperatures would favor GI.1 adhesion. Regardless of temperature, increased ionic strength would increase GII.4 adhesion but would decrease GI.1 adhesion. FCV adsorption would be greater at refrigeration, pasteurization, or high temperature combined with a low salt concentration or at a higher NaCl concentration regardless of temperature. Norovirus adhesion mediated by hydrophobic interaction may depend on hydrophobic residues normally exposed on the capsid surface at pH 3, pH 8, physiological ionic strength, and low temperature, while at pasteurization temperatures it may rely more on buried hydrophobic residues exposed upon structural rearrangement.

  18. Bond Strength of a Novel One Bottle Multi-mode Adhesive to Human Dentin After Six Months of Storage

    Science.gov (United States)

    Manfroi, Fernanda Borguetti; Marcondes, Maurem Leitão; Somacal, Deise Caren; Borges, Gilberto Antonio; Júnior, Luiz Henrique Burnett; Spohr, Ana Maria

    2016-01-01

    Objective: The aim of the study was to evaluate the microtensile bond strength (µTBS) of Scotchbond Universal to dentin using the etch-and-rinse or the self-etch technique after 24 h and 6 months of storage. Materials and Methods: Flat dentin surfaces were obtained in 24 third molars. The teeth were divided into four groups: G1 – Scotchbond Universal applied in the etch-and-rinse mode; G2 – Scotchbond Universal applied in the self-etch mode; G3 – Scotchbond Multi-Purpose; G4 – Clearfil SE Bond. A block of composite was built on the adhesive area. The tooth/resin sets were cut parallel to the long axis to obtain 40 beams (~0.8 mm2) for each group. Twenty specimens were immediately submitted to the µTBS test, and the remaining 20 were stored in water for 6 months. Failures and the adhesive interface were analyzed by SEM. Results: According to two-way ANOVA, the interaction between adhesive and storage time was significant (p=0.015).The µTBS (MPa) means were the following: 24 h – G1 (39.37±10.82), G2 (31.02±13.76), G3 (35.09±14.03) and G4 (35.84±11.06); 6 months – G1 (36.99±8.78), G2 (40.58±8.07), G3 (32.44±6.07) and G4 (41.75±8.25). Most failures were mixed. Evidence of hybrid layer and numerous resin tags were noted for Scotchbond Universal applied with the etch-and-rinse mode and Scotchbond Multi-Purpose. A thinner hybrid layer and fewer resin tags were noted for Scotchbond Universal applied in the self-etch mode and Clearfil SE Bond. Conclusion: The results indicate that the µTBS for Scotchbond Universal is comparable to the gold-standard adhesives. Scotchbond Universal applied in the self-etch mode and Clearfil SE Bond revealed higher bond stability compared to the etch-and-rinse mode. PMID:27347230

  19. Assessment of the Shear Bond Strength between Nanofilled Composite Bonded to Glass-ionomer Cement Using Self-etch Adhesive with Different pHs and Total-Etch Adhesive

    Directory of Open Access Journals (Sweden)

    Farahnaz Sharafeddin

    2016-03-01

    Full Text Available Statement of the Problem: In the sandwich technique, the undesirable bond between the composite resin and glass-ionomer cement (GIc is one of the most important factors which lead to the failure of restoration. Total-etch and self-etch adhesives may improve the bond strength based on their pH. Purpose: The purpose of this study was to evaluate the shear bond strength between the nanofilled composite resin and GIc using different adhesives. Materials and Method: In this experimental study, 40 specimens (6×6mm in 4 groups (n=10 were prepared in acrylic mold. Each specimen contained conventional GI ChemFil Superior with a height of 3mm, bonded to Z350 composite resin with a height measured 3mm. In order to bond the composite to the GI, the following adhesives were used, respectively: A: mild Clearfil SE Bond self-etch (pH=2, B: intermediate OptiBond self-etch (pH=1.4, C: strong Adper Prompt L-Pop (pH=1, and D: Adper Single Bond 2 total-etch (pH=7.2. The shear bond strength was measured by using universal testing machine with a crosshead speed of 1mm/min. One-way ANOVA and Tukey’s test were used to analyze the data (p< 0.05. Results: The shear bond strength in group A was significantly higher than group B (p= 0.002, C (p< 0.001, and D (p< 0.001. Moreover, the shear bond strength of groups A and B (self-etch was significantly different from group D (total-etch (p< 0.001; and C (self-etch with D (p= 0.024. Conclusion: The results of this study showed that applying the mild self-etch adhesive between the composite and the GIc results in stronger shear bond strength compared to intermediate and strong self-etch adhesives. Moreover, the self-etch adhesive increased the shear bond strength between composite resin and GIc more significantly than total-etch adhesive.

  20. Effect of biological contamination on dentine bond strength of adhesive resins.

    Science.gov (United States)

    van Schalkwyk, J H; Botha, F S; van der Vyver, P J; de Wet, F A; Botha, S J

    2003-05-01

    The purpose of this in vitro study was to determine the effect of saliva (S) and blood (B) contamination on the dentine bond strength of two single-component dentine bonding systems. The occlusal thirds of 120 recently extracted, human molars were removed with a low speed saw and subsequently embedded in Bencor rings by means of self-curing, acrylic resin. The occlusal surfaces were ground wet on 600-grit silicone carbide paper in a polishing machine to expose superficial dentine and to create a smear layer. The teeth were randomly divided into 12 groups (n = 10). All the dentine surfaces were etched with 34% phosphoric acid for 15 seconds rinsed with water, air-dried for 3 seconds, leaving the surfaces visibly moist. For the control groups (C) the etched dentine surfaces were treated with either, Scotchbond 1 (SB1, 3M) or Prime & Bond NT (PBNT, Dentsply) according to the manufacturer's instructions. In the contaminated groups, the saliva or blood was applied by means of a disposable brush, left undisturbed for 1 minute, and the excess then thinned by air spray. The dentine bonding systems were then applied, also according to manufacturer's instructions. Composite (Z250 and TPH) and Compomer (F2000 and Dyract AP (D-AP)) stubs were packed and cured incrementally to the corresponding pretreated dentine surfaces. All specimens were stored for 24 hours under water at 37 degrees C. The bonds were then stressed to failure with a Zwick testing machine, operating at a crosshead speed of 0.5 mm/min. Fractured samples were examined in a Scanning Electron Microscope. The data were statistically analysed (Student-t test). The mean SBS (MPa) were. SB1 with Z250: C = 19.1 +/- 4.4; S = 17.3 +/- 3.5; B = 2.6 +/- 0.9; SB1 with F2000: C = 11.8 +/- 3.3; S = 9.7 +/- 1.8; B = 4.7 +/- 1.6. PBNT with TPH: C = 9.2 +/- 3.2; S = 6.5 +/- 3.0; B = 4.3 +/- 1.5; PBNT with D-AP: C = 10.2 +/- 3.6; S = 9.3 +/- 2.9 and B = 7.3 +/- 2.5. There was no statistical significant difference in shear bond

  1. Evaluation of the tensile bond strength of an adhesive system self-etching in dentin irradiated with Er:YAG laser

    International Nuclear Information System (INIS)

    Since Buonocore (1955), several researchers have been seeking for the best adhesive system and treatment for the enamel and dentin surfaces. The use of the acid has been presented as one of the best techniques of dentin conditioning , because this promotes the removal of the 'smear layer and exhibition of dentinal structure, for a best penetration and micro- retention of the adhesive system. However, some conditioning methods have been appearing in the literature, for the substitution or interaction with the acid substances, as the laser. The objective of this work is to evaluate the tensile bond strength of the adhesive system self-etching' associated to a composed resin, in dentin surfaces conditioned with the Er:YAG laser. For this study, freshly extracted human teeth were used and in each one the dentinal surfaces , which were treated with three sandpapers of different granulations (120,400,600), to obtain a standard of the smear layer, before the irradiation of the laser and of the restoring procedure. After these procedures the specimens were storage in distilled water at 37 deg C for 24 hours. Soon after, they were submitted to the tensile strength test .After analyzing the results, we can concluded that the use of the Er:YAG laser can substitute the drill without the need of conditioning, when using the adhesive system 'self-etching' in the dentinal surfaces because there was a decline in the strength of adhesion in the groups conditioned with the laser. (author)

  2. In vitro comparative bond strength of contemporary self-adhesive resin cements to zirconium oxide ceramic with and without air-particle abrasion.

    Science.gov (United States)

    Blatz, Markus B; Phark, Jin-Ho; Ozer, Fusun; Mante, Francis K; Saleh, Najeed; Bergler, Michael; Sadan, Avishai

    2010-04-01

    This study compared shear bond strengths of six self-adhesive resin cements to zirconium oxide ceramic with and without air-particle abrasion. One hundred twenty zirconia samples were air-abraded (group SB; n = 60) or left untreated (group NO). Composite cylinders were bonded to the zirconia samples with either BisCem (BC), Maxcem (MC), G-Cem (GC), RelyX Unicem Clicker (RUC), RelyX Unicem Applicator (RUA), or Clearfil SA Cement (CSA). Shear bond strength was tested after thermocycling, and data were analyzed with analysis of variance and Holm-Sidak pairwise comparisons. Without abrasion, RUA (8.0 MPa), GC (7.9 MPa), and CSA (7.6 MPa) revealed significantly higher bond strengths than the other cements. Air-particle abrasion increased bond strengths for all test cements (p CSA (18.4 MPa) revealed the highest bond strengths in group SB. Bond strengths of self-adhesive resin cements to zirconia were increased by air-particle abrasion. Cements containing adhesive monomers (MDP/4-META) were superior to other compositions. PMID:19415350

  3. GEP-based method to formulate adhesion strength and hardness of Nb PVD coated on Ti-6Al-7Nb aimed at developing mixed oxide nanotubular arrays.

    Science.gov (United States)

    Rafieerad, A R; Bushroa, A R; Nasiri-Tabrizi, B; Fallahpour, A; Vadivelu, J; Musa, S N; Kaboli, S H A

    2016-08-01

    PVD process as a thin film coating method is highly applicable for both metallic and ceramic materials, which is faced with the necessity of choosing the correct parameters to achieve optimal results. In the present study, a GEP-based model for the first time was proposed as a safe and accurate method to predict the adhesion strength and hardness of the Nb PVD coated aimed at growing the mixed oxide nanotubular arrays on Ti67. Here, the training and testing analysis were executed for both adhesion strength and hardness. The optimum parameter combination for the scratch adhesion strength and micro hardness was determined by the maximum mean S/N ratio, which was 350W, 20 sccm, and a DC bias of 90V. Results showed that the values calculated in the training and testing in GEP model were very close to the actual experiments designed by Taguchi. The as-sputtered Nb coating with highest adhesion strength and microhardness was electrochemically anodized at 20V for 4h. From the FESEM images and EDS results of the annealed sample, a thick layer of bone-like apatite was formed on the sample surface after soaking in SBF for 10 days, which can be connected to the development of a highly ordered nanotube arrays. This novel approach provides an outline for the future design of nanostructured coatings for a wide range of applications. PMID:26874249

  4. Evaluation of adhesion strength of Er2O3 coating layer for an advanced breeding blanket system applied to thermal cycles using nano-scratch method

    International Nuclear Information System (INIS)

    The electrical insulator and hydrogen permeation barrier coatings are important materials to realize the liquid metal and molten-salt typed breeding blanket systems. We found that erbium oxide (Er2O3) is one of the promising materials as the electrical insulator and hydrogen permeation restraint coatings. Establishing the mechanical property evaluation method for these coating is extremely important to certify the durability of coating material in the blanket systems. The adhesion strength property, which is one of the key mechanical properties of coating materials, was investigated using the nano-scratch method. From the results, it was found that the nano-scratch test was able to evaluate the adhesion strength of the Er2O3 coating synthesized by the Metal Organic Chemical Vapor Deposition (MOCVD) process with high reproducibility. Furthermore, the adhesion strength of the Er2O3 coating before and after thermal cycling was evaluated using this method. The adhesion strength after 50 thermal cycles at 700degC was kept around 70% compared with that before thermal cycling. (author)

  5. Adhesive strength of total knee endoprostheses to bone cement - analysis of metallic and ceramic femoral components under worst-case conditions.

    Science.gov (United States)

    Bergschmidt, Philipp; Dammer, Rebecca; Zietz, Carmen; Finze, Susanne; Mittelmeier, Wolfram; Bader, Rainer

    2016-06-01

    Evaluation of the adhesive strength of femoral components to the bone cement is a relevant parameter for predicting implant safety. In the present experimental study, three types of cemented femoral components (metallic, ceramic and silica/silane-layered ceramic) of the bicondylar Multigen Plus knee system, implanted on composite femora were analysed. A pull-off test with the femoral components was performed after different load and several cementing conditions (four groups and n=3 components of each metallic, ceramic and silica/silane-layered ceramic in each group). Pull-off forces were comparable for the metallic and the silica/silane-layered ceramic femoral components (mean 4769 N and 4298 N) under standard test condition, whereas uncoated ceramic femoral components showed reduced pull-off forces (mean 2322 N). Loading under worst-case conditions led to decreased adhesive strength by loosening of the interface implant and bone cement using uncoated metallic and ceramic femoral components, respectively. Silica/silane-coated ceramic components were stably fixed even under worst-case conditions. Loading under high flexion angles can induce interfacial tensile stress, which could promote early implant loosening. In conclusion, a silica/silane-coating layer on the femoral component increased their adhesive strength to bone cement. Thicker cement mantles (>2 mm) reduce adhesive strength of the femoral component and can increase the risk of cement break-off. PMID:25781660

  6. GEP-based method to formulate adhesion strength and hardness of Nb PVD coated on Ti-6Al-7Nb aimed at developing mixed oxide nanotubular arrays.

    Science.gov (United States)

    Rafieerad, A R; Bushroa, A R; Nasiri-Tabrizi, B; Fallahpour, A; Vadivelu, J; Musa, S N; Kaboli, S H A

    2016-08-01

    PVD process as a thin film coating method is highly applicable for both metallic and ceramic materials, which is faced with the necessity of choosing the correct parameters to achieve optimal results. In the present study, a GEP-based model for the first time was proposed as a safe and accurate method to predict the adhesion strength and hardness of the Nb PVD coated aimed at growing the mixed oxide nanotubular arrays on Ti67. Here, the training and testing analysis were executed for both adhesion strength and hardness. The optimum parameter combination for the scratch adhesion strength and micro hardness was determined by the maximum mean S/N ratio, which was 350W, 20 sccm, and a DC bias of 90V. Results showed that the values calculated in the training and testing in GEP model were very close to the actual experiments designed by Taguchi. The as-sputtered Nb coating with highest adhesion strength and microhardness was electrochemically anodized at 20V for 4h. From the FESEM images and EDS results of the annealed sample, a thick layer of bone-like apatite was formed on the sample surface after soaking in SBF for 10 days, which can be connected to the development of a highly ordered nanotube arrays. This novel approach provides an outline for the future design of nanostructured coatings for a wide range of applications.

  7. Adhesive luting of all-ceramic restorations--the impact of cementation variables and short-term water storage on the strength of a feldspathic dental ceramic.

    LENUS (Irish Health Repository)

    Addison, Owen

    2008-08-01

    To investigate the impact of resin cement luting variables and short-term water storage on the strength of an adhesively luted all-ceramic restorative material. An understanding of the strengthening mechanisms will result in optimisation of operative techniques and materials selection criteria.

  8. Shear Bond Strength of MDP-Containing Self-Adhesive Resin Cement and Y-TZP Ceramics: Effect of Phosphate Monomer-Containing Primers

    Directory of Open Access Journals (Sweden)

    Jin-Soo Ahn

    2015-01-01

    Full Text Available Purpose. This study was conducted to evaluate the effects of different phosphate monomer-containing primers on the shear bond strength between yttria-tetragonal zirconia polycrystal (Y-TZP ceramics and MDP-containing self-adhesive resin cement. Materials and Methods. Y-TZP ceramic surfaces were ground flat with #600-grit SiC paper and divided into six groups (n=10. They were treated as follows: untreated (control, Metal/Zirconia Primer, Z-PRIME Plus, air abrasion, Metal/Zirconia Primer with air abrasion, and Z-PRIME Plus with air abrasion. MDP-containing self-adhesive resin cement was applied to the surface-treated Y-TZP specimens. After thermocycling, a shear bond strength test was performed. The surfaces of the Y-TZP specimens were analyzed under a scanning electron microscope. The bond strength values were statistically analyzed using one-way analysis of variance and the Student–Newman–Keuls multiple comparison test (P<0.05. Results. The Z-PRIME Plus treatment combined with air abrasion produced the highest bond strength, followed by Z-PRIME Plus application, Metal/Zirconia Primer combined with air abrasion, air abrasion alone, and, lastly, Metal/Zirconia Primer application. The control group yielded the lowest results (P<0.05. Conclusion. The application of MDP-containing primer resulted in increased bond strength between Y-TZP ceramics and MDP-containing self-adhesive resin cements.

  9. Noteworthy impacts of polyurethane-urea ionomers as the efficient polar coatings on adhesion strength of plasma treated polypropylene

    Science.gov (United States)

    Chashmejahanbin, Mohammad. R.; Daemi, Hamed; Barikani, Mehdi; Salimi, Ali

    2014-10-01

    In present research, polypropylene (PP) was selected as a model nonpolar substrate for chemical modification using plasma. In the first step, the PP samples were treated using oxygen and argon atmospheres, individually. The prepared samples were analyzed using both FTIR and AFM techniques. The output of these techniques revealed that the carbonyl, carboxylic acid and its derivatives have been formed on the surface of PP. Afterward, a series of aqueous polyurethane-urea dispersions were synthesized as the novel polar coating for modified nonpolar polymers and characterized by different techniques including FTIR, DSC, TGA, mechanical properties and contact angle. Finally, the plasma treated samples were coated by prepared polyurethane ionomer. The results of pull-off analysis confirmed the significant role of the polyurethane as an extremely polar coating to create hydrogen bonding with functional groups on the surface of treated PP. The adhesion strength of polypropylenes increased from 0.04 MPa to 0.61 MPa for neat and oxygen-based plasma treated samples, respectively.

  10. Push-out bond strength of quartz fibre posts to root canal dentin using total-etch and self-adhesive resin cements

    OpenAIRE

    Kahnamouei, Mehdi A.; Mohammadi, Narmin; Navimipour, Elmira J.; Shakerifar, Maryam

    2011-01-01

    Objectives: Several adhesive systems are available for cementation of fibre posts into the root canal. The aim of the present study was to investigate the push-out bond strengths of quartz fibre posts to root dentin with the use of different total-etch and self-adhesive resin cements. Study Design: Ninety single-rooted human premolars were endodontically treated and standardized post-spaces were prepared. Fibre posts were cemented with different luting agents: total-etch (Nexus NX3, Duo-Link,...

  11. Shear Bond Strength of an Etch-and-rinse Adhesive to Er:YAG Laser- and/or Phosphoric Acid-treated Dentin

    OpenAIRE

    2013-01-01

    Background and aims. Er:YAG laser irradiation has been claimed to improve the adhesive properties of dentin; therefore, it has been proposed as an alternative to acid etching. The aim of this in vitro study was to investigate the shear bond strength of an etch-and-rinse adhesive system to dentin surfaces following Er:YAG laser and/or phosphoric acid etching. Materials and methods. The roots of 75 sound maxillary premolars were sectioned below the CEJ and the crowns were embedded in auto-polym...

  12. Evaluation of microshear bond strength of resin composites to enamel of dental adhesive systems associated with Er,Cr:YSGG laser

    Science.gov (United States)

    Cassimiro-Silva, Patricia F.; Zezell, Denise M.; Monteiro, Gabriela Q. d. M.; Benetti, Carolina; de Paula Eduardo, Carlos; Gomes, Anderson S. L.

    2016-02-01

    The aim of this in vitro study was to evaluate the microshear bond strength (μSBS) of resin composite to enamel etching by Er,Cr:YSGG laser with the use of two differents adhesives systems. Fifty freshly extracted human molars halves were embedded in acrylic resin before preparation for the study, making a total of up to 100 available samples. The specimens were randomly assigned into six groups (η=10) according to substrate pre-treatment and adhesive system on the enamel. A two-step self-etching primer system (Clearfil SE Bond) and a universal adhesive used as an etch-andrinse adhesive (Adper Single Bond Universal) were applied to the nonirradiated enamel surface according to manufacturer's instructions, as control groups (Control CF and Control SB, respectively). For the other groups, enamel surfaces were previously irradiated with the Er,Cr:YSGG laser with 0.5 W, 75 mJ and 66 J/cm2 (CF 5 Hz and SB 5 Hz) and 1.25 W, 50 mJ and 44 J/cm2 (CF 15 Hz and SB 15 Hz). Irradiation was performed under air (50%) and water (50%) cooling. An independent t-test was performed to compare the adhesive systems. Mean μSBS ± sd (MPa) for each group was 16.857 +/- 2.61, 17.87 +/- 5.83, 12.23 +/- 2.02, 9.88 +/- 2.26, 15.94 +/- 1.98, 17.62 +/- 2.10, respectively. The control groups and the 50 mJ laser groups showed no statistically significant differences, regardless of the adhesive system used. The results obtained lead us to affirm that the bonding interaction of adhesives to enamel depends not only on the morphological aspects of the dental surface, but also on the characteristics of the adhesive employed and the parameters of the laser.

  13. Effect of different adhesive strategies on microtensile bond strength of computer aided design/computer aided manufacturing blocks bonded to dentin

    Science.gov (United States)

    Roperto, Renato; Akkus, Anna; Akkus, Ozan; Lang, Lisa; Sousa-Neto, Manoel Damiao; Teich, Sorin; Porto, Thiago Soares

    2016-01-01

    Background: The aim of this study was to determine the microtensile bond strength (μTBS) of ceramic and composite computer aided design-computer aided manufacturing (CAD-CAM) blocks bonded to dentin using different adhesive strategies. Materials and Methods: In this in vitro study, 30 crowns of sound freshly extracted human molars were sectioned horizontally 3 mm above the cementoenamel junction to produce flat dentin surfaces. Ceramic and composite CAD/CAM blocks, size 14, were sectioned into slices of 3 mm thick. Before bonding, CAD/CAM block surfaces were treated according to the manufacturer's instructions. Groups were created based on the adhesive strategy used: Group 1 (GI) - conventional resin cement + total-etch adhesive system, Group 2 (GII) - conventional resin cement + self-etch adhesive system, and Group 3 (GIII) - self-adhesive resin cement with no adhesive. Bonded specimens were stored in 100% humidity for 24h at 37΀C, and then sectioned with a slow-speed diamond saw to obtain 1 mm × 1 mm × 6 mm microsticks. Microtensile testing was then conducted using a microtensile tester. μTBS values were expressed in MPa and analyzed by one-way ANOVA with post hoc (Tukey) test at the 5% significance level. Results: Mean values and standard deviations of μTBS (MPa) were 17.68 (±2.71) for GI/ceramic; 17.62 (±3.99) for GI/composite; 13.61 (±6.92) for GII/composite; 12.22 (±4.24) for GII/ceramic; 7.47 (±2.29) for GIII/composite; and 6.48 (±3.10) for GIII/ceramic; ANOVA indicated significant differences among the adhesive modality and block interaction (P CAD/CAM restorations, either composite or ceramic, can be significantly affected by different adhesive strategies used. PMID:27076825

  14. Effect of the pre-treatment and the aggregate content on the adhesion strength of repair mortars on Miocene porous limestone

    Science.gov (United States)

    Szemerey-Kiss, Balázs; Török, Ákos

    2016-04-01

    The adhesion between porous limestone and newly prepared repair mortars are crucial in the preservation of historic stone structures. Besides mechanical compatibility other matches such as chemical composition and porosity are also essential, but the current research focuses on the adhesion strength of repair mortars that are used in the restoration of Hungarian porous limestone. 8 mortars (4 commercial and 4 specially prepared) were selected for the tests. Mortars with different amount of aggregate were prepared and caste to stone surface. The stone substrate was highly porous Miocene limestone. The strength was tested by standardized pull-out tests which method is commonly used for concrete testing. The limestone surfaces were either used in their natural conditions or were pre-treated (pre-wetting). The strength of the stone/mortar bond was tested. The failure mechanism was documented and various failure modes were identified. Strength test results suggest that especially pre-treatment influences strongly the pull-out strength at mortar/stone interface. Increasing aggregate content also reduces pull out strength of tested repair mortars, but at various rates depending on the mortar type. The financial support of OTKA post-doctoral grant to BSZK (reference number is: PD 112-955) and National Research, Development and Innovation (NKFI) Fund to ÁT (ref. no. K 116532) are appreciated.

  15. The effect of adhesive strength of hydroxyapatite coating on the stability of hydroxyapatite-coated prostheses in vivo at the early stage of implantation

    OpenAIRE

    Duan, Yonghong; Zhu, Shu; Guo, Fei; Zhu, Jinyu; Li,Mao; Ma, Jie; Zhu, Qingsheng

    2012-01-01

    Introduction With the increase in joint revision surgery after arthroplasty, defects of hydroxyapatite (HA)-coated prostheses have been observed increasingly often. These defects adversely affect the prosthetic stability in vivo. This study has analyzed the potential effect of the adhesive strength of HA coating on the stability of HA-coated prostheses in vivo after its implantation. Material and methods Sixty experimental rabbits were divided into HA- and Ti-coated groups. HA-coated prosthes...

  16. Influence of Air Abrasion and Sonic Technique on Microtensile Bond Strength of One-Step Self-Etch Adhesive on Human Dentin

    Directory of Open Access Journals (Sweden)

    Baraba Anja

    2015-01-01

    Full Text Available The purpose of this in vitro study was to evaluate the microtensile bond strength of one-step self-etch adhesive to human dentin surface modified with air abrasion and sonic technique and to assess the morphological characteristics of the pretreated dentin surface. The occlusal enamel was removed to obtain a flat dentin surface for thirty-six human molar teeth. The teeth were randomly divided into three experimental groups (n = 12 per group, according to the pretreatment of the dentin: (1 control group, (2 air abrasion group, and (3 sonic preparation group. Microtensile bond strength test was performed on a universal testing machine. Two specimens from each experimental group were subjected to SEM examination. There was no statistically significant difference in bond strength between the three experimental groups (P > 0.05. Mean microtensile bond strength (MPa values were 35.3 ± 12.8 for control group, 35.8 ± 13.5 for air abrasion group, and 37.7 ± 12.0 for sonic preparation group. The use of air abrasion and sonic preparation with one-step self-etch adhesive does not appear to enhance or impair microtensile bond strength in dentin.

  17. Nanotec : In a DLC film, new technology, by the close adhesion strength with the metal; DLC seimaku ni singijutsu, kinzoku tono micchaku kyodo bai

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-12-31

    Nanotec and a Japanese University college of science and engineering established a light film plastic technology that a diamond like carbon (DLC) film and close adhesion strength of the metal material were doubled by the cooperation. Though a frictional coefficient was low and it was partly adopted in the cutting tool and the gold type, as for a DLC film, which had a high hardness surface character, it was a fault to be poor at the surface pressure and to exfoliate easily. This time established technology made the PS2 technology which three-dimensional ion injection could be done in the DC electric discharge ion source technology, which are characteristic of Nanotec and the low voltage in large quantities, by a hybrid. Close adhesion strength improves with 180 Newton and Haas steel and dice steel for the general gold type in 70 Newton beyond the usual double when it is coated to the super-alloy. The choices of the metal, which becomes a base, are spread, and improvement in the close adhesion strength expands use for a DLC film into the large area industry field. The way, which the metal of the low cost is applied to as a substitutive material of the super-alloy is opened. (translated by NEDO)

  18. Comparison of the Shear Bond Strength of Light-cured and Chemically-cured Resin Adhesive%光固化和化学固化树脂粘接剂剪切强度的对比研究

    Institute of Scientific and Technical Information of China (English)

    张隆祺; 王野平

    2001-01-01

    Objective To compare the shear bond strength of light-cured and chemically-cured resin adhesive. Methods Twenty recently extracted human premolars were randomly divided into two groups of 10 each.: Group A, using the chemically-cured resin adhesive (Jing Jinenamel adhesive) and Group B, using the light-cured resin adhesive (Transbond XT,3M Unitek). The brackets were bonded to prepared enamel surfaces and the samples were placed in a water bath at 37℃ for 24 hours, then measured the shear bond strength and assessed the remaining adhesive after debonded. Results The shear bond strength and assessing the remaining adhesive after debonded both had no statistical significanct difference between two adhesives. Conclusion The light-cured and the chemically-cured resin adhesive both have strong bond strength, but the light-cured resin adhesive has the advantage to offer more sufficient time for positioning and bonding the brackets, so it is recommended for using.%-05)。结论光固化和化学固化树脂粘接剂均具有较强的粘接强度,但光固化树脂粘接剂能够为托槽的定位和粘接提供充足的时间,推荐使用。

  19. PH dependent adhesive peptides

    Science.gov (United States)

    Tomich, John; Iwamoto, Takeo; Shen, Xinchun; Sun, Xiuzhi Susan

    2010-06-29

    A novel peptide adhesive motif is described that requires no receptor or cross-links to achieve maximal adhesive strength. Several peptides with different degrees of adhesive strength have been designed and synthesized using solid phase chemistries. All peptides contain a common hydrophobic core sequence flanked by positively or negatively charged amino acids sequences.

  20. Surface Physicochemistry and Ionic Strength Affects eDNA’s Role in Bacterial Adhesion to Abiotic Surfaces

    OpenAIRE

    Regina, Viduthalai R.; Lokanathan, Arcot R.; Jakub J Modrzyński; Sutherland, Duncan S; Rikke L Meyer

    2014-01-01

    Extracellular DNA (eDNA) is an important structural component of biofilms formed by many bacteria, but few reports have focused on its role in initial cell adhesion. The aim of this study was to investigate the role of eDNA in bacterial adhesion to abiotic surfaces, and determine to which extent eDNA-mediated adhesion depends on the physicochemical properties of the surface and surrounding liquid. We investigated eDNA alteration of cell surface hydrophobicity and zeta potential, and subsequen...

  1. Effect of collagen cross-linkers on the shear bond strength of a self-etch adhesive system to deep dentin

    Directory of Open Access Journals (Sweden)

    Sakhamuri Srinivasulu

    2013-01-01

    Full Text Available Objectives: To evaluate the shear bond strength of composite resin to deep dentin, bonded using a self-etch adhesive, after treatment with two collagen cross-linkers at varying time intervals. Materials and Methods: Thirty extracted human incisors were sectioned longitudinally into equal mesial and distal halves ( n = 60. The proximal deep dentin was exposed and the specimens were divided based on the surface treatment of dentin prior to bonding as follows: Group I ( n = 12, control: No prior dentin surface treatment; group II ( n = 24: Dentin surface pretreated with 10% sodium ascorbate; and group III ( n = 24: Dentin surface pretreated with 6.5% proanthocyanidin. Groups II and III were further divided into two subgroups based on the pre-treatment time of five and 10 min. Shear bond strength of the specimens was tested using universal testing machine and the data were statistically analyzed. Results: Significantly higher shear bond strength to deep dentin was observed in teeth treated with 10% sodium ascorbate and 6.5% proanthocyanidin compared to control group. No significant difference was observed between 5 min and 10 min pre-treatment times. Conclusion: Dentin surface pre-treatment with both 10% sodium ascorbate and 6.5% proanthocyanidin resulted in significant improvement in bond strength of self-etch adhesive to deep dentin.

  2. Comparison of shear bond strength of self-etching fluoride releasing adhesives with and without pumice prophylaxis

    Directory of Open Access Journals (Sweden)

    V R Shobbana Devi

    2015-01-01

    Conclusions: Fluoride releasing adhesives combined with antibacterial monomer can play a vital role in reducing white spot lesions by enhancing the cariostatic effect especially in noncompliant\\medically compromised patients.

  3. PLASMA POLYMER FILMS AS ADHESION PROMOTING PRIMERS FOR ALUMINUM. PART II: STRENGTH AND DURABILITY OF LAP JOINTS

    Science.gov (United States)

    Plasma polymerized hexamethyldisiloxane (HMDSO) films (~800 A in thickness) were deposited onto 6111-T4 aluminum substrates in radio frequency and microwave powered reactors and used as primers for structural adhesive bonding. Processing variables such as substrate pre-treatment,...

  4. Shear Bond Strength of Self-Etching Adhesive Systems to Er:YAG Laser-Prepared Dentine with and without Pulpal Pressure Simulation

    OpenAIRE

    Brulat, Nathalie; Leforestier, Eric; Rocca, Jean-Paul; Darque-Ceretti, Evelyne; Bertrand, Marie-France

    2008-01-01

    Objective: This study was conducted to study the role of pulpal pressure on the shear bond strength of composite resin bonded to Er:YAG laser-prepared or bur-prepared dentine surfaces using a self-etching adhesive system. Materials and Methods: The occlusal surfaces of 80 human third molars were ground flat to expose the dentine. The dentine was prepared using either a carbide bur or an Er: YAG laser at 350 mJ/pulse and 10 Hz (fluence 44.5 J/cm(2)). Clearfil SE Bond was then applied with or w...

  5. MEASUREMENT OF ADHESION STRENGTH OF Mo-Ti-N AND Mo-Сu-N COATINGS USING «SCRATCH-TESTER» DEVICE

    OpenAIRE

    V. M. Anischik; A. K. Kuleshov; V. V. Uglov; D. P. Rusalsky; A. F. Syschenko

    2015-01-01

    The new «scratch-tester» device for measurement of adhesion strength of coatings is presented. The device has a number of advantages as compared with known analogues – the expanded range of investigated sample sizes and more simple procedure of sample positioning, more precise measurement of scratching length, additional manner of registration of coating destruction or tearing off instant on the base of friction force. The device was used for investigation of Mo-Ti-N and Mo-Сu-N coatings on c...

  6. Comparative evaluation of shear bond strength of two self-etching adhesives (sixth and seventh generation on dentin of primary and permanent teeth: An in vitro study

    Directory of Open Access Journals (Sweden)

    Yaseen S

    2009-03-01

    Full Text Available Aim: The present study was undertaken to compare and evaluate shear bond strength of two self-etching adhesives (sixth and seventh generation on dentin of primary and permanent teeth. Materials and Methods: Flat dentin surface of 64 human anterior teeth (32 primary and 32 permanent divided into four groups of 16 each. Groups A and C were treated with Contax (sixth generation, while groups B and D were treated with Clearfil S3 (seventh generation. A teflon mold was used to build the composite (Filtek Z-350 cylinders on the dentinal surface of all the specimens. Shear bond strength was tested for all the specimens with an Instron Universal Testing Machine. Data were statistically analyzed using one-way ANOVA for multiple group comparison, followed by student′s unpaired ′t′ test for group-wise comparison. Results: There was no statistically significant difference in shear bond strength among the study groups except that primary teeth bonded with Contax exhibited significantly lesser shear bond strength than permanent teeth bonded with Clearfil S3. Conclusion: This study revealed that Clearfil S3 could be of greater advantage in pediatric dentistry than Contax because of its fewer steps and better shear bond strength in dentin of both primary and permanent teeth.

  7. Effect of different blood contaminated adherent surface treatments on shear bond strength of compomer and composite resin to dentin, using a self etching adhesive

    Directory of Open Access Journals (Sweden)

    Mortazavi V.

    2005-06-01

    Full Text Available Statement of Problem: Blood contamination is a common problem in dentistry that can decrease bond strength dramatically which may be affected by methods of decontamination as well. Purpose: The aim of this study was to evaluate and compare the influence of blood contamination on shear bond strength of composite and compomer to dentin using Prompt L-Pop as an adhesive system. Also, to assess the effectiveness of different surface treatments on the bond strength. Materials and Methods: In this experimental study, 120 molar teeth were sectioned to provide flat occlusal dentinal surfaces. Specimens were embedded in acrylic resin with the flat surface exposed. The dentinal expose surfaces were polished to 600 grit. The teeth were randomly divided into five groups of twelve specimens (F1–F5 for compomer material and five other groups (Z1- Z5 for composite resin. After application of Promt L-Pop to dentinal surfaces of specimens, the surfaces in all groups, except for F1 and Z1, (as controls were contaminated with human blood and then one of the following surface treatments was applied. Groups F2 and Z2 without any treatment, groups F3 and Z3 rinsing with water, groups F4 and Z4 rinsing with water and reapplication of adhesive, groups F5 and Z5 rinsing with NaOCl and using Prompt L-Pop again. Restorative materials were applied to treated surfaces using plastic molds. After thermocycling, shear bond strengths, mode of failures and morphology of dentin-material interfaces were evaluated. The data were statistically analyzed using Factorial analysis of Variance, One-Way ANOVA, Duncan, T-student and Chi-Square tests with P<0.05 as the limit of significance. Results: Compomer showed statistically significant higher bond strength in comparison to composite (P<0.001. Duncan test showed significant differences between all compomer groups, except between groups F4 and F5, and between all composite groups except for groups Z1 and Z4 and for groups Z2 and Z3

  8. Effect of Water Storage on the Micro-shear Bond Strength of Two Self-etch Adhesives to Enamel and Dentin

    Directory of Open Access Journals (Sweden)

    Z. Jaberi Ansari

    2007-06-01

    Full Text Available Objective: This study evaluated the influence of storage time on micro-shear bond strength of two self-etching materials to enamel and dentin.Materials and Methods: Human third molar teeth were sectioned to 1.5 mm thick beams and randomly divided into 2 groups. In group I, SE Bond and in group II, Tri-S Bond was used to bond a composite rod (AP-X to each treated surface. Specimens were prepared according to manufacturer instructions. Each group was further divided into three subgroups according to water storage time; 1 day, 6 and 12 months. Microshear bond strengths were determined under a crosshead speed of 1mm/min using a universal testing machine and expressed in MPa. Data was statistically analyzed by ANOVA and Dunnett post hoc test.Results: Micro-shear bond strength of two adhesives to enamel and dentin showed a slight but not significant decrease over time (P>0.5. After one day, the mean bond strength of enamel in groups I and II were 39.47 and 34.65 MPa and in dentin were 45.20 and 36.0 MPa respectively. There was no statistically significant differencebetween two materials (P=0.190, P=0.082. After six months the bond strength in group I and II was 35.93 and 35.18 MPa for enamel, and 38.27and 35.19 MPa for dentin respectively, these differences was not statistically significant (P=0.520, P=0.179.After one year, the bond strength of enamel in groups I and II, were 34.47and 29.91MPa, and in dentin were 33.86 and 32.53 MPa respectively which was not statistically significant (P=0.609, P=0.991.Conclusion: The micro-shear bond strength of both adhesives to enamel and dentin decreased slightly over time; however these decreases were not statistically significant.

  9. Influence of the inter-layer adhesion on the structural strength of sandwich pipes; Influencia da adesao entre camadas na resistencia estrutural de dutos sanduiche

    Energy Technology Data Exchange (ETDEWEB)

    Castello, Xavier; Estefen, Segen [Universidade Federal, Rio de Janeiro, RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia. Programa de Engenharia Oceanica

    2005-07-01

    Sandwich pipes composed of two steel layers separated by a polypropylene annulus can be used for the transport of oil and gas in deep waters, combining high structural resistance with thermal insulation in order to prevent blockage by paraffin and hydrates. In this work, sandwich pipes with typical inner diameters of those employed in the offshore production are analyzed numerically regarding to the influence of the inter-layer adhesion of steel pipes and polymer on the limit strength under external pressure and longitudinal bending as well as the bending and straightening process representative of the reeling installation method. The numerical model incorporates geometric and material non-linearity, which had been based on previous works of the authors. Tests of specimens under tension and segments of sandwich pipes are carried through to evaluate the maximum shear stresses of the interfaces metal-polymer. The adhesion is modeled by contact adopting a maximum shear stress value to allow the relative displacement between the layers. It was observed that the structural resistance of the sandwich pipe is strongly dependent on the shear stress acting at the interface, occurring the collapse of the pipe when the maximum shear stress is reached. The results obtained are analyzed to determine the minimum shear strength at the union which provides adequate structural resistance for the sandwich pipe under representative conditions of the installation and operation loading phases. (author)

  10. First principles calculation of stable structure and adhesive strength of plated Ni/Fe(100) or Cu/Fe(100) interfaces

    Institute of Scientific and Technical Information of China (English)

    Ryota NAKANISHI; Koji SUEOKA; Seiji SHIBA; Makoto HINO; Koji MURAKAMI; Ken MURAOKA

    2009-01-01

    A study the with first principles calculation of the interfaces of the Ni layer or Cu layer on the Fe(100) surface formed with metal plating was performed. Ni or Cu atoms were shown to adopt the corresponding position to the bcc structure of the Fe(100) substrate. Other calculations showed that the interfaces of Ni (5 atomic layers)/Fe(100) (5 layers) or Cu (5 atomic layers)/Fe(100) (5 layers) had square lattices. The orientation relationship of Ni/Fe(100) interface corresponds to fcc-Ni(100)//bcc-Fe(100), Ni[011]//Fe[010], and Similar results were obtained for Cu/Fe(100) interfaces. This structure was supported by TEM analysis of plated Ni layer on Fe(100) surfaces. The adhesion strength of the Ni/Fe(100) interface evaluated by first principles calculation was higher than that of the Cu/Fe(100) interface. The experimental results of Hull cell iron plated with Ni or Cu supported the results of the calculation. These results indicate that the first principles calculation, which deals with the ideal interface at the atomic scale, has the potential to evaluate the adhesion strength of metallic material interfaces.

  11. Enhancement of mechanical strength of particleboard using environmentally friendly pine (Pinus pinaster L.) tannin adhesives with cellulose nanofibers

    OpenAIRE

    Cui, Juqing; Lu, Xiaoning; Zhou, Xiaojian; Chrusciel, Laurent; Deng, Yuhe; Zhou, Handong; Zhu, Shangwu; Brosse, Nicolas

    2015-01-01

    Context Condensed tannins have been successfully used as substitutes for phenol in the production of resins for wood products. However, the enhancement of the properties of tannin-based resins with nontoxic and cost effective additives is of great interest.• Methods In the present work, the performance enhancement of tannin-based particleboards with cellulose nanofibers was investigated.• Results In presence of 2 % of cellulose nanofibers, the viscosity of tannin-based adhesives and the inter...

  12. Dependence of adhesion strength between GaN LEDs and sapphire substrate on power density of UV laser irradiation

    Science.gov (United States)

    Park, Junsu; Sin, Young-Gwan; Kim, Jae-Hyun; Kim, Jaegu

    2016-10-01

    Selective laser lift-off (SLLO) is an innovative technology used to manufacture and repair micro-light-emitting diode (LED) displays. In SLLO, laser is irradiated to selectively separate micro-LED devices from a transparent sapphire substrate. The light source used is an ultraviolet (UV) laser with a wavelength of 266 nm, pulse duration of 20 ns, and repetition rate of 30 kHz. Controlled adhesion between a LED and the substrate is key for a SLLO process with high yield and reliability. This study examined the fundamental relationship between adhesion and laser irradiation. Two competing mechanisms affect adhesion at the irradiated interface between the GaN LED and sapphire substrate: Ga precipitation caused by the thermal decomposition of GaN and roughened interface caused by thermal damage on the sapphire. The competition between these two mechanisms leads to a non-trivial SLLO condition that needs optimization. This study helps understand the SLLO process, and accelerate the development of a process for manufacturing micro-LED displays via SLLO for future applications.

  13. The Study of the Grit-blasting Parameters and Their Effects on the Adhesive Strength of the Plasma Sprayed Coatings

    Institute of Scientific and Technical Information of China (English)

    M; Heydarzadeh; Sohi; M; Frooghieh; Sh; Khameneh; Asl

    2002-01-01

    Surface Preparation is very important in adhesive b on ding of spray coatings to the surface of a work piece. The common practice is gr it-blasting of the surface before subjecting it to the spray coating process. In this study, grit-blasting of an AISI 4130 steel (of different heat treatmen ts) with Al 2O 3 particles was studied. Various grit-blasting parameters such as blasting particle size, the distance between blasting nozzle and the work pi ece (25, 30 and 40 cm.), blasting pressure (3,4,5,6 and ...

  14. Shear Bond Strength of an Etch-and-rinse Adhesive to Er:YAG Laser- and/or Phosphoric Acid-treated Dentin.

    Science.gov (United States)

    Davari, Abdolrahim; Sadeghi, Mostafa; Bakhshi, Hamid

    2013-01-01

    Background and aims. Er:YAG laser irradiation has been claimed to improve the adhesive properties of dentin; therefore, it has been proposed as an alternative to acid etching. The aim of this in vitro study was to investigate the shear bond strength of an etch-and-rinse adhesive system to dentin surfaces following Er:YAG laser and/or phosphoric acid etching. Materials and methods. The roots of 75 sound maxillary premolars were sectioned below the CEJ and the crowns were embedded in auto-polymerizing acrylic resin with the buccal surfaces facing up. The buccal surfaces were ground using a diamond bur and polished until the dentin was exposed; the samples were randomly divided into five groups (n=15) according to the surface treatment: (1) acid etching; (2) laser etching; (3) laser etching followed by acid etching; (4) acid etching followed by laser etching and (5) no acid etching and no laser etching (control group). Composite resin rods (Point 4, Kerr Co) were bonded to treated dentin surfaces with an etch-and-rise adhesive system (Optibond FL, Kerr Co) and light-cured.After storage for two weeks at 37°C and 100% humidity and then thermocycling, bond strength was measured with a Zwick Universal Testing Machine at a crosshead speed of 1 mm/min. Data was analyzed using parametric and non-parametric tests (P<0.05). Results. Mean shear bond strength for acid etching (20.1±1.8 MPa) and acid+laser (15.6±3.5 MPa) groups were significantly higher than those for laser+acid (15.6±3.5 MPa), laser etching (14.1±3.4 MPa) and control (8.1±2.1 MPa) groups. However, there were no significant differences between acid etching and acid+laser groups, and between laser+acid and laser groups. Conclusion. When the cavity is prepared by bur, it is not necessary to etch the dentin surface by Er:YAG laser following acid etching and acid etching after laser etching. PMID:23875083

  15. Direct Tensile Strength and Characteristics of Dentin Restored with All-Ceramic, Resin-Composite, and Cast Metal Prostheses Cemented with Resin Adhesives

    Directory of Open Access Journals (Sweden)

    Morakot Piemjai

    2015-01-01

    Full Text Available A dentin-cement-prosthesis complex restored with either all-porcelain, cured resin-composite, or cast base metal alloy and cemented with either of the different resin cements was trimmed into a mini-dumbbell shape for tensile testing. The fractured surfaces and characterization of the dentin-cement interface of bonded specimens were investigated using a Scanning Electron Microscope. A significantly higher tensile strength of all-porcelain (12.5 ± 2.2 MPa than that of cast metal (9.2 ± 3.5 MPa restorations was revealed with cohesive failure in the cement and failure at the prosthesis-cement interface in Super-Bond C&B group. No significant difference in tensile strength was found among the types of restorations using the other three cements with adhesive failure on the dentin side and cohesive failure in the cured resin. SEM micrographs demonstrated the consistent hybridized dentin in Super-Bond C&B specimens that could resist degradation when immersed in hydrochloric acid followed by NaOCl solutions whereas a detached and degraded interfacial layer was found for the other cements. The results suggest that when complete hybridization of resin into dentin occurs tensile strength at the dentin-cement is higher than at the cement-prosthesis interfaces. The impermeable hybridized dentin can protect the underlying dentin and pulp from acid demineralization, even if detachment of the prosthesis has occurred.

  16. STRENGTH OF ADHESIVE JOINTS OF WOOD ON THE BASIS OF ELECTRICALLY TREATED GLUES Прочность клеевых соединений древесины на основе электрообработанных клеев

    Directory of Open Access Journals (Sweden)

    Mozgovoy N. V.

    2012-01-01

    Full Text Available The article considers the problem of creating of wood adhesive joints of high strength, through the use of adhesives, which were subjected to electrical treat-ment. We study the effect on the cohesive and adhe-sive strength of the joints on glues on the wet ability of wood adhesives and adhesive viscosity, exposed to electric field treatment

  17. STRENGTH OF ADHESIVE JOINTS OF WOOD ON THE BASIS OF ELECTRICALLY TREATED GLUES Прочность клеевых соединений древесины на основе электрообработанных клеев

    OpenAIRE

    Mozgovoy N. V.

    2012-01-01

    The article considers the problem of creating of wood adhesive joints of high strength, through the use of adhesives, which were subjected to electrical treat-ment. We study the effect on the cohesive and adhe-sive strength of the joints on glues on the wet ability of wood adhesives and adhesive viscosity, exposed to electric field treatment

  18. Resistência adesiva de resinas compostas à dentina Adhesive strength between composite resin and dentin substract

    Directory of Open Access Journals (Sweden)

    Joel BIANCHI

    1999-01-01

    Full Text Available As pesquisas relacionadas com adesão à dentina, em virtude da ampla aplicabilidade, são de grande interesse para a Odontologia. O objetivo deste estudo foi avaliar, através de ensaios de tração, a resistência adesiva ao substrato dentinário, em função de dois sistemas adesivos (3M e Kerr, dois níveis de rugosidade do substrato dentinário (lixas 220 e 600, duas áreas de colagem (3,14 mm2 - 12,56 mm2, e duas condições de armazenagem (inicial e final. A análise dos resultados evidenciou que: 1 houve diferença estatisticamente significativa entre os dois sistemas adesivos, sendo que o da Kerr apresentou os valores mais elevados de resistência adesiva; 2 diferenças significativas não ficaram evidentes na resistência da adesão entre os dois níveis de rugosidade dentinária; 3 as colagens em áreas menores apresentaram, em nível altamente significativo, maior resistência adesiva; 4 a condição de armazenagem influiu nos resultados dependendo da área e do sistema adesivo.There is a wealthy literature on bonding strength of composites to dentine. One of the reasons for the large number of studies is the continuous introduction of new bonding agents in combination with accumulated knowledge about the dentine substrate conditions. The aim of the present study was to compare the "in vitro" tensile bond strengths of two dentine bonding systems (3M and Kerr applied to different dentine roughness (220 and 600 gritand two sizes of bonding areas (3,14 mm2 and 12,56 mm2. Different storage conditions (initial and final were also considered. One hundred and sixty human teeth were randomly allocated in 4 groups. The Kerr system groups and the smallest bonding area groups showed the highest tensile strengths. The storage condition and the substrate roughness did not display a significant influence on bond strengths.

  19. Bond strength of adhesive systems to human tooth enamel Resistência adesiva de sistemas adesivos ao esmalte dentário humano

    Directory of Open Access Journals (Sweden)

    Thaís Cachuté Paradella

    2007-03-01

    Full Text Available The purpose of this study was to evaluate in vitro three adhesive systems: a total etching single-component system (G1 Prime & Bond 2.1, a self-etching primer (G2 Clearfil SE Bond, and a self-etching adhesive (G3 One Up Bond F, through shear bond strength to enamel of human teeth, evaluating the type of fracture through stereomicroscopy, following the ISO guidance on adhesive testing. Thirty sound premolars were bisected mesiodistally and the buccal and lingual surfaces were embedded in acrylic resin, polished up to 600-grit sandpapers, and randomly assigned to three experimental groups (n = 20. Composite resin cylinders were added to the tested surfaces. The specimens were kept in distilled water (37°C/24 h, thermocycled for 500 cycles (5°C-55°C and submitted to shear testing at a crosshead speed of 0.5 mm/min. The type of fracture was analyzed under stereomicroscopy and the data were submitted to Anova, Tukey and Chi-squared (5% statistical analyses. The mean adhesive strengths were G1: 18.13 ± 6.49 MPa, (55% of resin cohesive fractures; G2: 17.12 ± 5.80 MPa (90% of adhesive fractures; and G3: 10.47 ± 3.14 MPa (85% of adhesive fractures. In terms of bond strength, there were no significant differences between G1 and G2, and G3 was significantly different from the other groups. G1 presented a different type of fracture from that of G2 and G3. In conclusion, although the total etching and self-etching systems presented similar shear bond strength values, the types of fracture presented by them were different, which can have clinical implications.O objetivo deste estudo foi avaliar in vitro três sistemas adesivos: um monocomponente com condicionamento ácido total (G1 Prime & Bond 2.1, um "primer" autocondicionante (G2 Clearfil SE Bond e um adesivo autocondicionante (G3 One Up Bond F, através de resistência ao cisalhamento ao esmalte de dentes humanos, avaliando o tipo de fratura por estereomicroscopia, seguindo as normas ISO para testes

  20. Study on the Effect Factors of Lap-Shear Strength of Chloroprene Rubber Adhesive%氯丁型胶粘剂拉伸剪切强度的影响因素探讨

    Institute of Scientific and Technical Information of China (English)

    凌辉; 朱明新; 梁银齐; 毛秋燕; 陈炳江; 陈炳耀

    2011-01-01

    The author studies on the test conditions of lap-shear strength of chloroprene rubber adhesive by considering the effect factors such as the contact area of adhesive test samples,the waiting-time after being brushed,drying and compression.Then search on the suitable condition for testing the lap-shear strength of chloroprene rubber adhesive.%主要从胶粘剂测试试件粘接面积、晾胶时间以及干燥和加压等影响因素着手,对氯丁型胶粘剂拉伸剪切强度的测试条件进行了研究与讨论。得出测试氯丁型胶粘剂拉伸剪切强度较为合适的条件。

  1. Comparison of the effect of shear bond strength with silane and other three chemical presurface treatments of a glass fiber-reinforced post on adhesion with a resin-based luting agent: An in vitro study

    Directory of Open Access Journals (Sweden)

    Vaibhavi Ramkrishna Belwalkar

    2016-01-01

    Full Text Available Background: Loss of retention has been cited to be the most common cause of the failure of postretained restoration with irreversible consequences when materials with different compositions are in intimate contact at the post/adhesive interface. With this background, a study was conducted to improve the adhesion at the resin phase of fiber posts using silane and other chemical pretreatments. Materials and Methods: Hundred glass fiber-reinforced posts were tested with 4 different protocols (n = 25 using silane as a control (Group A and other three experimental groups, namely, Group B-20% potassium permanganate, Group C-4% hydrofluoric acid, and Group D-10% hydrogen peroxide were pretreated on the postsurface followed by silanization. These specimens were bonded with dual-polymerizing resin-based luting agent, which were then loaded at the crosshead speed of 1 mm/min to record the shear bond strength at the post/adhesive interface. The data were analyzed using one-way ANOVA test for multiple group comparisons and the post hoc Bonferroni test for pairwise comparisons (P < 0.05. Results: Group B showed more influence on the shear bond strength when compared to other protocols, respectively (P < 0.001. Conclusion: Alone silanization as a surface treatment did not improve the bond strength. Combination of chemical presurface treatments followed by silanization significantly enhanced the bond strength at the post/adhesive interface.

  2. Comparison of the effect of shear bond strength with silane and other three chemical presurface treatments of a glass fiber-reinforced post on adhesion with a resin-based luting agent: An in vitro study

    Science.gov (United States)

    Belwalkar, Vaibhavi Ramkrishna; Gade, Jaykumar; Mankar, Nikhil Purushottam

    2016-01-01

    Background: Loss of retention has been cited to be the most common cause of the failure of postretained restoration with irreversible consequences when materials with different compositions are in intimate contact at the post/adhesive interface. With this background, a study was conducted to improve the adhesion at the resin phase of fiber posts using silane and other chemical pretreatments. Materials and Methods: Hundred glass fiber-reinforced posts were tested with 4 different protocols (n = 25) using silane as a control (Group A) and other three experimental groups, namely, Group B-20% potassium permanganate, Group C-4% hydrofluoric acid, and Group D-10% hydrogen peroxide were pretreated on the postsurface followed by silanization. These specimens were bonded with dual-polymerizing resin-based luting agent, which were then loaded at the crosshead speed of 1 mm/min to record the shear bond strength at the post/adhesive interface. The data were analyzed using one-way ANOVA test for multiple group comparisons and the post hoc Bonferroni test for pairwise comparisons (P < 0.05). Results: Group B showed more influence on the shear bond strength when compared to other protocols, respectively (P < 0.001). Conclusion: Alone silanization as a surface treatment did not improve the bond strength. Combination of chemical presurface treatments followed by silanization significantly enhanced the bond strength at the post/adhesive interface. PMID:27307666

  3. Water interaction and bond strength to dentin of dye-labelled adhesive as a function of the addition of rhodamine B

    Science.gov (United States)

    WANG, Linda; BIM, Odair; LOPES, Adolfo Coelho de Oliveira; FRANCISCONI-DOS-RIOS, Luciana Fávaro; MAENOSONO, Rafael Massunari; D’ALPINO, Paulo Henrique Perlatti; HONÓRIO, Heitor Marques; ATTA, Maria Teresa

    2016-01-01

    ABSTRACT Objective This study investigated the effect of the fluorescent dye rhodamine B (RB) for interfacial micromorphology analysis of dental composite restorations on water sorption/solubility (WS/WSL) and microtensile bond strength to dentin (µTBS) of a 3-step total etch and a 2-step self-etch adhesive system. Material and Methods The adhesives Adper Scotchbond Multi-Purpose (MP) and Clearfil SE Bond (SE) were mixed with 0.1 mg/mL of RB. For the WS/WSL tests, cured resin disks (5.0 mm in diameter x 0.8 mm thick) were prepared and assigned into four groups (n=10): MP, MP-RB, SE, and SE-RB. For µTBS assessment, extracted human third molars (n=40) had the flat occlusal dentin prepared and assigned into the same experimental groups (n=10). After the bonding and restoration procedures, specimens were sectioned in rectangular beams, stored in water and tested after seven days or after 12 months. The failure mode of fractured specimens was qualitatively evaluated under optical microscope (x40). Data from WS/WSL and µTBS were assessed by one-way and three-way ANOVA, respectively, and Tukey’s test (α=5%). Results RB increased the WSL of MP and SE. On the other hand, WS of both MP and SE was not affected by the addition of RB. No significance in µTBS between MP and MP-RB for seven days or one year was observed, whereas for SE a decrease in the µTBS means occurred in both storage times. Conclusions RB should be incorporated into non-simplified DBSs with caution, as it can interfere with their physical-mechanical properties, leading to a possible misinterpretation of bonded interface. PMID:27556201

  4. Resistência de união à dentina de quatro sistemas adesivos Bond strength of four adhesive systems to dentin

    Directory of Open Access Journals (Sweden)

    Marcela Rocha de Oliveira Carrilho

    2002-09-01

    Full Text Available O objetivo do presente estudo foi avaliar a resistência adesiva de quatro sistemas adesivos, composicionalmente diferentes, aplicados à dentina humana. Doze dentes terceiros molares humanos tiveram o esmalte oclusal removido para exposição de uma superfície plana de dentina, na qual foram realizados os procedimentos de adesão. Os dentes foram aleatoriamente divididos em quatro grupos, considerando-se o sistema adesivo e a resina composta a serem empregados: Grupo 1 - Single Bond + P60 (SB; Grupo 2 - Bond 1 + Surefil (B1; Grupo 3 - Prime & Bond NT + Alert (NT e Grupo 4 - Prime & Bond 2.1 + TPH (2.1. Após 24 h de armazenagem em água destilada a 37ºC, os dentes foram seccionados, longitudinalmente, em cortes perpendiculares entre si, para que fossem obtidos espécimes em formato de um paralelogramo com secção transversal retangular de 0,8 mm² de área e 10 mm de comprimento, em média. Os espécimes foram submetidos ao teste de microtração. A análise de variância (alfa = 0,05 demonstrou não haver diferença significante entre os valores médios de resistência obtidos pelos quatro adesivos, embora a análise dos espécimes que sofreram fratura precoce tenha evidenciado menor sensibilidade para o sistema SB.The purpose of the present study was to evaluate the bond strength of four adhesive systems to dentin. Twelve human third molars had their occlusal enamel removed in order to expose a flat dentinal surface, on which the adhesive procedures were carried out. The teeth were divided into four groups, according to the employed adhesive system and composite resin: Group 1 - Single Bond + P60 (SB; Group 2 - Bond 1 + Surefil (B1; Group 3 - Prime & Bond NT + Alert (NT; and Group 4 - Prime & Bond 2.1 + TPH (2.1. After 24 h in distilled water at 37ºC, the teeth were longitudinally sectioned in two perpendicular directions in order to obtain parallelogram-shaped specimens with a cross-sectional area of 0.8 mm² and 10 mm of length, on the

  5. Evaluation of Er,Cr:YSGG Laser Effect on Microshear Bond Strength of a Self-Adhesive Flowable Composite in the Dentin of Permanent Molar: An In Vitro Study

    Science.gov (United States)

    Moslemi, Masoumeh; Javadi, Fatemeh; Khalili Sadrabad, Zahra; Shadkar, Zahra; Shadkar, Mohammad Saeid

    2016-01-01

    Aim and Background. Recently, new restorative materials such as self-adhesive flowable composites, because of their simple use and no need to bonding and etching, are considered important, particularly in pediatric dentistry. The aim of this study is to evaluate the effect of Er,Cr:YSGG laser on microshear bond strength of self-adhesive flowable composite on permanent teeth dentin in vitro. Material and Methods. In this experimental study, 40 dentin sections were prepared from healthy third molars and divided into two groups according to their surface preparation by Er,Cr:YSGG laser or without laser, only with silicon carbide paper. In each group, two groups of 10 teeth were treated with self-adhesive flowable composite (Dyad) and conventional flowable composite (acid etch and bonding). Samples were stored in normal saline and after 48 hours their bond strength was measured. The failure mode of samples was observed on stereomicroscope. In order to analyse the results, the one way ANOVA and Tukey's test for multiple comparisons were used. Result. The maximum bond strength was related to conventional flowable composite with laser preparation group (24/21 Mpa). The lowest one was seen in Dyad composite without laser emitting (9/89 Mpa). The statistical difference between this two groups was significant (P value = 0/0038). The microshear bond strength differences between Dyad composite groups with laser preparation (mean = 16/427 ± 1/79) and without laser preparation (mean = 12/85 ± 1/90) were statistically significant too (P value = 0/01). Conclusion. Self-adhesive flowable composite has lower microshear bond strength than conventional flowable composite. Moreover, the laser irradiation as a surface treatment can improve this bond strength. PMID:27493829

  6. Evaluation of Er,Cr:YSGG Laser Effect on Microshear Bond Strength of a Self-Adhesive Flowable Composite in the Dentin of Permanent Molar: An In Vitro Study.

    Science.gov (United States)

    Moslemi, Masoumeh; Fotouhi Ardakani, Faezeh; Javadi, Fatemeh; Khalili Sadrabad, Zahra; Shadkar, Zahra; Shadkar, Mohammad Saeid

    2016-01-01

    Aim and Background. Recently, new restorative materials such as self-adhesive flowable composites, because of their simple use and no need to bonding and etching, are considered important, particularly in pediatric dentistry. The aim of this study is to evaluate the effect of Er,Cr:YSGG laser on microshear bond strength of self-adhesive flowable composite on permanent teeth dentin in vitro. Material and Methods. In this experimental study, 40 dentin sections were prepared from healthy third molars and divided into two groups according to their surface preparation by Er,Cr:YSGG laser or without laser, only with silicon carbide paper. In each group, two groups of 10 teeth were treated with self-adhesive flowable composite (Dyad) and conventional flowable composite (acid etch and bonding). Samples were stored in normal saline and after 48 hours their bond strength was measured. The failure mode of samples was observed on stereomicroscope. In order to analyse the results, the one way ANOVA and Tukey's test for multiple comparisons were used. Result. The maximum bond strength was related to conventional flowable composite with laser preparation group (24/21 Mpa). The lowest one was seen in Dyad composite without laser emitting (9/89 Mpa). The statistical difference between this two groups was significant (P value = 0/0038). The microshear bond strength differences between Dyad composite groups with laser preparation (mean = 16/427 ± 1/79) and without laser preparation (mean = 12/85 ± 1/90) were statistically significant too (P value = 0/01). Conclusion. Self-adhesive flowable composite has lower microshear bond strength than conventional flowable composite. Moreover, the laser irradiation as a surface treatment can improve this bond strength.

  7. Evaluation of Er,Cr:YSGG Laser Effect on Microshear Bond Strength of a Self-Adhesive Flowable Composite in the Dentin of Permanent Molar: An In Vitro Study.

    Science.gov (United States)

    Moslemi, Masoumeh; Fotouhi Ardakani, Faezeh; Javadi, Fatemeh; Khalili Sadrabad, Zahra; Shadkar, Zahra; Shadkar, Mohammad Saeid

    2016-01-01

    Aim and Background. Recently, new restorative materials such as self-adhesive flowable composites, because of their simple use and no need to bonding and etching, are considered important, particularly in pediatric dentistry. The aim of this study is to evaluate the effect of Er,Cr:YSGG laser on microshear bond strength of self-adhesive flowable composite on permanent teeth dentin in vitro. Material and Methods. In this experimental study, 40 dentin sections were prepared from healthy third molars and divided into two groups according to their surface preparation by Er,Cr:YSGG laser or without laser, only with silicon carbide paper. In each group, two groups of 10 teeth were treated with self-adhesive flowable composite (Dyad) and conventional flowable composite (acid etch and bonding). Samples were stored in normal saline and after 48 hours their bond strength was measured. The failure mode of samples was observed on stereomicroscope. In order to analyse the results, the one way ANOVA and Tukey's test for multiple comparisons were used. Result. The maximum bond strength was related to conventional flowable composite with laser preparation group (24/21 Mpa). The lowest one was seen in Dyad composite without laser emitting (9/89 Mpa). The statistical difference between this two groups was significant (P value = 0/0038). The microshear bond strength differences between Dyad composite groups with laser preparation (mean = 16/427 ± 1/79) and without laser preparation (mean = 12/85 ± 1/90) were statistically significant too (P value = 0/01). Conclusion. Self-adhesive flowable composite has lower microshear bond strength than conventional flowable composite. Moreover, the laser irradiation as a surface treatment can improve this bond strength. PMID:27493829

  8. Influence of artificial aging on the shear bond strength of zirconia-composite interfaces after pretreatment with new 10-MDP adhesive systems

    Directory of Open Access Journals (Sweden)

    p.c pott

    2016-03-01

    Full Text Available Introduction: This in-vitro study investigates the bond strength of different zirconia composites  with three different modern adhesive systems after artificial aging using thermocycling and water storage. Methods: A total of 90 specimens of zirconia (InCoris, Sirona, Germany, Bernsheim were ground using a 165 µm grit rotating diamond disc. Thirty specimens were additionally treated with either Futurabond U “FBU” (VOCO GmbH, or Futurabond M+ “FBM” (VOCO GmbH or Futurabond M+ in combination with the DCA activator “FBMD” (VOCO GmbH. One of the three different types of composites – BifixSE “BS”, BifixQM “BQ” or GrandioSO “G” (VOCO GmbH – was bonded to the ten specimens of each group. All of the specimens underwent artificial aging using thermocycling between 5°C and 55°C for 5000 cycles followed by water storage for 100 days. Shear bond strength (SBS was determined in a universal testing machine. The type of failure was evaluated using fluorescence microscopy. The data were compared to existing data without artificial aging. Statistical analysis was performed with ANOVA and the Tukey test. Results: FBM and FBMD had higher SBS than FBU in combination with all tested composites, except BifixSE. In nearly all groups, artificial aging had no effect, with the exception of the combination of FBMD with BifixSE, in which there was a significant decrease in SBS after the aging process (p

  9. Hierarchical fabrication of heterojunctioned SrTiO3/TiO2 nanotubes on 3D microporous Ti substrate with enhanced photocatalytic activity and adhesive strength

    Science.gov (United States)

    Zhou, Jie; Yin, Lu; Zha, Kang; Li, Huirong; Liu, Zhiyuan; Wang, Jianxin; Duan, Ke; Feng, Bo

    2016-03-01

    Recently, construction of three-dimensional (3D) architecture and design of heterostructure have been proved to be two important approaches for improving photocatalytic (PC) properties of TiO2-based catalysts. In this work, a 3D microporous surface on Ti substrate (MPT) was prepared by simple acid etching. Then, heterojunctioned SrTiO3/TiO2 nanotubes with dominant {001} facets of anatase TiO2were successfully fabricated on MPT by combining anodization with hydrothermal treatment. The 3D microporous-patterned SrTiO3/TiO2 nanotubes heterojunction shows significantly enhanced photo-current density and ∼200% improved PC effect in degradation of Rhodamine B owing to its higher specific surface area, stronger light-harvesting ability and positive heterojunction effect in comparison with TiO2 nanotubes formed on flat Ti substrate. Moreover, the 3D microporous structure on Ti substrate improved the adhesive strength between the nanotubes layer and Ti substrate, which can be ascribed to the effective release of internal stress. Therefore, this present strategy is expected to expand the application of TiO2-based catalysts in many fields which require excellent PC properties and mechanical stability.

  10. Resistência ao cisalhamento da colagem com compósitos utilizando potencializador de adesão Shear bond strength of composites using an adhesion booster

    Directory of Open Access Journals (Sweden)

    Edivaldo de Morais

    2011-10-01

    Full Text Available OBJETIVO: avaliar a resistência ao cisalhamento dos compósitos Transbond XT e Concise Ortodôntico utilizando o potencializador de adesão Ortho Primer. MÉTODOS: a amostra consistiu de 90 incisivos bovinos divididos em seis grupos (n=15. Todos os dentes receberam profilaxia com pedra-pomes e condicionamento do esmalte com ácido fosfórico. No Grupo I, utilizou-se Transbond XT de maneira convencional. O Grupo II foi semelhante ao I, porém, aplicou-se o Ortho Primer ao invés do XT Primer. No Grupo III, após condicionamento, o esmalte foi contaminado com saliva, aplicou-se o Ortho Primer e colagem com Transbond XT. No Grupo IV, utilizou-se o Concise Ortodôntico de maneira convencional. O Grupo V foi semelhante ao IV, porém, utilizou-se o Ortho Primer ao invés da resina fluida. No Grupo VI, após condicionamento, o esmalte foi contaminado com saliva, aplicou-se o Ortho Primer e colagem com Concise. Os corpos de prova foram armazenados em água destilada em estufa a 37ºC por 24h e submetidos ao ensaio de resistência ao cisalhamento. Os dados foram submetidos à ANOVA e ao teste de Tukey (5%. RESULTADOS: a resistência da colagem no Grupo IV foi estatisticamente superior à dos Grupos II, III e VI (p0,05. O Transbond XT e o Concise utilizados convencionalmente obtiveram os maiores valores adesivos. O Ortho Primer em esmalte seco atuou efetivamente como agente de união dos compósitos avaliados. Em esmalte contaminado, a colagem com Concise obteve baixa resistência adesiva.OBJECTIVE: The aim of this study was to evaluate the shear bond strength of the Transbond XT and Concise Orthodontics composites using the Ortho Primer adhesion booster. METHODS: The sample consisted of 90 bovine incisors divided in 6 groups (n=15. All teeth were submitted to prophylaxes with pumice stone and etching with phosphoric acid. In Group I the Transbond XT was used conventionally. Group II was similar to Group I, however, Ortho Primer was used instead of XT

  11. Preparation and performance of epoxy resin adhesive with high peeling strength for FCCL%挠性覆铜板用高剥离强度环氧胶的制备及性能

    Institute of Scientific and Technical Information of China (English)

    王成; 俞娟; 王晓东; 黄培

    2011-01-01

    用液体端羧基丁腈橡胶(CTBN)对环氧树脂E-51进行改性,合成了CTBN/E-51预聚物。采用红外光谱、示差扫描量热仪、万能试验机及电子显微镜表征了产物结构,确定了固化工艺,研究了预聚反应温度、时间,CTBN含量对环氧胶剥离强度的影响,并观察了剥离断面的形貌。结果表明,CTBN质量分数为15%,预聚温度为90℃,反应时间2 h所制得环氧胶的剥离强度最高,其粘接强度随预聚时间的增加而增加。该胶可满足挠性覆铜板的生产需要。%The epoxy resin E-51 was modified with liquid carboxyl-terminated poly(butadiene-co-acrylonitrile)(CTBN)-and the prepolymer was synthesized.The structure of the propolymer was characterized by FTIR.The curing precess was determined by DSC.The effects of the prepolymerization temperature,time and the CTBN contents on the peeling strength of the epoxy adhesive were investigated by universal testing machine.The morphology of stripping cross-section was observed by SEM.The result showed the optimum preparation conditions for epoxy adhesive were as followed:15% mass fraction of CTBN,prepolymerization temperature 90 ℃and reaction time 2 h and the peeling strength of the epoxy adhesive reached the maximum.The adhesive strength was increased with the increasing of prepolymerization time.The adhesives could meet the needs of FCCL production.

  12. Electro-dry-adhesion.

    Science.gov (United States)

    Krahn, Jeffrey; Menon, Carlo

    2012-03-27

    This work presents novel conductive bioinspired dry adhesives with mushroom caps that enable the use of a synergistic combination of electrostatic and van der Waals forces (electro-dry-adhesion). An increase in shear adhesion bond strength of up to 2046% on a wide range of materials is measured when a maximum electrical field of 36.4 V μm(-1) is applied. A suction effect, due to the shape of the dry adhesive fibers, on overall adhesion was not noted for electro-dry-adhesives when testing was performed at both atmospheric and reduced pressure. Utilization of electrostatics to apply a preloading force to dry adhesive fiber arrays allows increased adhesion even after electrostatic force generation has been halted by ensuring the close contact necessary for van der Waals forces to be effective. A comparison is made between self-preloading of the electro-dry-adhesives and the direct application of a normal preloading pressure resulting in nearly the same shear bond strength with an applied voltage of 3.33 kV on the same sample.

  13. Dry adhesives with sensing features

    Science.gov (United States)

    Krahn, J.; Menon, C.

    2013-08-01

    Geckos are capable of detecting detachment of their feet. Inspired by this basic observation, a novel functional dry adhesive is proposed, which can be used to measure the instantaneous forces and torques acting on an adhesive pad. Such a novel sensing dry adhesive could potentially be used by climbing robots to quickly realize and respond appropriately to catastrophic detachment conditions. The proposed torque and force sensing dry adhesive was fabricated by mixing Carbon Black (CB) and Polydimethylsiloxane (PDMS) to form a functionalized adhesive with mushroom caps. The addition of CB to PDMS resulted in conductive PDMS which, when under compression, tension or torque, resulted in a change in the resistance across the adhesive patch terminals. The proposed design of the functionalized dry adhesive enables distinguishing an applied torque from a compressive force in a single adhesive pad. A model based on beam theory was used to predict the change in resistance across the terminals as either a torque or compressive force was applied to the adhesive patch. Under a compressive force, the sensing dry adhesive was capable of measuring compression stresses from 0.11 Pa to 20.9 kPa. The torque measured by the adhesive patch ranged from 2.6 to 10 mN m, at which point the dry adhesives became detached. The adhesive strength was 1.75 kPa under an applied preload of 1.65 kPa for an adhesive patch with an adhesive contact area of 7.07 cm2.

  14. Evaluation of tensile strength of tissue adhesives and sutures for clear corneal incisions using porcine and bovine eyes, with a novel standardized testing platform

    Directory of Open Access Journals (Sweden)

    Kaja S

    2012-02-01

    Full Text Available Simon Kaja, Daryl L Goad, Fatima Ali, Ashley Abraham, R Luke Rebenitsch, Savak Teymoorian, Rohit Krishna, Peter KoulenVision Research Center and Department of Ophthalmology, University of Missouri-Kansas City, School of Medicine, Kansas City, MO, USABackground: Tissue adhesives for ophthalmologic applications were proposed almost 50 years ago, yet to date no adequate tissue glues have been identified that combine strong sealing properties with adequate safety and absence of postsurgical side effects. In recent years, cataract surgeries and Descemet's stripping with endothelial keratoplasty procedures have significantly increased the number of clear corneal incisions performed. One of the obstacles to discovery and development of novel tissue adhesives has been the result of nonstandardized testing of potential tissue glues.Methods: We developed an instrument capable of controlling intraocular pressure in explanted porcine and bovine eyes in order to evaluate sealants, adhesives, and surgical closure methods used in ophthalmic surgery in a controlled, repeatable, and validated fashion. We herein developed and validated our instrument by testing the adhesive properties of cyanoacrylate glue in both porcine and bovine explant eyes.Results: The instrument applied and maintained intraocular pressure through a broad range of physiological intraocular pressures. Cyanoacrylate-based glues showed significantly enhanced sealing properties of clear corneal incisions compared with sutured wounds.Conclusion: This study shows the feasibility of our instrument for reliable and standardized testing of tissue adhesive for ophthalmological surgery.Keywords: manometer, intraocular pressure, applanation tonometry, clear corneal incision, tissue adhesive, ocular surgery

  15. Abdominal Adhesions

    Science.gov (United States)

    ... adhesions? Abdominal adhesions can cause intestinal obstruction and female infertility—the inability to become pregnant after a year of trying. Abdominal adhesions can lead to female infertility by preventing fertilized eggs from reaching the uterus, ...

  16. 表面处理对5083铝合金板胶接性能的影响%Effects of Surface Treatment on Adhesion Strength of 5083 Aluminium Alloy Plates

    Institute of Scientific and Technical Information of China (English)

    刘晓静; 陈春焕; 赵志强

    2013-01-01

    以α-氰基丙烯酸酯类瞬干胶为胶粘剂,采用剪切试验、接触角试验和扫描电镜观察系统研究了丙酮简单清洗、喷砂处理、阳极氧化处理以及偶联剂处理对5083铝合金板胶接接头剪切强度的影响.结果表明:经简单清洗后,所得胶接接头的剪切强度最低;在附着力和机械啮合的共同作用下,喷砂处理和阳极氧化处理胶接接头的强度得到了提高,其中阳极氧化处理的效果最为明显,与简单清洗胶接接头相比,剪切强度提高了223.1%;胶接前适当使用偶联剂可以使简单清洗和喷砂处理胶接接头的剪切强度提高,在该试验条件下,KH-550偶联剂体积分数为5%时,胶接接头的剪切强度均达到了最大值;但偶联剂使阳极氧化处理形成的纳米小孔不能发挥机械啮合作用,所得胶接接头的剪切强度相比未使用偶联剂的反而降低.%Using crcyanoaerylate as adhesive, the effect of surface treatments such as simple cleaning, sand blasting, anodic oxidation and coupling agent treatment on adhesion strength of 5083 aluminium alloy plates was studied by shearing test, contact angle test and SEM observation. The results indicate that through simple cleaning, the shear strength of the adhesive joints was the lowest. With the combined function of adhesive force and mechanical meshing, the shear strength of the adhesive joints which pretreated by sand blasting and anodic oxidation was increased, the effect of anodic oxidation treatment was the most obvious, and the shear strength of joints pretreated by anodic oxidation increased 223. 1% than that of joints pretreated by simple cleaning. Proper using of coupling agent before adhesion resulted in the improvement of shear strength of joints pretreated by simple cleaning and sand blasting. Under this test condition, the proper volume fraction of KH-550 coupling agent was 5%, and bonding with which the shear strength of the joints got to the highest

  17. Improvement of Interfacial Adhesion Strength and Thermal Stability of Cu/p-SiC:H/SiOC:H Film Stack by Plasma Treatment on the Surface of Cu Film

    International Nuclear Information System (INIS)

    A highly reliable interface of self-aligned barrier CuSiN thin layer between the Cu film and the nano-porous SiC:H (p-SiC:H) capping barrier (k=3.3) has been developed in the present work. With the introduction of self-aligned barrier (SAB) CuSiN between a Cu film and a p-SiC:H capping barrier, the interfacial thermal stability and the adhesion of the Cu/p-SiC:H film are considerably enhanced. A significant improvement of adhesion strength and thermal stability of Cu/p-SiC:H/SiOC:H film stack has been achieved by optimizing the pre-clean step before cap-layer deposition and by forming the CuSiN-like phase. This cap layer on the surface of the Cu can provide a more cohesive interface and effectively suppress Cu atom migration as well.

  18. Strength behavior and applicability of plastic-metal-adhesive-joints for lightweight automotive construction; Festigkeitsverhalten und Anwendungspotentiale von Kunststoff-Metall-Klebeverbindungen fuer den Fahrzeugleichtbau

    Energy Technology Data Exchange (ETDEWEB)

    Dorn, L.; Hofmann, F. [Inst. fuer Werkzeugmaschinen und Fabrikbetrieb - FG Fuegetechnik und Beschichtungstechnik (Germany)

    2001-07-01

    Adhesive bonding offers considerable advantages in the automotive construction for many application areas opposite to other joining methods. In view of the lightweight construction and use of synthetic materials adhesive joining technology will attain in future a greater importance in the vehicle engineering. In combination with the development of new adhesives the economic solution of till now still open joining problems is possible. (orig.) [German] Das Kleben bietet im Fahrzeugbau fuer viele Anwendungsgebiete erhebliche Vorteile gegenueber anderen Fuegeverfahren. Gerade im Hinblick auf den Leichtbau und den Einsatz von Kunststoffen wird die Klebtechnik in Zukunft noch groessere Bedeutung im Fahrzeugbau erlangen. Durch Ihren Einsatz in Verbindung mit der Entwicklung neuer Klebstoffe ist die wirtschaftliche Loesung bisher noch offener Verbindungsprobleme moeglich. (orig.)

  19. 固化光源对正畸托槽光敏粘结剂抗剪切强度及粘结剂残留指数影响的研究%Effects of Light- curing Units on Shear Bond Strength and Adhesive Remnant Index of Light- curing Orthodontic Adhesives

    Institute of Scientific and Technical Information of China (English)

    赖颖真; 丘雨蓓; 林珊

    2012-01-01

    Objective: To evaluate the effect of quartz-tungsten-halogen light(QTH) and LED curing systems on shear bond strength of resin adhesive (3M) and resin-modified glass ionomer adhesive (GC); and to provide evidences for clinical chose of curing lights and orthodontic adhesives. Methods: 48 freshly-extracted human premo-lars were randomly assigned into 4 bonding groups (n=12/group) , brackets were respectively bonded with different adhesives and Light-curing units. The shear bond strength of the adhesive system was evaluated with an Universal testing machine. Adhesive remnant index (ARI) scores were determined after bracket failure. Results: The shear bond strength and ARI of 3M was significant lager than GC(P<0. 05). No matter which adhensive was used, no significant difference was found in shear bond strength and ARI between the LED and QTH. Conclusion: Both two kinds of light curing adhensives can satisfy the clinic need of orthodontics. Resin- modified glass ionomer adhesive has significantly less incidences of enamel failure. Orthodontic adhesives cured with LED was statistically equivalent to those cured with a QTH. LED can save the time and be suggested for the polymerization of orthodontic bonding adhesives.%目的:研究普通卤素灯(QTH)和发光二级管灯(LED)对正畸托槽复合树脂光敏粘结剂(3M)和树脂加强型玻璃离子光敏粘结剂((C)抗剪切力的影响,为临床正畸粘结材料和固化光源的选择提供一定依据.方法:选取新鲜拔除的第一双尖牙48颗,随机分为4组,使用不同粘结材料和不同光源配合粘结标准网底方丝弓托槽,采用微机万能材料实验机对托槽的粘结强度进行检测,同时记录粘结剂残留指数(ARI).结果:3M抗剪切力及ARI值均显著大于GC(P<0.05);QTH和LED对3M和GC的抗剪切力及ARI值影响差别无统计学意义.结论:2种正畸光敏粘结剂抗剪切强度均符合临床要求,托槽去除后GC对牙面破坏较小;LED灯照可以节约

  20. Tensile bond strength of adhesive systems: effects of primer and thermocycling Resistência à tração de sistemas adesivos: efeitos do “ primer” e dos ciclos térmicos

    OpenAIRE

    Luciana Tibiriçá AGUILAR; de Rezende, Nathalie Pepe Medeiros; REIS, Alessandra; Alessandro Dourado LOGUERCIO; Grande, Rosa Helena Miranda; BALLESTER Rafael Yagüe; Julio da Motta SINGER

    2002-01-01

    The objective of this study was to evaluate the effects of primer and thermocycling on the bond strength of multi-purpose adhesive systems applied to enamel, under tensile stress. The following bonding systems were applied, according to the manufacturers' instructions, on unground enamel buccal surfaces of 96 premolars, with or without the application of primer: Scotchbond MP, OptiBond FL, Amalgambond Plus and OptiBond (dual-cure). A composite resin (Z100, 3M) was applied and light-cured in a...

  1. Evaluation of tensile strength of tissue adhesives and sutures for clear corneal incisions using porcine and bovine eyes, with a novel standardized testing platform

    OpenAIRE

    Kaja S; Goad DL; Ali F; Abraham A; Rebenitsch RL; Teymoorian S; Krishna R; Koulen P

    2012-01-01

    Simon Kaja, Daryl L Goad, Fatima Ali, Ashley Abraham, R Luke Rebenitsch, Savak Teymoorian, Rohit Krishna, Peter KoulenVision Research Center and Department of Ophthalmology, University of Missouri-Kansas City, School of Medicine, Kansas City, MO, USABackground: Tissue adhesives for ophthalmologic applications were proposed almost 50 years ago, yet to date no adequate tissue glues have been identified that combine strong sealing properties with adequate safety and absence of postsurgical side ...

  2. Study on Modification of Octyl-α-Cyanoacrylate Medical Adhesive

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Objective:In order that the adhesive character could be improved to modify the octyl-α-cyanoacrylate(OCA) medical adhesive.Methods:Suitable modifiers involving polycaprolactone(PCL),dibutyl phthalate (DBP),dioctyl phthalate(DOP) and poly octyl methacrylat(POMA) have been chosen to modify the OCA adhesive,then tensile shear strength and adhesive strength are tested to evaluate the bond character of adhesives.Results:The PCL group's tensile shear strength and adhesive strength in normal temperature are descen...

  3. Adhesive Categories

    DEFF Research Database (Denmark)

    Lack, Stephen; Sobocinski, Pawel

    2003-01-01

    We introduce adhesive categories, which are categories with structure ensuring that pushouts along monomorphisms are well-behaved. Many types of graphical structures used in computer science are shown to be examples of adhesive categories. Double-pushout graph rewriting generalises well...... to rewriting on arbitrary adhesive categories....

  4. Adhesive Categories

    DEFF Research Database (Denmark)

    Lack, Stephen; Sobocinski, Pawel

    2004-01-01

    We introduce adhesive categories, which are categories with structure ensuring that pushouts along monomorphisms are well-behaved. Many types of graphical structures used in computer science are shown to be examples of adhesive categories. Double-pushout graph rewriting generalises well...... to rewriting on arbitrary adhesive categories....

  5. Poly-L-lactide/sodium alginate/chitosan microsphere hybrid scaffolds made with braiding manufacture and adhesion technique: Solution to the incongruence between porosity and compressive strength.

    Science.gov (United States)

    Lin, Jia-Horng; Chen, Chih-Kuang; Wen, Shih-Peng; Lou, Ching-Wen

    2015-01-01

    Bone scaffolds require a three-dimensional structure, high porosity, interconnected pores, adequate mechanical strengths, and non-toxicity. A high porosity is incongruent with mechanical strengths. Therefore, this study combines a braiding method and microsphere solution to create bone scaffolds with a high porosity and sufficient mechanical strengths. First, poly-L-lactide (PLLA) plied yarns are braided into 5-, 10-, 15-, 20-, and 25-layer hollow braids, and then thermally treated at 165 °C for various durations. Next, sodium alginate (SA) microspheres, cross-linked with CaCl2 solution with various concentrations, are combined with PLLA porous braided bone scaffolds to form PLLA/SA/CS microsphere hybrid scaffolds, which are then observed for surface observation, and tested for porosity, water contact angle, compressive strength, MTT assay, bioactivity, alkaline phosphatase (ALP) assay, cell attachment, and statistical analyses. The test results show that the layer amount of the bone scaffold is proportional to the compressive strength. With the same number of layers, the compressive strength is inversely proportional to the concentration of the CaCl2 solution. The results of surface observation, porosity, and water contact angle tests show that PLLA/SA/CS microsphere hybrid scaffolds possess a high porosity and good hydrophilicity; as a result, the braiding manufacture and the bonding technique effectively solve the confliction between porosity and mechanical strength. The concentration of CaCl2 does not pertain to cell activity and ALP results, exemplified by good cell attachment on bone scaffolds for each specification. PMID:25953547

  6. Optimizing Adhesive Design by Understanding Compliance.

    Science.gov (United States)

    King, Daniel R; Crosby, Alfred J

    2015-12-23

    Adhesives have long been designed around a trade-off between adhesive strength and releasability. Geckos are of interest because they are the largest organisms which are able to climb utilizing adhesive toepads, yet can controllably release from surfaces and perform this action over and over again. Attempting to replicate the hierarchical, nanoscopic features which cover their toepads has been the primary focus of the adhesives field until recently. A new approach based on a scaling relation which states that reversible adhesive force capacity scales with (A/C)(1/2), where A is the area of contact and C is the compliance of the adhesive, has enabled the creation of high strength, reversible adhesives without requiring high aspect ratio, fibrillar features. Here we introduce an equation to calculate the compliance of adhesives, and utilize this equation to predict the shear adhesive force capacity of the adhesive based on the material components and geometric properties. Using this equation, we have investigated important geometric parameters which control force capacity and have shown that by controlling adhesive shape, adhesive force capacity can be increased by over 50% without varying pad size. Furthermore, we have demonstrated that compliance of the adhesive far from the interface still influences shear adhesive force capacity. Utilizing this equation will allow for the production of adhesives which are optimized for specific applications in commercial and industrial settings.

  7. A physical model to describe the distribution of adhesion strength in MEMS, or why one MEMS device sticks and another ‘identical’ one does not

    International Nuclear Information System (INIS)

    In this paper a model is presented that describes the distribution of adhesion values typically experimentally observed for different MEMS devices that have been fabricated in the same way. This spread is attributed to the fact that different devices differ in the details of their surface roughness, even if these surface roughnesses are modeled as coming from the same ‘parent’ stochastic process. Using Monte Carlo simulations, the effect of surface roughness and relative humidity has been evaluated in detail, both on the expected mean value of the surface interaction energy between the MEMS surfaces, and the expected spread on this value from device to device. By comparing the new model to existing literature reporting this experimentally observed spread, we have found excellent agreement between the experimental spread observed, and the spread calculated with the theoretical model using Monte Carlo simulations. This work paves the way to detailed adhesion failure predictive modeling. It may be used to assess the reliability of MEMS designs that rely on contacting surfaces for their operation, but have a limited restoring force available to separate the surfaces when in contact. (paper)

  8. Tensile bond strength of self-etching versus total-etching adhesive systems under different dentinal substrate conditions Resistência de união à tração de sistemas adesivos autocondicionantes versus de condicionamento total, em diferentes condições de substrato dentinário

    OpenAIRE

    Alexandre Henrique Susin; Walison Arthuso Vasconcellos; José Roberto Cury Saad; Osmir Batista de Oliveira Junior

    2007-01-01

    The use of acid etchants to produce surface demineralization and collagen network exposure, allowing adhesive monomers interdiffusion and consequently the formation of a hybrid layer, has been considered the most efficient mechanism of dentin bonding. The aim of this study was to compare the tensile bond strength to dentin of three adhesive systems, two self-etching ones (Clearfil SE Bond - CSEB and One Up Bond F - OUBF) and one total-etching one (Single Bond - SB), under three dentinal subst...

  9. The Effects of Poly(vinyl acetate Filled with Nanoclay and Cellulose Nanofibrils on Adhesion Strength of Poplar and Scots Pine Wood

    Directory of Open Access Journals (Sweden)

    Gökhan Gündüz

    2016-03-01

    Full Text Available Cellulose nanofibrils (CNFs and nanoclay (NC were selected to determine the effects of different fillers on the characterization of poly(vinyl acetate (PVA. Characterizations of the PVA composites obtained were studied by thermogravimetric analysis (TGA/DTG, scanning electron microscopy (SEM and the lap joint shear strength (LJSS. The morphological studies revealed that some clumpings were observed in SEM images for 1%, 2%, and 4% wt loadings for CNFs and NC fillers. Dispersed particle orientation morphology and the wave sheets appear to be uniformly distributed on the surface of the composites. Seen as the effects of fillers on the thermal stability, the results showed that NC has a greater effect than CNFs, depending on the loading rates of fillers. Lap joint shear strength generally increased after adding CNFs and NC to PVA matrix. Thus, it can be said that PVA has higher bonding performance and can be used in applications requiring higher bonding strength.

  10. Effect of adhesive thickness on adhesively bonded T-joint

    Science.gov (United States)

    Abdullah, A. R.; Afendi, Mohd; Majid, M. S. Abdul

    2013-12-01

    The aim of this work is to analyze the effect of adhesive thickness on tensile strength of adhesively bonded stainless steel T-joint. Specimens were made from SUS 304 Stainless Steel plate and SUS 304 Stainless Steel perforated plate. Four T-joint specimens with different adhesive thicknesses (0.5, 1.0, 1.5 and 2.0 mm) were made. Experiment result shows T-joint specimen with adhesive thickness of 1.0 mm yield highest maximum load. Identical T-joint specimen jointed by spot welding was also tested. Tensile test shows welded T-Joint had eight times higher tensile load than adhesively bonded T-joint. However, in low pressure application such as urea granulator chamber, high tensile strength is not mandatory. This work is useful for designer in fertilizer industry and others who are searching for alternative to spot welding.

  11. Adhesion of rhodium films on metallic substrates

    Energy Technology Data Exchange (ETDEWEB)

    Marot, L. [Department of Physics, University of Basel, Klingelbergstrasse 82, CH-4056 Basel (Switzerland)], E-mail: laurent.marot@unibas.ch; Covarel, G.; Tuilier, M.-H. [Laboratoire Mecanique, Materiaux et Procedes de Fabrication, Pole STIC-SPI-Math 61 rue Albert Camus, Universite de Haute-Alsace, F-68093 - Mulhouse Cedex (France); Steiner, R.; Oelhafen, P. [Department of Physics, University of Basel, Klingelbergstrasse 82, CH-4056 Basel (Switzerland)

    2008-09-01

    Rhodium coated metallic films were prepared by magnetron sputtering on metallic substrates. All films were elaborated in same conditions on copper, molybdenum and stainless steel. Adhesion strength tests were carried out by scratch test. The results reveal that the adhesion strength between the film and the substrate is influenced by the hardness of the substrate. Increase of deposition temperature improves the adhesion of the coating. In addition, pre-treatment of substrates by a filtered cathodic vacuum arc and the layer thickness have has some effects on the final adhesion strength.

  12. Application of the Blister Test in Study of Epoxy Adhesive

    Institute of Scientific and Technical Information of China (English)

    Fei Xiong; Ingegerd Annergren

    2000-01-01

    Shaft-loaded blister test technique is used as an effective quantitative tool to measure adhesion strength. Investigation on conductive adhesive was done by modified blister test. It is found that shaftloaded blister test can be a good solution for the debonding of thin film adhesion. The intrinsic stable interface debonding process has been proved an attractive alternative to the conventional adhesion measurement techniques. In our study, epoxy matrix adhesive was studied using blister test technique in comparison with the traditional test-lap shear test. Adhesion strength was studied as a function of surface treatment and the metallization of substrate. It was found that surface conditions of substrate have significant impact on adhesion behaviour. The oxidation of surface is responsible for the poor adhesion. Activating chemical treatment and Plasma cleaning on substrate surface has been found to be a way of dreamatically improving adhesion strength of electronic conductive adhesive.

  13. Adaptation of Campylobacter jejuni to biocides used in the food industry affects biofilm structure, adhesion strength, and cross-resistance to clinical antimicrobial compounds.

    Science.gov (United States)

    Techaruvichit, Punnida; Takahashi, Hajime; Kuda, Takashi; Miya, Satoko; Keeratipibul, Suwimon; Kimura, Bon

    2016-08-01

    The emergence of biocide-adapted Campylobacter jejuni strains that developed into biofilms and their potential to develop clinical resistance to antimicrobial compounds was studied. C. jejuni was grown in sub-lethal concentrations of five biocides used in the food industry. C. jejuni exhibited adaptation to these biocides with increased minimum inhibitory concentrations. The 3-D structures of the biofilms produced by the biocide-adapted cells were investigated by atomic force microscopy (AFM). The results revealed marked variability in biofilm architecture, including ice-crystal-like structures. Adaptation to the biocides enhanced biofilm formation, with significant increases in biovolume, surface coverage, roughness, and the surface adhesion force of the biofilms. Adaptation to commercial biocides induced resistance to kanamycin and streptomycin. This study suggests that the inappropriate use of biocides may lead to cells being exposed to them at sub-lethal concentrations, which can result in adaptation of the pathogens to the biocides and a subsequent risk to public health. PMID:27353218

  14. Effect of Ethylene diamine tetra acetic acid and sodium hypochlorite solution conditioning on microtensile bond strength of one-step self-etch adhesives

    Directory of Open Access Journals (Sweden)

    Shahin Kasraei

    2013-01-01

    Settings and Design: It was an in-vitro study. Materials and Methods: Seventy-two teeth were divided into eight groups and their crowns were ground perpendicular to their long axis to expose dentin. The teeth were polished with silicon-carbide papers. The groups were treated as follows: No conditioning, 0.5-M EDTA conditioning, 2.5% NaOCl conditioning, NaOCl + EDTA conditioning. The surfaces were rinsed and blot-dried. Clearfil S3 and I-Bond were applied according to manufacturers′ instructions and restored with Z100 composite. After 500 cycles of thermo-cycling between 5±C and 55±C, the samples were sectioned and tested for μTBS. Statistical Analysis: Data were analyzed by two-way ANOVA and Tukey-HSD test. Results: The highest μTBS was recorded with Clearfil S3 + NaOCl + EDTA, and the lowest was recorded with I-Bond without conditioning. μTBS in EDTA-and EDTA + NaOCl-treated groups was significantly higher than the control and NaOCl-conditioned groups. Conclusions: Application of EDTA or EDTA + NaOCl before one-step self-etch adhesives increased μTBS.

  15. Bond strength of seventh generation adhesives to normal and caries-affected dentine%第7代黏接剂与正常和龋损牙本质黏接强度的比较

    Institute of Scientific and Technical Information of China (English)

    王清; 邓婧; 范春

    2011-01-01

    BACKGROUND: Researchers in China and abroad have done a lot of experiments to study the bond strength of dentine adhesives from generation one to six,which have received satisfied results. However,there are still no reports about the bond strength of the seventh generation adhesive (Adper EasyTM one). OBJECTIVE: To evaluate the bond strength of the Adper EasyTM one to normal dentine and caries-affected dentine,and to compare the results with total-etching adhesives. METHODS: A total of 12 healthy posterior teeth were randomly divided into group A and B; 12 posterior teeth with chronic occlusal caries were divided into group C and D. Adper EasyTM one was applied for group A and C,while Single bond 2 for group B and D. The modes of group A,B,C,D were subjected to microtensile bond strength test. Interfacial morphologies were analyzed by Stereo-Microscopy. RESULTS AND CONCLUSION: The microtensile bond strength of group A and B was (21.84±3.98),(27.10±4.85) MPa,which was (16.44±3.46) and (21.48±4.85) MPa in the group C and D. The differences between group A and B,group C and D,group A and C,as well as group B and D were statistical significant (P < 0.05). Failures mostly occur along the resin-dentine interface. The total-etching adhesives performed more effectively to both normal dentine and caries-affected dentine than Adper EasyTM one. For the same adhesive,the healthy dentine yielded higher bond strength than the caries-affected dentine.%背景:对于第1~6代牙本质黏接剂的黏接强度,内外学者做了大量的研究并取得了满意的成果,尚未见对第7代黏接剂Adper EasyTM one黏接性能的相关报道.目的:比较3M第7代自酸蚀黏接剂对正常和龋损牙本质黏接强度的差异,与传统全酸蚀黏接剂进行对比.方法:取健康磨牙和牙合面慢性龋磨牙各12颗,为A、B(健康磨牙),、D(牙合面慢性龋磨牙)4组,中A、C组用Adper EasyTM one黏接剂,、D组用Single bond 2黏接剂.测试4组试件的微

  16. Evaluation of the tensile bond strength of an adhesive system self-etching in dentin irradiated with Er:YAG laser; Avaliacao da resistencia a tracao de um sistema adesivo self-etching em dentina irradiada com Er:YAG laser

    Energy Technology Data Exchange (ETDEWEB)

    Mello, Andrea Malluf Dabul de

    2000-07-01

    Since Buonocore (1955), several researchers have been seeking for the best adhesive system and treatment for the enamel and dentin surfaces. The use of the acid has been presented as one of the best techniques of dentin conditioning , because this promotes the removal of the 'smear layer and exhibition of dentinal structure, for a best penetration and micro- retention of the adhesive system. However, some conditioning methods have been appearing in the literature, for the substitution or interaction with the acid substances, as the laser. The objective of this work is to evaluate the tensile bond strength of the adhesive system self-etching' associated to a composed resin, in dentin surfaces conditioned with the Er:YAG laser. For this study, freshly extracted human teeth were used and in each one the dentinal surfaces , which were treated with three sandpapers of different granulations (120,400,600), to obtain a standard of the smear layer, before the irradiation of the laser and of the restoring procedure. After these procedures the specimens were storage in distilled water at 37 deg C for 24 hours. Soon after, they were submitted to the tensile strength test .After analyzing the results, we can concluded that the use of the Er:YAG laser can substitute the drill without the need of conditioning, when using the adhesive system 'self-etching' in the dentinal surfaces because there was a decline in the strength of adhesion in the groups conditioned with the laser. (author)

  17. [FTIR spectroscopic studies of facial prosthetic adhesives].

    Science.gov (United States)

    Kang, Biao; Yang, Qing-fang; Liang, Jian-feng; Zhao, Yi-min

    2008-10-01

    According to the composition of the traditional facial prosthetic adhesives, most of adhesives can be classified into two categories: acrylic polymer-based adhesive and silicone-based adhesive. In previous studies, measurements of various mechanical bond strengths were carried out, whereas the functional groups of the adhesives were evaluated seldom during the adhesion. In the present study the analysis of two facial prosthetic adhesives (Epithane and Secure Adhesive) was carried out by using infrared spectroscopy. Two adhesives in the form of fluid or semisolid were submitted to FTIR spectroscopy, respectively. The results showed that water and ammonia residue volatilized during the solidification of Epithane, and absorption peak reduction of carbonyl was due to the volatilization of acetate vinyl from Secure Adhesive. Similar silicone functional groups both in the silicone-based adhesive and in silicone elastomer could be the key to higher bond strength between silicone elastomer and skin with silicone-based adhesive. The position, shape of main absorption peaks of three adhesives didn't change, which showing that their main chemicals and basic structures didn't change during solidification. PMID:19123392

  18. Photochemical tissue bonding with chitosan adhesive films

    Directory of Open Access Journals (Sweden)

    Piller Sabine C

    2010-09-01

    Full Text Available Abstract Background Photochemical tissue bonding (PTB is a promising sutureless technique for tissue repair. PTB is often achieved by applying a solution of rose bengal (RB between two tissue edges, which are irradiated by a green laser to crosslink collagen fibers with minimal heat production. In this study, RB has been incorporated in chitosan films to create a novel tissue adhesive that is laser-activated. Methods Adhesive films, based on chitosan and containing ~0.1 wt% RB were manufactured and bonded to calf intestine by a solid state laser (λ = 532 nm, Fluence~110 J/cm2, spot size~0.5 cm. A single-column tensiometer, interfaced with a personal computer, tested the bonding strength. K-type thermocouples recorded the temperature (T at the adhesive-tissue interface during laser irradiation. Human fibroblasts were also seeded on the adhesive and cultured for 48 hours to assess cell growth. Results The RB-chitosan adhesive bonded firmly to the intestine with adhesion strength of 15 ± 2 kPa, (n = 31. The adhesion strength dropped to 0.5 ± 0.1 (n = 8 kPa when the laser was not applied to the adhesive. The average temperature of the adhesive increased from 26°C to 32°C during laser exposure. Fibroblasts grew confluent on the adhesive without morphological changes. Conclusion A new biocompatible chitosan adhesive has been developed that bonds photochemically to tissue with minimal temperature increase.

  19. Stretchable, adhesion-tunable dry adhesive by surface wrinkling.

    Science.gov (United States)

    Jeong, Hoon Eui; Kwak, Moon Kyu; Suh, Kahp Y

    2010-02-16

    We introduce a simple yet robust method of fabricating a stretchable, adhesion-tunable dry adhesive by combining replica molding and surface wrinkling. By utilizing a thin, wrinkled polydimethyl siloxane (PDMS) sheet with a thickness of 1 mm with built-in micropillars, active, dynamic control of normal and shear adhesion was achieved. Relatively strong normal (approximately 10.8 N/cm(2)) and shear adhesion (approximately 14.7 N/cm(2)) forces could be obtained for a fully extended (strained) PDMS sheet (prestrain of approximately 3%), whereas the forces could be rapidly reduced to nearly zero once the prestrain was released (prestrain of approximately 0.5%). Moreover, durability tests demonstrated that the adhesion strength in both the normal and shear directions was maintained over more than 100 cycles of attachment and detachment.

  20. Stretchable, Adhesion-Tunable Dry Adhesive by Surface Wrinkling

    KAUST Repository

    Jeong, Hoon Eui

    2010-02-16

    We introduce a simple yet robust method of fabricating a stretchable, adhesion-tunable dry adhesive by combining replica molding and surface wrinkling. By utilizing a thin, wrinkled polydimethyl siloxane (PDMS) sheet with a thickness of 1 mm with built-in micropillars, active, dynamic control of normal and shear adhesion was achieved. Relatively strong normal (∼10.8 N/cm2) and shear adhesion (∼14.7 N/cm2) forces could be obtained for a fully extended (strained) PDMS sheet (prestrain of∼3%), whereas the forces could be rapidly reduced to nearly zero once the prestrain was released (prestrain of ∼0.5%). Moreover, durability tests demonstrated that the adhesion strength in both the normal and shear directions was maintained over more than 100 cycles of attachment and detachment. © 2010 American Chemical Society.

  1. Adhesion enhancement of biomimetic dry adhesives by nanoparticle in situ synthesis

    Science.gov (United States)

    Díaz Téllez, J. P.; Harirchian-Saei, S.; Li, Y.; Menon, C.

    2013-10-01

    A novel method to increase the adhesion strength of a gecko-inspired dry adhesive is presented. Gold nanoparticles are synthesized on the tips of the microfibrils of a polymeric dry adhesive to increase its Hamaker constant. Formation of the gold nanoparticles is qualitatively studied through a colour change in the originally transparent substance and quantitatively analysed using ultraviolet-visible spectrophotometry. A pull-off force test is employed to quantify the adhesion enhancement. Specifically, adhesion forces of samples with and without embedded gold nanoparticles are measured and compared. The experimental results indicate that an adhesion improvement of 135% can be achieved.

  2. Tensile bond strength of adhesive systems: effects of primer and thermocycling Resistência à tração de sistemas adesivos: efeitos do “ primer” e dos ciclos térmicos

    Directory of Open Access Journals (Sweden)

    Luciana Tibiriçá AGUILAR

    2002-03-01

    Full Text Available The objective of this study was to evaluate the effects of primer and thermocycling on the bond strength of multi-purpose adhesive systems applied to enamel, under tensile stress. The following bonding systems were applied, according to the manufacturers' instructions, on unground enamel buccal surfaces of 96 premolars, with or without the application of primer: Scotchbond MP, OptiBond FL, Amalgambond Plus and OptiBond (dual-cure. A composite resin (Z100, 3M was applied and light-cured in a cast metal hollow cone, which was previously fixed to the enamel surfaces. Half of the sample was subjected to 3,000 thermocycles (5-37ºC; 37-55ºC, dwell time of 60 s, and the other half was stored in water at 37ºC for the same period. The data were treated by means of ANOVA and no significant effects were detected, which indicates that tensile bond strength was not affected by the adhesive systems, application of primer or thermocycling.O objetivo desta pesquisa foi o de verificar o efeito do "primer" e dos ciclos térmicos na resistência da união entre adesivos multiuso e esmalte dental, sob ensaios de tração. Os seguintes sistemas adesivos foram aplicados, de acordo com as instruções dos fabricantes, na superfície vestibular (sem desgaste de 96 pré-molares com ou sem a aplicação prévia do "primer": Scotchbond MP, OptiBond FL, Amalgambond Plus e OptiBond - "dual cure". Após a aplicação do sistema adesivo, foi confeccionado um cone de resina composta (Z100, 3M, e fotoativado dentro de um molde metálico. Metade do total de espécimes foi submetida a 3.000 ciclos térmicos (5-37ºC; 37-55ºC, 60 s de imersão; a outra metade permaneceu imersa em água a 37ºC pelo mesmo tempo dispensado no procedimento anterior. Os dados foram submetidos a uma análise de variância (p = 0,05 e nenhum efeito significante foi detectado, indicando que a resistência de união não foi afetada pelo sistema adesivo, pela aplicação do "primer" ou pelos ciclos térmicos.

  3. Microstructure and adhesion strength of Sn-9Zn-1.5Ag-xBi (x = 0 wt% and 2 wt%)/Cu after electrochemical polarization in a 3.5 wt% NaCl solution

    Energy Technology Data Exchange (ETDEWEB)

    Li, W.-L. [Department of Mechanical Engineering, National Kaohsiung University of Applied Sciences, 415 Chien-Kung Road, Kaohsiung 80782, Taiwan (China); Institute of Nanotechnology and Microsystems Engineering, National Cheng Kung University, 1 Ta-Hsueh Road, Tainan 70101, Taiwan (China); Chen, Y.-R.; Chang, K.-M. [Department of Mechanical Engineering, National Kaohsiung University of Applied Sciences, 415 Chien-Kung Road, Kaohsiung 80782, Taiwan (China); Liu, C.-Y.; Hon, M.-H. [Department of Materials Science and Engineering, National Cheng Kung University, 1 Ta-Hsueh Road, Tainan 70101, Taiwan (China); Wang, M.-C. [Faculty of Fragrance and Cosmetics, Kaohsiung Medical University, 100 Shihchuan 1st Road, Kaohsiung 80728, Taiwan (China)], E-mail: mcwang@kmu.edu.tw

    2008-08-11

    The microstructure and adhesion strength of the Sn-9Zn-1.5Ag-xBi (x = 0 wt% and 2 wt%)/Cu interface after electrochemical polarization have been studied by X-ray diffraction (XRD), scanning electron microscopy (SEM) and pull-off testing. The equilibrium potentials of Sn-9Zn-1.5Ag/Cu and Sn-9Zn-1.5Ag-2Bi/Cu are -1.31 V{sub sce} and -1.22 V{sub sce}, respectively, indicating that Sn-9Zn-1.5Ag-2Bi/Cu has a better corrosion resistance than that of Sn-9Zn-1.5Ag/Cu. The intermetallic compounds of Cu{sub 6}Sn{sub 5}, Cu{sub 5}Zn{sub 8} and Ag{sub 3}Sn are formed at the soldered interface between the Sn-9Zn-1.5Ag-xBi solder alloy and the Cu substrate. The scallop-shaped Cu{sub 6}Sn{sub 5} is close to the Cu substrate and the scallop-shaped Cu{sub 5}Zn{sub 8} is found at the interface in the solder matrix after soldering at 250 deg. C for 10 s. The corrosion products are ZnCl{sub 2}, SnCl{sub 2} and ZnO. On the other hand, pits are also formed on the surface of both solder alloys. The interfacial adhesion strength of the Sn-9Zn-1.5Ag/Cu and Sn-9Zn-1.5Ag-2Bi/Cu decreases from 8.27 {+-} 0.56 MPa and 12.67 {+-} 0.45 MPa to 4.78 {+-} 0.45 MPa and 8.14 {+-} 0.38 MPa, respectively, after electrochemical polarization in a 3.5 wt% NaCl solution. The fracture path of the Sn-9Zn-1.5Ag-2Bi/Cu is along the solder alloy/ZnO and solder/Cu{sub 6}Sn{sub 5} interfaces.

  4. Microstructure and adhesion strength of Sn-9Zn-1.5Ag-xBi (x = 0 wt% and 2 wt%)/Cu after electrochemical polarization in a 3.5 wt% NaCl solution

    International Nuclear Information System (INIS)

    The microstructure and adhesion strength of the Sn-9Zn-1.5Ag-xBi (x = 0 wt% and 2 wt%)/Cu interface after electrochemical polarization have been studied by X-ray diffraction (XRD), scanning electron microscopy (SEM) and pull-off testing. The equilibrium potentials of Sn-9Zn-1.5Ag/Cu and Sn-9Zn-1.5Ag-2Bi/Cu are -1.31 Vsce and -1.22 Vsce, respectively, indicating that Sn-9Zn-1.5Ag-2Bi/Cu has a better corrosion resistance than that of Sn-9Zn-1.5Ag/Cu. The intermetallic compounds of Cu6Sn5, Cu5Zn8 and Ag3Sn are formed at the soldered interface between the Sn-9Zn-1.5Ag-xBi solder alloy and the Cu substrate. The scallop-shaped Cu6Sn5 is close to the Cu substrate and the scallop-shaped Cu5Zn8 is found at the interface in the solder matrix after soldering at 250 deg. C for 10 s. The corrosion products are ZnCl2, SnCl2 and ZnO. On the other hand, pits are also formed on the surface of both solder alloys. The interfacial adhesion strength of the Sn-9Zn-1.5Ag/Cu and Sn-9Zn-1.5Ag-2Bi/Cu decreases from 8.27 ± 0.56 MPa and 12.67 ± 0.45 MPa to 4.78 ± 0.45 MPa and 8.14 ± 0.38 MPa, respectively, after electrochemical polarization in a 3.5 wt% NaCl solution. The fracture path of the Sn-9Zn-1.5Ag-2Bi/Cu is along the solder alloy/ZnO and solder/Cu6Sn5 interfaces

  5. Analysis of Influencing Factors on Critical Load of Adhesion Strength in Scratch Test%划痕法结合强度临界载荷值的影响因素分析

    Institute of Scientific and Technical Information of China (English)

    杜军; 王红美; 王鑫

    2015-01-01

    Objective In order to determine precise adhesion strength of hard film, the effects of parameters of scratch test on the critical failure load were studied and discussed. Methods Titanium Nitride ( TiN) film was deposited on 304 stainless steel plates and Si wafer by magnetron sputtering. The cross-section morphology and thickness of TiN film were observed by Scanning E-lectric Microscopy ( SEM) , the hardness was evaluated by nano-indentation method, the adhesion strength was studied by scratch tester, and the influences of slide length, slide speed and loading rate on the critical load were analyzed. Results As-deposited TiN film possessed dense morphology with a thickness of about 2 μm. The hardness of TiN film was about 2300HV and the TiN/304 stainless steel system was hard film and soft substrate. The increase of slide speed (1~3 mm/min) resulted in the first acoustic e-mission (AE) signal delay under the same load (10 N) and slide length (3 mm) conditions, the increase of slide length (3~9 mm) resulted in the gradual weakening of III and IV failure mode under the same load (10 N) and slide speed(3 mm/min) condi-tions. Conclusion In order to evaluate ideal adhesion strength, I to IV failure mode appearance should be observed in single scratch path with specific AE signal. Critical load repeated itself within proper range of testing parameters. Position 4. 9 N AE sig-nal appeared during several tests under different setting parameters, in combination with the scratch morphology, it clarified that the adhesion strength of as-deposited TiN film was 4. 9 N.%目的:研究划痕法测试参数对临界失效载荷的影响,以便更准确地测定硬质薄膜的结合强度。方法采用磁控溅射技术在304不锈钢和Si片上制备氮化钛( TiN )薄膜。采用扫描电镜观察薄膜的截面形貌和厚度,采用纳米压入法测试薄膜的硬度,采用划痕法测试薄膜的结合强度,研究不同划痕长度、划动速率和加载速率对临界

  6. Application of Bonded Joints for Quantitative Analysis of Adhesion

    Directory of Open Access Journals (Sweden)

    Jarmila Trpčevská

    2016-01-01

    Full Text Available The performance of hot-dip coated steel sheets is associated with properties of the zinc coatings on steel substrate. For the characterization of the adhesion behaviour of zinc coating on steel various tests were employed. The study was focused on quantification assessment of galvanized coating adhesion to substrates. Methods for evaluation of the bonding strength of zinc coating by the shear strength and the T-peel tests applying four special types of adhesives were used. The experimental tests of bonded joints show that the adhesion of the zinc coating to the substrate was higher than that of the applied adhesive with the highest strength.

  7. Effect of Green Or Desensitizer on Shear Bond Strength of Adhesive Agents to Dentin%极固宁对水门汀与牙本质间剪切强度的影响

    Institute of Scientific and Technical Information of China (English)

    秦玉杰; 程祥荣; 徐东选; 陈小冬

    2011-01-01

    目的:评价极固宁脱敏剂对5种水门汀剪切强度的影响.方法:收集双尖牙30颗.包埋牙齿,暴露牙本质面,用水砂纸打磨牙本质面.所有牙齿被分为实验组和对照组.实验组的牙本质面首先用极固宁脱敏处理,然后分别用5种水门汀将树脂小柱粘在牙本质表面.对照组的牙本质不涂脱敏剂,使用前述提到的水门汀粘固树脂小柱.所有试样放在37℃水浴中浸泡24 h后测量剪切强度.结果:极固宁脱敏剂没有显著降低聚羧酸锌水门汀和玻璃离子水门汀的剪切强度,但却会使磷酸锌水门汀的剪切强度大幅下降.极固宁也使树脂加强玻璃离子水门汀和树脂水门汀的粘接强度下降.结论:极固宁对磷酸锌水门汀、树脂加强玻璃离子水门汀、树脂水门汀与牙本质间粘接强度有不利影响,对聚羧酸锌水门汀和玻璃离子水门汀与牙本质间粘接强度无不利影响.%Objective: To investigate the effect of Green Or desensitizer on shear bond strength of five adhesive a-gents to dentin. Methods: Thirty human premolars were used. Dentin surfaces were ground with silicon carbide abrasive papers. Teeth were randomly divided into two groups: the tested group and the control group. For the tested group, dentin surfaces were treated with Green Or desensitizer, then Solidex cylinders were positioned over the dentin surface with five cements respectively. For the control group, no desensitizer was applied, resin cylinders were bonded with cements mentioned above. Shear bond strengths were detemined. Results: The results indicate that Green Or desensitizer-treated dentin did not affect the shear bond strength of glass ionomer or polycarboxylate cements, but produced a large decrease in the shear bond strength of zinc phosphate. For resin-forced glass ionomer and resin luting agents, the application of Green Or desensitizer significantly reduced the shear bond strength of both materials. Conclusion: Green Or

  8. Resistência ao cisalhamento de um selante associado a componentes de um sistema adesivo dental Shear bond strength of an enamel sealant using components of a dental adhesive system

    Directory of Open Access Journals (Sweden)

    Zilda Maria MUSSOLINO

    1998-10-01

    significant differences in the shear bond strength of the sealant when the Probond Adhesive System was applied with or without "primer". The shear bond strength of enamel sealant was higher in the incisal third than in the cervical third.

  9. Advances in modeling and design of adhesively bonded systems

    CERN Document Server

    Kumar, S

    2013-01-01

    The book comprehensively charts a way for industry to employ adhesively bonded joints to make systems more efficient and cost-effective Adhesively bonded systems have found applications in a wide spectrum of industries (e.g., aerospace, electronics, construction, ship building, biomedical, etc.) for a variety of purposes. Emerging adhesive materials with improved mechanical properties have allowed adhesion strength approaching that of the bonded materials themselves. Due to advances in adhesive materials and the many potential merits that adhesive bonding offers, adhesive bonding has replac

  10. Co元素对硬质合金基底金刚石涂层膜基界面结合强度的影响∗%The Influence of Co binding phase on adhesive strength of diamond coating with cemented carbide substrate

    Institute of Scientific and Technical Information of China (English)

    简小刚; 陈军

    2015-01-01

    Diamond coating has many excellent properties as the same as those of the natural diamond, such as extreme hard-ness, high thermal conductivity, low thermal expansion coefficient, high chemical stability, and good abrasive resistance, which is considered as the best tool coating material applied to the high-silicon aluminum alloy cutting. We can use the hot filament chemical vapor deposition method (HFCVD) to deposit a 2—20 µm diamond coating on the cemented carbide tool to improve the cutting performance and increase the tool life significantly. Many experiments have proved that the existence of cobalt phase can weaken the adhesive strength of diamond coating. However, we still lack a perfect theory to explain why the Co element can reduce the adhesive strength of diamond coating is still lacking. What we can do now is only to improve the adhesive strength of diamond coating by doing testing many times in experiments. Compared with these traditional experiments, the first principles simulation based on quantum mechanics can describe the microstructure property and electron density of materials. It is successfully used to investigate the surface, interface, electron component, and so on etc. We can also use this method to study the interface problem at an atomic level. So the first principles based upon density functional theory (DFT) is used to investigate the influence of cobalt binding phase in cemented carbide substrate on adhesive strength of diamond coating. In this article, we uses Material Studios software to build WC/diamond and WC-Co/diamond interface models to evaluate the influence of cobalt phase on the adhesive strength of diamond coating with CASTEP program which can calculate the most stablest structure of film-substrate interface. We use PBE functional form to obtain the exchange potential and relevant potential, and to solve the self-consistent Kohn-Sham equations. We calculate the interfacial bonding energy, analyse the electron density of

  11. Bacterial Adhesion & Blocking Bacterial Adhesion

    DEFF Research Database (Denmark)

    Vejborg, Rebecca Munk

    2008-01-01

    tract to the microbial flocs in waste water treatment facilities. Microbial biofilms may however also cause a wide range of industrial and medical problems, and have been implicated in a wide range of persistent infectious diseases, including implantassociated microbial infections. Bacterial adhesion...... is the first committing step in biofilm formation, and has therefore been intensely scrutinized. Much however, still remains elusive. Bacterial adhesion is a highly complex process, which is influenced by a variety of factors. In this thesis, a range of physico-chemical, molecular and environmental parameters......, which influence the transition from a planktonic lifestyle to a sessile lifestyle, have been studied. Protein conditioning film formation was found to influence bacterial adhesion and subsequent biofilm formation considerable, and an aqueous extract of fish muscle tissue was shown to significantly...

  12. Chitosan Adhesive Films for Photochemical Tissue Bonding

    Science.gov (United States)

    Lauto, Antonio; Mawad, Damia; Barton, Matthew; Piller, Sabine C.; Longo, Leonardo

    2011-08-01

    Photochemical tissue bonding (PTB) is a promising sutureless technique for tissue repair. PTB is often achieved by applying a solution of rose bengal (RB) between two tissue edges, which are irradiated by a green laser to crosslink collagen fibers with minimal heat production. In this study, RB has been incorporated in chitosan films to create a novel tissue adhesive that is laser-activated. Materials and Methods. Adhesive films, based on chitosan and containing ˜0.1wt% RB were manufactured and bonded to calf intestine by a solid state laser (wavelength = 532 nm, Fluence ˜110 J/cm2, spot size ˜5 mm). A single-column tensiometer, interfaced with a personal computer, tested the bonding strength. K-type thermocouples recorded the temperature (T) at the adhesive-tissue interface during laser irradiation. Human fibroblasts were also seeded on the adhesive and cultured for 48 hours to assess cell growth. Results and Conclusion. The RB-chitosan adhesive bonded firmly to the intestine (15±2 kPa, n = 31). The adhesion strength dropped to 0.5±0.1 kPa (n = 8) when the laser was not applied to the adhesive. The average temperature of the adhesive increased from 26 °C to 32 °C during laser exposure. Fibroblasts grew confluent on the adhesive without morphological changes. A new biocompatible chitosan adhesive has been developed that bonds photochemically to tissue with minimal temperature increase.

  13. Adhesion Strength of Biomass Ash Deposits

    OpenAIRE

    Laxminarayan, Yashasvi; Jensen, Peter Arendt; Wu, Hao; Bøjer, M.; Jappe Frandsen, Flemming; Glarborg, Peter

    2016-01-01

    Ash deposition on boiler surfaces is a major problem encountered during biomass combustion. Ash deposition adversely influences the boiler efficiency, may corrode heat transfer surfaces, and may even completely block flue gas channels in severe cases, causing expensive unscheduled boiler shutdowns. Therefore, timely removal of ash deposits is essential for optimal boiler operation. In order to improve the qualitative and quantitative understanding of deposit shedding in boilers, this study in...

  14. Influence of process parameters on adhesive strength of the coatings on mold copper substrate by HVOF spray%结晶器铜板超音速火焰喷涂工艺参数对涂层结合强度的影响

    Institute of Scientific and Technical Information of China (English)

    张颖; 王国星

    2013-01-01

    The CoNiCrAlY coatings were deposited on mould substrate ( CrZrCu ) by high velocity oxy-fuel spray ( HVOF ) process.It has studied the influence of process parameters on adhesive strength of the coatings .The results show that adhesive strength of the coatings markedly increases with the increase of fuel flow , adhesive strength increases at first and then descends with the increase of oxygen flow and spraying distance , and that adhesive strength enormously increases after sandblasting .It is more im-portant to obtain high quality coating through selecting appropriate powder shape and particle size .%文中采用超音速火焰喷涂( HVOF)在结晶器铜板表面喷涂了CoNiCrAlY涂层,研究了喷涂主要工艺参数对涂层结合强度的影响。结果表明:涂层的结合强度随着燃油流量的增大而显著增大,随着氧气流量与喷涂距离的增加结合强度均出现先增加后下降趋势,喷砂后较未喷砂结合强度大大提高。选择合适的粉末形状与粒径对于获得高质量的涂层较为重要。

  15. Effect of sodium hypochlorite on the bond strength of an adhesive system to superficial and deep dentin Efeito do hipoclorito de sódio na resistência de união de um sistema adesivo na dentina superficial e profunda

    OpenAIRE

    Ninoshka Uceda-Gómez; Alessandra Reis; Marcela Rocha de Oliveira Carrilho; Alessandro Dourado Loguercio; Leonardo Eloy Rodriguez Filho

    2003-01-01

    The objective of this study was to evaluate the bond strength to superficial (SU) and deep (D) dentin, accessed via apical (DA) or occlusal (DO), using One-Step adhesive system applied according to the manufacturer's instructions (C) or following deproteinization with 10% sodium hypochlorite (H) for 60s, after acid etching. Three sound extracted human molars were prepared for each experimental condition. Restorations were performed using Z100 in 2mm increments, each one being light-cured for ...

  16. Testing Bond Strength, a Review of the Literature

    OpenAIRE

    de Munck, Jan; Mine, Atsushi; Poitevin, André; Van Ende, Annelies; Meerbeek, Bart Van

    2009-01-01

    Objectives: Worldwide bond strength tests are used to evaluate bonding effectiveness of different adhesive techniques. The purpose of this study was to systematically collect these data to identify the primary parameters that affect the outcome of bond strength tests, and to attempt to disclose trends in adhesive performance of the different adhesive approaches today available. Materials and Methods: 871 studies were identified by enterin...

  17. Adhesion property of epoxidized natural rubber (ENR-based adhesives containing calcium carbonate

    Directory of Open Access Journals (Sweden)

    2008-06-01

    Full Text Available The adhesion property (i.e. viscosity, loop tack and peel strength of epoxidized natural rubber (ENR 25 and ENR 50 grade-based pressure-sensitive adhesive was studied in the presence of calcium carbonate. The range of calcium carbonate loaded was from 10 to 50 parts per hundred parts of rubber (phr. Coumarone-indene resin was used as the tackifier and its concentration was fixed at 80 phr. Toluene was chosen as the solvent throughout the investigation. The substrates (PET film/paper were coated with the adhesive using a SHEEN hand coater at a coating thickness of 60 µm. Viscosity of the adhesive was measured by a HAAKE Rotary Viscometer whereas loop tack and peel strength were determined by a Llyod Adhesion Tester operating at 30 cm/min. Results show that viscosity of ENR-based adhesives increases gradually with increase in calcium carbonate loading due to the concentration effect of the filler. However, for loop tack and peel strength, it passes through a maximum at 30 phr calcium carbonate, an observation which is attributed to the optimum wettability of adhesive on the substrate at this adhesive composition. ENR 25-based adhesive consistently exhibits higher adhesion property than ENR 50 for all calcium carbonate loadings studied.

  18. Improved stress prediction in adhesive bonded optical components

    NARCIS (Netherlands)

    Vreugd, J. de; Voert, M.J.A. te; Nijenhuis, J.R.; Pijnenburg, J.A.C.M.; Tabak, E.

    2012-01-01

    Adhesives are widely used in optomechanical structures for bonding optical components to their mounts. The main advantage of using adhesives is the excellent strength to weight ratio. Adhesive bonding is seen as a desirable joining technique as it allows for greater flexibility in design. A disadvan

  19. Capillarity-based switchable adhesion.

    Science.gov (United States)

    Vogel, Michael J; Steen, Paul H

    2010-02-23

    Drawing inspiration from the adhesion abilities of a leaf beetle found in nature, we have engineered a switchable adhesion device. The device combines two concepts: The surface tension force from a large number of small liquid bridges can be significant (capillarity-based adhesion) and these contacts can be quickly made or broken with electronic control (switchable). The device grabs or releases a substrate in a fraction of a second via a low-voltage pulse that drives electroosmotic flow. Energy consumption is minimal because both the grabbed and released states are stable equilibria that persist with no energy added to the system. Notably, the device maintains the integrity of an array of hundreds to thousands of distinct interfaces during active reconfiguration from droplets to bridges and back, despite the natural tendency of the liquid toward coalescence. We demonstrate the scaling of adhesion strength with the inverse of liquid contact size. This suggests that strengths approaching those of permanent bonding adhesives are possible as feature size is scaled down. In addition, controllability is fast and efficient because the attachment time and required voltage also scale down favorably. The device features compact size, no solid moving parts, and is made of common materials.

  20. Tensile adhesion test measurements on plasma-sprayed coatings

    Science.gov (United States)

    Berndt, C. C.

    1986-01-01

    Adhesion measurements on plasma-sprayed coatings are briefly studied, including a critical analysis of the experimental scatter for duplicate tests. The application of a simple method which presents adhesion strength data in a fracture mechanics perspective is demonstrated. Available data are analyzed in a way which suggests an approach to finding the overall defect contribution to reducing the apparent strength of coatings.

  1. Synthesis and Properties of Waterborne Polyurethane (WBPU/Modified Lignin Amine (MLA Adhesive: A Promising Adhesive Material

    Directory of Open Access Journals (Sweden)

    Mohammad Mizanur Rahman

    2016-08-01

    Full Text Available A series of waterborne polyurethane (WBPU/modified lignin amine (MLA adhesives was prepared using MLA as a chain extender by a prepolymer mixing process. A successful Mannich reaction was achieved during the synthesis of MLA by reacting lignin with bis(3-aminopropylamine. Higher tensile strength, Young’s modulus, and thermal stability were recorded for WBPU/MLA adhesives with higher MLA contents. The WBPU/MLA adhesive materials were used to coat polyvinyl chloride (PVC substrates. The adhesive strength increased with increasing MLA content. More importantly, the MLA also enhanced the WBPU/MLA coating in terms of adhesive strength at moderately high temperatures as well as under natural weather exposed conditions. The adhesive strength was essentially unaffected with 6.48 mol % MLA in the WBPU/MLA coating after exposure to natural weather conditions for 180 days.

  2. 电镀铬-金刚石复合过渡层提高金刚石膜/基结合力%Improvement of Adhesive Strength of Diamond Films by Plating Cr-diamond Composite Interlayer

    Institute of Scientific and Technical Information of China (English)

    邱万奇; 潘建伟; 刘仲武; 余红雅; 钟喜春; 曾德长

    2012-01-01

    The diamond films were fabricated by using a two-step process on copper substrates. Firstly, chromium (Cr)-diamond composite interlayer was electroplated on copper substrates, then continuous diamond films were deposited by using hot-filament chemical vapor deposition (HFCVD) method. The interfacial characteristics were investigated by indentation test. The film surface morphology, phase structure and inner stress were analyzed by scanning electron microscope (SEM), X-ray diffraction (XRD) and Raman spectrum. The results show that the diamond particles are deeply imbedded in chromium layer and the amorphous Cr in the composite interlayer is car-borized to Cr3C2 in the CVD process. Low inner stress is detected in the diamond films and good adhesive strength between film and substrate is obtained due to the deep anchoring of the diamond particles in the Cr3C2 matrix. Concentric cracks but no delaminate area and radial cracks are observed on the periphery of the indentation in 294 N load indentation test.%在铜基体上沉积铬-金刚石复合过渡层,用热丝CVD系统在复合过渡层上沉积连续的金刚石涂层.用扫描电镜(SEM)、X射线(XRD)、拉曼光谱及压痕试验对所沉积的镶嵌结构界面金刚石膜的相结构及膜/基结合性能进行了研究.结果表明,非晶态的电镀Cr在CVD过程中转变成Cr3C2,由于金刚石颗粒与Cr3C2的相互咬合作用,金刚石膜/基结合力高;在294 N载荷压痕试验时,压痕外围不产生大块涂层崩落和径向裂纹,只形成环状裂纹.

  3. Adhesion and Cohesion

    Directory of Open Access Journals (Sweden)

    J. Anthony von Fraunhofer

    2012-01-01

    Full Text Available The phenomena of adhesion and cohesion are reviewed and discussed with particular reference to dentistry. This review considers the forces involved in cohesion and adhesion together with the mechanisms of adhesion and the underlying molecular processes involved in bonding of dissimilar materials. The forces involved in surface tension, surface wetting, chemical adhesion, dispersive adhesion, diffusive adhesion, and mechanical adhesion are reviewed in detail and examples relevant to adhesive dentistry and bonding are given. Substrate surface chemistry and its influence on adhesion, together with the properties of adhesive materials, are evaluated. The underlying mechanisms involved in adhesion failure are covered. The relevance of the adhesion zone and its importance with regard to adhesive dentistry and bonding to enamel and dentin is discussed.

  4. ROLE OF ADHESIVES IN TRANSDERMAL DRUG DELIVERY: A REVIEW

    Directory of Open Access Journals (Sweden)

    Arshad bashir Khan et al

    2012-10-01

    Full Text Available Transdermal drug delivery systems (TDDS also commonly known as “patches” are dosage forms designed to deliver a therapeutically effective amount of drug across a patient’s skin. The therapeutic performance of a transdermal delivery system (TDS can be affected by the quality of contact between the patch and the skin. The adhesion of the TDS to the skin is obtained by using pressure-sensitive adhesives (PSAs, which are defined as adhesives capable of bonding to surfaces with the application of light pressure. This article provides an overview of types of transdermal, the anatomical considerations and role of adhesion, the possible adhesion failure modes and how adhesion can be measured. Several in vitro techniques have been used to monitor adhesive performance such as peel adhesion, tack and shear strength. This article provides a frame work for further discussion and scientific work to improve transdermal adhesive performance.

  5. Relationships between water wettability and ice adhesion.

    Science.gov (United States)

    Meuler, Adam J; Smith, J David; Varanasi, Kripa K; Mabry, Joseph M; McKinley, Gareth H; Cohen, Robert E

    2010-11-01

    Ice formation and accretion may hinder the operation of many systems critical to national infrastructure, including airplanes, power lines, windmills, ships, and telecommunications equipment. Yet despite the pervasiveness of the icing problem, the fundamentals of ice adhesion have received relatively little attention in the scientific literature and it is not widely understood which attributes must be tuned to systematically design "icephobic" surfaces that are resistant to icing. Here we probe the relationships between advancing/receding water contact angles and the strength of ice adhesion to bare steel and twenty-one different test coatings (∼200-300 nm thick) applied to the nominally smooth steel discs. Contact angles are measured using a commercially available goniometer, whereas the average strengths of ice adhesion are evaluated with a custom-built laboratory-scale adhesion apparatus. The coatings investigated comprise commercially available polymers and fluorinated polyhedral oligomeric silsesquioxane (fluorodecyl POSS), a low-surface-energy additive known to enhance liquid repellency. Ice adhesion strength correlates strongly with the practical work of adhesion required to remove a liquid water drop from each test surface (i.e., with the quantity [1 + cos θ(rec)]), and the average strength of ice adhesion was reduced by as much as a factor of 4.2 when bare steel discs were coated with fluorodecyl POSS-containing materials. We argue that any further appreciable reduction in ice adhesion strength will require textured surfaces, as no known materials exhibit receding water contact angles on smooth/flat surfaces that are significantly above those reported here (i.e., the values of [1 + cos θ(rec)] reported here have essentially reached a minimum for known materials). PMID:20949900

  6. Elimination of the reactivation process in the adhesion of chlorinated SBS rubber with polychloroprene adhesives

    Directory of Open Access Journals (Sweden)

    2007-04-01

    Full Text Available Chlorination treatment of a thermoplastic styrene-butadiene-styrene rubber (SBS with a 3 wt% solution of trichloroisocyanuric acid (TCI in methyl ethyl ketone (MEK introduces chlorinated and oxidized moieties on the rubber surface which increase its surface energy and produces surface microroughness. Consequently adhesion properties, evaluated by T-peel strength measurements in chlorinated SBS/solvent based-polyurethane adhesive/leather joints, are enhanced. In this study, two solvent-based polychloroprene adhesives (PCP0 and PCP30R have been considered as an alternative to the commonly used solvent-based polyurethane adhesive (PU. A thermoreactive phenolic resin was added to one of the polychloroprene adhesive formulations (PCP30R. This tackifier resin favors chlorination of the adhesive and reinforces the interface between the chlorinated adhesive and the chlorinated rubber surface. Besides, PCP30R adhesive does not need adhesive reactivation and considerable high T-peel strength value (5.7±0.3 kN/m was obtained. Elimination of the reactivation process implies a considerable improvement of the manufacturing process in the footwear industry.

  7. Advanced adhesives in electronics

    CERN Document Server

    Bailey, C

    2011-01-01

    Adhesives are widely used in the manufacture of electronic devices to act as passive and active components. Recently there has been considerable interest in the use of conductive adhesives. This book reviews key types of conductive adhesives, processing methods, properties and the way they can be modelled as well as potential applications.$bAdhesives for electronic applications serve important functional and structural purposes in electronic components and packaging, and have developed significantly over the last few decades. Advanced adhesives in electronics reviews recent developments in adhesive joining technology, processing and properties. The book opens with an introduction to adhesive joining technology for electronics. Part one goes on to cover different types of adhesive used in electronic systems, including thermally conductive adhesives, isotropic and anisotropic conductive adhesives and underfill adhesives for flip-chip applications. Part two focuses on the properties and processing of electronic ...

  8. Adhesion of PBO Fiber in Epoxy Composites

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The high mechanical and thermal performance of poly p-phenylene- 2, 6-benzobisoxazole ( PBO ) fiber provides great potential applications as reinforcement fibers for composites. A composite of PBO fiber and epoxy resin has excellent electrical insulation properties, therefore, it is considered to be the best choice for the reinforcement in high magnetic field coils for pulsed magnetic fields up to 100 T.However, poor adhesion between PBO fiber and matrix is found because of the chemically inactive and/or relatively smooth surface of the reinforcement fiber preventing efficient chemical bonding in the interface, which is a challenging issue to improve mechanical properties. Here, we report the surface modification of PBO fibers by ultraviolet (UV)irradiation, O2 and NH3 plasma, as well as acidic treatments. The interfacial adhesion strength values of all the treatments show the similar level as determined for aramid fibers by pull-out tests, a significant impact on fibermatrix-adhesion was not achieved. The surface free energy and roughness are increased for both sized and extracted fibers after plasma treatments together with maleic anhydride grafting. The sized fiber shows marginal improvement in adhesion strength and no change in fiber tensile strength because of the barrier effect of the finish.For the extracted fiber, different surface treatments either show no apparent effect or cause reduction in adhesion strength. Atomic force microscopy (AFM) topography analysis of the fracture surfaces proved adhesive failure at the fiber surface. The fiber surface roughness is increased and more surface flaws are induced, which could result in coarse interface structures when the treated fiber surface has no adequate wetting and functional groups. The adhesion failure is further confirmed by similar adhesion strength and compression shear strength values when the fiber was embedded in various epoxy resins with different temperature behavior. The tensile strength of fiber

  9. Strong, reversible underwater adhesion via gecko-inspired hydrophobic fibers.

    Science.gov (United States)

    Soltannia, Babak; Sameoto, Dan

    2014-12-24

    Strong, reversible underwater adhesion using gecko-inspired surfaces is achievable through the use of a hydrophobic structural material and does not require surface modification or suction cup effects for this adhesion to be effective. Increased surface energy can aid in dry adhesion in an air environment but strongly degrades wet adhesion via reduction of interfacial energy underwater. A direct comparison of structurally identical but chemically different mushroom shaped fibers shows that strong, reversible adhesion, even in a fully wetted, stable state, is feasible underwater if the structural material of the fibers is hydrophobic and the mating surface is not strongly hydrophilic. The exact adhesion strength will be a function of the underwater interfacial energy between surfaces and the specific failure modes of individual fibers. This underwater adhesion has been calculated to be potentially greater than the dry adhesion for specific combinations of hydrophobic surfaces.

  10. Adhesion Between Poly(dimethylsiloxane) Layers

    DEFF Research Database (Denmark)

    Yu, Liyun; Daugaard, Anders Egede; Skov, Anne Ladegaard

    Different adhesion methods of poly(dimethylsiloxane) (PDMS) layers were studied with respect to adhesional force and the resulting rheology of the two-layered PDMS films were investigated. The role of adhesion between PDMS layers on the performances of two-layer structures was studied with peel...... strength test and by SEM pictures. The rheology of the double-layered compared to the monolayer films changed in some cases which indicates that the adhesion process needs to be carefully introduced in order not to alter the final properties....

  11. Adhesion in microelectronics

    CERN Document Server

    Mittal, K L

    2014-01-01

    This comprehensive book will provide both fundamental and applied aspects of adhesion pertaining to microelectronics in a single and easily accessible source. Among the topics to be covered include; Various theories or mechanisms of adhesionSurface (physical or chemical) characterization of materials as it pertains to adhesionSurface cleaning as it pertains to adhesionWays to improve adhesionUnraveling of interfacial interactions using an array of pertinent techniquesCharacterization of interfaces / interphasesPolymer-polymer adhesionMetal-polymer adhesion  (metallized polymers)Polymer adhesi

  12. Effects of surface treatment and adhesive application on shear bond strength between zirconia and enamel%表面处理及粘结剂对氧化锆与牙釉质间剪切粘结强度的影响

    Institute of Scientific and Technical Information of China (English)

    李颖慧; 吴补领; 孙风阳

    2013-01-01

    目的 研究表面喷砂处理及不同正畸粘结剂对氧化锆陶瓷与牙釉质间剪切粘结强度的影响.方法 40颗离体上颌第一前磨牙,应用计算机辅助设计与计算机辅助制作系统设计和制作粘结面与牙面紧密贴合的个性化氧化锆陶瓷试件.将试件随机分为4组,分别选择粘结面喷砂处理和粘结面无处理,选择京津釉质粘结剂和3M Transbond XT光固化粘结剂.按要求粘结24 h后,万能材料试验机测定剪切粘结强度,并进行统计学分析.结果 喷砂组剪切粘结强度显著高于未喷砂组(P<0.05),两种粘结剂的剪切粘结强度无显著差异(P>0.05).结论 表面喷砂处理后,无论使用京津釉质粘结剂或是3M Transbond XT光固化粘结剂,氧化锆陶瓷与牙釉质间均可获得足够的剪切粘结强度.%Objective To evaluate the effects of sandblasting and different orthodontic adhesives on shear bond strength between zirconia and enamel. Methods Zirconia ceramic samples were designed and manufactured for 40 extracted human maxillary first premolars with CAD/CAM system. The samples were randomized into 4 groups for surface treatment with sandblasting and non-treated with adhesives of 3M Transbond XT or Jingjin dental enamel bonding resin. After 24 h of bonded fixation, the shear bond strengths were measured by universal mechanical testing machine and analyzed with factorial variance analysis. Results The shear bond strength was significantly higher in sandblasting group than in untreated group (P0.05). Conclusion The shear bond strength between zirconia and enamel is sufficient after sandblasting regardless of the application of either adhesive.

  13. Evaluation of polyaryl adhesives in elastomer-stainless steel joints

    Energy Technology Data Exchange (ETDEWEB)

    Miura, M.; Carciello, N.; Sugama, T.; Kukacka, L.E.

    1992-10-01

    Polyaryl thermoplastic adhesives (polyetheretherketone, PEEK, polyphenylene sulfide PPS, polyphenylethersulfone, PES) were evaluated for ability to bond elastomer to metal for use in geothermal environments. Strength of elastomer-to-metal joints adhesives blends (such as in drill pipe or casing protectors) were determined using peel tests. Parameters involved in making the joints were temperature, time and atmosphere, in addition to type of adhesive. Physical chemical analyses have aided endeavors to determine the cause of adhesion failure in the joint: differential thermal analyses, thermal gravimetric analyses, infrared spectroscopy and electron spectroscopy for chemical analysis. Tests showed that joints made of adhesive blends which contained greater than 50% PES survived simulated geothermal conditions (200C, water vapor pressure 200 psi) for weeks without significant decrease in peel strength. Chemical components of the adhesive appear to be highly stable under the conditions required to make the joints and in subsequent exposure to the simulated geothermal environment.

  14. The effect of acrylic latex-based polymer on cow blood adhesive resins for wood composites

    Science.gov (United States)

    Yan, J.; Lin, H. L.; Feng, G. Z.; Gunasekaran, S.

    2016-07-01

    In this paper, alkali-modified cow blood adhesive (BA) and blood adhesive/acrylic latex-based adhesive (BA/ALB) were prepared. The physicochemical and adhesion properties of cow blood adhesive such as UV- visible spectra, particle size, viscosity were evaluated; share strength, water resistance were tested. UV- visible spectra indicates that the strong bonding strength of BA/ALB appeared after incorporating; the particle size of adhesive decreased with the increase of ALB concentration, by mixing ALB and BA, hydrophilic polymer tends locate or extand the protein chains and provide stability of the particles; viscosity decreased as shear rate increased in concordance with a pseudoplastic behavior; both at dry and soak conditions, BA and ALB/BA show significant difference changes when mass fraction of ALB in blend adhesive was over 30% (p cow blood and acrylic latex-based adhesive significantly increased the strength and water resistance of the resulting wood.

  15. Four-year water degradation of a total-etch and two self-etching adhesives bonded to dentin

    NARCIS (Netherlands)

    A.I. Abdalla; A.J. Feilzer

    2008-01-01

    Objectives: To evaluate effect of direct and indirect water storage on the microtensile dentin bond strength of one total-etch and two self-etching adhesives. Methods: The adhesive materials were: one total-etch adhesive; ‘Admira Bond’ and two selfetch adhesives; ‘Clearfil SE Bond’ and ‘Hybrid Bond’

  16. Adhesive strength of hydroxyl apatite (HA) coating and biomechanics behavior of HA-coated prosthesis: an experimental study%羟基磷灰石涂层人工假体的涂层附着力及其生物力学行为研究

    Institute of Scientific and Technical Information of China (English)

    张天阳; 段永宏; 朱澍; 朱锦宇; 朱庆生

    2011-01-01

    Objective To explore the influence of adhesive strength of hydroxyapatite (HA) coating on the post-implantation stability of HA-coated prosthesis. Methods The adhesive strength and biomechanics behavior of HA coating were studied by histopathological observation, material parameters and biomechanical testing, the titanium (Ti)-coated prosthesis was employed as control.Results Scratch test showed that the adhesive strength of HA coating was significantly lower than that of Ti coating (P<0.01).Histopathological examination and bone morphometry showed that, at the early stage of prosthesis implantation, the bony growth around HA-coated prosthesis was significantly higher than that around Ti-coated prosthesis (P<0. 01), but the ultimate shear strength of HA-coated prosthesis was much lower than that of Ti-coated prosthesis (P<0. 01). After the push-out test with prosthesis, histopathological observation showed that there were accumulations of clump- and strip-like granular residues on the surface of bones that newly grew around the HA-coated prosthesis, and surface energy-dispersive X-ray spectroscopy (EDX) analysis also confirmed that the shear stress induced HA decohesion from the substrate of prosthesis. Conclusions Although HA coating showed a satisfactory effect on early bone formation and prosthetic stability, due to the deficiencies of adhesive strength, the early stability of prosthesis may be gradually destroyed by the shear loads of human body and coating degradation.%目的 探讨羟基磷灰石(HA)涂层结合强度对HA涂层人工假体植入后稳定性的影响.方法 以钛(Ti)涂层假体作为对照,通过组织病理学观察、涂层结合强度及生物力学检测对HA涂层假体的涂层附着力及其生物力学行为进行研究.结果 划痕法检测结果显示,HA涂层结合强度明显低于Ti涂层(P<0.01).假体植入早期组织病理学观察及骨计量学结果显示HA涂层假体周围的成骨

  17. Determinação da força de adesão da metalização com alumínio em filmes plásticos utilizados em embalagens flexíveis Adhesion strength of aluminum on metallized plastic films used in flexible packages - development and validation of a test procedure

    Directory of Open Access Journals (Sweden)

    Léa M. Oliveira

    2011-01-01

    Full Text Available Filmes de BOPP e de PET metalizados são muito utilizados em embalagens multicamadas, pois reúnem boas propriedades mecânicas e de barreira a gases e umidade, as quais, bem como a aparência e a integridade, são comprometidas quando ocorre a delaminação da estrutura multicamada. Um dos principais fatores que influem na resistência à delaminação é a força de adesão da camada de alumínio ao substrato polimérico, parâmetro para o qual não há um método de quantificação normalizado. O objetivo deste trabalho foi estabelecer e validar um método de ensaio para determinar esta força de adesão. O método foi definido usando um planejamento experimental com fatores fixos e variáveis sendo que, para cada variável, foram definidos dois níveis. O método de ensaio estabelecido mostrou-se estável, preciso, robusto e replicável. Consiste, basicamente, na termosselagem de um filme plástico à face metalizada da amostra, em condições específicas de temperatura/tempo/pressão, e medida da força para destacamento da metalização, em ângulo e velocidade específicos, em máquina universal de ensaios.OPP and OPET metallized films are widely used as substrates in multilayer packages, since they bring together good mechanical properties and barrier to gases and water vapor, which are damaged with delamination of the film layers, together with the visual appearance and package integrity. One of the main factors that affect the package delamination is the adhesion strength of aluminum layer to the polymeric substrate, a parameter for which there is no standard procedure to quantify. The aim of this work was to establish and validate a procedure to determine the adhesion strength of the aluminum to the polymer. This test procedure was carried out using experimental design with fixed and variables parameters with two levels for each variable. The test procedure was stable, robust and replicable. It consisted basically of the heat sealing

  18. Tile adhesive production by Inorganic materials

    Directory of Open Access Journals (Sweden)

    Fasil Alemayehu Hayilu

    2013-07-01

    Full Text Available In modern construction, ceramic tile and mosaic which are used for finishing and decoration are attached to the surface by using tile adhesives. It was a long way for tiling technology to arrive at the current cement based modified adhesive. The development in additives and modifier are the paramount factor to improve workability, higher flexibility, and better adhesion. In this document tile adhesive has been produced for economical and high performance formulation. These products have been produced by considering the effect of aggregate. These two products with different size of aggregate have been compared and tested. The test made was slip, bending, and compression test. Economical formulation consists of components like cement, quartz sand, cellulose ether and tartaric acid. But high performance consists of limestone and cellulose fiber in addition to these components. The modifier added has enhanced the final product resistance to sliding, bending and compression strength. In terms of compression strength test about 17.27% high performance is stronger than economical formulation. And in addition high performance is stronger than economical formulation by about 16.89% in terms of bending strength. The other thing is the effect of grain size, the component that has low grain size have shown great strength and resistant to slide.

  19. Strength Training

    Science.gov (United States)

    ... person's own weight to build muscles and strength. Olympic lifting, or powerlifting, which people often think of ... in the group effectively. Here are some basic rules to follow in strength training: Start with body ...

  20. Avaliação in vitro da resistência de união de diferentes combinações entre adesivos e resinas compostas In vitro evaluation of the bond strength of different combinations of adhesives and composite resins

    Directory of Open Access Journals (Sweden)

    Eduardo Batista FRANCO

    2000-09-01

    37ºC for one week. Then, they were replaced in the matrix for the building of the second half and divided into groups to combine each composite resin with each one of the three adhesives. The specimens were stored in distilled water at 37ºC and after the period of 7 days they were submitted to the tensile strength test in a Kratos machine. It was concluded that: generally, the composite resins and the adhesives showed to be compatible; the combination AP.H/XR-Bond showed the highest discrepancy, since the tensile strength was statistically smaller than that of the combination proposed by the manufacturer; the other combinations of the adhesives and the composite resins showed tensile strengths statistically similar to or greater than that of the combination recommended by the manufacturer.

  1. 高粘结高抗渗水泥基渗透结晶型防水材料的研究%Study on cement-based permeable crystalline waterproof material with high adhesive strength and high anti-permeability

    Institute of Scientific and Technical Information of China (English)

    郭璞

    2016-01-01

    选取多种活性物质,通过正交试验方法,配制了一种高粘结、高抗渗在役混凝土复合增强材料 HCIM,测试了 HCIM 的各项性能指标,分析了其渗透修补机理,指出 HCIM 满足相关规范的要求。%Selecting various active materials,through orthogonal testing method,the PaPer makes uP a kind of in-service high-adhesive and high anti-Permeability concrete comPosite strengthening material HCIM,tests various Performance indicators of HCIM,analyzes its Permeability rePai-ring mechanism,and finally Points out that:HCIM meets relevant demands.

  2. Prevention of bacterial adhesion

    DEFF Research Database (Denmark)

    Klemm, Per; Vejborg, Rebecca Munk; Hancock, Viktoria

    2010-01-01

    that imposes selection pressure for resistant bacteria. New approaches are urgently needed. Targeting bacterial virulence functions directly is an attractive alternative. An obvious target is bacterial adhesion. Bacterial adhesion to surfaces is the first step in colonization, invasion, and biofilm formation....... As such, adhesion represents the Achilles heel of crucial pathogenic functions. It follows that interference with adhesion can reduce bacterial virulence. Here, we illustrate this important topic with examples of techniques being developed that can inhibit bacterial adhesion. Some of these will become...

  3. Particle adhesion and removal

    CERN Document Server

    Mittal, K L

    2015-01-01

    The book provides a comprehensive and easily accessible reference source covering all important aspects of particle adhesion and removal.  The core objective is to cover both fundamental and applied aspects of particle adhesion and removal with emphasis on recent developments.  Among the topics to be covered include: 1. Fundamentals of surface forces in particle adhesion and removal.2. Mechanisms of particle adhesion and removal.3. Experimental methods (e.g. AFM, SFA,SFM,IFM, etc.) to understand  particle-particle and particle-substrate interactions.4. Mechanics of adhesion of micro- and  n

  4. Adhesion enhancement of Al coatings on carbon/epoxy composite surfaces by atmospheric plasma

    International Nuclear Information System (INIS)

    Adhesion strengths between aluminium thin film coatings and manufactured carbon/epoxy composite surfaces were measured by assessing fracture tensile strengths using pull-off tests. The effect of the substrate roughness (nm to μm) of these composite surfaces on adhesion was studied by examining the surface free energies and adhesion strengths. The adhesion strengths of the coatings varied significantly. To improve the coating adhesion, each composite surface was treated with atmospheric plasma prior to deposition, which resulted in an increase in the surface free energy from approximately 40 mJ/m2 to 70 mJ/m2 because the plasma pretreatment led to the formation of hydrophilic C-O and C=O bonds on the composite surfaces, as demonstrated by X-ray photoelectron spectroscopy analyses. The adhesion strengths of the coatings were enhanced for all surface roughnesses studied. In our study, the effect of mechanical adhesion due to roughness was separated from the effect of modifying the chemical bonds with plasma activation. The adhesion ability of the pure resin was relatively weak. Increasing the surface roughness largely improved the adhesion of the resin surface. Plasma treatment of the pure resin also increased the surface adhesion. Our study shows that plasma activation effectively enhances the adhesion of manufactured composites, even when the surface roughness is on the order of microns. The ageing of the surface activation was also investigated, and the results demonstrate that atmospheric plasma has potential for use in the pretreatment of composite materials.

  5. Determination of carbon fiber adhesion to thermoplastic polymers using the single fiber/matrix tensile test

    Science.gov (United States)

    Bascom, W. D.; Cordner, L. W.; Hinkley, J. L.; Johnston, N. J.

    1986-01-01

    The single fiber adhesion shear test has been adapted to testing the adhesion between carbon fiber and thermoplastic polymers. Tests of three thermoplastics, polycarbonate, polyphenylene oxide and polyetherimide indicate the shear adhesion strength is significantly less than of an epoxy polymer to the same carbon fiber.

  6. An adhesion-dependent switch between mechanisms that determine motile cell shape.

    Directory of Open Access Journals (Sweden)

    Erin L Barnhart

    2011-05-01

    Full Text Available Keratocytes are fast-moving cells in which adhesion dynamics are tightly coupled to the actin polymerization motor that drives migration, resulting in highly coordinated cell movement. We have found that modifying the adhesive properties of the underlying substrate has a dramatic effect on keratocyte morphology. Cells crawling at intermediate adhesion strengths resembled stereotypical keratocytes, characterized by a broad, fan-shaped lamellipodium, clearly defined leading and trailing edges, and persistent rates of protrusion and retraction. Cells at low adhesion strength were small and round with highly variable protrusion and retraction rates, and cells at high adhesion strength were large and asymmetrical and, strikingly, exhibited traveling waves of protrusion. To elucidate the mechanisms by which adhesion strength determines cell behavior, we examined the organization of adhesions, myosin II, and the actin network in keratocytes migrating on substrates with different adhesion strengths. On the whole, our results are consistent with a quantitative physical model in which keratocyte shape and migratory behavior emerge from the self-organization of actin, adhesions, and myosin, and quantitative changes in either adhesion strength or myosin contraction can switch keratocytes among qualitatively distinct migration regimes.

  7. Contact between rough surfaces and a criterion for macroscopic adhesion.

    Science.gov (United States)

    Pastewka, Lars; Robbins, Mark O

    2014-03-01

    At the molecular scale, there are strong attractive interactions between surfaces, yet few macroscopic surfaces are sticky. Extensive simulations of contact by adhesive surfaces with roughness on nanometer to micrometer scales are used to determine how roughness reduces the area where atoms contact and thus weakens adhesion. The material properties, adhesive strength, and roughness parameters are varied by orders of magnitude. In all cases, the area of atomic contact is initially proportional to the load. The prefactor rises linearly with adhesive strength for weak attractions. Above a threshold adhesive strength, the prefactor changes sign, the surfaces become sticky, and a finite force is required to separate them. A parameter-free analytic theory is presented that describes changes in these numerical results over up to five orders of magnitude in load. It relates the threshold adhesive strength to roughness and material properties, explaining why most macroscopic surfaces do not stick. The numerical results are qualitatively and quantitatively inconsistent with classical theories based on the Greenwood-Williamson approach that neglect the range of adhesion and do not include asperity interactions. PMID:24550489

  8. Controlled release in transdermal pressure sensitive adhesives using organosilicate nanocomposites.

    Science.gov (United States)

    Shaikh, Sohel; Birdi, Anil; Qutubuddin, Syed; Lakatosh, Eric; Baskaran, Harihara

    2007-12-01

    Polydimethyl siloxane (PDMS) based pressure sensitive adhesives (PSA) incorporating organo-clays at different loadings were fabricated via solution casting. Partially exfoliated nanocomposites were obtained for the hydroxyl terminated PDMS in ethyl acetate solvent as determined by X-ray diffraction and atomic force microscopy. Drug release studies showed that the initial burst release was substantially reduced and the drug release could be controlled by the addition of organo-clay. Shear strength and shear adhesion failure temperature (SAFT) measurements indicated substantial improvement in adhesive properties of the PSA nanocomposite adhesives. Shear strength showed more than 200% improvement at the lower clay loadings and the SAFT increased by about 21% due to the reinforcement provided by the nano-dispersed clay platelets. It was found that by optimizing the level of the organosilicate additive to the polymer matrix, superior control over drug release kinetics and simultaneous improvements in adhesive properties could be attained for a transdermal PSA formulation. PMID:17786555

  9. Adhesion Improvement of Zirconium Coating on Polyurethane Modified by Plasmas

    Science.gov (United States)

    Gao, Yi; Hao, Xiaofei; Liu, Jiwei

    2016-02-01

    In order to improve the adhesion of the middle frequency magnetic sputtered zirconium coating on a polyurethane film, an anode layer source was used to pretreat the polyurethane film with nitrogen and oxygen ions. SEMs and AFM roughness profiles of treated samples and the contrast groups were obtained. Besides, XPS survey spectrums and high resolution spectrums were also investigated. The adhesion test revealed that ion bombardment could improve the adhesion to the polyurethane coating substrate. A better etching result of oxygen ions versus nitrogen predicts a higher bonding strength of zirconium coating on polyurethane and, indeed, the highest bonding strengths are for oxygen ion bombardment upto 13.3 MPa. As demonstrated in X-ray photoelectron spectroscopy, the oxygen ion also helps to introduce more active groups, and, therefore, it achieves a high value of adhesion strength.

  10. An accelerated buoyancy adhesion assay combined with 3-D morphometric analysis for assessing osteoblast adhesion on microgrooved substrata.

    Science.gov (United States)

    Sobral, J M; Malheiro, V N; Clyne, T W; Harris, J; Rezk, R; O'Neill, W; Markaki, A E

    2016-07-01

    An accelerated negative buoyancy method has been developed to assess cell adhesion strength. This method has been used in conjunction with 3-D morphometric analysis to understand the effects of surface topology on cell response. Aligned micro-grooved surface topographies (with a range of groove depths) were produced on stainless steel 316L substrates by laser ablation. An investigation was carried out on the effect of the micro-grooved surface topography on cell adhesion strength, cell and nucleus volumes, cell phenotypic expression and attachment patterns. Increased hydrophobicity and anisotropic wettability was observed on surfaces with deeper grooves. A reduction was noted in cell volume, projected areas and adhesion sites for deeper grooves, linked to lower cell proliferation and differentiation rates and also to reduced adhesion strength. The results suggest that the centrifugation assay combined with three-dimensional cell morphometric analysis has considerable potential for obtaining improved understanding of the cell/substrate interface. PMID:26773651

  11. Surface pretreatments for medical application of adhesion

    Directory of Open Access Journals (Sweden)

    Weber Michael

    2003-09-01

    Full Text Available Abstract Medical implants and prostheses (artificial hips, tendono- and ligament plasties usually are multi-component systems that may be machined from one of three material classes: metals, plastics and ceramics. Typically, the body-sided bonding element is bone. The purpose of this contribution is to describe developments carried out to optimize the techniques , connecting prosthesis to bone, to be joined by an adhesive bone cement at their interface. Although bonding of organic polymers to inorganic or organic surfaces and to bone has a long history, there remains a serious obstacle in realizing long-term high-bonding strengths in the in vivo body environment of ever present high humidity. Therefore, different pretreatments, individually adapted to the actual combination of materials, are needed to assure long term adhesive strength and stability against hydrolysis. This pretreatment for metal alloys may be silica layering; for PE-plastics, a specific plasma activation; and for bone, amphiphilic layering systems such that the hydrophilic properties of bone become better adapted to the hydrophobic properties of the bone cement. Amphiphilic layering systems are related to those developed in dentistry for dentine bonding. Specific pretreatment can significantly increase bond strengths, particularly after long term immersion in water under conditions similar to those in the human body. The bond strength between bone and plastic for example can be increased by a factor approaching 50 (pealing work increasing from 30 N/m to 1500 N/m. This review article summarizes the multi-disciplined subject of adhesion and adhesives, considering the technology involved in the formation and mechanical performance of adhesives joints inside the human body.

  12. Study on heat and humidity resistance of high-strength polyurethane adhesive & sealant%高强度聚氨酯粘接密封胶耐湿热性研究

    Institute of Scientific and Technical Information of China (English)

    唐礼道; 刘鹏; 吴燕锋; 韩胜利; 赵祖培

    2012-01-01

    The high-strength polyurethane sealants for windshield were prepared from polyurethane prepolymers.plasticizer and carbon black as the main raw materials,which reached the technical requirements of an OEM.The sealants have excellent weather resistance.The influence of polyurethane prepolymers and plasticizer to heat and humidity resistance of the polyurethane sealants was discussed.We also studied the effect of prepolymer type on shear strength.%以聚氨酯预聚物、增塑剂、炭黑为主要原料制备出一种高强度挡风玻璃粘接密封胶,该胶耐候性优异,达到了某主机厂的技术要求;重点探讨了聚氨酯预聚物和增塑剂对聚氨酯胶耐湿热性能的影响,研究了预聚物种类对剪切强度的影响.

  13. 反应釜耐蚀涂层厚度对涂层与基体结合强度的影响%Effect of the Thickness of Arc Spraying Coatings on Adhesion Strength of Base metal and Coatings

    Institute of Scientific and Technical Information of China (English)

    邓琳

    2012-01-01

    利用电弧喷涂设备在低碳钢试件表面制备了0Cr18Ni9涂层,并在金相显微镜下观察涂层的显微组织结构,同时用拉伸试验机对不同厚度涂层的结合强度进行了测试。实验结果表明:涂层的成形良好,组织比较均匀;厚度对涂层与试件的结合强度有显著的影响,为保证涂层的使用性能,涂层厚度应不大于0.6mm。%Effects of three substrate surface roughening methods such as sandblasting, spraying base coating and electrospark roughening on microstructure, microhardness and bonding strength were studied. The results show that coatings may spall without sandblasting. Spraying base coating after sandblasting and electrospark roughening after sandblasting can dramatically improve the microstructure, microhardness and bonding strength.

  14. Effects of metal coatings on adhesive characteristics of Gecko-like microstructures

    Energy Technology Data Exchange (ETDEWEB)

    Kim Kyu Hye; An, Tea Chang; Hwang, Hui Yun [Dept. of Mechanical Design Engineering, Andong National University, Andong (Korea, Republic of)

    2015-11-15

    Recently, there have been several studies on the inspiration and application of optimized natural structures. One study introduced a new adhesion method that was inspired by the feet of geckos because of their superior features such as high adhesion strength, ease-of-removal, and they are environmentally friendly. Various micro- or nano-structures were fabricated and tested for gecko-like dry adhesives, but gecko-like dry adhesives that were developed became easily worn from frequent use. In this study, we propose a metal-coating method to improve the durability of gecko-like dry adhesives. We evaluate the initial adhesion strength and durability by performing repeated adhesion tests on a glass plate. The initial adhesive strength of gold-coated micro-structures was 60% of that for non-coated ones. However, the adhesive strength of gold-coated micro-structures was kept as 58% of their initial adhesion strength, while that of non-coated ones was only 40%.

  15. Reversible Thermoset Adhesives

    Science.gov (United States)

    Mac Murray, Benjamin C. (Inventor); Tong, Tat H. (Inventor); Hreha, Richard D. (Inventor)

    2016-01-01

    Embodiments of a reversible thermoset adhesive formed by incorporating thermally-reversible cross-linking units and a method for making the reversible thermoset adhesive are provided. One approach to formulating reversible thermoset adhesives includes incorporating dienes, such as furans, and dienophiles, such as maleimides, into a polymer network as reversible covalent cross-links using Diels Alder cross-link formation between the diene and dienophile. The chemical components may be selected based on their compatibility with adhesive chemistry as well as their ability to undergo controlled, reversible cross-linking chemistry.

  16. Effect of Surface Pretreatment on Adhesive Properties of Aluminum Alloys

    Institute of Scientific and Technical Information of China (English)

    Jinsheng ZHANG; Xuhui ZHAO; Yu ZUO; Jinping XIONG; Xiaofeng ZHANG

    2008-01-01

    The lap-shear strength and durability of adhesive bonded AI alloy joints with different pretreatments were studied by the lap-shear test and wedge test. The results indicate that the maximum lap-shear strength and durability of the bonding joints pretreated by different processes are influenced by the grade of abrasive papers and can be obviously improved by phosphoric acid anodizing. Alkali etching can obviously improve the durability of bonding joints although it slightly influences the maximum lap-shear strength. The process which is composed of grit-finishing, acetone degreasing, alkali etching and phosphoric acid anodizing, provides a better adhesive bonding property of AI alloy.

  17. Optimization of adhesion mode atomic force microscopy resolves individual molecules in topography and adhesion

    NARCIS (Netherlands)

    Willemsen, O.H.; Snel, M.M.E.; Noort, van S.J.T.; Werf, van der K.O.; Grooth, de B.G.; Figdor, C.G.; Greve, J.

    1999-01-01

    The force sensor of an atomic force microscope (AFM) is sensitive enough to measure single molecular binding strengths by means of a force–distance curve. In order to combine high-force sensitivity with the spatial resolution of an AFM in topography mode, adhesion mode has been developed. Since this

  18. Friction and adhesion of hierarchical carbon nanotube structures for biomimetic dry adhesives: multiscale modeling.

    Science.gov (United States)

    Hu, Shihao; Jiang, Haodan; Xia, Zhenhai; Gao, Xiaosheng

    2010-09-01

    With unique hierarchical fibrillar structures on their feet, gecko lizards can walk on vertical walls or even ceilings. Recent experiments have shown that strong binding along the shear direction and easy lifting in the normal direction can be achieved by forming unidirectional carbon nanotube array with laterally distributed tips similar to gecko's feet. In this study, a multiscale modeling approach was developed to analyze friction and adhesion behaviors of this hierarchical fibrillar system. Vertically aligned carbon nanotube array with laterally distributed segments at the end was simulated by coarse grained molecular dynamics. The effects of the laterally distributed segments on friction and adhesion strengths were analyzed, and further adopted as cohesive laws used in finite element analysis at device scale. The results show that the laterally distributed segments play an essential role in achieving high force anisotropy between normal and shear directions in the adhesives. Finite element analysis reveals a new friction-enhanced adhesion mechanism of the carbon nanotube array, which also exists in gecko adhesive system. The multiscale modeling provides an approach to bridge the microlevel structures of the carbon nanotube array with its macrolevel adhesive behaviors, and the predictions from this modeling give an insight into the mechanisms of gecko-mimicking dry adhesives.

  19. Comparative study of etched enamel and dentin for the adhesion of composite resins with the Er:YAG 2,94 μm laser and CO2 9,6 μm laser: morphological (SEM) and tensile bond strength analysis

    International Nuclear Information System (INIS)

    The aim of this study was to evaluate and compare the tensile bond strength of a composite resin adhered to the enamel and dentin which have received superficial irradiation with an Er:YAG laser (2.94 μm) or with CO2 laser ( 9.6 μm) and later on etched with the phosphoric acid at 35%. After the use of the adhesive system, resin cones were made on the etched surfaces by both lasers and tensile bond strength tests were performed. All samples were observed at the SEM - there was an increase of the degree of fusion and resolidification in the irradiated enamel and dentin samples with the CO2 laser (9.6 μm), creating a vitrified layer with tiny craters. With the Er:YAG laser (2.94 μm) there were typical morphological explosive microablation with the exposition of the tubules in the dentin.The surface acquired by the association of the CO2 laser ( 9.6 μm) plus acid etching no longer presented the aspect of fusion being this layer completely removed. There were statistical significant differences among ali three methods of etching in the treatment of the enamel and dentin surface. The tensile bond strength test showed that etching of these enamel and dentin surfaces with acid exclusively (control group) presented great values, surpassing the values of the etching acquired with the Er:YAG laser (2.94 μ) plus acid or the CO2 laser (9.6 μm) plus acid. With the parameters used in this experiment the Er:YAG laser (2.94 μm) showed to be more effective than the CO2 laser (9.6 μm) for the hard dental surfaces etching procedure. (author)

  20. Extreme positive allometry of animal adhesive pads and the size limits of adhesion-based climbing.

    Science.gov (United States)

    Labonte, David; Clemente, Christofer J; Dittrich, Alex; Kuo, Chi-Yun; Crosby, Alfred J; Irschick, Duncan J; Federle, Walter

    2016-02-01

    Organismal functions are size-dependent whenever body surfaces supply body volumes. Larger organisms can develop strongly folded internal surfaces for enhanced diffusion, but in many cases areas cannot be folded so that their enlargement is constrained by anatomy, presenting a problem for larger animals. Here, we study the allometry of adhesive pad area in 225 climbing animal species, covering more than seven orders of magnitude in weight. Across all taxa, adhesive pad area showed extreme positive allometry and scaled with weight, implying a 200-fold increase of relative pad area from mites to geckos. However, allometric scaling coefficients for pad area systematically decreased with taxonomic level and were close to isometry when evolutionary history was accounted for, indicating that the substantial anatomical changes required to achieve this increase in relative pad area are limited by phylogenetic constraints. Using a comparative phylogenetic approach, we found that the departure from isometry is almost exclusively caused by large differences in size-corrected pad area between arthropods and vertebrates. To mitigate the expected decrease of weight-specific adhesion within closely related taxa where pad area scaled close to isometry, data for several taxa suggest that the pads' adhesive strength increased for larger animals. The combination of adjustments in relative pad area for distantly related taxa and changes in adhesive strength for closely related groups helps explain how climbing with adhesive pads has evolved in animals varying over seven orders of magnitude in body weight. Our results illustrate the size limits of adhesion-based climbing, with profound implications for large-scale bio-inspired adhesives. PMID:26787862

  1. Molecular mechanics of mussel adhesion proteins

    Science.gov (United States)

    Qin, Zhao; Buehler, Markus J.

    2014-01-01

    Mussel foot protein (mfp), a natural glue produced by marine mussel, is an intriguing material because of its superior ability for adhesion in various environments. For example, a very small amount of this material is sufficient to affix a mussel to a substrate in water, providing structural support under extreme forces caused by the dynamic effects of waves. Towards a more complete understanding of its strength and underwater workability, it is necessary to understand the microscropic mechanisms by which the protein structure interacts with various substrates. However, none of the mussel proteins' structure is known, preventing us from directly using atomistic modeling to probe their structural and mechanical properties. Here we use an advanced molecular sampling technique to identify the molecular structures of two mussel foot proteins (mfp-3 and mfp-5) and use those structures to study their mechanics of adhesion, which is then incorporated into a continuum model. We calculate the adhesion energy of the mussel foot protein on a silica substrate, compute the adhesion strength based on results obtained from molecular modeling, and compare with experimental data. Our results show good agreement with experimental measurements, which validates the multiscale model. We find that the molecular structure of the folded mussel foot protein (ultimately defined by its genetic sequence) favors strong adhesion to substrates, where L-3,4-dihydroxyphenylalanine (or DOPA) protein subunits work in a cooperative manner to enhance adhesion. Our experimental data suggests a peak attachment force of 0.4±0.1 N, which compares favorably with the prediction from the multiscale model of Fc=0.21-0.33 N. The principles learnt from those results could guide the fabrication of new interfacial materials (e.g. composites) to integrate organic with inorganic surfaces in an effective manner.

  2. Tissue adhesives in otorhinolaryngology

    Directory of Open Access Journals (Sweden)

    Schneider, Gerlind

    2009-01-01

    Full Text Available The development of medical tissue adhesives has a long history without finding an all-purpose tissue adhesive for clinical daily routine. This is caused by the specific demands which are made on a tissue adhesive, and the different areas of application. In otorhinolaryngology, on the one hand, this is the mucosal environment as well as the application on bones, cartilage and periphery nerves. On the other hand, there are stressed regions (skin, oral cavity, pharynx, oesophagus, trachea and unstressed regions (middle ear, nose and paranasal sinuses, cranial bones. But due to the facts that adhesives can have considerable advantages in assuring surgery results, prevention of complications and so reduction of medical costs/treatment expenses, the search for new adhesives for use in otorhinolaryngology will be continued intensively. In parallel, appropriate application systems have to be developed for microscopic and endoscopic use.

  3. A design methodology for biologically inspired dry fibrillar adhesives

    Science.gov (United States)

    Aksak, Burak

    Realization of the unique aspects of gecko adhesion and incorporating these aspects into a comprehensive design methodology is essential to enable fabrication of application oriented gecko-inspired dry fibrillar adhesives. To address the need for such a design methodology, we propose a fibrillar adhesion model that evaluates the effect of fiber dimensions and material on adhesive performance of fiber arrays. A fibrillar adhesion model is developed to predict the adhesive characteristics of an array of fibrillar structures, and quantify the effect of fiber length, radius, spacing, and material. Photolithography techniques were utilized to fabricate elastomer microfiber arrays. Fibers that are fabricated from stiff SU-8 photoresist are used to fabricate a flexible negative mold that facilitates fabrication of fiber arrays from various elastomers with high yield. The tips of the cylindrical fibers are modified to mushroom-like tip shapes. Adhesive strengths in excess of 100 kPa is obtained with mushroom tipped elastomer microfibers. Vertically aligned carbon nanofibers (VACNFs) are utilized as enhanced friction materials by partially embedding inside soft polyurethanes. Friction coefficients up to 1 were repeatedly obtained from the resulting VACNF composite structures. A novel fabrication method is used to attach Poly(n-butyl acrylate) (PBA) molecular brush-like structures on the surface of polydimethylsiloxane (PDMS). These brushes are grown on unstructured PDMS and PDMS fibers with mushroom tips. Pull-off force is enhanced by up to 7 times with PBA brush grafted micro-fiber arrays over unstructured PDMS substrate. Adhesion model, initially developed for curved smooth surfaces, is extended to self-affine fractal surfaces to better reflect the adhesion performance of fiber arrays on natural surfaces. Developed adhesion model for fiber arrays is used in an optimization scheme which estimates optimal design parameters to obtain maximum adhesive strength on a given

  4. Strength of glue line for reforestation wood

    Directory of Open Access Journals (Sweden)

    Pedro Gutemberg de Alcântara Segundinho

    2015-05-01

    Full Text Available This paper aims to evaluate the shear strength of glued laminated timber (glulam made of three wood species: Tectona grandis, Pinus oocarpa and Eucalyptus sp.. The bonds were made with lamellae with no chemical treatment, using two-component adhesive based on melamine-urea-formaldehyde (MUF. Glue line shear tests were made for wood in local moisture content and high humidity, as well as delamination tests. The results presented in the glue line shear strength tests in dry condition and delamination for the three species indicate better performance of Pinus oocarpa. It was concluded that this species there is potential to produce MLC utilizing the MUF adhesive.

  5. Effects of contact cap dimension on dry adhesion of bioinspired mushroom-shaped surfaces

    Science.gov (United States)

    Wang, Yue; Shao, Jinyou; Ding, Yucheng; Li, Xiangming; Tian, Hongmiao; Hu, Hong

    2015-03-01

    Dry adhesion observed in small creatures, such as spiders, insects, and geckos, has many great advantages such as repeatability and strong adhesiveness. In order to mimic these unique performances, fibrillar surface with a mushroom shaped end has drawn lots of attentions because of its advantage in efficiently enhancing adhesion compared with other sphere or simple flat ends. Here, in order to study the effects of contact cap dimension on adhesion strength, patterned surfaces of mushroom-shaped micropillars with differing cap diameters are fabricated based on the conventional photolithography and molding. The normal adhesion strength of these dry adhesives with varying cap diameters is measured with home-built equipment. The strength increases with the rise of cap diameter, and interestingly it becomes strongest when the mushroom caps join together.

  6. STRAW BASED PARTICLEBOARD BONDED WITH COMPOSITE ADHESIVES

    Directory of Open Access Journals (Sweden)

    Mingwei Di

    2011-02-01

    Full Text Available Environmentally friendly particleboard was prepared with wheat straw, an inexpensive material. The particleboard was produced by a mixing process, using a composite adhesive comprised of urea-formaldehyde (UF adhesives and EPU. The performance of the board was evaluated by measuring internal bonding strength (IB, thickness swelling, modulus of rupture (MOR, modulus of elasticity (MOE, and formaldehyde emission. The experimental results showed that maximum of dry and wet internal bonding strength, modulus of rupture, modulus of elasticity were 0.45MPa, 0.18MPa, 31.80MPa, and 5043MPa, respectively. The thickness swelling (TS2h and thickness swelling (TS24h were 3.9% and 10.7%, respectively. The composite adhesives and particleboards were measured by differential scanning calorimentry (DSC, dynamic mechanical analyzer (DMA, X-ray photoelectron spectroscopy (XPS and scanning electron microscope (SEM measurements. The results indicated that the composite adhesive of UF/EPU could contribute to excellent mechanical, thermal, and water-resistant properties of the wheat straw particleboards.

  7. A feasibility study of using two-component polyurethane adhesive in constructing wooden structures

    Institute of Scientific and Technical Information of China (English)

    Mohammad Derikvand; Ghanbar Ebrahimi; Mehdi Tajvidi

    2014-01-01

    This investigation was conducted to determine the feasibility of using a two-component polyurethane (PUR) adhesive, with special waterproof properties, in constructing wooden structures. We designed and conducted tests to compare the shear strength and adhesion per-formance of PUR with polyvinyl acetate (PVAc) adhesive on block-shear specimens constructed of oriental beech (Fagus orientalis L.), fir (Abies alba Mill.), poplar (Populus deltoides Bartr.), white oak (Quercus alba L.), sycamore (Platanus orientalis L.) and white walnut (Juglans cinerea L.). The values of the percentage of wood failure were also determined in specimens constructed with each adhesive. The highest shear strength values of both adhesives were obtained in specimens constructed of beech, while the lowest shear strength values were obtained in fir and poplar specimens. Average shear strength of the PUR adhesive was 16.5%higher than that of the PVAc adhesive. Specimens constructed of fir, poplar and sycamore were characterised by the highest percentages of wood failure, whereas the lowest average percentages of wood failure were obtained in beech and oak specimens. With the exception of oak specimens, there was no statistically significant difference between per-centage of wood failure among the PUR and PVAc adhesives. Generally, the PUR adhesive showed an acceptable adhesion performance on wood materials used in our study.

  8. Combined dry and wet adhesion between a particle and an elastic substrate.

    Science.gov (United States)

    Qian, Jin; Lin, Ji; Shi, Mingxing

    2016-12-01

    We theoretically model the combined dry and wet adhesion between a rigid sphere and an elastic substrate, where the dry contact area is surrounded by a liquid meniscus. The influence of the liquid on the interfacial adhesion is twofold: inducing the Laplace pressure around the dry contact area and altering the adhesion energy between solid surfaces. The behavior of such combined dry and wet adhesion shows a smooth transition between the JKR and DMT models for hydrophilic solids, governed by the prescribed liquid volume or environmental humidity. The JKR-DMT transition vanishes when the solids become hydrophobic. An inverse scaling law of adhesive strength indicates that size reduction helps to enhance the adhesive strength until a theoretical limit is reached. This study also demonstrates the jumping-on and jumping-off hysteresis between the combined dry-wet adhesion and pure liquid bridge in a complete separation and approach cycle. PMID:27567029

  9. Combined dry and wet adhesion between a particle and an elastic substrate.

    Science.gov (United States)

    Qian, Jin; Lin, Ji; Shi, Mingxing

    2016-12-01

    We theoretically model the combined dry and wet adhesion between a rigid sphere and an elastic substrate, where the dry contact area is surrounded by a liquid meniscus. The influence of the liquid on the interfacial adhesion is twofold: inducing the Laplace pressure around the dry contact area and altering the adhesion energy between solid surfaces. The behavior of such combined dry and wet adhesion shows a smooth transition between the JKR and DMT models for hydrophilic solids, governed by the prescribed liquid volume or environmental humidity. The JKR-DMT transition vanishes when the solids become hydrophobic. An inverse scaling law of adhesive strength indicates that size reduction helps to enhance the adhesive strength until a theoretical limit is reached. This study also demonstrates the jumping-on and jumping-off hysteresis between the combined dry-wet adhesion and pure liquid bridge in a complete separation and approach cycle.

  10. Preparation and testing of plant seed meal-based wood adhesives.

    Science.gov (United States)

    He, Zhongqi; Chapital, Dorselyn C

    2015-01-01

    Recently, the interest in plant seed meal-based products as wood adhesives has steadily increased, as these plant raw materials are considered renewable and environment-friendly. These natural products may serve as alternatives to petroleum-based adhesives to ease environmental and sustainability concerns. This work demonstrates the preparation and testing of the plant seed-based wood adhesives using cottonseed and soy meal as raw materials. In addition to untreated meals, water washed meals and protein isolates are prepared and tested. Adhesive slurries are prepared by mixing a freeze-dried meal product with deionized water (3:25 w/w) for 2 hr. Each adhesive preparation is applied to one end of 2 wood veneer strips using a brush. The tacky adhesive coated areas of the wood veneer strips are lapped and glued by hot-pressing. Adhesive strength is reported as the shear strength of the bonded wood specimen at break. Water resistance of the adhesives is measured by the change in shear strength of the bonded wood specimens at break after water soaking. This protocol allows one to assess plant seed-based agricultural products as suitable candidates for substitution of synthetic-based wood adhesives. Adjustments to the adhesive formulation with or without additives and bonding conditions could optimize their adhesive properties for various practical applications.

  11. Modeling and characterization of interfacial adhesion and fracture

    Science.gov (United States)

    Yao, Qizhou

    2000-09-01

    The loss of interfacial adhesion is mostly seen in the failure of polymer adhesive joints. In addition to the intrinsic physical attraction across the interface, the interfacial adhesion strength is believed to highly depend on a number of factors, such as adhesive chemistry/structure, surface topology, fracture pattern, thermal and elastic mismatch across the interface. The fracture failure of an adhesive joint involves basically three aspects, namely, the intrinsic interfacial strength, the driving force for fracture and other energy dissipation. One may define the intrinsic interfacial strength as the maximum value of the intrinsic interfacial adhesion. The total work done by external forces to the component that contains the interface is partitioned into two parts. The first part is consumed by all other energy dissipation mechanisms (plasticity, heat generation, viscosity, etc.). The second part is used to debond the interface. This amount should equal to the intrinsic adhesion of the interface according to the laws of conservation of energy. It is clear that in order to understand the fundamental physics of adhesive joint failure, one must be able to characterize the intrinsic interfacial adhesion and be able to identify all the major energy dissipation mechanisms involved in the debonding process. In this study, both physical and chemical adhesion mechanisms were investigated for an aluminum-epoxy interface. The physical bonding energy was estimated by computing the Van de Waals forces across the interface. A hydration model was proposed and the associated chemical bonding energy was calculated through molecular simulations. Other energy dissipation mechanisms such as plasticity and thermal residual stresses were also identified and investigated for several four-point bend specimens. In particular, a micromechanics based model was developed to estimate the adhesion enhancement due to surface roughness. It is found that for this Al-epoxy system the major

  12. STRENGTH OF NANOMODIFIED HIGH-STRENGTH LIGHTWEIGHT CONCRETES

    Directory of Open Access Journals (Sweden)

    NOZEMTСEV Alexandr Sergeevich

    2013-02-01

    Full Text Available The paper presents the results of research aimed at development of nanomodified high-strength lightweight concrete for construction. The developed concretes are of low average density and high ultimate compressive strength. It is shown that to produce this type of concrete one need to use hollow glass and aluminosilicate microspheres. To increase the durability of adhesion between cement stone and fine filler the authors offer to use complex nanodimensinal modifier based on iron hydroxide sol and silica sol as a surface nanomodifier for hollow microspheres. It is hypothesized that the proposed modifier has complex effect on the activity of the cement hydration and, at the same time increases bond strength between filler and cement-mineral matrix. The compositions for energy-efficient nanomodified high-strength lightweight concrete which density is 1300…1500 kg/m³ and compressive strength is 40…65 MPa have been developed. The approaches to the design of high-strength lightweight concrete with density of less than 2000 kg/m³ are formulated. It is noted that the proposed concretes possess dense homogeneous structure and moderate mobility. Thus, they allow processing by vibration during production. The economic and practical implications for realization of high-strength lightweight concrete in industrial production have been justified.

  13. Handbook of adhesion

    CERN Document Server

    Packham, D E

    2006-01-01

    This second edition of the successful Handbook of Adhesion provides concise and authoritative articles covering many aspects of the science and technology associated with adhesion and adhesives. It is intended to fill a gap between the necessarily simplified treatment of the student textbook and the full and thorough treatment of the research monograph and review article. The articles are structured in such a way, with internal cross-referencing and external literature references, that the reader can build up a broader and deeper understanding, as their needs require.This second edition includ

  14. [Endothelial cell adhesion molecules].

    Science.gov (United States)

    Ivanov, A N; Norkin, I A; Puchin'ian, D M; Shirokov, V Iu; Zhdanova, O Iu

    2014-01-01

    The review presents current data concerning the functional role of endothelial cell adhesion molecules belonging to different structural families: integrins, selectins, cadherins, and the immunoglobulin super-family. In this manuscript the regulatory mechanisms and factors of adhesion molecules expression and distribution on the surface of endothelial cells are discussed. The data presented reveal the importance of adhesion molecules in the regulation of structural and functional state of endothelial cells in normal conditions and in pathology. Particular attention is paid to the importance of these molecules in the processes of physiological and pathological angiogenesis, regulation of permeability of the endothelial barrier and cell transmigration.

  15. Lactobacillus Adhesion to Mucus

    Directory of Open Access Journals (Sweden)

    Maxwell L. Van Tassell

    2011-05-01

    Full Text Available Mucus provides protective functions in the gastrointestinal tract and plays an important role in the adhesion of microorganisms to host surfaces. Mucin glycoproteins polymerize, forming a framework to which certain microbial populations can adhere, including probiotic Lactobacillus species. Numerous mechanisms for adhesion to mucus have been discovered in lactobacilli, including partially characterized mucus binding proteins. These mechanisms vary in importance with the in vitro models studied, which could significantly affect the perceived probiotic potential of the organisms. Understanding the nature of mucus-microbe interactions could be the key to elucidating the mechanisms of probiotic adhesion within the host.

  16. Preparation of an Adhesive in Emulsion for Maxillofacial Prosthetic

    Science.gov (United States)

    Sánchez-García, Judith A.; Ortega, Alejandra; Barceló-Santana, Federico H.; Palacios-Alquisira, Joaquín

    2010-01-01

    Maxillofacial prostheses is a dental medicine specialty aimed at restoring anatomical facial defects caused by cancer, trauma or congenital malformations through an artificial device, which is commonly attached to the skin with the help of an adhesive. The purpose of our research was to develop a pressure-sensitive adhesive (PSA) based on acrylic monomers, characterizing and determining its drying kinetics, that is to say the time it takes to lose 50 to 90% of its moisture. The adhesive synthesis was realized by means of emulsion polymerization; the composition of formulations was: (AA-MMA-EA) and (AA-MMA-2EHA) with different molar ratios. The formulation based on (AA-MMA-2EHA) with 50 w% of solids, presented good adhesive properties such as tack, bond strength, and short drying time. We propose this formulation as a PSA, because it offers an alternative for systemically compromised patients, by less irritation compared to organic solvent-based adhesives. PMID:21152308

  17. Preparation of an Adhesive in Emulsion for Maxillofacial Prosthetic

    Directory of Open Access Journals (Sweden)

    Joaquín Palacios-Alquisira

    2010-10-01

    Full Text Available Maxillofacial prostheses is a dental medicine specialty aimed at restoring anatomical facial defects caused by cancer, trauma or congenital malformations through an artificial device, which is commonly attached to the skin with the help of an adhesive. The purpose of our research was to develop a pressure-sensitive adhesive (PSA based on acrylic monomers, characterizing and determining its drying kinetics, that is to say the time it takes to lose 50 to 90% of its moisture. The adhesive synthesis was realized by means of emulsion polymerization; the composition of formulations was: (AA‑MMA‑EA and (AA‑MMA‑2EHA with different molar ratios. The formulation based on (AA‑MMA‑2EHA with 50 w% of solids, presented good adhesive properties such as tack, bond strength, and short drying time. We propose this formulation as a PSA, because it offers an alternative for systemically compromised patients, by less irritation compared to organic solvent-based adhesives.

  18. Analysis of the microtensile bond strength to enamel of two adhesive systems polymerized by halogen light or LED Análise da microtração em esmalte de dois sistemas adesivos ativados por LED ou por luz halógena

    Directory of Open Access Journals (Sweden)

    Ana Paula Morales Cobra Carvalho

    2005-12-01

    Full Text Available With the development of composite resin polymerization techniques, LEDs were introduced to the market place. Based on the studied literature, the aim of this study was to evaluate, through microtensile testing, the bond strength to enamel of a composite resin associated to a conventional (multi-bottle adhesive system or to a self etching primer adhesive system, polymerized by halogen light or LED (light emitting diode. Bovine teeth were divided into 4 groups with 10 teeth each (n = 10. Then the adhesives Scotchbond Multipurpose Plus (3M-ESPE and Clearfil SE Bond (Kuraray were applied following the manufacturers’ instructions. Both systems were polymerized for 10 s by halogen light (Degulux Soft Start - Degussa Hulls set at 550 mW/cm² or by LED (Kerr Demetron set at 600 mW/cm². The composite resin Filtek Z-250 was applied in four 1 mm increments with the aid of a square, condensation silicon, 5 mm x 5 mm matrix, and polymerized by either of light sources for 40 s. Scotchbond Multipurpose Plus polymerized by halogen light presented the highest bond strength values (39.69 ± 7.07 MPa, and the other groups did not present statistically significant differences: Scotchbond Multipurpose Plus polymerized by LED (22.28 ± 2.63 MPa, Clearfil SE Bond polymerized by halogen light (27.82 ± 2.65 MPa and by LED (22.89 ± 5.09 MPa.Com a grande busca pelo desenvolvimento das técnicas de polimerização das resinas compostas e dos sistemas adesivos, foram introduzidos no mercado os LEDs. Com base na literatura estudada, neste trabalho é avaliada a força de união da resina composta ao esmalte associado a um sistema adesivo convencional e a um sistema autocondicionante polimerizados por luz halógena e LED, por meio do teste de microtração. Os dentes bovinos foram divididos em 4 grupos com 10 dentes em cada um (n = 10, para aplicação do adesivo Scotchbond Multipurpose Plus (3M-ESPE e do Clearfil SE Bond (Kuraray conforme orientação do fabricante

  19. Estudo comparativo in vitro da resistência ao cisalhamento da colagem e do índice de remanescente adesivo entre os compósitos Concise e Fill Magic A in vitro comparative stuabout shear bond strength and adhesive remnant index of the Concdy ise and Fill Magic composites

    Directory of Open Access Journals (Sweden)

    Matheus Melo Pithon

    2006-08-01

    Full Text Available OBJETIVO: comparar a resistência ao cisalhamento da colagem e o Índice de Remanescente Adesivo (IRA entre os compósitos Concise e Fill Magic Orthodontic. METODOLOGIA: a amostra consistiu de 24 incisivos inferiores permanentes bovinos divididos em dois grupos. No primeiro grupo foram colados 12 braquetes com o compósito Concise e no segundo grupo 12 com o compósito Fill Magic Orthodontic. Foi feito o ensaio de cisalhamento e a avaliação do IRA de toda a amostra. RESULTADO E CONCLUSÃO: não foram encontradas diferenças estatísticas significantes entre as colagens, nos dois itens avaliados.AIM: to compare the shear bond strength and adhesive remnant index (IRA between the composites Concise and Fill Magic Orthodontic. METHODS: the sample consisted of 24 cattle permanent low incisors divided in two groups. In the first group 12 brackets were bonded with the Concise composite and in the second group 12 with the Fill Magic Orthodontic composite. The tests of the shear and the evaluation of the ARI were developed with the whole sample. RESULTS AND CONCLUSION: there were not significant statistic differences between the composites in the two evaluated items.

  20. The minimal essential unit for cadherin-mediated intercellular adhesion comprises extracellular domains 1 and 2

    DEFF Research Database (Denmark)

    Shan, Weisong; Yagita, Yoshiki; Wang, Zhaohui;

    2004-01-01

    , the following questions remain unanswered: what is the minimal domain combination that can generate cell adhesion, how is domain organization related to adhesive strength, and does the cytoplasmic domain serve to facilitate extracellular domain interaction? To address these issues, we made serial constructs...... of the extracellular domains of N-cadherin and produced various cell lines to examine adhesion properties. We show that the first domain of N-cadherin alone on the cell surface fails to generate adhesive activity and that the first two domains of N-cadherin form the "minimal essential unit" to mediate cell adhesion...... domains of N-cadherin have distinct roles in cell adhesion, i.e. the first two domains are responsible for homophilic adhesion activity, and the other domains promote adhesion efficiency most likely by positioning essential domains relatively far out from the cell surface....

  1. Adhesion quality of glued joints from different commercial wood species

    Directory of Open Access Journals (Sweden)

    Alexandre Miguel do Nascimento

    2013-12-01

    Full Text Available The objective of this study was to determine the effect of wood density, adhesive type and gluing pressure on the shear strength of glued joints of fourteen commercial wood species. Wood pieces were classified in three density classes (Class 1: less than 0.55 g cm-3; Class 2: from 0.55 to 0.75 g cm-3; and Class 3: greater than 0.75 g cm-3 and joints bonded with two adhesives: polyvinyl acetate (PVA and urea-formaldehyde (UF, under two different pressures: 6 and 12 kgf cm-2. Glued joints bonded with PVA adhesive presented higher shear strength than those bonded with UF adhesive. For percentage of wood failure, the PVA adhesive had the best performance, however, only Classes 1 and 2 reached the values required by ASTM 3110 standard. Glued joints from Class 3, bonded with UF adhesive, did not reach the values of solid wood. The gluing pressure of 12 kgf cm-2 was more efficient for Class 3, for both shear strength and percentage of wood failure.

  2. Adhesion between coating layers based on epoxy and silicone

    DEFF Research Database (Denmark)

    Svendsen, Jacob R.; Kontogeorgis, Georgios; Kiil, Søren;

    2007-01-01

    The adhesion between a silicon tie-coat and epoxy primers, used in marine coating systems, has been studied in this work. Six epoxy coatings (with varying chain lengths of the epoxy resins), some of which have shown problems with adhesion to the tie-coat during service life, have been considered....... The experimental investigation includes measurements of the surface tension of the tie-coat and the critical surface tensions of the epoxies, topographic investigation of the surfaces of cured epoxy coatings via atomic force microscopy (AFM), and pull-off tests for investigating the strength of adhesion...

  3. Shape insensitive optimal adhesion of nanoscale fibrillar structures

    OpenAIRE

    Gao, Huajian; Yao, Haimin

    2004-01-01

    Gecko and many insects have adopted nanoscale fibrillar structures on their feet as adhesion devices. Here, we consider adhesion between a single fiber and a substrate by van der Waals or electrostatic interactions. For a given contact area A, the theoretical pull-off force of the fiber is σthA where σth is the theoretical strength of adhesion. We show that it is possible to design an optimal shape of the tip of the fiber to achieve the theoretical pull-off force. However, such design tends t...

  4. Microleakage comparison of three types of adhesive systems versus GIC-based adhesive in class V composite restorations

    OpenAIRE

    Mostafa Sadeghi

    2016-01-01

    Background and aims: New dentin bonding agents and techniques have been developed to reduce microleakage and create higher bond strength. This in-vitro study compared the microleakage of three resin-based adhesives versus a GIC-based adhesive on class V composite restorations.  Materials and Methods: Class V cavities were prepared on the buccal surfaces of 72 sound premolars, randomly assigned to six groups (n=12) and treated as follows: without any treatment (negative control group); total-e...

  5. Leukocyte Adhesion Deficiency (LAD)

    Science.gov (United States)

    ... Content Marketing Share this: Main Content Area Leukocyte Adhesion Deficiency (LAD) LAD is an immune deficiency in ... are slow to heal also may have LAD. Treatment and Research Doctors prescribe antibiotics to prevent and ...

  6. The feasibility of bench tests for disposable ECG electrode adhesiveness.

    Science.gov (United States)

    Baker, C D; Schoenberg, A A; Booth, H E

    1979-01-01

    The feasibility of recommending one standard bench test that adequately qualifies electrode adhesives for clinical use was examined by UBTL. Small strips, cut from whole, commercially available disposable ECG electrodes, were attached to three types of surfaces, and samples of each type of electrode were peel tested at 15 minutes, 8 hours, and 48 hours after attachment. A program was developed to average, display, and calculate peel strength parameters. Analysis of the data showed that (a) the peel strength of electrodes varied by more than a factor of 10 when measured on human skin, and by more than a factor of 3 when measured on bench test surfaces, and (b) the peel strength of the electrode adhesive strips did not correlate with intact electrode loss on ambulatory subjects. Therefore, UBTL could not recommend one bench test that would measure adhesion performance for all electrode types appropriate for inclusion in an AAMI ECG electrode standard.

  7. Experimental and Numerical Failure Analysis of Adhesive Composite Joints

    Directory of Open Access Journals (Sweden)

    Farhad Asgari Mehrabadi

    2012-01-01

    Full Text Available In the first section of this work, a suitable data reduction scheme is developed to measure the adhesive joints strain energy release rate under pure mode-I loading, and in the second section, three types of adhesive hybrid lap-joints, that is, Aluminum-GFRP (Glass Fiber Reinforced Plastic, GFRP-GFRP, and Steel-GFRP were employed in the determination of adhesive hybrid joints strengths and failures that occur at these assemblies under tension loading. To achieve the aims, Double Cantilever Beam (DCB was used to evaluate the fracture state under the mode-I loading (opening mode and also hybrid lap-joint was employed to investigate the failure load and strength of bonded joints. The finite-element study was carried out to understand the stress intensity factors in DCB test to account fracture toughness using J-integral method as a useful tool for predicting crack failures. In the case of hybrid lap-joint tests, a numerical modeling was also performed to determine the adhesive stress distribution and stress concentrations in the side of lap-joint. Results are discussed in terms of their relationship with adhesively bonded joints and thus can be used to develop appropriate approaches aimed at using adhesive bonding and extending the lives of adhesively bonded repairs for aerospace structures.

  8. Management of adhesive capsulitis

    OpenAIRE

    Neviaser, Andrew

    2015-01-01

    Kristen L Stupay,1 Andrew S Neviaser2 1Tulane University School of Medicine, New Orleans, LA, USA; 2George Washington University Medical Faculty Associates, Washington, DC, USA Abstract: Adhesive capsulitis of the shoulder is a condition of capsular contracture that reduces both active and passive glenohumeral motion. The cause of adhesive capsulitis is not known but it is strongly associated with endocrine abnormalities such as diabetes. Diverse terminology and the absence of definitive cri...

  9. Adhesive bond performance of heat-treated wood at various conditions.

    Science.gov (United States)

    Kol, Hamiyet Sahin; Özbay, Günay

    2016-07-01

    Heat treatment of wood leads to chemical, structural and physical changes in wood constituents, which can significantly affect the bonding performance of wood in several ways depending on the adhesive type used. In the present study, fir (Abies bornmülleriana Mattf.) and beech (Fagus orientalis L.) were heat treated at 170 degrees C, 180 degrees C, 190 degrees C, 200 and 212 degrees C for 2 hours. Four different types of adhesives were used for bonding process: melamine-urea-formaldehyde (MUF), melamine formaldehyde (MF), phenol formaldehyde (PF), and polyurethane (PUR). For all the pretreatment conditions, highest shear strength of adhesive bonds of each adhesive system was observed for untreated samples and shear strength decreased with increasing heat treatment. The strength of each adhesive bond of samples which were soaked in water was much less than dry samples, approximately half of the dry strength. Generally, the shear strength of the adhesive bonds after boiling was smaller than or similar to the values obtained for soaking. The untreated samples lost more strength after soaking and boiling than heat treated samples. With increasing heat treatment severity, reduction in shear strength increased in dry samples while decreased in soaking and boiling samples. For instance, after soaking, the untreated samples lost more strength (almost 39%) than heat treated samples (almost 24% for most severely heat treated samples). The results showed that the shear strength of adhesive bonds was influenced by heat treatment and depended on pretreatment of samples prior to testing. In general, all adhesives used performed in quite a similar way for all pretreatment conditions, and the bonding performance of heat treated fir wood was less satisfactory than that of beech wood for all adhesive system and condition.

  10. Bioinspired pressure actuated adhesive system

    NARCIS (Netherlands)

    Paretkar, D.R.; Kamperman, M.M.G.; Schneider, A.S.; Martina, D.; Creton, C.; Arzt, E.

    2011-01-01

    We developed a dry synthetic adhesive system inspired by gecko feet adhesion that can switch reversibly from adhesion to non-adhesion with applied pressure as external stimulus. Micropatterned polydimethylsiloxane (PDMS) surfaces with pillars of 30 µm length and 10 µm diameter were fabricated using

  11. Adhesion properties of styrene-butadiene rubber (SBR/Standard Malaysian Rubber (SMR L-based adhesives in the presence of phenol formaldehyde resin

    Directory of Open Access Journals (Sweden)

    2007-10-01

    Full Text Available The adhesion properties, i. e. viscosity, tack and peel strength of styrene-butadiene rubber (SBR/Standard Malaysian Rubber (SMR L-based pressure-sensitive adhesive was studied using phenol formaldehyde resin as the tackifying resin. Toluene was used as the solvent throughout the experiment. SBR composition in SBR/SMR L blend used was 0, 20, 40, 60, 80, 100%. Three different resin loadings, i. e. 40, 80 and 120 parts per hundred parts of rubber (phr were used in the adhesive formulation. The viscosity of adhesive was determined by a HAAKE Rotary Viscometer whereas loop tack and peel strength of paper/polyethylene terephthalate (PET film were measured using a Lloyd Adhesion Tester operating at 30 cm/min. Results indicate that the viscosity of adhesive decreases with increasing % SBR whereas loop tack passes through a maximum value at 20% SBR for all resin loadings. Except for the control sample (without resin, the peel strength shows a maximum value at 60% SBR for the three modes of peel tests. For a fixed % SBR, adhesive sample containing 40 phr phenol formaldehyde resin always exhibits the highest loop tack and peel strength, an observation which is associated to the optimum wettability of adhesive on the substrate.

  12. Bacterial adhesion to glass and metal-oxide surfaces.

    Science.gov (United States)

    Li, Baikun; Logan, Bruce E

    2004-07-15

    Metal oxides can increase the adhesion of negatively-charged bacteria to surfaces primarily due to their positive charge. However, the hydrophobicity of a metal-oxide surface can also increase adhesion of bacteria. In order to understand the relative contribution of charge and hydrophobicity to bacterial adhesion, we measured the adhesion of 8 strains of bacteria, under conditions of low and high-ionic strength (1 and 100 mM, respectively) to 11 different surfaces and examined adhesion as a function of charge, hydrophobicity (water contact angle) and surface energy. Inorganic surfaces included three uncoated glass surfaces and eight metal-oxide thin films prepared on the upper (non-tin-exposed) side of float glass by chemical vapor deposition. The Gram-negative bacteria differed in lengths of lipopolysaccharides on their outer surface (three Escherichia coli strains), the amounts of exopolysaccharides (two Pseudomonas aeruginosa strains), and their known relative adhesion to sand grains (two Burkholderia cepacia strains). One Gram positive bacterium was also used that had a lower adhesion to glass than these other bacteria (Bacillus subtilis). For all eight bacteria, there was a consistent increase in adhesion between with the type of inorganic surface in the order: float glass exposed to tin (coded here as Si-Sn), glass microscope slide (Si-m), uncoated air-side float glass surface (Si-a), followed by thin films of (Co(1-y-z)Fe(y)Cr(z))3O4, Ti/Fe/O, TiO2, SnO2, SnO2:F, SnO2:Sb, A1(2)O3, and Fe2O3 (the colon indicates metal doping, a slash indicates that the metal is a major component, while the dash is used to distinguish surfaces). Increasing the ionic strength from 1 to 100 mM increased adhesion by a factor of 2.0 +/- 0.6 (73% of the sample results were within the 95% CI) showing electrostatic charge was important in adhesion. However, adhesion was not significantly correlated with bacterial charge and contact angle. Adhesion (A) of the eight strains was

  13. A biodegradable and biocompatible gecko-inspired tissue adhesive.

    Science.gov (United States)

    Mahdavi, Alborz; Ferreira, Lino; Sundback, Cathryn; Nichol, Jason W; Chan, Edwin P; Carter, David J D; Bettinger, Chris J; Patanavanich, Siamrut; Chignozha, Loice; Ben-Joseph, Eli; Galakatos, Alex; Pryor, Howard; Pomerantseva, Irina; Masiakos, Peter T; Faquin, William; Zumbuehl, Andreas; Hong, Seungpyo; Borenstein, Jeffrey; Vacanti, Joseph; Langer, Robert; Karp, Jeffrey M

    2008-02-19

    There is a significant medical need for tough biodegradable polymer adhesives that can adapt to or recover from various mechanical deformations while remaining strongly attached to the underlying tissue. We approached this problem by using a polymer poly(glycerol-co-sebacate acrylate) and modifying the surface to mimic the nanotopography of gecko feet, which allows attachment to vertical surfaces. Translation of existing gecko-inspired adhesives for medical applications is complex, as multiple parameters must be optimized, including: biocompatibility, biodegradation, strong adhesive tissue bonding, as well as compliance and conformability to tissue surfaces. Ideally these adhesives would also have the ability to deliver drugs or growth factors to promote healing. As a first demonstration, we have created a gecko-inspired tissue adhesive from a biocompatible and biodegradable elastomer combined with a thin tissue-reactive biocompatible surface coating. Tissue adhesion was optimized by varying dimensions of the nanoscale pillars, including the ratio of tip diameter to pitch and the ratio of tip diameter to base diameter. Coating these nanomolded pillars of biodegradable elastomers with a thin layer of oxidized dextran significantly increased the interfacial adhesion strength on porcine intestine tissue in vitro and in the rat abdominal subfascial in vivo environment. This gecko-inspired medical adhesive may have potential applications for sealing wounds and for replacement or augmentation of sutures or staples.

  14. Clinical Effect of Dental Adhesive on Marginal Integrity in Class I And Class II Resin-Composite Restorations

    OpenAIRE

    Manchorova-Veleva Neshka A.; Vladimirov Stoyan B.; Keskinova Donka А.

    2016-01-01

    BACKGROUND: Dental adhesives are believed to influence marginal adaptation and marginal discoloration when used under posterior resin-based composite restorations. Studies on the latest adhesive systems reveal that the group of the three-step etch-and-rinse adhesive (3-E&RA) and the one-step self-etch adhesive (1-SEA) have entirely different bonding mechanisms, as well as different bond strength and resistance to chemical, thermal and mechanical factors. STUDY OBJECTIVES: A hypothesis that a ...

  15. Bonding Interface Imaging and Shear Strength Prediction by Ultrasound

    International Nuclear Information System (INIS)

    The propagation of a longitudinal ultrasonic wave normally incident upon an adhesively bonded structure is studied. The structure consists of adherend and adhesive layers with finite thickness. Interfaces between adherend and adhesive are regarded as distributed springs. Theoretical and experimental results show that resonant frequencies of the bonded structure vary sensitively with the interface stiffness constants and adhesive thickness, and these interface characteristics are inversed by the simulation annealing (SA) method. Furthermore, the distribution image of interface stiffnesses is compared with the state of fracture interface, and quantitative prediction of shear strength is achieved based on the distribution of interface stiffnesses and adhesive thicknesses by using a back-propagation neutral network. The average relative error of the shear strength from prediction to real value is 10.7%. (fundamental areas of phenomenology (including applications))

  16. Influence of different luting protocols on shear bond strength of computer aided design/computer aided manufacturing resin nanoceramic material to dentin

    Directory of Open Access Journals (Sweden)

    Claudio Poggio

    2016-01-01

    Conclusion: Within the limitations of this in vitro study, conventional resin cements (coupled with etch and rinse or self-etch adhesives showed better shear strength values compared to self-adhesive resin cements. Furthermore, conventional resin cements used together with a self-etch adhesive reported the highest values of adhesion.

  17. Adhesion and Thin-Film Module Reliability: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    McMahon, T. J.; Jorgensen, G. J.

    2006-05-01

    Among the infrequently measured but essential properties for thin-film (T-F) module reliability are the interlayer adhesion and cohesion within a layer. These can be cell contact layers to glass, contact layers to the semiconductor, encapsulant to cell, glass, or backsheet, etc. We use an Instron mechanical testing unit to measure peel strengths at 90{sup o} or 180{sup o} and, in some cases, a scratch and tape pull test to evaluate inter-cell layer adhesion strengths. We present peel strength data for test specimens laminated from the three T-F technologies, before and after damp heat, and in one instance at elevated temperatures. On laminated T-F cell samples, failure can occur uniformly at any one of the many interfaces, or non-uniformly across the peel area at more than one interface. Some peel strengths are << 1 N/mm. This is far below the normal Instron mechanical testing unit Instron mechanical testing unit; glass interface values of >10 N/mm. We measure a wide range of adhesion strengths and suggest that adhesion measured under higher temperature and relative humidity conditions is more relevant for module reliability.

  18. Effect of Curing Procedure on the Properties of Copper-Powder-Filled Conductive Adhesives

    Institute of Scientific and Technical Information of China (English)

    ZHENG Xiaoling; ZHANG Lulu; YOU Min; WU Jianhao; YU Haizhou; YANG Derong; MAO Yuping

    2008-01-01

    By means of testing the shear strength with single lap joint, measuring electrical resistivity for cured products and the curing strain with strain gauges, the effect of cure parameters on the properties of HT1012 conductive adhesive filled with copper powder was investigated, and the residual stress in the conductive adhesives was also estimated. The experimental results show that the properties such as shear strength of the adhesives, electrical resistivity of products as well as the residual stress of cured HT1012 copper-filled conductive adhesive were evidently affected by curing temperature and time. The diagrams of scanning electron microscopy (SEM) and Fourier transform infrared (FT-IR) were also used to determine the properties. The higher mechanical property was achieved under the condition of curing the adhesive 3h at 60℃ as the density of the hydrogen links or linkages existed in the adhesive was relatively higher and the lower electrical resistivity occurred at 80℃.

  19. Magnetic field switchable dry adhesives.

    Science.gov (United States)

    Krahn, Jeffrey; Bovero, Enrico; Menon, Carlo

    2015-02-01

    A magnetic field controllable dry adhesive device is manufactured. The normal adhesion force can be increased or decreased depending on the presence of an applied magnetic field. If the magnetic field is present during the entire normal adhesion test cycle which includes both applying a preloading force and measuring the pulloff pressure, a decrease in adhesion is observed when compared to when there is no applied magnetic field. Similarly, if the magnetic field is present only during the preload portion of the normal adhesion test cycle, a decrease in adhesion is observed because of an increased stiffness of the magnetically controlled dry adhesive device. When the applied magnetic field is present during only the pulloff portion of the normal adhesion test cycle, either an increase or a decrease in normal adhesion is observed depending on the direction of the applied magnetic field.

  20. Curing of natural rubber and epoxy adhesive

    International Nuclear Information System (INIS)

    Low molecular weight epoxy resin based on diglycidyl ether of bisphenol A was synthesized and mixed at constant percentages with natural rubber. The rubber epoxy system was cured with various types of curing agents such as ethylene diamine, maleic anhydride as well as the prepared resole phenol formaldehyde. A study of the photo-induced crosslinking of the prepared elastic adhesives and film samples was carried out by exposure to ultraviolet lamp (300 w) for 2 weeks at 20 deg. C. Samples containing ethylene diamine were cured at 25 + - 1 deg. C. for 24 h while samples containing maleic anhydride or resole phenol formaldehyde resins were thermally cured at 150-170 deg. C. for 10 min. Cured adhesive compositions were tested mechanically and physically and evaluated as wood adhesives. While hardness, chemical resistance as well as heat stability of the prepared cured film sample were investigated. The obtained data indicate that the highest epoxy resin content and the presence of resole phenol formaldehyde resin in composition improve the tensile strength and adhesion properties on wood. While their cured film sample have the best hardness properties, chemical resistance and heat stability. (author)

  1. Tensile bond strength of self-etching versus total-etching adhesive systems under different dentinal substrate conditions Resistência de união à tração de sistemas adesivos autocondicionantes versus de condicionamento total, em diferentes condições de substrato dentinário

    Directory of Open Access Journals (Sweden)

    Alexandre Henrique Susin

    2007-03-01

    Full Text Available The use of acid etchants to produce surface demineralization and collagen network exposure, allowing adhesive monomers interdiffusion and consequently the formation of a hybrid layer, has been considered the most efficient mechanism of dentin bonding. The aim of this study was to compare the tensile bond strength to dentin of three adhesive systems, two self-etching ones (Clearfil SE Bond - CSEB and One Up Bond F - OUBF and one total-etching one (Single Bond - SB, under three dentinal substrate conditions (wet, dry and re-wet. Ninety human, freshly extracted third molars were sectioned at the occlusal surface to remove enamel and to form a flat dentin wall. The specimens were restored with composite resin (Filtek Z250 and submitted to tensile bond strength testing (TBS in an MTS 810. The data were submitted to two-way ANOVA and Tukey's test (p = 0.05. Wet dentin presented the highest TBS values for SB and CSEB. Dry dentin and re-wet produced significantly lower TBS values when using SB. OUBF was not affected by the different conditions of the dentin substrate, producing similar TBS values regardless of the surface pretreatments.O uso de condicionadores ácidos para desmineralizar a superfície dental e expor a rede de fibras colágenas para interdifusão dos monômeros adesivos e conseqüente formação da camada híbrida tem sido considerado o mais eficiente mecanismo de adesão dos agentes de união. O objetivo deste estudo foi comparar a resistência de união à dentina de três sistemas adesivos, dois autocondicionantes (Clearfil SE Bond - CSEB e One Up Bond F - OUBF e um de condicionamento total (Single Bond - SB, sob três diferentes condições de substrato dentinário (úmido, seco e reidratado. Noventa terceiros molares humanos recém-extraídos foram cortados na superfície oclusal, para se remover o esmalte e formar uma parede plana de dentina. Os espécimes foram restaurados com resina composta (Filtek Z250 e submetidos ao teste de

  2. The effect of adhesive layer elasticity on the fracture mechanics of a blister test specimen

    Science.gov (United States)

    Updike, D. P.

    1975-01-01

    An analytical model of a blister type specimen for evaluating adhesive bond strength was developed. Plate theory with shear deformation was used to model the deformation of the plate, and elastic deformation of the adhesive layer is taken into account. It is shown that the inclusion of the elastic deformation of the adhesive layer can have a significant influence in the energy balance calculations of fracture mechanics.

  3. Rational Design and Enhanced Biocompatibility of a Dry Adhesive Medical Skin Patch

    KAUST Repository

    Kwak, Moon Kyu

    2011-07-28

    A new type of medical skin patch is developed that contains high-density, mushroom-like micropillars. Such dry-adhesive micropillars are highly biocompatible, have minimized side effects, and provide reasonable normal adhesion strength. To arrive at optimal conditions for the dry adhesive skin patch, the proper design of various structural and material parameters of micropillars is investigated. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Strength scaling of adhesive joints in polymer–matrix composites

    DEFF Research Database (Denmark)

    Sørensen, Bent F.; Goutianos, Stergios; Jacobsen, Torben K.

    2009-01-01

    increased with increasing crack length, eventually reaching a steady-state level (R-curve behaviour). The steady-state fracture resistance level increased with increasing amount of tangential crack opening displacement. Cohesive laws, obtained from fracture resistance data, were used for prediction the load...

  5. Physical properties of halthane series adhesives, part 2 of 2. Period covered: October--December 1976. [Urethanes: tensile adhesion; bulk viscosity; hardness

    Energy Technology Data Exchange (ETDEWEB)

    Lichte, H.W.

    1976-01-01

    The Halthane series of urethane adhesives have sufficient adhesive strengths and cure times for most assembly processes at Pantex. The efficiency of preparation and handling of the three systems are nearly equal. Physical properties are more consistent between samples for the 87-1. The 73-18 system is ranked in the middle and 73-14 as the least consistent. The 87-1 system is high in viscosity and adhesive bond strength. The low viscosity of 73-18 and 73-14 allows more consistency in bond thickness control. The Halthane 73-18 system in this series of development tests is considered best for processing/assembly capability.

  6. Adhesion in hydrogel contacts

    Science.gov (United States)

    Torres, J. R.; Jay, G. D.; Kim, K.-S.; Bothun, G. D.

    2016-05-01

    A generalized thermomechanical model for adhesion was developed to elucidate the mechanisms of dissipation within the viscoelastic bulk of a hyperelastic hydrogel. Results show that in addition to the expected energy release rate of interface formation, as well as the viscous flow dissipation, the bulk composition exhibits dissipation due to phase inhomogeneity morphological changes. The mixing thermodynamics of the matrix and solvent determines the dynamics of the phase inhomogeneities, which can enhance or disrupt adhesion. The model also accounts for the time-dependent behaviour. A parameter is proposed to discern the dominant dissipation mechanism in hydrogel contact detachment.

  7. Lap Shear Testing of Candidate Radiator Panel Adhesives

    Science.gov (United States)

    Ellis, David; Briggs, Maxwell; McGowan, Randy

    2013-01-01

    During testing of a subscale radiator section used to develop manufacturing techniques for a full-scale radiator panel, the adhesive bonds between the titanium heat pipes and the aluminum face sheets failed during installation and operation. Analysis revealed that the thermal expansion mismatch between the two metals resulted in relatively large shear stresses being developed even when operating the radiator at moderate temperatures. Lap shear testing of the adhesive used in the original joints demonstrated that the two-part epoxy adhesive fell far short of the strength required. A literature review resulted in several candidate adhesives being selected for lap shear joint testing at room temperature and 398 K, the nominal radiator operating temperature. The results showed that two-part epoxies cured at room and elevated temperatures generally did not perform well. Epoxy film adhesives cured at elevated temperatures, on the other hand, did very well with most being sufficiently strong to cause yielding in the titanium sheet used for the joints. The use of an epoxy primer generally improved the strength of the joint. Based upon these results, a new adhesive was selected for the second subscale radiator section.

  8. Adhesion enhancement of ion beam mixed Cu/Al/polyimide

    International Nuclear Information System (INIS)

    Cu (400 Angstrom)/polyimide was mixed with 80 keV Ar+ and N2+ from 1.0x1015 to 2.0x1016 ions/cm2. The same processes were repeated for the Cu (400 Angstrom)/Al (50 Angstrom)/polyimide system which has Al as a buffer layer. The quantitative adhesion strength was measured by a standard scratch test. X-ray photoelectron spectroscopy was employed to investigate the change in the chemical bonds of the ion beam mixed polyimide substrate and the intermediate effects for the adhesion enhancement in Cu/Al/polyimide. Two distinct tendencies are observed in the adhesion strength: Cu/Al/polyimide is more adhesive than Cu/polyimide after ion beam mixing, and N2+ ions are more effective in the adhesion enhancement than Ar+. The formation of an interlayer compound of CuAl2O4 accounts for the former, while the latter is understood by the fact that N2+ ions produce more pyridinelike moiety, amide group and tertiary amine moiety which are known as adhesion promoters. copyright 1997 American Institute of Physics

  9. Carbon nanotube based gecko inspired self-cleaning adhesives

    Science.gov (United States)

    Sethi, Sunny; Ge, Liehui; Ajayan, Pulickel; Ali, Dhinojwala

    2008-03-01

    Wall climbing organisms like geckos have unique ability to attach to different surfaces without use of any viscoelastic material. The hairy structure found in gecko feet allows them to obtain intimate contact over a large area thus allowing then to adhere using van der Waals interactions. Not only high adhesion, the geometry of the hairs makes gecko feet self cleaning, thus allowing them to walk continuously without worrying about loosing adhesive strength. Such properties if mimicked synthetically could form basis of a new class of materials, which, unlike conventional adhesives would show two contradictory properties, self cleaning and high adhesion. Such materials would form essential component of applications like wall climbing robot. We tried to synthesize such material using micropatterened vertically aligned carbon nanotubes. When dealing with large areas, probability of defects in the structure increase, forming patterns instead of using uniform film of carbon nanotubes helps to inhibit crack propagation, thus gives much higher adhesive strength than a uniform film. When carbon nanotube patterns with optimized aspect ratio are used, both high adhesion and self cleaning properties are observed.

  10. A New Flexible Soy-Based Adhesive Enhanced with Neopentyl Glycol Diglycidyl Ether: Properties and Application

    Directory of Open Access Journals (Sweden)

    Jing Luo

    2016-09-01

    Full Text Available Soy-based adhesives inherently possess low water resistance and brittleness, which limit their application on plywood fabrication. This investigation involves using a long chain cross-linker, neopentyl glycol diglycidyl ether (NGDE, to produce an intrinsic toughening effect to reduce the brittleness and improve the water resistance of a soybean meal–based adhesive. The solids content, viscosity, functional groups, fracture surface micrographs, and thermal stability of the adhesives were measured. Three-layer plywood was fabricated using the resultant adhesive, and the tensile shear strength of the plywood was measured. All adhesive properties were compared with a soybean meal/polyamidoamine-epichlorohydrin (PAE adhesive and commercial melamine urea formaldehyde resin. The results showed that adding 6 g NGDE improved the water resistance of the soybean meal-based adhesive by 12.5%. This improvement is attributed to the following reasons: (1 a dense cross-linked network is formed by the chemical reaction between NGDE and protein molecules; (2 the toughness of the adhesive increases and a smooth and homogeneous fracture surface is created, which effectively prevents moisture intrusion; (3 the addition of NGDE increases the thermostability of the cured adhesive. The tensile shear strength of the plywood bonded with the soybean meal-based adhesive with 6 g NGDE was 286.2% higher than that without NGDE and attained 1.12 MPa, which was attributed to the reduction in the adhesive’s viscosity, and the improvement in the water resistance and toughness of the adhesive. The tensile shear strength of the plywood bonded with 6 g NGDE was 19.1% higher than that with 6 g PAE and was similar to the MUF resin, which validated the novel adhesive being suitable for use as an industrial plywood adhesive.

  11. Glass Fiber Reinforced Polypropylene Mechanical Properties Enhancement by Adhesion Improvement

    Directory of Open Access Journals (Sweden)

    Mariana Etcheverry

    2012-06-01

    Full Text Available Glass fibers (GF are the reinforcement agent most used in polypropylene (PP based composites, as they have good balance between properties and costs. However, their final properties are mainly determined by the strength and stability of the polymer-fiber interphase. Fibers do not act as an effective reinforcing material when the adhesion is weak. Also, the adhesion between phases can be easily degraded in aggressive environmental conditions such as high temperatures and/or elevated moisture, and by the stress fields to which the material may be exposed. Many efforts have been done to improve polymer-glass fiber adhesion by compatibility enhancement. The most used techniques include modifications in glass surface, polymer matrix and/or both. However, the results obtained do not show a good costs/properties improvement relationship. The aim of this work is to perform an accurate analysis regarding methods for GF/PP adhesion improvement and to propose a new route based on PP in-situ polymerization onto fibers. This route involves the modification of fibers with an aluminum alkyl and hydroxy-α-olefin and from there to enable the growth of the PP chains using direct metallocenic copolymerization. The adhesion improvements were further proved by fragmentation test, as well as by mechanical properties measurements. The strength and toughness increases three times and the interfacial strength duplicates in PP/GF composites prepared with in-situ polymerized fibers.

  12. Switchable Adhesion in Vacuum Using Bio-Inspired Dry Adhesives

    OpenAIRE

    Purtov, Julia; Frensemeier, Mareike; Kroner, Elmar

    2015-01-01

    Suction based attachment systems for pick and place handling of fragile objects like glass plates or optical lenses are energy-consuming and noisy and fail at reduced air pressure, which is essential, e.g., in chemical and physical vapor deposition processes. Recently, an alternative approach toward reversible adhesion of sensitive objects based on bioinspired dry adhesive structures has emerged. There, the switching in adhesion is achieved by a reversible buckling of adhesive pillar structur...

  13. Use of additives to enhance the properties of cottonseed protein as wood adhesives

    Science.gov (United States)

    Soy protein is currently being used commercially as a “green” wood adhesive. Previous work in this laboratory has shown that cottonseed protein isolate, tested on maple wood veneer, produced higher adhesive strength and hot water resistance relative to soy protein. In the present study, cottonseed...

  14. Nanostructured niobium oxide coatings influence osteoblast adhesion.

    Science.gov (United States)

    Eisenbarth, E; Velten, D; Müller, M; Thull, R; Breme, J

    2006-10-01

    The interaction of osteoblasts was correlated to the roughness of nanosized surface structures of Nb(2)O(5) coatings on polished CP titanium grade 2. Nb(2)O(5) sol-gel coatings were selected as a model surface to study the interaction of osteoblasts with nanosized surface structures. The surface roughness was quantified by determination of the average surface finish (Ra number) by means of atomic force microscopy. Surface topographies with Ra = 7, 15, and 40 nm were adjusted by means of the annealing process parameters (time and temperature) within a sol-gel coating procedure. The observed osteoblast migration was fastest on smooth surfaces with Ra = 7 nm. The adhesion strength, spreading area, and collagen-I synthesis showed the best results on an intermediate roughness of Ra = 15 nm. The surface roughness of Ra = 40 nm was rather peaked and reduced the speed of cell reactions belonging to the adhesion process. PMID:16788971

  15. Biological tissue adhesive for multiple use in the accident and emergency department

    OpenAIRE

    Gerrard, C.; S. Moore; Ryan, B

    2000-01-01

    Objective—To assess the strength of the glue and microbial contamination over 28 days from opening a vial of tissue adhesive in the accident and emergency setting, and to quantify cost savings of repeated use of the vials.

  16. Nanohairs and nanotubes: Efficient structural elements for gecko-inspired artificial dry adhesives

    KAUST Repository

    Jeong, Hoon Eui

    2009-08-01

    An overview of the recent progress in the development of gecko-inspired synthetic dry adhesives is presented, with particular emphasis on two major structural elements of nanohairs and nanotubes. With the advance of nanofabrication techniques, recently developed dry adhesives made of nanohairs and nanotubes show excellent adhesion strength, smart directional adhesion as well as rough surface adaptability by better mimicking gecko foot hairs. After a brief description of the requirements for high-performance artificial dry adhesives, a variety of synthetic adhesives are described based on materials and structural features of the gecko-inspired nanostructures. In addition, current challenges and future directions towards an optimized synthetic dry adhesive are presented. © 2009 Elsevier Ltd. All rights reserved.

  17. Switchable Adhesion in Vacuum Using Bio-Inspired Dry Adhesives.

    Science.gov (United States)

    Purtov, Julia; Frensemeier, Mareike; Kroner, Elmar

    2015-11-01

    Suction based attachment systems for pick and place handling of fragile objects like glass plates or optical lenses are energy-consuming and noisy and fail at reduced air pressure, which is essential, e.g., in chemical and physical vapor deposition processes. Recently, an alternative approach toward reversible adhesion of sensitive objects based on bioinspired dry adhesive structures has emerged. There, the switching in adhesion is achieved by a reversible buckling of adhesive pillar structures. In this study, we demonstrate that these adhesives are capable of switching adhesion not only in ambient air conditions but also in vacuum. Our bioinspired patterned adhesive with an area of 1 cm(2) provided an adhesion force of 2.6 N ± 0.2 N in air, which was reduced to 1.9 N ± 0.2 N if measured in vacuum. Detachment was induced by buckling of the structures due to a high compressive preload and occurred, independent of air pressure, at approximately 0.9 N ± 0.1 N. The switch in adhesion was observed at a compressive preload between 5.6 and 6.0 N and was independent of air pressure. The difference between maximum adhesion force and adhesion force after buckling gives a reasonable window of operation for pick and place processes. High reversibility of the switching behavior is shown over 50 cycles in air and in vacuum, making the bioinspired switchable adhesive applicable for handling operations of fragile objects. PMID:26457864

  18. Switchable Adhesion in Vacuum Using Bio-Inspired Dry Adhesives.

    Science.gov (United States)

    Purtov, Julia; Frensemeier, Mareike; Kroner, Elmar

    2015-11-01

    Suction based attachment systems for pick and place handling of fragile objects like glass plates or optical lenses are energy-consuming and noisy and fail at reduced air pressure, which is essential, e.g., in chemical and physical vapor deposition processes. Recently, an alternative approach toward reversible adhesion of sensitive objects based on bioinspired dry adhesive structures has emerged. There, the switching in adhesion is achieved by a reversible buckling of adhesive pillar structures. In this study, we demonstrate that these adhesives are capable of switching adhesion not only in ambient air conditions but also in vacuum. Our bioinspired patterned adhesive with an area of 1 cm(2) provided an adhesion force of 2.6 N ± 0.2 N in air, which was reduced to 1.9 N ± 0.2 N if measured in vacuum. Detachment was induced by buckling of the structures due to a high compressive preload and occurred, independent of air pressure, at approximately 0.9 N ± 0.1 N. The switch in adhesion was observed at a compressive preload between 5.6 and 6.0 N and was independent of air pressure. The difference between maximum adhesion force and adhesion force after buckling gives a reasonable window of operation for pick and place processes. High reversibility of the switching behavior is shown over 50 cycles in air and in vacuum, making the bioinspired switchable adhesive applicable for handling operations of fragile objects.

  19. Electrochemical deposition of conductive and adhesive polypyrrole-dopamine films

    Science.gov (United States)

    Kim, Semin; Jang, Lindy K.; Park, Hyun S.; Lee, Jae Young

    2016-07-01

    Electrode surfaces have been widely modified with electrically conductive polymers, including polypyrrole (PPY), to improve the performance of electrodes. To utilize conductive polymers for electrode modification, strong adhesion between the polymer films and electrode substrates should be ensured with high electrical/electrochemical activities. In this study, PPY films were electrochemically polymerized on electrodes (e.g., indium tin oxide (ITO)) with dopamine as a bio-inspired adhesive molecule. Efficient and fast PPY electrodeposition with dopamine (PDA/PPY) was found; the resultant PDA/PPY films exhibited greatly increased adhesion strengths of up to 3.7 ± 0.8 MPa and the modified electrodes had electrochemical impedances two to three orders of magnitude lower than that of an unmodified electrode. This electrochemical deposition of adhesive and conductive PDA/PPY offers a facile and versatile electrode modification for various applications, such as biosensors and batteries.

  20. Ultrastructural and Histochemical Characterization of the Zebra Mussel Adhesive Apparatus

    Science.gov (United States)

    Farsad, Nikrooz

    Since their accidental introduction into the Great Lakes in mid- to late-1980s, the freshwater zebra mussels, Dreissena polymorpha, have colonized most lakes and waterways across eastern North America. Their rapid spread is partly attributed to their ability to tenaciously attach to hard substrates via an adhesive apparatus called the byssus, resulting in serious environmental and economic impacts. A detailed ultrastructural study of the byssus revealed a 10 nm adhesive layer at the attachment interface. Distributions of the main adhesive amino acid, 3,4-dihydroxyphenylalanine (DOPA), and its oxidizing (cross-linking) enzyme, catechol oxidase, were determined histochemically. It was found that, upon aging, DOPA levels remained high in the portion of the byssus closest to the interface, consistent with an adhesive role. In contrast, reduced levels of DOPA corresponded well with high levels of catechol oxidase in the load-bearing component of the byssus, presumably forming cross-links and increasing the cohesive strength.

  1. Surfactant and adhesive formulations from alkaline biomass extracts

    Science.gov (United States)

    Baxter, Matthew

    This work studies the ability to produce effective surfactant and adhesive formulations using surface active biological material extracted from different biomass sources using alkaline extraction methods. Two urban waste biomass sources were used to produce surfactants, Return Activated Sludge (RAS), and solid Urban Refuse (UR). The third biomass source investigated was isolated mustard protein (MP). RAS and MP extracts were investigated for adhesive production. The results indicate that extracts from the waste biomass sources, RAS and UR, can be combined with a commercial surfactant, sodium dioctyl sulfosuccinate (AOT), to produce surfactants with low interfacial tensions against various oils. These highly surface-active formulations were shown to be useful in the removal of bitumen from contaminated sand. RAS and MP showed potential as protein-based wood adhesives. These sources were used in adhesive formulations to produce a strong bond strength under low-pressure, ambient pressing conditions.

  2. Study of Materials and Adhesives for Superconducting Cable Feedthroughs

    CERN Document Server

    Perin, A; Métral, L

    2002-01-01

    Powering superconducting magnets requires the use of cryogenic feedthroughs for the superconducting cables capable of withstanding severe thermal, mechanical and electrical operating conditions. Such feedthrough shall provide the continuity of the superconducting circuit while ensuring a hydraulic separation at cryogenic temperature. A study about the adhesive and polymers required for the production of thermal shock resistant feedthroughs is presented. The strength of the busbar to adhesive joints was first investigated by compression/shear tests as well as pin and collar tests performed with four epoxy adhesives. After the selection of the most appropriate adhesive, pin and collar tests were performed with four different polymers. Based on the results, a superconducting cable feedthrough for 6 busbars of 6 kA and 12 busbars of 120 A was constructed and successfully tested.

  3. Electrochemical deposition of conductive and adhesive polypyrrole-dopamine films.

    Science.gov (United States)

    Kim, Semin; Jang, Lindy K; Park, Hyun S; Lee, Jae Young

    2016-01-01

    Electrode surfaces have been widely modified with electrically conductive polymers, including polypyrrole (PPY), to improve the performance of electrodes. To utilize conductive polymers for electrode modification, strong adhesion between the polymer films and electrode substrates should be ensured with high electrical/electrochemical activities. In this study, PPY films were electrochemically polymerized on electrodes (e.g., indium tin oxide (ITO)) with dopamine as a bio-inspired adhesive molecule. Efficient and fast PPY electrodeposition with dopamine (PDA/PPY) was found; the resultant PDA/PPY films exhibited greatly increased adhesion strengths of up to 3.7 ± 0.8 MPa and the modified electrodes had electrochemical impedances two to three orders of magnitude lower than that of an unmodified electrode. This electrochemical deposition of adhesive and conductive PDA/PPY offers a facile and versatile electrode modification for various applications, such as biosensors and batteries. PMID:27459901

  4. The Influence of Nano-Al2O3 Additive on the Adhesion between Epoxy Resin and Steel Substrate

    Institute of Scientific and Technical Information of China (English)

    ZHAILan-lan; LINGGuo-ping

    2004-01-01

    The influence of nano-A1203 additive on the adhesion between epoxy resin and steel substrate has been investigated. The results of tensile testing indicated that the adhesion strength was increased dramatically by addition of Al2O3 nanoparticles in epoxy resin compared with that of the unmodified resin. The highest adhesion strength was obtained with 1 wt% nano-Al2O3 added in epoxy adhesive, more than two times higher than that of the unmodified. Scanning electronic microscope (SEM) revealed that a boundary layer exists between epoxy and steel substrate, energy spectrum analysis indicates there is enrichment of the nano-Al2O3 particle. Those results confirmed that the nano-Al2O3 additive was closely related to the change of interface morphology and the improvement of adhesion strength. The reason for adhesion improvement was also be discussed.

  5. The Influence of Nano-Al2O3 Additive on the Adhesion between Epoxy Resin and Steel Substrate

    Institute of Scientific and Technical Information of China (English)

    ZHAI Lan-lan; LING Guo-ping

    2004-01-01

    The influence of nano-Al2O3 additive on the adhesion between epoxy resin and steel substrate has been investigated. The results of tensile testing indicated that the adhesion strength was increased dramatically by addition of Al2O3 nanoparticles in epoxy resin compared with that of the unmodified resin. The highest adhesion strength was obtained with 1 wt% nano-Al2O3 added in epoxy adhesive, more than two times higher than that of the unmodified. Scanning electronic microscope (SEM) revealed that a boundary layer exists between epoxy and steel substrate, energy spectrum analysis indicates there is enrichment of the nano-Al2O3 particle. Those results confirmed that the nano-Al2O3 additive was closely related to the change of interface morphology and the improvement of adhesion strength. The reason for adhesion improvement was also be discussed.

  6. Influence of Various Pulp Properties on the Adhesion Between Tissue Paper and Yankee Cylinder Surface

    OpenAIRE

    Boudreau, Jonna; Germgård, Ulf

    2014-01-01

    The strength of the adhesion between the paper and the drying Yankee cylinder is of great importance with respect to the final properties of a tissue paper product. Therefore, the effects of a few potentially important pulp properties have been evaluated in laboratory experiments. Four highly different kraft pulps were used, and the adhesion strength was measured by means of the force required when scraping off a paper from a metal surface with a specifically designed knife mounted on a movin...

  7. Orthogonal Control of Stability and Tunable Dry Adhesion by Tailoring the Shape of Tapered Nanopillar Arrays.

    Science.gov (United States)

    Cho, Younghyun; Kim, Gyuseok; Cho, Yigil; Lee, Su Yeon; Minsky, Helen; Turner, Kevin T; Gianola, Daniel S; Yang, Shu

    2015-12-16

    Tapered nanopillar structures of different cross-sectional geometries including cone-, pencil-like, and stepwise are prepared from anodized aluminum oxide templates. The shape effect on the adhesion strength is investigated in experiments and simulation. Cone-shaped nanopillars are highly bendable under load and can recover after unloading, thus, warranting high adhesion strength, 34 N cm(-2) . The pencil-like and stepwise nano-pillars are, however, easily fractured and are not recoverable under the same conditions.

  8. Interfacial adhesion of laser clad functionally graded materials

    NARCIS (Netherlands)

    De Hosson, JTM; Pei, YT; Ocelik, [No Value; Sudarshan, TS; Stiglich, JJ; Jeandin, M

    2002-01-01

    Specially designed samples of laser clad AlSi40 functionally graded materials (FGM) are made for evaluating the interfacial adhesion. To obtain the interfacial bond strength notches are made right at the interface of the FGMs. In-sitit microstructural observations during straining in an FEG-ESEM (fi

  9. Interfacial adhesion of laser clad functionally graded materials

    NARCIS (Netherlands)

    Pei, Y. T.; Ocelik, V.; De Hosson, J. T. M.

    2003-01-01

    Specially designed samples of laser clad AlSi40 functionally graded materials (FGM) are made for evaluating the interfacial adhesion. To obtain the interfacial bond strength notches are made right at the interface of the FGMs. In-situ microstructural observations during straining in a field-emission

  10. Magnetically actuated patterns for bioinspired reversible adhesion (dry and wet).

    Science.gov (United States)

    Drotlef, Dirk-Michael; Blümler, Peter; del Campo, Aránzazu

    2014-02-01

    A facile strategy to obtain magnetically actuated arrays of micropillars able to undergo reversible, homogeneous, drastic, and tunable geometrical changes upon application of a magnetic field with variable strength is demonstrated. A magnetically tunable gecko-inspired adhesive that works under dry and wet conditions is realized using elastomeric micropatterns containing magnetic microparticles.

  11. Development and characterization of a novel hydrogel adhesive for soft tissue applications

    Science.gov (United States)

    Sanders, Lindsey Kennedy

    With laparoscopic and robotic surgical techniques advancing, the need for an injectable surgical adhesive is growing. To be effective, surgical adhesives for internal organs require bulk strength and compliance to avoid rips and tears, and adhesive strength to avoid leakage at the application site, while not hindering the natural healing process. Although a number of tissue adhesives and sealants approved by the FDA for surgical use are currently available, attaining a useful balance in all of these qualities has proven difficult, particularly when considering applications involving highly expandable tissue, such as bladder and lung. The long-term goal of this project is to develop a hydrogel-based tissue adhesive that provides proper mechanical properties to eliminate the need for sutures in various soft tissue applications. Tetronic (BASF), a 4-arm poly(propylene oxide)-poly(ethylene oxide) (PPO-PEO) block copolymer, has been selected as the base material for the adhesive hydrogel system. Solutions of Tetronic T1107 can support reverse thermal gelation at physiological temperatures, which can be combined with covalent crosslinking to achieve a "tandem gelation" process making it ideal for use as a tissue adhesive. The objective of this doctoral thesis research is to improve the performance of the hydrogel based tissue adhesive developed previously by Cho and co-workers by applying a multi-functionalization of Tetronic. Specifically, this research aimed to improve bonding strength of Tetronic tissue adhesive using bi-functional modification, incorporate hemostatic function to the bi-functional Tetronic hydrogel, and evaluate the safety of bi-functional Tetronic tissue adhesive both in vitro and in vivo. In summary, we have developed a fast-curing, mechanically strong hemostatic tissue adhesive that can control blood loss in wet conditions during wound treatment applications (bladder, liver and muscle). Specifically, the bi-functional Tetronic adhesive (TAS) with a

  12. Pathogenesis of postoperative adhesion formation

    NARCIS (Netherlands)

    Hellebrekers, B.W.J.; Kooistra, T.

    2011-01-01

    Background: Current views on the pathogenesis of adhesion formation are based on the "classical concept of adhesion formation", namely that a reduction in peritoneal fibrinolytic activity following peritoneal trauma is of key importance in adhesion development. Methods: A non-systematic literature s

  13. Shear bond strength of metallic brackets: influence of saliva contamination

    Directory of Open Access Journals (Sweden)

    Luciana Borges Retamoso

    2009-06-01

    Full Text Available OBJECTIVE: To evaluate the influence of saliva contamination on shear bond strength and the bond failure pattern of 3 adhesive systems (Transbond XT, AdheSE and Xeno III on orthodontic metallic brackets bonded to human enamel. MATERIAL AND METHODS: Seventy-two permanent human molars were cut longitudinally in a mesiodistal direction, producing seventy-two specimens randomly divided into six groups. Each system was tested under 2 different enamel conditions: no contamination and contaminated with saliva. In T, A and X groups, the adhesive systems were applied to the enamel surface in accordance with manufacturer's instructions. In TS, AS and XS groups, saliva was applied to enamel surface followed by adhesive system application. The samples were stored in distilled water at 37ºC for 24 h, and then tested for shear bond strength in a universal testing machine (Emic, DL 2000 running at a crosshead speed of 1 mm/min. After bond failure, the enamel surfaces were observed under an optical microscope at 40x magnification. RESULTS: The control and contaminated groups showed no significant difference in shear bond strength for the same adhesive system. However, shear bond strength of T group (17.03±4.91 was significantly higher than that of AS (8.58±1.73 and XS (10.39±4.06 groups (p<0.05. Regarding the bond failure pattern, TS group had significantly higher scores of no adhesive remaining on the tooth in the bonding area than other groups considering the adhesive remnant index (ARI used to evaluate the amount of adhesive left on the enamel. CONCLUSIONS: Saliva contamination showed little influence on the 24-h shear bond strength of orthodontic brackets.

  14. Effect of sodium hypochlorite on the bond strength of an adhesive system to superficial and deep dentin Efeito do hipoclorito de sódio na resistência de união de um sistema adesivo na dentina superficial e profunda

    Directory of Open Access Journals (Sweden)

    Ninoshka Uceda-Gómez

    2003-09-01

    Full Text Available The objective of this study was to evaluate the bond strength to superficial (SU and deep (D dentin, accessed via apical (DA or occlusal (DO, using One-Step adhesive system applied according to the manufacturer's instructions (C or following deproteinization with 10% sodium hypochlorite (H for 60s, after acid etching. Three sound extracted human molars were prepared for each experimental condition. Restorations were performed using Z100 in 2mm increments, each one being light-cured for 40s. Teeth were longitudinally sectioned to obtain stick-shaped specimens with a cross-sectional area of 0.8mm², which were submitted to bond strength test (0.6mm/min. Results obtained after statistical analysis using a two-way ANOVA (substrate vs. surface treatment and Tukey's test were: SU (35.4 ± 12.3, DO (26.5 ± 8.5, DA (26.1 ± 10.2 following conventional surface treatment, and SU (28.82 ± 12.7, DO (24.3 ± 8.3 and DA (23.5 ± 8.5, after surface treatment using sodium hypochlorite. The interaction of the factors was not significant (p>0.05. However, the main factors were significant (pDO=DA. The conventional surface treatment resulted in higher bond strength values than the sodium hypochlorite treatment (pO objetivo foi avaliar a resistência de união (RU de dentina superficial (SU e profunda (P, obtida por acesso apical (PA ou oclusal (PO, ao adesivo One-Step com (H ou sem aplicação de hipoclorito de sódio a 10% (C após o condicionamento ácido. Para os 6 grupos foram utilizados seis molares hígidos. Nos grupos SUC, PAC e POC, o adesivo e a resina Z100 foram aplicados. Nos grupos SUH, PAH e POH, após condicionamento, aplicou-se H por 60s, adesivo e Z100. Os dentes foram fatiados em cortes paralelos e perpendiculares para a obtenção de cp de 0,8mm² e testados sob tração (0,6mm/min. Os valores de RU foram submetidos a ANOVA de dois fatores. Não se detectou diferença para a interação (p=0,209, porém os fatores principais foram diferentes (p

  15. 不同表面处理对氧化锆陶瓷与自粘结树脂粘结强度的影响%Influence of different surface treatments on shear bond strength of self-adhesive resin bonding to zirconia ceramic

    Institute of Scientific and Technical Information of China (English)

    吴雪勋; 郭庆平; 王洋; 缪颖

    2015-01-01

    Objective This study is to evaluate Influence of different surface treatments on shear bond strength(SBS) of self-adhesive resin bonding to zirconia ceramic. Methods 80 square-like zirconia samples were polished and randomly assigned in four groups according to different surface treat⁃ments.Group A:air-abraded and silica coating;group B:Er:YAG laser irradiation;group C:laser fol⁃lowed by air-abraded and silica coating;group D:no treatment.Each group was divided into two sub⁃groups(a and b) according the resin tested: BiFixSE and Clearfil SA.A shear bond strength test was performed using a universal testing machine. Results Bonded with BiFixSE,group Ca showed no dif⁃ference with group Aa in SBS(P>0.05),but they both showed higher SBS than group Ba(P<0.05), and group Ba showed higher SBS than group Da(P<0.05). Bonded with Clearfil SA,it was group Cb, Ab, Bb,Db aranging from high to low. In group C,Clearfil SA showed higher SBS than BiFixSE( P<0.05). Concluison Although Er:YAG laser irradiation alone showed lower SBS,it can enhance bonding strength by combined application.%目的:研究不同表面处理方法对氧化锆陶瓷与两种自粘结树脂粘结强度的影响,为临床上氧化锆陶瓷修复体粘结选择合适的表面处理方法和粘结树脂提供参考。方法:将80个氧化锆瓷片随机分为A、B、C、D四组。A组采用喷砂+硅涂层法,B组采用Er:YAG激光蚀刻,C组先Er:YAG激光蚀刻后再用喷砂+硅涂层法。D组作为对照组不做处理。每组再分为a、b两个组,分别用BifixSE自粘结树脂和Clearfil SA自粘结树脂粘结,最后置于万能材料力学测试机测得剪切强度。结果:使用BifixSE自粘结树脂粘结时,Ca组与Aa组比较,差异无统计学意义(P>0.05);但两组均大于Ba组,差异有统计学意义(P<0.05),Ba组大于Da组(P<0.05),差异有统计学意义。使用Clearfil SA自粘结树脂粘结时(b组),各组粘结强

  16. Modification on epoxy-based adhesive

    Institute of Scientific and Technical Information of China (English)

    ZhengXiaoxia; QianChunxiang

    2003-01-01

    This research adopted four methods to toughen epoxy adhesives. They were liquid hydroxyl group terminated polybutadiene (HTPB) rubber modification, silicon rubber modification, polyacrylate multiplicity elastomer particulates emulsion modification and chemical grafting modification. After modification, the shearing strength and the rapture elongation were tested. The interface and the chemical reaction between the modifiers and the epoxy were analyzed by scanning electron microscope (SEM) and infrared optical spectrum. The results show that the elastomer particulates modification and the chemical grafting modification can reach the better toughening effects.

  17. Strategies to improve the adhesion of rubbers to adhesives by means of plasma surface modification

    Science.gov (United States)

    Martín-Martínez, J. M.; Romero-Sánchez, M. D.

    2006-05-01

    The surface modifications produced by treatment of a synthetic sulfur vulcanized styrene-butadiene rubber with oxidizing (oxygen, air, carbon dioxide) and non oxidizing (nitrogen, argon) RF low pressure plasmas, and by treatment with atmospheric plasma torch have been assessed by ATR-IR and XPS spectroscopy, SEM, and contact angle measurements. The effectiveness of the low pressure plasma treatment depended on the gas atmosphere used to generate the plasma. A lack of relationship between surface polarity and wettability, and peel strength values was obtained, likely due to the cohesive failure in the rubber obtained in the adhesive joints. In general, acceptable adhesion values of plasma treated rubber were obtained for all plasmas, except for nitrogen plasma treatment during 15 minutes due to the creation of low molecular weight moieties on the outermost rubber layer. A toluene wiping of the N{2 } plasma treated rubber surface for 15 min removed those moieties and increased adhesion was obtained. On the other hand, the treatment of the rubber with atmospheric pressure by means of a plasma torch was proposed. The wettability of the rubber was improved by decreasing the rubber-plasma torch distance and by increasing the duration because a partial removal of paraffin wax from the rubber surface was produced. The rubber surface was oxidized by the plasma torch treatment, and the longer the duration of the plasma torch treatment, the higher the degree of surface oxidation (mainly creation of C O moieties). However, although the rubber surface was effectively modified by the plasma torch treatment, the adhesion was not greatly improved, due to the migration of paraffin wax to the treated rubber-polyurethane adhesive interface once the adhesive joint was produced. On the other hand, the extended treatment with plasma torch facilitated the migration of zinc stearate to the rubber-adhesive interface, also contributing to deteriorate the adhesion in greater extent. Finally

  18. COHESIVE STRENGTH OF DENTIN RESISTÊNCIA COESIVA DA DENTINA

    OpenAIRE

    DEMARCO, Flávio Fernando; Turbino, Miriam Lacalle; Edmir MATSON

    1997-01-01

    The bond strength of dentin adhesives to dentin has increased after each generation. Although dentin substratum is part of the bonding process, little importance has been given to measure dentin cohesive strength. The aim of this study was to evaluate the cohesive strength of dentin in human canines. Seventeen non carious canines were selected. All of them had been extracted for more than one year. The teeth were ground until dentin square samples with approximately 2 X 2 mm were obtained. Th...

  19. UV-cured adhesives for carbon fiber composite applications

    Science.gov (United States)

    Lu, Hsiao-Chun

    Carbon fiber composite materials are increasingly used in automobile, marine, and aerospace industries due to their unique properties, including high strength, high stiffness and low weight. However, due to their brittle characteristic, these structures are prone to physical damage, such as a bird strike or impact damage. Once the structure is damaged, it is important to have fast and reliable temporary repair until the permanent repair or replacement can take place. In this dissertation, UV-based adhesives were used to provide a bonding strength for temporary repair. Adhesively bonded patch repair is an efficient and effective method for temporary repair. In this study, precured patches (hard patches) and dry fabric patches with laminating resins (soft patches) were performed. UV-based epoxy adhesives were applied to both patch repair systems. For precured patch repair, the bonding strengths were investigated under different surface treatments for bonding area and different adhesives thicknesses. The shear stresses of different UV exposure times and curing times were tested. Besides, the large patch repair was investigated as well. For soft patch repair, the hand wet lay-up was applied due to high viscosity of UV resins. A modified single lap shear testing (ASTM D5868) was applied to determine the shear stress. The large patches used fiber glass instead of carbon fiber to prove the possibility of repair with UV epoxy resin by hand wet lay-up process. The hand lay-up procedure was applied and assisted by vacuum pressure to eliminate the air bubbles and consolidate the patches. To enhance the bonding strength and effective soft patch repair, vacuum assisted resin transferring molding (VaRTM) is the better option. However, only low viscosity resins can be operated by VaRTM. Hence, new UV-based adhesives were formulated. The new UV-based adhesives included photoinitiator (PI), epoxy and different solvents. Solvents were used to compound the photoinitiator into epoxy

  20. Dry chemical pretreatment of titanium and polymers for adhesive bonding. Trockenchemische Vorbehandlung von Titan und Kunststoffen fuer das Kleben

    Energy Technology Data Exchange (ETDEWEB)

    Krueger, G.; Hennemann, O.D. (Fraunhofer-Institut fuer Angewandte Materialforschung, Bremen (Germany))

    1993-01-01

    Titan alloys have to be pretreated to increase the adhesive bonding strength. Because of environmental reasons dry chemical pretreatment methods are preferred compared to wet chemical techniques. One successful method is a silicatisation referring to the Saco-technique. Layers generated by this method on titanium or polymer substrates lead to highly water-resistant adhesive bondings. Also adhesive joints of Ti with polymer show high bond strength when polymer and Ti are Saco treated. With a suitable optimization of the technological parameters it is possible to adhesively bond polymers also with anaerobic acrylic esters. (orig.).

  1. Management of adhesive capsulitis

    Directory of Open Access Journals (Sweden)

    Stupay KL

    2015-08-01

    Full Text Available Kristen L Stupay,1 Andrew S Neviaser2 1Tulane University School of Medicine, New Orleans, LA, USA; 2George Washington University Medical Faculty Associates, Washington, DC, USA Abstract: Adhesive capsulitis of the shoulder is a condition of capsular contracture that reduces both active and passive glenohumeral motion. The cause of adhesive capsulitis is not known but it is strongly associated with endocrine abnormalities such as diabetes. Diverse terminology and the absence of definitive criteria for diagnosis make evaluating treatment modalities difficult. Many treatment methods have been reported, most with some success, but few have been proved to alter the natural course of this disease. Most afflicted patients will achieve acceptable shoulder function without surgery. Those who remain debilitated after 8–12 months are reasonable candidates for invasive treatments. Here, the various treatment methods and the data to support their use are reviewed. Keywords: frozen shoulder, stiff shoulder, periarthritis, painful shoulder 

  2. Syndecans and cell adhesion

    DEFF Research Database (Denmark)

    Couchman, J R; Chen, L; Woods, A

    2001-01-01

    Now that transmembrane signaling through primary cell-matrix receptors, integrins, is being elucidated, attention is turning to how integrin-ligand interactions can be modulated. Syndecans are transmembrane proteoglycans implicated as coreceptors in a variety of physiological processes, including...... cell adhesion, migration, response to growth factors, development, and tumorigenesis. This review will describe this family of proteoglycans in terms of their structures and functions and their signaling in conjunction with integrins, and indicate areas for future research....

  3. Blister Test for Measurements of Adhesion and Adhesion Degradation of Organic Polymers on AA2024-T3

    Science.gov (United States)

    Rincon Troconis, Brendy Carolina

    A key parameter for the performance of corrosion protective coatings applied to metals is adhesion. Surface preparation prior to coating application is known to be critical, but there is a lack of understanding of what controls adhesion. Numerous techniques have been developed in the last decades to measure the adhesion strength of coatings to metals. Nonetheless, they are generally non-quantitative, non-reproducible, performed in dry conditions, or overestimate adhesion. In this study, a quantitative and reproducible technique, the Blister Test (BT), is used. The BT offers the ability to study the effects of a range of parameters, including the presence or absence of a wetting liquid, and simulates the stress situation in the coating/substrate interface. The effects of roughness and surface topography were studied by the BT and Optical Profilometry, using AA2024-T3 substrates coated with polyvinyl butyral (PVB). Random abrasion generated a surface with lower average roughness than aligned abrasion due to the continual cross abrasion of the grooves. The BT could discern the effects of different mechanical treatments. An adhesion strength indicator was defined and found to be a useful parameter. The effectiveness of standard adhesion techniques such as ASTM D4541 (Pull-off Test) and ASTM D3359 (Tape Test) was compared to the BT. Also, different attempts to measure adhesion and adhesion degradation of organic polymers to AA2024-T3 were tested. The pull-off test does not produce adhesive failure across the entire interface, while the tape test is a very qualitative technique and does not discern between the effects of different coating systems on the adhesion performance. The BT produces adhesive failure of the primer studied, is very reproducible, and is able to rank different coating systems. Therefore, it was found to be superior to the others. The approaches tested for adhesion degradation were not aggressive enough to have a measurable effect. The effects of

  4. Antibacterial Effect of Dental Adhesive Containing Dimethylaminododecyl Methacrylate on the Development of Streptococcus mutans Biofilm

    Directory of Open Access Journals (Sweden)

    Suping Wang

    2014-07-01

    Full Text Available Antibacterial bonding agents and composites containing dimethylaminododecyl methacrylate (DMADDM have been recently developed. The objectives of this study were to investigate the antibacterial effect of novel adhesives containing different mass fractions of DMADDM on Streptococcus mutans (S. mutans biofilm at different developmental stages. Different mass fractions of DMADDM were incorporated into adhesives and S. mutans biofilm at different developmetal stages were analyzed by MTT assays, lactic acid measurement, confocal laser scanning microscopy and scanning electron microscopy observations. Exopolysaccharides (EPS staining was used to analyze the inhibitory effect of DMADDM on the biofilm extracellular matrix. Dentin microtensile strengths were also measured. Cured adhesives containing DMADDM could greatly reduce metabolic activity and lactic acid production during the development of S. mutans biofilms (p < 0.05. In earlier stages of biofilm development, there were no significant differences of inhibitory effects between the 2.5% DMADDM and 5% DMADDM group. However, after 72 h, the anti-biofilm effects of adhesives containing 5% DMADDM were significantly stronger than any other group. Incorporation of DMADDM into adhesive did not adversely affect dentin bond strength. In conclusion, adhesives containing DMADDM inhibited the growth, lactic acid production and EPS metabolism of S. mutans biofilm at different stages, with no adverse effect on its dentin adhesive bond strength. The bonding agents have the potential to control dental biofilms and combat tooth decay, and DMADDM is promising for use in a wide range of dental adhesive systems and restoratives.

  5. Antibacterial effect of dental adhesive containing dimethylaminododecyl methacrylate on the development of Streptococcus mutans biofilm.

    Science.gov (United States)

    Wang, Suping; Zhang, Keke; Zhou, Xuedong; Xu, Ning; Xu, Hockin H K; Weir, Michael D; Ge, Yang; Wang, Shida; Li, Mingyun; Li, Yuqing; Xu, Xin; Cheng, Lei

    2014-07-18

    Antibacterial bonding agents and composites containing dimethylaminododecyl methacrylate (DMADDM) have been recently developed. The objectives of this study were to investigate the antibacterial effect of novel adhesives containing different mass fractions of DMADDM on Streptococcus mutans (S. mutans) biofilm at different developmental stages. Different mass fractions of DMADDM were incorporated into adhesives and S. mutans biofilm at different developmetal stages were analyzed by MTT assays, lactic acid measurement, confocal laser scanning microscopy and scanning electron microscopy observations. Exopolysaccharides (EPS) staining was used to analyze the inhibitory effect of DMADDM on the biofilm extracellular matrix. Dentin microtensile strengths were also measured. Cured adhesives containing DMADDM could greatly reduce metabolic activity and lactic acid production during the development of S. mutans biofilms (p biofilm development, there were no significant differences of inhibitory effects between the 2.5% DMADDM and 5% DMADDM group. However, after 72 h, the anti-biofilm effects of adhesives containing 5% DMADDM were significantly stronger than any other group. Incorporation of DMADDM into adhesive did not adversely affect dentin bond strength. In conclusion, adhesives containing DMADDM inhibited the growth, lactic acid production and EPS metabolism of S. mutans biofilm at different stages, with no adverse effect on its dentin adhesive bond strength. The bonding agents have the potential to control dental biofilms and combat tooth decay, and DMADDM is promising for use in a wide range of dental adhesive systems and restoratives.

  6. Superhydrophobic nanocomposite surface topography and ice adhesion.

    Science.gov (United States)

    Davis, Alexander; Yeong, Yong Han; Steele, Adam; Bayer, Ilker S; Loth, Eric

    2014-06-25

    A method to reduce the surface roughness of a spray-casted polyurethane/silica/fluoroacrylic superhydrophobic nanocomposite coating was demonstrated. By changing the main slurry carrier fluid, fluoropolymer medium, surface pretreatment, and spray parameters, we achieved arithmetic surface roughness values of 8.7, 2.7, and 1.6 μm on three test surfaces. The three surfaces displayed superhydrophobic performance with modest variations in skewness and kurtosis. The arithmetic roughness level of 1.6 μm is the smoothest superhydrophobic surface yet produced with these spray-based techniques. These three nanocomposite surfaces, along with a polished aluminum surface, were impacted with a supercooled water spray in icing conditions, and after ice accretion occurred, each was subjected to a pressurized tensile test to measure ice-adhesion. All three superhydrophobic surfaces showed lower ice adhesion than that of the polished aluminum surface. Interestingly, the intermediate roughness surface yielded the best performance, which suggests that high kurtosis and shorter autocorrelation lengths improve performance. The most ice-phobic nanocomposite showed a 60% reduction in ice-adhesion strength when compared to polished aluminum.

  7. Staying sticky: contact self-cleaning of gecko-inspired adhesives.

    Science.gov (United States)

    Mengüç, Yigit; Röhrig, Michael; Abusomwan, Uyiosa; Hölscher, Hendrik; Sitti, Metin

    2014-05-01

    The exceptionally adhesive foot of the gecko remains clean in dirty environments by shedding contaminants with each step. Synthetic gecko-inspired adhesives have achieved similar attachment strengths to the gecko on smooth surfaces, but the process of contact self-cleaning has yet to be effectively demonstrated. Here, we present the first gecko-inspired adhesive that has matched both the attachment strength and the contact self-cleaning performance of the gecko's foot on a smooth surface. Contact self-cleaning experiments were performed with three different sizes of mushroom-shaped elastomer microfibres and five different sizes of spherical silica contaminants. Using a load-drag-unload dry contact cleaning process similar to the loads acting on the gecko foot during locomotion, our fully contaminated synthetic gecko adhesives could recover lost adhesion at a rate comparable to that of the gecko. We observed that the relative size of contaminants to the characteristic size of the microfibres in the synthetic adhesive strongly determined how and to what degree the adhesive recovered from contamination. Our approximate model and experimental results show that the dominant mechanism of contact self-cleaning is particle rolling during the drag process. Embedding of particles between adjacent fibres was observed for particles with diameter smaller than the fibre tips, and further studied as a temporary cleaning mechanism. By incorporating contact self-cleaning capabilities, real-world applications of synthetic gecko adhesives, such as reusable tapes, clothing closures and medical adhesives, would become feasible.

  8. Behaviour of Bi-Adhesive in Double-Strap Joint with Embedded Patch Subjected to Bending

    Directory of Open Access Journals (Sweden)

    Temiz Şemsettin

    2015-09-01

    Full Text Available In this study, behaviour of bi-adhesive used in the repair of damaged parts was analyzed, using the finite element method. In a double-strap joint with an embedded patch, patch is embedded into the adherents for structural requirements. In addition, to increase the strength of the joint, two adhesives are used to bond the adherents. This approach reduces stress concentration at the overlap ends, increases the load capacity and delays the failure. These effects give rise to higher joint strength. For this purpose, a stiff adhesive, FM73 produced by Cytec Fiberite, was applied in the middle portion of the overlap, while a softer adhesive, SBT9244 from 3M, was applied towards the edges, prone to stress concentrations. Non-linear finite element analyses were carried out to predict the failure loads, to assist with the geometric design and to identify effective ratios of sizes to maximize joint strength.

  9. High-adhesion Cu patterns fabricated by nanosecond laser modification and electroless copper plating

    Science.gov (United States)

    Lv, Ming; Liu, Jianguo; Zeng, Xiaoyan; Du, Qifeng; Ai, Jun

    2015-10-01

    Adhesion strength is a crucial factor for the performance and reliability of metallic patterns on insulator substrates. In this study, we present an efficient technique for selective metallization of alumina ceramic with high adhesion strength by using nanosecond laser modification and electroless copper plating. Specifically, a 355 nm Nd:YVO4 ultraviolet (UV) laser was employed not only to decompose palladium chloride film locally for catalyzing the electroless reaction, but also to modify the ceramic surface directly using its high fluence. An orthogonal experiment was undertaken to study the effects of processing parameters including laser fluence, scanning speed and scanning line interval on adhesion strength. The adhesion strength was measured by pulling a metallic wire soldered into the copper coating perpendicular to the substrate using a pull tester. The results have shown that a strong adhesion between the copper coating and the alumina ceramic, higher than the tensile strength of tin-lead solder was obtained. Surface and interface characteristics were investigated to understand that, whose results have shown that the high-aspect-ratio microstructures formed by the laser modification is the major reason for the improvement of adhesion.

  10. Tensile bond strength of polyvinyl siloxane impressions bonded to a custom tray as a function of drying time: Part I.

    Science.gov (United States)

    Cho, G C; Donovan, T E; Chee, W W; White, S N

    1995-05-01

    Time-dependent bond strength studies of two polyvinyl siloxane impression materials to acrylic resin disks with their respective adhesives were studied to determine the optimal time for maximum bond strength. Six groups were tested with varying adhesive dry times of 0, 7, 15, and 60 minutes and 8 and 24 hours before testing. The results indicated that the bond strength of the adhesive increased at least twofold from time zero to 7 minutes adhesive dry time and peaked at 60 minutes for one of the materials and at 8 hours for the other. Bond strengths increased rapidly to the 15-minute test interval and then seemed to plateau. Both materials exhibited decreased adhesive bond strengths at 24 hours.

  11. Validity of bond strength tests: A critical review: Part I.

    Science.gov (United States)

    Sirisha, Kantheti; Rambabu, Tankonda; Shankar, Yalavarthi Ravi; Ravikumar, Pabbati

    2014-07-01

    Adhesive systems are selected based on their bond strengths achieved while testing in laboratories. These bond strengths can predict the longevity of a restoration to some extent. There were several discrepancies in the reported bond strengths. To critically review the reliability of macro-bond strength tests used to evaluate resin-tooth interface. Relevant literature published between January 1983 and May 2013 was collected from PubMed database, Google scholar, and hand-searched journals of Conservative Dentistry, Endodontics and Dental materials. Variables that influence the test outcome are categorized into substrate-related factors, factors related to specimen properties, preparation of specimens, and test methodology. Impact of these variables on the test outcome is critically analyzed. There is lack of a standard format for reporting the bond strength tests, which could lead to misinterpretation of the data and bonding abilities of adhesives. PMID:25125840

  12. Improving copper plating adhesion on glass using laser machining techniques and areal surface texture parameters

    Science.gov (United States)

    He, Baofeng; Petzing, Jon; Webb, Patrick; Leach, Richard

    2015-12-01

    Glass is a promising substitute substrate material being evaluated for electronic packaging technology. Improving the electroless copper plated layer adhesion of the glass is one of the most important considerations for development of the technology. An excimer laser (248 nm) was used for structured texturing of glass surfaces (to improve adhesion) by changing mask dimensions, laser operating parameters and overlapping pitch spacing, and therefore producing a range of micro-scale features. Electroless plated copper adhesion strength was assessed using quantitative scratch testing, demonstrating that micro-patterned structures can significantly improve copper/glass adhesion. New ISO 25178 Part 2 areal surface texture parameters were used to characterise the surface roughness of ablated glass surfaces, and correlated to the scratch testing results. Highly correlated parameters were identified that could be used as predictive surface design tools, directly linking surface topography to adhesion performance, without the need for destructive adhesion quantification via scratch testing.

  13. Bond strength between acrylic resin and maxillofacial silicone

    Directory of Open Access Journals (Sweden)

    Marcela Filié Haddad

    2012-12-01

    Full Text Available The development of implant dentistry improved the possibilities of rehabilitation with maxillofacial prosthesis. However, clinically it is difficult to bond the silicone to the attachment system. OBJECTIVES: This study aimed to evaluate the effect of an adhesive system on the bond strength between acrylic resin and facial silicone. MATERIAL AND METHODS: A total of 120 samples were fabricated with auto-polymerized acrylic resin and MDX 4-4210 facial silicone. Both materials were bonded through mechanical retentions and/or application of primers (DC 1205 primer and Sofreliner primer S and adhesive (Silastic Medical Adhesive Type A or not (control group. Samples were divided into 12 groups according to the method used to attach the silicone to the acrylic resin. All samples were subjected to a T-peel test in a universal testing machine. Failures were classified as adhesive, cohesive or mixed. The data were evaluated by the analysis of variance (ANOVA and the Tukey's HSD test (α=.05. RESULTS: The highest bond strength values (5.95 N/mm; 3.07 N/mm; 4.75 N/mm were recorded for the samples that received a Sofreliner primer application. These values were significantly higher when the samples had no scratches and did not receive the application of Silastic Medical Adhesive Type A. CONCLUSIONS: The most common type of failure was adhesive. The use of Sofreliner primer increased the bond strength between the auto-polymerized acrylic resin and the Silastic MDX 4-4210 facial silicone.

  14. Gecko-Inspired, Controlled Adhesion and Its Applications

    Science.gov (United States)

    Menguc, Yigit

    ). So far synthetic gecko adhesives fail to capture this behavior and self-cleaning remains the least studied characteristic in the field gecko-inspired adhesives. In this work we use two distinct arrays of micropillars with mushroom-shaped tips made from polyurethane. The two geometries we use all have the same aspect ratios of pillar height to base diameter of about 2 to 1, and all have mushroom tips that are twice the diameter of base. The pillar tip diameters are 20 mum and 95 mum, and we will refer to them as the small and large pillars, respectively. We contaminate the adhesives with simulated dirt particles in the form of well-characterized soda lime glass spheres ranging in diameter from 1 to 250 mum. Both micropillar arrays recovered adhesive strength after contamination and cleaning through dry, shearing contact with glass. In a best case scenario, we found that large pillars contaminated with 150-250 mum diameter particles can rid the tips of contaminating particles completely and recover 90% of the initial adhesive strength. This finding is significant because it is the first demonstration of adhesion recovery through dry self-cleaning by contact to a non-sticky cleaning substrate. The degree to which adhesion is recovered is superior to any conventional adhesive and is nearly identical to the gecko itself. This thesis presents a study of controlling adhesion in gecko-inspired adhesives. This control is achieved by maximizing or minimizing attachment strength on demand by simple mechanical loading, and enables robotic manipulation tasks and the recovery of adhesion after contamination. Looking forward, we can predict what is possible for gecko-inspired adhesives if the discoveries in this thesis are implemented, and if other shortcomings in the field are resolved. Looking at the applications already under development, it seems clear that medical adhesives have great potential, and climbing robots might achieve significant utility. In consumer products, gecko-adhesives

  15. Nanoparticle adhesion in proton exchange membrane fuel cell electrodes

    Science.gov (United States)

    He, Qianping; Joy, David C.; Keffer, David J.

    2013-11-01

    Carbon supported platinum (Pt/C) catalyst remains among the most preferable catalyst materials for Proton Exchange Membrane (PEM) fuel cells. However, platinum (Pt) particles suffer from poor durability and encounter electrochemical surface area (ESA) loss under operation with the accompany of Pt nanoparticle coarsening. Several proposed mechanisms have involved the Pt detachment from its carbonate support as an initial step for the deactivation of Pt nanoparticles. In this study, we investigated the detachment mechanism from the nano-adhesion point of view. Classic molecular dynamics simulations are performed on systems contain Pt nanoparticles of different sizes and shapes. A thin Nafion film (1 nm) at different hydration levels is also included in the system to study the environmental effect on nanoparticle adhesion. We found that the adhesion force strengthens as the Pt size goes up. Pt nanoparticles of tetrahedral shape exhibit relatively stronger connection with the carbon substrate due to its unique ‘anchor-like’ structure. Adhesion is enhanced with the introduction of a Nafion. The humidity level in the Nafion film has a rather complicated effect on the strength of nanoparticle adhesion. The binding energies and maximum adhesive forces are reported for all systems studied.

  16. Improved dental adhesive formulations based on reactive nanogel additives.

    Science.gov (United States)

    Morães, R R; Garcia, J W; Wilson, N D; Lewis, S H; Barros, M D; Yang, B; Pfeifer, C S; Stansbury, J W

    2012-02-01

    Current challenges in adhesive dentistry include over-hydrophilic bonding formulations, which facilitate water percolation through the hybrid layer and result in unreliable bonded interfaces. This study introduces nanogel-modified adhesives as a way to control the material's hydrophobic character without changing the basic monomer formulation (keeping water-chasing capacity and operatory techniques unaltered). Nanogel additives of varied hydrophobicity were synthesized in solution, rendering 10- to 100-nm-sized particles. A model BisGMA/HEMA solvated adhesive was prepared (control), to which reactive nanogels were added. The increase in adhesive viscosity did not impair solvent removal by air-thinning. The degree of conversion in the adhesive was similar between control and nanogel-modified materials, while the bulk dry and, particularly, the wet mechanical properties were significantly improved through nanogel-based network reinforcement and reduced water solubility. As preliminary validation of this approach, short-term micro-tensile bond strengths to acid-etched and primed dentin were significantly enhanced by nanogel inclusion in the adhesive resins. PMID:22019910

  17. A new adhesive technique for internal fixation in midfacial surgery

    Directory of Open Access Journals (Sweden)

    Riediger Dieter

    2008-05-01

    Full Text Available Abstract Background The current surgical therapy of midfacial fractures involves internal fixation in which bone fragments are fixed in their anatomical positions with osteosynthesis plates and corresponding screws until bone healing is complete. This often causes new fractures to fragile bones while drilling pilot holes or trying to insert screws. The adhesive fixation of osteosynthesis plates using PMMA bone cement could offer a viable alternative for fixing the plates without screws. In order to achieve the adhesive bonding of bone cement to cortical bone in the viscerocranium, an amphiphilic bone bonding agent was created, analogous to the dentin bonding agents currently on the market. Methods The adhesive bonding strengths were measured using tension tests. For this, metal plates with 2.0 mm diameter screw holes were cemented with PMMA bone cement to cortical bovine bone samples from the femur diaphysis. The bone was conditioned with an amphiphilic bone bonding agent prior to cementing. The samples were stored for 1 to 42 days at 37 degrees C, either moist or completely submerged in an isotonic NaCl-solution, and then subjected to the tension tests. Results Without the bone bonding agent, the bonding strength was close to zero (0.2 MPa. Primary stability with bone bonding agent is considered to be at ca. 8 MPa. Moist storage over 42 days resulted in decreased adhesion forces of ca. 6 MPa. Wet storage resulted in relatively constant bonding strengths of ca. 8 MPa. Conclusion A new amphiphilic bone bonding agent was developed, which builds an optimizied interlayer between the hydrophilic bone surface and the hydrophobic PMMA bone cement and thus leads to adhesive bonding between them. Our in vitro investigations demonstrated the adhesive bonding of PMMA bone cement to cortical bone, which was also stable against hydrolysis. The newly developed adhesive fixing technique could be applied clinically when the fixation of osteosynthesis plates

  18. Effectiveness of immediate bonding of etch-and-rinse adhesives to simplified ethanol-saturated dentin

    Directory of Open Access Journals (Sweden)

    Leandro Afonso Guimarães

    2012-04-01

    Full Text Available This study examined the immediate bond strength of etch-and-rinse adhesives to demineralized dentin saturated with either water or absolute ethanol. The research hypothesis was that there would be no difference in bond strength to dentin between water or ethanol wet-bonding techniques. The medium dentin of 20 third molars was exposed (n = 5. The dentin surface was then acid-etched, left moist and randomly assigned to be saturated via either water wet-bonding (WBT or absolute ethanol wet-bonding (EBT. The specimens were then treated with one of the following etch-and-rinse adhesive systems: a 3-step, water-based system (Adper Scotchbond Multipurpose, or SBMP or a 2-step, ethanol/water-based system (Adper Single Bond 2, or SB. Resin composite build-ups were then incrementally constructed. After water storage for 24 h at 37°C, the tensile strength of the specimens was tested in a universal testing machine (0.5 mm/min. Data were analyzed by two-way ANOVA and Tukey's test (a = 5%. The failure modes were verified using a stereomicroscope (40'. For both adhesives, no significant difference in bond strength was observed between WBT and EBT (p > 0.05. The highest bond strength was observed for SB, regardless of the bonding technique (p < 0.05. No significant interaction between adhesives and bonding techniques was noticed (p = 0.597. There was a predominance of adhesive failures for all tested groups. The EBT and WBT displayed similar immediate bond strength means for both adhesives. The SB adhesive exhibited higher means for all conditions tested. Further investigations are needed to evaluate long-term bonding to dentin mediated by commercial etch-and-rinse adhesives using the EBT approach.

  19. Frictional adhesion: A new angle on gecko attachment.

    Science.gov (United States)

    Autumn, K; Dittmore, A; Santos, D; Spenko, M; Cutkosky, M

    2006-09-01

    Directional arrays of branched microscopic setae constitute a dry adhesive on the toes of pad-bearing geckos, nature's supreme climbers. Geckos are easily and rapidly able to detach their toes as they climb. There are two known mechanisms of detachment: (1) on the microscale, the seta detaches when the shaft reaches a critical angle with the substrate, and (2) on the macroscale, geckos hyperextend their toes, apparently peeling like tape. This raises the question of how geckos prevent detachment while inverted on the ceiling, where body weight should cause toes to peel and setal angles to increase. Geckos use opposing feet and toes while inverted, possibly to maintain shear forces that prevent detachment of setae or peeling of toes. If detachment occurs by macroscale peeling of toes, the peel angle should monotonically decrease with applied force. In contrast, if adhesive force is limited by microscale detachment of setae at a critical angle, the toe detachment angle should be independent of applied force. We tested the hypothesis that adhesion is increased by shear force in isolated setal arrays and live gecko toes. We also tested the corollary hypotheses that (1) adhesion in toes and arrays is limited as on the microscale by a critical angle, or (2) on the macroscale by adhesive strength as predicted for adhesive tapes. We found that adhesion depended directly on shear force, and was independent of detachment angle. Therefore we reject the hypothesis that gecko toes peel like tape. The linear relation between adhesion and shear force is consistent with a critical angle of release in live gecko toes and isolated setal arrays, and also with our prior observations of single setae. We introduced a new model, frictional adhesion, for gecko pad attachment and compared it to existing models of adhesive contacts. In an analysis of clinging stability of a gecko on an inclined plane each adhesive model predicted a different force control strategy. The frictional adhesion

  20. Adhesive tape exfoliation

    DEFF Research Database (Denmark)

    Bohr, Jakob

    2015-01-01

    cleaving of a single chunk of graphite. For both cases, parallel and serial exfoliation, it is investigated how many generations of cleavages are needed. An approximate model with the probability distribution expressed as a simple closed form is presented and compared with the simulations.......Single-crystal graphite can be cleaved by the use of an adhesive tape. This was also the initial route for obtaining graphene, a one-layer thick graphite slab. In this letter a few simple and fun considerations are presented in an attempt to shed some light on why this procedure is successful...

  1. [Adhesive cutaneous pharmaceutical forms].

    Science.gov (United States)

    Gafiţanu, E; Matei, I; Mungiu, O C; Pavelescu, M; Mîndreci, I; Apostol, I; Ionescu, G

    1989-01-01

    The adhesive cutaneous pharmaceutical forms aimed to local action release the drug substance in view of a dermatological, traumatological, antirheumatic, cosmetic action. Two such preparations were obtained and their stability, consistency and pH were determined. The "in vitro" tests of their bioavailability revealed the dynamics of calcium ions release according to the associations of each preparation. The bioavailability determined by evaluating the pharmacological response demonstrated the antiinflammatory action obtained by the association of calcium ions with the components extracted from poplar muds. The therapeutical efficiency of the studied preparations has proved in the treatment of some sport injuries.

  2. Syndecan proteoglycans and cell adhesion

    DEFF Research Database (Denmark)

    Woods, A; Oh, E S; Couchman, J R

    1998-01-01

    It is now becoming clear that a family of transmembrane proteoglycans, the syndecans, have important roles in cell adhesion. They participate through binding of matrix ligand to their glycosaminoglycan chains, clustering, and the induction of signaling cascades to modify the internal microfilament...... organization. Syndecans can modulate the type of adhesive responses induced by other matrix ligand-receptor interactions, such as those involving the integrins, and so contribute to the control of cell morphology, adhesion and migration....

  3. Adhesion properties of gecko setae

    Science.gov (United States)

    Hill, Ginel; Peattie, Anne; Daniels, Roxanne; Full, Robert; Kenny, Thomas

    2005-03-01

    Millions of keratin hairs on gecko feet, called setae, act as a spectacular dry adhesive. Each seta branches into hundreds of smaller fibers that terminate in spatula-shaped ends. Morphological differences between the setae from different gecko species are suspected to affect both single-seta and whole-animal adhesion properties. Single-seta adhesive force measurements made using a MEMS piezoresistive cantilever capable of two-axis measurements are presented.

  4. Puerperal endometritis and intrauterine adhesions.

    Science.gov (United States)

    Polishuk, W Z; Anteby, S O; Weinstein, D

    1975-08-01

    The role of puerperal endometritis in intrauterine adhesion formation was studied by hysterography in 171 women who had cesarean sections. Of 28 patients who developed significant endometritis, only one developed intracervical adhesions. In the control group of 143 cases, there was also only one such case. Endometritis alone apparently does not play a significant role in intrauterine and endocervical adhesion formation. The possible role of placental fibroblasts in preventing endometrial regeneration is discussed. PMID:1158622

  5. The neural cell adhesion molecule

    DEFF Research Database (Denmark)

    Berezin, V; Bock, E; Poulsen, F M

    2000-01-01

    During the past year, the understanding of the structure and function of neural cell adhesion has advanced considerably. The three-dimensional structures of several of the individual modules of the neural cell adhesion molecule (NCAM) have been determined, as well as the structure of the complex...... between two identical fragments of the NCAM. Also during the past year, a link between homophilic cell adhesion and several signal transduction pathways has been proposed, connecting the event of cell surface adhesion to cellular responses such as neurite outgrowth. Finally, the stimulation of neurite...

  6. Shear bond strength, failure modes, and confocal microscopy of bonded amalgam restorations.

    Science.gov (United States)

    Cianconi, Luigi; Conte, Gabriele; Mancini, Manuele

    2011-01-01

    This study evaluated the shear bond strength, failure modes, and confocal microscopy of two different amalgam alloy restorations lined with five adhesive systems. Two regular-set high-copper dental amalgam alloys, Amalcap Plus and Valiant Ph.D, and five commercially available adhesive systems were selected. One hundred and twenty freshly-extracted human third molars were used for the study. The results were statistically evaluated using two-factor analysis of variance (ANOVA). The shear bond strength (SBS) of amalgam to dentin was significantly affected by both the adhesive (pValiant Ph.D, 31 of 50 exhibited adhesive failure, and 19 displayed mixed failure. Laser optical microscopy (OM) of the bonded interface revealed the presence of a good hybrid layer was evident in all experimental groups. Higher bond strengths were measured for four of the five adhesives when used in combination with the spherical alloy. PMID:21383518

  7. Hemodynamic aspects of reduced platelet adhesion on bioinspired microstructured surfaces.

    Science.gov (United States)

    Pham, Tam Thanh; Wiedemeier, Stefan; Maenz, Stefan; Gastrock, Gunter; Settmacher, Utz; Jandt, Klaus D; Zanow, Jürgen; Lüdecke, Claudia; Bossert, Jörg

    2016-09-01

    Occlusion by thrombosis due to the absence of the endothelial cell layer is one of the most frequent causes of failure of artificial vascular grafts. Bioinspired surface structures may have a potential to reduce the adhesion of platelets contributing to hemostasis. The aim of this study was to investigate the hemodynamic aspects of platelet adhesion, the main cause of thrombosis, on bioinspired microstructured surfaces mimicking the endothelial cell morphology. We tested the hypothesis that platelet adhesion is statistically significantly reduced on bioinspired microstructured surfaces compared to unstructured surfaces. Platelet adhesion as a function of the microstructure dimensions was investigated under flow conditions on polydimethylsiloxane (PDMS) surfaces by a combined experimental and theoretical approach. Platelet adhesion was statistically significantly reduced (by up to 78%; p≤0.05) on the microstructured PDMS surfaces compared to that on the unstructured control surface. Finite element method (FEM) simulations of blood flow dynamic revealed a micro shear gradient on the microstructure surfaces which plays a pivotal role in reducing platelet adhesion. On the surfaces with the highest differences of the shear stress between the top of the microstructures and the ground areas, platelet adhesion was reduced most. In addition, the microstructures help to reduce the interaction strength between fluid and surfaces, resulting in a larger water contact angle but no higher resistance to flow compared to the unstructured surface. These findings provide new insight into the fundamental mechanisms of reducing platelet adhesion on microstructured bioinspired surfaces and may lay the basis for the development of innovative next generation artificial vascular grafts with reduced risk of thrombosis. PMID:27239904

  8. Comparison of shear bond strength of amalgam bonded to primary and permanent dentin

    OpenAIRE

    Mahdi S; Bahman S; Arghavan A; Fatemeh M

    2008-01-01

    Amalgam′s non-adhesive characteristics necessitate cavity preparations incorporating retentive features, which often require the removal of non-carious tooth structure. Use of adhesives beneath amalgam restorations, would be helpful to overcome this disadvantage. This study was undertaken to compare the mean shear bond strength of amalgam bonded to primary and permanent dentin, to evaluate the efficacy of amalgam adhesives in pediatric dentistry.27 primary and 28 permanent posterior te...

  9. Pressure sensitive adhesives from renewable resources

    OpenAIRE

    Maaßen, Wiebke

    2015-01-01

    Pressure-sensitive adhesives (PSAs) represent an important segment of the adhesives market. In this work, novel insights into the adhesive performance of bio-based pressure sensitive adhesives are presented. Three different homopolymers based on fatty acids derived from native vegetable oils as renewable feedstock were characterized in terms of their mechanical and adhesive properties.

  10. Improved Adhesion and Compliancy of Hierarchical Fibrillar Adhesives.

    Science.gov (United States)

    Li, Yasong; Gates, Byron D; Menon, Carlo

    2015-08-01

    The gecko relies on van der Waals forces to cling onto surfaces with a variety of topography and composition. The hierarchical fibrillar structures on their climbing feet, ranging from mesoscale to nanoscale, are hypothesized to be key elements for the animal to conquer both smooth and rough surfaces. An epoxy-based artificial hierarchical fibrillar adhesive was prepared to study the influence of the hierarchical structures on the properties of a dry adhesive. The presented experiments highlight the advantages of a hierarchical structure despite a reduction of overall density and aspect ratio of nanofibrils. In contrast to an adhesive containing only nanometer-size fibrils, the hierarchical fibrillar adhesives exhibited a higher adhesion force and better compliancy when tested on an identical substrate.

  11. Improved Adhesion and Compliancy of Hierarchical Fibrillar Adhesives.

    Science.gov (United States)

    Li, Yasong; Gates, Byron D; Menon, Carlo

    2015-08-01

    The gecko relies on van der Waals forces to cling onto surfaces with a variety of topography and composition. The hierarchical fibrillar structures on their climbing feet, ranging from mesoscale to nanoscale, are hypothesized to be key elements for the animal to conquer both smooth and rough surfaces. An epoxy-based artificial hierarchical fibrillar adhesive was prepared to study the influence of the hierarchical structures on the properties of a dry adhesive. The presented experiments highlight the advantages of a hierarchical structure despite a reduction of overall density and aspect ratio of nanofibrils. In contrast to an adhesive containing only nanometer-size fibrils, the hierarchical fibrillar adhesives exhibited a higher adhesion force and better compliancy when tested on an identical substrate. PMID:26167951

  12. Isolation and characterization of lignin from the oak wood bioethanol production residue for adhesives.

    Science.gov (United States)

    Lee, Soo Jung; Kim, Hyun Joo; Cho, Eun Jin; Song, Younho; Bae, Hyeun-Jong

    2015-01-01

    Lignin was isolated from the residue of bioethanol production with oak wood via alkaline and catalyzed organosolv treatments at ambient temperature to improve the purity of lignin for the materials application. The isolated lignins were analyzed for their chemical composition by nitrobenzene oxidation method and their functionality was characterized via wet chemistry method, element analysis, (1)H NMR, GPC and FTIR-ATR. The isolated lignin by acid catalyzed organosolv treatment (Acid-OSL) contained a higher lignin content, aromatic proton, phenolic hydroxyl group and a lower nitrogen content that is more reactive towards chemical modification. The lignin-based adhesives were prepared and the bond strength was measured to evaluate the enhanced reactivity of lignin by the isolation. Two steps of phenolation and methylolation were applied for the modification of the isolated lignins and their tensile strengths were evaluated for the use as an adhesive. The acid catalyzed organosolv lignin-based adhesives had comparable bond strength to phenol-formaldehyde adhesives. The analysis of lignin-based adhesives by FTIR-ATR and TGA showed structural similarity to phenol adhesive. The results demonstrate that the reactivity of lignin was enhanced by isolation from hardwood bioethanol production residues at ambient temperature and it could be used in a value-added application to produce lignin-based adhesives.

  13. Increased adhesion of polydimethylsiloxane (PDMS) to acrylic adhesive tape for medical use by surface treatment with an atmospheric pressure rotating plasma jet

    Science.gov (United States)

    Jofre-Reche, José Antonio; Pulpytel, Jérôme; Arefi-Khonsari, Farzaneh; Martín-Martínez, José Miguel

    2016-08-01

    The surface properties of polydimethylsiloxane (PDMS) were modified by treatment with an atmospheric pressure rotating plasma jet (APPJ) and the surface modifications were studied to assess its hydrophilicity and adhesion to acrylic adhesive tape intended for medical applications. Furthermore, the extent of hydrophobic recovery under different storage conditions was studied. The surface treatment of PDMS with the APPJ under optimal conditions noticeably increased the oxygen content and most of the surface silicon species were fully oxidized. A brittle silica-like layer on the outermost surface was created showing changes in topography due to the formation of grooves and cracks. A huge improvement in T-peel and the shear adhesive strength of the APPJ-treated PDMS surface/acrylic tape joints was obtained. On the other hand, the hydrophilicity of the PDMS surface increased noticeably after the APPJ treatment, but 24 h after treatment almost 80% hydrophobicity was recovered and the adhesive strength was markedly reduced with time after the APPJ treatment. However, the application of an acrylic adhesive layer on the just-APPJ-treated PDMS surface retained the adhesive strength, limiting the extent of hydrophobic recovery.

  14. Influence of receptor lateral mobility on adhesion strengthening between membranes containing LFA-3 and CD2.

    Science.gov (United States)

    Chan, P Y; Lawrence, M B; Dustin, M L; Ferguson, L M; Golan, D E; Springer, T A

    1991-10-01

    We have used an in vitro model system of glass-supported planar membranes to study the effects of lateral mobility of membrane-bound receptors on cell adhesion. Egg phosphatidylcholine (PC) bilayers were reconstituted with two anchorage isoforms of the adhesion molecule lymphocyte function-associated antigen 3 (LFA-3). The diffusion coefficient of glycosyl phosphatidylinositol (GPI)-anchored LFA-3 approached that of phospholipids in the bilayers, whereas the transmembrane (TM)-anchored isoform of LFA-3 was immobile. Both static and laminar flow assays were used to quantify the strength of adherence to the lipid bilayers of the T lymphoma cell line Jurkat that expresses the counter-receptor CD2. Cell adhesion was dependent on LFA-3 density and was more efficient on membranes containing the GPI isoform than the TM isoform. Kinetic measurements demonstrated an influence of contact time on the strength of adhesion to the GPI isoform at lower site densities (25-50 sites/microns2), showing that the mobility of LFA-3 is important in adhesion strengthening. At higher site densities (1,500 sites/microns2) and longer contact times (20 min), Jurkat cell binding to the TM and GPI isoforms of LFA-3 showed equivalent adhesion strengths, although adhesion strength of the GPI isoform developed twofold more rapidly than the TM isoform. Reduction of CD2 mobility on Jurkat cells at 5 degrees C greatly decreased the rate of adhesion strengthening with the TM isoform of LFA-3, resulting in a 30-fold difference between the two LFA-3 isoforms. Our results demonstrate that the ability of a membrane receptor and its membrane-bound counter-receptor to diffuse laterally enhances cell adhesion both by allowing accumulation of ligands in the cell contact area and by increasing the rate of receptor-ligand bond formation. PMID:1717480

  15. Adhesive Characterization and Progressive Damage Analysis of Bonded Composite Joints

    Science.gov (United States)

    Girolamo, Donato; Davila, Carlos G.; Leone, Frank A.; Lin, Shih-Yung

    2014-01-01

    The results of an experimental/numerical campaign aimed to develop progressive damage analysis (PDA) tools for predicting the strength of a composite bonded joint under tensile loads are presented. The PDA is based on continuum damage mechanics (CDM) to account for intralaminar damage, and cohesive laws to account for interlaminar and adhesive damage. The adhesive response is characterized using standard fracture specimens and digital image correlation (DIC). The displacement fields measured by DIC are used to calculate the J-integrals, from which the associated cohesive laws of the structural adhesive can be derived. A finite element model of a sandwich conventional splice joint (CSJ) under tensile loads was developed. The simulations indicate that the model is capable of predicting the interactions of damage modes that lead to the failure of the joint.

  16. Adhesion of DOPA-Functionalized Model Membranes to Hard and Soft Surfaces.

    Science.gov (United States)

    Guvendiren, Murat; Brass, David A; Messersmith, Phillip B; Shull, Kenneth R

    2009-01-01

    The adhesive proteins secreted by marine mussels form a natural glue that cures rapidly to form strong and durable bonds in aqueous environments. These mussel adhesive proteins contain an unusual amino acid, 3,4-dihydroxy-L-phenylalanine (DOPA), which is largely responsible for their cohesive and adhesive strengths. In this study, we incorporated DOPA into diblock and triblock polymers and developed a membrane contact experiment to assess the adhesive interactions of these materials with TiO(2) and tissue surfaces. In a typical experiment a micrometer-thick DOPA-functionalized elastomeric membrane is attached to the end of a cylindrical glass tube. Application of a positive pressure to the tube brings the membrane into contact with the surface of interest. The negative pressure needed to separate the membrane from the substrate is a measure of the strength of the adhesive interaction. The test confirms previous results obtained with TiO(2) substrates. Because the membrane geometry is well suited for rough or chemically heterogeneous surfaces, it is ideal for studies of tissue adhesion. DOPA was found to give strong adhesion to tissue surfaces, with the strongest adhesion obtained when the DOPA groups were oxidized while in contact with the tissue surface. PMID:21461121

  17. Effect of EDTA Conditioning and Carbodiimide Pretreatment on the Bonding Performance of All-in-One Self-Etch Adhesives

    Directory of Open Access Journals (Sweden)

    Shipra Singh

    2015-01-01

    Full Text Available Objective. This study evaluated the effect of ethylenediaminetetraacetic acid (EDTA conditioning and carbodiimide (EDC pretreatment on the shear bond strength of two all-in-one self-etch adhesives to dentin. Methods. Flat coronal dentin surfaces were prepared on one hundred and sixty extracted human molars. Teeth were randomly divided into eight groups according to two different self-etch adhesives used [G-Bond and OptiBond-All-In-One] and four different surface pretreatments: (a adhesive applied following manufacturer’s instructions; (b dentin conditioning with 24% EDTA gel prior to application of adhesive; (c EDC pretreatment followed by application of adhesive; (d application of EDC on EDTA conditioned dentin surface followed by application of adhesive. Composite restorations were placed in all the samples. Ten samples from each group were subjected to immediate and delayed (6-month storage in artificial saliva shear bond strength evaluation. Data collected was subjected to statistical analysis using three-way ANOVA and post hoc Tukey’s test at a significance level of p<0.05.  Results and Conclusion. EDTA preconditioning as well as EDC pretreatment alone had no significant effect on the immediate and delayed bond strengths of either of the adhesives. However, EDC pretreatment on EDTA conditioned dentin surface resulted in preservation of resin-dentin bond strength of both adhesives with no significant fall over six months.

  18. Cleaning properties of dry adhesives

    Institute of Scientific and Technical Information of China (English)

    J.; P.; DíAZ; TéLLEZ; D.; SAMEOTO; C.; MENON

    2010-01-01

    In this paper we present a study into the cleaning properties of synthetic dry adhesives. We have manufactured the adhesive micro-fibres through a low-cost, high yield fabrication method using Sylgard 184 Polydimethylsiloxane (PDMS) as the structural material. We deliberately contaminated the adhesive samples with different sized particles in the micro and macro scales and tested different cleaning methods for their efficacy with respect to each particle size. We investigated different cleaning methods, which included the use of wax moulding, vibration and pressure sensitive adhesives. For adhesion testing we used a custom system with a linear stage and a force sensor indenting a hemispherical probe into the adhesive surface and measuring the pull-off force. To characterize the cleaning efficacy we visually inspected each sample in a microscope and weighed the samples with a microgram-accuracy analytical balance. Results showed that the moulding method induced adhesion recovery in a greater percentage than the other cleaning methods and even helped with the recovery of collapsed posts in some cases. On the other hand pressure sensitive adhesives seem to have the upper hand with regards to certain particle sizes that can potentially pose problems with the moulding method.

  19. Polyurethane structural adhesives applied in automotive composite joints

    Directory of Open Access Journals (Sweden)

    Josue Garcia Quini

    2012-06-01

    Full Text Available In recent years structural adhesives technology has demonstrated great potential for application due to its capacity to transform complex structures into solid unitary and monolithic assemblies using different materials. Thus, seams or joints integrate these structures providing, besides a reduction in weight, a considerable increase in the mechanical resistance and stiffness. The increase in the industrial use of structural adhesives is mainly due to their ability to efficiently bond different materials in an irreversible manner, even replacing systems involving mechanical joints. In the automobile industry structural adhesives have been widely used for the bonding of metal substrates, thermoplastics and composites, frequently employing these in combination, particularly glass fiber and polyester resin composites molded using RTM and SMC processes. However, the use of urethane structural adhesives in applications involving composites and thermoplastics has been the subject of few investigations. In this study the effects of temperature and time on the shear strength of RTM, SMC and ABS joints, applying temperatures of -40, 25, 80, 120 and 177 °C and times of 20 minutes and 500 hours, were determined. The objective was to evaluate the performance under extreme conditions of use in order to assess whether these joints could be used in passenger or off-road vehicles. The results showed that the urethane structural adhesive promoted the efficient bonding of these materials, considering that due to the high adhesive strength the failures occurred in the substrates without adversely affecting the bonded area. For each test condition the joint failure modes were also determined.

  20. [Retention of adhesive bridges].

    Science.gov (United States)

    Raes, F; De Boever, J

    1994-04-01

    Since the development of adhesive bridges in the early seventies, the retention and therefore the durability of these bridges has been tremendously improved. Conditioning of the non-precious metal by silanisation, careful acid etching of the enamel and the use of the appropriate composite resin are of prime importance. Furthermore, the meticulous preparation with enough interproximal embrace, occlusal rests, interocclusal clearance and cingulum stops is equally important. Including more teeth in the design does not necessarily lead to an improved retention. Besides the material and technical aspects, the whole clinical procedure needs much attention. The retention does not depend on one single factor, but on the precision of all the necessary clinical steps and on a well-defined selection of the material. In this way a five-year survival rate of close to 80% can be obtained. PMID:11830965

  1. Hyaluronan-mediated cellular adhesion

    Science.gov (United States)

    Curtis, Jennifer

    2005-03-01

    Many cells surround themselves with a cushioning halo of polysaccharides that is further strengthened and organized by proteins. In fibroblasts and chrondrocytes, the primary component of this pericellular matrix is hyaluronan, a large linear polyanion. Hyaluronan production is linked to a variety of disease, developmental, and physiological processes. Cells manipulate the concentration of hyaluronan and hyaluronan receptors for numerous activities including modulation of cell adhesion, cell motility, and differentiation. Recent investigations by identify hyaluronan's role in mediating early-stage cell adhesion. An open question is how the cell removes the 0.5-10 micron thick pericellular matrix to allow for further mature adhesion events requiring nanometer scale separations. In this investigation, holographic optical tweezers are used to study the adhesion and viscoelastic properties of chondrocytes' pericellular matrix. Ultimately, we aim to shed further light on the spatial and temporal details of the dramatic transition from micron to nanometer gaps between the cell and its adhesive substrate.

  2. Comparing Properties of Adhesive Bonding, Resistance Spot Welding, and Adhesive Weld Bonding of Coated and Uncoated DP 600 Steel%Comparing Properties of Adhesive Bonding, Resistance Spot Welding, and Adhesive Weld Bonding of Coated and Uncoated DP 600 Steel

    Institute of Scientific and Technical Information of China (English)

    Fatih Hayat

    2011-01-01

    Zinc coated dual phase 600 steel (DP 600 grade) was investigated, utilisation of which has gradually increased with each passing day in the automotive industry. The adhesive bonding (AB), resistance spot welding (RSW), and adhesive weld bonding (AWB) ioints of the zinc coated DP 600 steel were investigated. Additionally, the zinc coating was removed using HCL acid in order to investigate the effect of the coating. The microstructure, tensile shear strengths, and fracture properties of adhesive bonding (AB), resistance spot welding (RSW), and adhesive weld bonding (AWB) joints of the coated and uncoated DP 600 steel were compared. In addition, a mechani cal-electrical-thermal coupled model in a finite element analysis environment was utilised. The thermal profile phe nomenon was calculated by simulating this process. The results of the tensile shear test indicated that the tensile load bearing capacity (TLBC) values of the coated specimens among the three welding methods were higher than those of the uncoated specimens. Additionally, the tensile strength of the AWB joints of the coated and uncoated specimens was higher than that of the AB and RSW joints. It was determined that the fracture behaviours and the deformation caused were different for the three welding methods.

  3. Mg Content Dependence of EML-PVD Zn-Mg Coating Adhesion on Steel Strip

    Science.gov (United States)

    Jung, Woo Sung; Lee, Chang Wook; Kim, Tae Yeob; De Cooman, Bruno C.

    2016-09-01

    The effect of coating thickness and Mg concentration on the adhesion strength of electromagnetic levitation physical vapor deposited Zn-Mg alloy coatings on steel strip was investigated. The phase fraction of Zn, Mg2Zn11, and MgZn2 was determined for a coating Mg concentration in the 0 to 15 wt pct range. Coatings with a Mg content less than 5 pct consisted of an Zn and Mg2Zn11 phase mixture. The coatings showed good adhesion strength and ductile fracture behavior. Coatings with a higher Mg concentration, which consisted of a Mg2Zn11 and MgZn2 phase mixture, had a poor adhesion strength and a brittle fracture behavior. The adhesion strength of PVD Zn-Mg alloy coatings was found to be related to the pure Zn phase fraction. The effect of coating thickness on adhesion strength was found to be negligible. The microstructure of the interface between steel and Zn-Mg alloy coatings was investigated in detail by electron microscopy, electron diffraction, and atom probe tomography.

  4. Effect of dispersion method and CNT loading on the quality and performance of nanocomposite soy protein/CNTs adhesive for wood application

    Science.gov (United States)

    Afolabi, Ayo Samuel; Oluwafolakemi Sadare, Olawumi; Olawale Daramola, Michael

    2016-09-01

    In this article the effect of dispersion method and carbon nanotubes (CNTs) loading on the quality and performance of a nanocomposite adhesive is reported. The nanocomposite soy protein isolate adhesive was successfully developed by incorporating CNTs into the soy protein isolate (SPI) for enhanced bond strength and water resistance. Dispersion methods, namely mechanical (shear) mixing and mechanical/sonication were employed to aid good dispersion and interfacial interaction between soy protein matrix and the carbon nanofillers during the preparation of the adhesive. The concentration of the CNT was varied from 0.1–0.7 wt% in the nanocomposite adhesive. The morphology and the surface chemistry of the adhesives were checked with SEM and FTIR, respectively. The shear strength of the developed adhesives was investigated according to European standard (EN-204) for interior wood application on a tensile testing machine. The morphological structure of the nanocomposite adhesive obtained from SEM images showed homogeneous dispersion of CNTs in SPI using the two dispersion methods; shear mixing and sonication/shear mixing. Fourier transform infrared spectra showed chemical functionalities and successful interaction between CNTs and SPI adhesive. Thermogravimetric profile of the adhesive samples showed that the newly developed nanocomposite adhesive was thermally stable at a temperature up to about 600 °C at a higher percentage loading of 0.5 wt% CNTs. The result showed that sonication method of dispersion of CNTs into the SPI adhesive had a higher shear strength compared to the mechanical method of dispersion both at dry and wet state.

  5. Effect of dispersion method and CNT loading on the quality and performance of nanocomposite soy protein/CNTs adhesive for wood application

    Science.gov (United States)

    Afolabi, Ayo Samuel; Oluwafolakemi Sadare, Olawumi; Olawale Daramola, Michael

    2016-09-01

    In this article the effect of dispersion method and carbon nanotubes (CNTs) loading on the quality and performance of a nanocomposite adhesive is reported. The nanocomposite soy protein isolate adhesive was successfully developed by incorporating CNTs into the soy protein isolate (SPI) for enhanced bond strength and water resistance. Dispersion methods, namely mechanical (shear) mixing and mechanical/sonication were employed to aid good dispersion and interfacial interaction between soy protein matrix and the carbon nanofillers during the preparation of the adhesive. The concentration of the CNT was varied from 0.1-0.7 wt% in the nanocomposite adhesive. The morphology and the surface chemistry of the adhesives were checked with SEM and FTIR, respectively. The shear strength of the developed adhesives was investigated according to European standard (EN-204) for interior wood application on a tensile testing machine. The morphological structure of the nanocomposite adhesive obtained from SEM images showed homogeneous dispersion of CNTs in SPI using the two dispersion methods; shear mixing and sonication/shear mixing. Fourier transform infrared spectra showed chemical functionalities and successful interaction between CNTs and SPI adhesive. Thermogravimetric profile of the adhesive samples showed that the newly developed nanocomposite adhesive was thermally stable at a temperature up to about 600 °C at a higher percentage loading of 0.5 wt% CNTs. The result showed that sonication method of dispersion of CNTs into the SPI adhesive had a higher shear strength compared to the mechanical method of dispersion both at dry and wet state.

  6. Neutron imaging inspections of composite honeycomb adhesive bonds

    International Nuclear Information System (INIS)

    Numerous commercial and military aircraft, including the Canadian Forces CF188 Hornet, use composite honeycomb structures in the design of their flight control surfaces (FCS). These structures provide excellent strength to weight ratios, but are often susceptible to degradation from moisture ingress. Once inside the honeycomb structure moisture causes the structural adhesive bonds to weaken, which can lead to complete failure of the FCS in flight. There are two critical structural adhesive bonds: the node bond and the filet bond. The node bond is integral to the honeycomb portion of the composite core and is located between the honeycomb cells. The filet bond is the adhesive bond located between the skin and the core. In order to asses overall structural degradation and develop repair procedures, it is important to determine the degree of degradation in each type of bond. Neutron radiography and tomography of the adhesive bonds was conducted at the Royal Military College (RMC) and FRM-II. Honeycomb samples were manufactured from FCS with in-service water ingress. The radiographs and tomograms provided important information about the degree of degradation in the core as well as about which adhesive bonds are more susceptible. The information obtained from this study will help to develop repair techniques and assess the flight worthiness of FCS.

  7. An upper bound to multiscale roughness-induced adhesion enhancement

    OpenAIRE

    Ciavarella, M.

    2016-01-01

    Recently Guduru and coworkers have demonstrated with neat theory and experiments that both increase of strength and of toughness are possible in the contact of a rigid sphere with concentric single scale of waviness, against a very soft material. The present note tries to answer the question of a multiscale enhancement of adhesion, considering a Weierstrass series to represent the multiscale roughness, and analytical results only are used. It is concluded that the enhancement is bounded for l...

  8. A low-cost, high-yield fabrication method for producing optimized biomimetic dry adhesives

    Science.gov (United States)

    Sameoto, D.; Menon, C.

    2009-11-01

    We present a low-cost, large-scale method of fabricating biomimetic dry adhesives. This process is useful because it uses all photosensitive polymers with minimum fabrication costs or complexity to produce molds for silicone-based dry adhesives. A thick-film lift-off process is used to define molds using AZ 9260 photoresist, with a slow acting, deep UV sensitive material, PMGI, used as both an adhesion promoter for the AZ 9260 photoresist and as an undercutting material to produce mushroom-shaped fibers. The benefits to this process are ease of fabrication, wide range of potential layer thicknesses, no special surface treatment requirements to demold silicone adhesives and easy stripping of the full mold if process failure does occur. Sylgard® 184 silicone is used to cast full sheets of biomimetic dry adhesives off 4" diameter wafers, and different fiber geometries are tested for normal adhesion properties. Additionally, failure modes of the adhesive during fabrication are noted and strategies for avoiding these failures are discussed. We use this fabrication method to produce different fiber geometries with varying cap diameters and test them for normal adhesion strengths. The results indicate that the cap diameters relative to post diameters for mushroom-shaped fibers dominate the adhesion properties.

  9. High orientation Al films growth on LiNbO3 single crystal and its adhesion

    Institute of Scientific and Technical Information of China (English)

    LI Dong-mei; CHEN Jing-jing; PAN Feng

    2004-01-01

    High orientation Al films were deposited on 64°Y-XLiNbO3 substrate by DC magnetron sputtering and the influence of deposition temperature on microstructure and adhesion properties of Al films were investigated. The results show that crystallographic orientation of films varies with substrate temperature and the adhesion strength between LiNbO3 and Al films strongly depends on crystallographic orientation of Al films. The (111) orientated Al films shows stronger adhesion strength to LiNbO3 substrate than (100) orientated films. There is an optimum substrate temperature of 60 ℃ and hardening temperature of 200 ℃ for obtaining high (111) orientated Al films with good surface structure and adhesion property. Using this Al film, we have successfully fabricated the SAW filters with high frequency of about 1.89 GHz.

  10. Adhesion and multi-materials

    International Nuclear Information System (INIS)

    Adhesion is a multidisciplinary science relevant to many practical fields. The main application of adhesion is bonding by adhesives. This technique is widely used in the industrial world and more specifically in the advanced technical domains. Adhesion is also involved in multi-component materials such as coatings, multilayer materials, polymer blends, composite materials... The multidisciplinary aspect of adhesion is well demonstrated by considering the wide variety of concepts, models and theories proposed for its description. An example of the adhesion between a fiber and a matrix in a composite material will lead to a general model relating the molecular properties of the interface to its capacity of stress transfer and hence to the macroscopic mechanical properties of the composite. This relationship is valid whatever the fiber (glass, carbon, polymeric) or the polymer matrix (thermoplastics, thermosetting). Any deviation from this model can be attributed to the existence of an interfacial zone or interphase exhibiting properties, mainly mechanical properties, different from the bulk matrix. Two examples are examined: the first one deals with the creation of a trans crystalline interphase in a semi-crystalline thermoplastic matrix and the second one is concerned with the formation of a pseudo glassy interphase in an elastomer matrix. These examples stress the need for complementary approaches in the understanding of adhesion phenomena at different levels of knowledge, from molecular to macroscopic. They also show how important it is to understand the mechanisms of formation of inter phases in order to be able to master the performance of multicomponent materials. (Author)

  11. Failure in a composite resin-dentin adhesive bond

    International Nuclear Information System (INIS)

    Composites are drawing more and more attention as preferred materials for teeth restoration. The success of teeth restoration has been generally limited by the Composite Resin-Dentin bond strength. A testing device has been developped to allow a satisfactory testing method for evaluating bonding strength in tension and shear, which led to reproducible results. A comparaison between different bond systems has shown no significant difference in the tensile and the shear strength as well as in the fracture behavior. Moreover, results showed difference between tensile and shear strength, when considering one same bond system. Failure mode examination turned out to be, either cohesive (composite rupture), or adhesive (interface rupture) or both (mixed rupture). (orig.)

  12. Focal Adhesion Kinases in Adhesion Structures and Disease

    Directory of Open Access Journals (Sweden)

    Pierre P. Eleniste

    2012-01-01

    Full Text Available Cell adhesion to the extracellular matrix (ECM is essential for cell migration, proliferation, and embryonic development. Cells can contact the ECM through a wide range of matrix contact structures such as focal adhesions, podosomes, and invadopodia. Although they are different in structural design and basic function, they share common remodeling proteins such as integrins, talin, paxillin, and the tyrosine kinases FAK, Pyk2, and Src. In this paper, we compare and contrast the basic organization and role of focal adhesions, podosomes, and invadopodia in different cells. In addition, we discuss the role of the tyrosine kinases, FAK, Pyk2, and Src, which are critical for the function of the different adhesion structures. Finally, we discuss the essential role of these tyrosine kinases from the perspective of human diseases.

  13. Focal adhesion kinases in adhesion structures and disease.

    Science.gov (United States)

    Eleniste, Pierre P; Bruzzaniti, Angela

    2012-01-01

    Cell adhesion to the extracellular matrix (ECM) is essential for cell migration, proliferation, and embryonic development. Cells can contact the ECM through a wide range of matrix contact structures such as focal adhesions, podosomes, and invadopodia. Although they are different in structural design and basic function, they share common remodeling proteins such as integrins, talin, paxillin, and the tyrosine kinases FAK, Pyk2, and Src. In this paper, we compare and contrast the basic organization and role of focal adhesions, podosomes, and invadopodia in different cells. In addition, we discuss the role of the tyrosine kinases, FAK, Pyk2, and Src, which are critical for the function of the different adhesion structures. Finally, we discuss the essential role of these tyrosine kinases from the perspective of human diseases. PMID:22888421

  14. Photovoltaic module with adhesion promoter

    Science.gov (United States)

    Xavier, Grace

    2013-10-08

    Photovoltaic modules with adhesion promoters and methods for fabricating photovoltaic modules with adhesion promoters are described. A photovoltaic module includes a solar cell including a first surface and a second surface, the second surface including a plurality of interspaced back-side contacts. A first glass layer is coupled to the first surface by a first encapsulating layer. A second glass layer is coupled to the second surface by a second encapsulating layer. At least a portion of the second encapsulating layer is bonded directly to the plurality of interspaced back-side contacts by an adhesion promoter.

  15. Adhesives from modified soy protein

    Science.gov (United States)

    Sun, Susan; Wang, Donghai; Zhong, Zhikai; Yang, Guang

    2008-08-26

    The, present invention provides useful adhesive compositions having similar adhesive properties to conventional UF and PPF resins. The compositions generally include a protein portion and modifying ingredient portion selected from the group consisting of carboxyl-containing compounds, aldehyde-containing compounds, epoxy group-containing compounds, and mixtures thereof. The composition is preferably prepared at a pH level at or near the isoelectric point of the protein. In other preferred forms, the adhesive composition includes a protein portion and a carboxyl-containing group portion.

  16. Focal Adhesion Kinases in Adhesion Structures and Disease

    OpenAIRE

    Pierre P. Eleniste; Angela Bruzzaniti

    2012-01-01

    Cell adhesion to the extracellular matrix (ECM) is essential for cell migration, proliferation, and embryonic development. Cells can contact the ECM through a wide range of matrix contact structures such as focal adhesions, podosomes, and invadopodia. Although they are different in structural design and basic function, they share common remodeling proteins such as integrins, talin, paxillin, and the tyrosine kinases FAK, Pyk2, and Src. In this paper, we compare and contrast the basic organiza...

  17. The surface properties of carbon fibers and their adhesion to organic polymers

    Science.gov (United States)

    Bascom, W. D.; Drzal, L. T.

    1987-01-01

    The state of knowledge of the surface properties of carbon fibers is reviewed, with emphasis on fiber/matrix adhesion in carbon fiber reinforced plastics. Subjects treated include carbon fiber structure and chemistry, techniques for the study of the fiber surface, polymer/fiber bond strength and its measurement, variations in polymer properties in the interphase, and the influence of fiber matrix adhesion on composite mechanical properties. Critical issues are summarized and search recommendations are made.

  18. Enhancement of Adhesion between EPDM and Polyester Fabric by Using Natural Rubber Modified by Maleic Anhydride

    OpenAIRE

    A. A. El-Wakil

    2011-01-01

    This study presents a new method for improving adhesion between ethylene propylene diene monomer (EPDM) rubber and polyester fabric. In this work, natural rubber was modified by maleic anhydride in order to improve the adhesion force between ethylene propylene diene monomer rubber and polyester fabric. The effect of thermal aging and ionizing radiation on the stability of the rubber mix as well as on the peel strength of the rubber-coated fabric was investigated. It was observed that the natu...

  19. Effect of tetracycline on the bond performance of etch-and-rinse adhesives to dentin

    OpenAIRE

    Rodrigo Stanislawczuk; Jully Anna da Costa; Luceli Grabicoski Polli; Alessandra Reis; Alessandro Dourado Loguercio

    2011-01-01

    This study evaluated the effect of modified tetracycline on the resin-dentin bond strength (µTBS), silver nitrate uptake (SNU) and solution homogeneity (SH) of two adhesives. Dentin surfaces were treated with phosphoric acid, rinsed off and either rewetted with water (control group - CO), 2% minocycline (MI), 2% doxycyline (DO) or 2% chlorhexidine (CH). Adhesive systems (Adper Single Bond 2 and Prime Bond NT) and composite were applied and light-polymerized. Specimens were sectioned to obtain...

  20. Nano-modified adhesive by graphene: the single lap-loint case

    OpenAIRE

    Almir Silva Neto; Diego Thadeu Lopes da Cruz; Antonio Ferreira Ávila

    2013-01-01

    This paper addresses the performance study on, low viscosity, nano-modified adhesives by graphene. For achieving this goal, single-lap joints following ASTM D 5868-01 were manufactured and tested. X-ray diffraction, scanning electron microscopy and nanoindentation were employed for graphene based nanostructures characterization. The increase on joint strength was around 57% when compared against the control group. Furthermore, all failures for the nano-modified adhesive were cohesive failure ...