Evaluation Of Adhesive Strength Research Articles

Biomimetic synthetic test system based on hydroxyapatite cement for adhesive strength evaluation of experimental mineral-organic bone adhesive materials.

The development of bone adhesive materials is a research field of high relevance for the advancement of clinical procedures. Despite this, there are currently no material candidates meeting the full range of requirements placed on such a material, such as biocompatibility, sufficient mechanical properties and bond strength under biological conditions, practical applicability in a clinical setting, and no adverse effect on the healing process itself. A serious obstacle to the advancement of the field is a lack in standardized methodology leading to comparable results between experiments and different research groups. Natural bone samples are the current gold-standard material used to perform adhesive strength experiments, however they come with a number of drawbacks, including high sample variability due to unavoidable natural causes and the impossibility to reliably recreate test conditions to repeat experiments. This paper introduces a valuable auxiliary test method capable of producing large numbers of synthetic test specimens which are chemically similar to bone and can be produced in different laboratories so to repeat experiments under constant conditions across laboratories. The substrate is based on a hydroxyapatite forming cement with addition of gelatine as organic component. Crosslinking of the organic component is performed to improve mechanical properties. In order to demonstrate the performance of the developed method, various experimental and commercial bone/tissue adhesive materials were tested and compared with results obtained by established methods to highlight the potential of the test system.

Development and Experimental Verification of Inorganic Electromagnetic Pulse Shielding Paint for Building Interiors Using Carbon-Based Materials.

The term electromagnetic pulse (EMP) generally refers to high-power electromagnetic waves and can be classified into EMPs caused by nuclear weapons, non-nuclear EMPs, and EMPs caused by natural phenomena. EMPs can cause catastrophic damage to any electronic device consisting of electromagnetic components, including communications devices and transportation. In this study, the shielding effectiveness of paint was evaluated depending on the type and content of carbon material and binder. To analyze the compatibility and dispersibility improvement of the raw materials used in paint manufacturing, experiments were conducted in two stages, using 27 mixtures. The shielding effectiveness was evaluated for the optimal mixture developed through mixture experiments. The results of this study confirmed that the developed EMP shielding paint can improve the shielding effectiveness of concrete by 25-40 dB. Additionally, the adhesion strength and moisture resistance evaluation of the EMP shielding paint were evaluated. The average adhesive strength of the EMP shielding paint was 1.26 MPa. In moisture-resistance testing at a temperature of 50 ± 3 °C and a relative humidity of 95% or higher for more than 120 h, no cracks or peeling were observed on the painted surface.

Evaluation of adhesive bond strength of restorative materials to hard tissues of deciduous teeth based on adhesion technique

Relevance. Treating caries in deciduous teeth remains one of the most complex challenges in pediatric dentistry. The bond strength between the enamel and dentin of deciduous teeth and restorative materials is crucial for the durability of hard tissue restorations in these teeth. This article evaluates the adhesive strength of restorative materials to the enamel and dentin of deciduous teeth using a universal adhesive system, both with and without prior etching with orthophosphoric acid.Purpose. To assess the adhesive bond strength of dental filling materials to the hard tissues of deciduous teeth, contingent upon the enamel and dentin etching techniques used with a universal adhesive system.Materials and methods. This study measured the adhesive strength of a composite filling material to the enamel and dentin of deciduous teeth using a universal adhesive system. The methods included both the absence of preliminary etching with 37% orthophosphoric acid (self-etch technique) and the application of preliminary etching of enamel and dentin with 37% orthophosphoric acid (total-etch technique). Sixty extracted deciduous teeth from children aged 6-8 years were used. Adhesive strength was assessed using the shear test of the filling material in cylinder form against the substrate surface.Results. Significant differences were observed in the adhesive bond strength of the composite material to the hard tissues of deciduous teeth when using 37% orthophosphoric acid before applying the adhesive system (total-etch technique) compared to no preliminary etching (self-etch technique). When filling carious lesions in deciduous teeth, if the defect is within the enamel, etching the surface with 37% orthophosphoric acid significantly (by two-fold) enhances the adhesive strength of the bond with the composite material using a universal adhesive. However, when repairing defects located deeper than the enamel layer in deciduous teeth, no statistically significant differences were observed in the adhesive strength with or without dentin etching. The optimal adhesive bond strength of composite materials to the hard tissues of deciduous teeth under laboratory conditions was attained by selectively etching the enamel with 37% orthophosphoric acid, followed by the application of a universal adhesive system to both the enamel and dentin.

Evaluation of Adhesion Strength of Coils of a High-Speed Motor Applying Welding-Less Coils

Evaluation of Adhesion Strength of Coils of a High-Speed Motor Applying Welding-Less Coils

Enhancement of adhesion strength and in-vivo evaluation of electrodeposited calcium phosphate/chitosan biocoatings on titanium substrate

Chitosan/calcium phosphate nanocomposites are widely used as a biocompatible coatings for titanium bioimplants in the fields of dentistry and orthopedics to enhance the integration between the implants and the hard bone. However, the poor adhesion strength between the coating and the metal substrate was found to be one of the major problems in the clinical application of these implants. In the current study, we reported the formation of Ca/P coating on titanium (Ti) substrate using electrodeposition. The key factor of the bath ingredients is the change of chitosan's solvent from a commonly used acetic acid to acrylic acid in the electrolyte. The structural analysis including X-ray diffraction (XRD), Raman spectroscopy, and attenuated total reflectance (ATR) confirmed the formation of three phases of Ca/P octacalcium phosphate (OCP), dicalcium phosphate dihydrate (DCPD) brushite, and hydroxyapatite (HA). The bond strength was performed by the tape test (ASTM D3359-09) which showed that nearly 65% of the coatings were removed in the case of using 2, 4, and 6% (v/v) acetic acid as chitosan solvent, while only 5% of the coatings were removed when high concentrations (4 and 6%) of acrylic acid is used in addition to increasing of the surface wettability. Furthermore, the morphology and thickness of the calcium phosphate layer coated on the surface of Ti metal were inspected by scanning electron microscopy (SEM). Finally, an in vivo application was conducted on the optimized coating by surgically placing the coated and control discs into rats’ clavicular bones for 2-weeks healing period. Then biomechanical evaluation was performed to verify the effect of treatment on the interface resistance to shear force, and histological analysis was performed to evaluate the bone tissue reactions to coated discs. The results showed that using acrylic acid instead of acetic acid to dissolve chitosan before in-situ electrodeposition might be an innovative approach to enhance the adhesion strength between chitosan/calcium phosphate-based coatings and titanium metal to be used in orthopedic and dental implant technology.

A Study on Evaluation Methods of Conserving Painted Sculpture

A lot of individual research on materials and methods suitable for the color of the paint layer has been conducted in the conservation of existing painted sculptures. However, there was no guidance standard for conservation treatment and repainting of painted sculptures, and an evaluation method for objective conservation management was required as deterioration continued in the outdoors. Therefore, in this study, the conservation treatment effect was confirmed by comparing and evaluating the physical properties of the original paint and the replacement paint by citing two cases. Based on the survey items : SEM observation (a cross-section and surface defect) and local EDS analysis, comparison of chromaticity and color difference, evaluation of adhesion and adhesive bond strength, and a salt spray test, a condition status table was prepared and applied to the specimen. Based on the results of applying the completed condition status table in the future, it is judged that it can be an objective data onto conservation treatment of outdoor painted sculptures and public artworks.

接着接合を併用した一面せん断高力ボルト接合部の耐力評価

Adhesive bonding has been increasingly used for seismic retrofit and repair recently. However, the interaction between bolt and bonding joints is not clear in detail. This study focuses on the hybrid joint method using adhesive bonding and high-strength bolts for the single-shear lapped joint to improve joint strength. Three experimental parameters, with or without adhesive, bonding area, and bolt tension, were adopted. The results show that the connection strength can be effectively increased by adhesive. Moreover, the effective adhesive area and strength evaluation formulas are proposed through the cohesion failure behavior.

Ex vivo evaluation of adhesive strength and barrier effect of a novel treatment for esophagitis

To investigate the mucoadhesive strength and barrier effect of Esophacare® (Atika Pharma SL, Las Palmas de Gran Canaria) in an ex vivo model of gastro-oesophageal reflux. An ex vivo evaluation through the Falling Liquide Film Technique with porcine esophagi was performed, compared to a positive control (Ziverel®; Norgine, Amsterdam), after different washing periods with saline, acidified saline (pH 1.2) and acidified saline with pepsin (2000 U/mL). The adhesive mean strength on the oesophageal mucosa of Esophacare was 94.7 (6.0)%, compared to 27.6 (19.1)% of the positive control (p < 0.05). These results were homogeneous across the different washes and throughout the tissue. The area covered by 1 mL of Esophacare, and its respective persistence after washing was also assessed, yielding a mean global persistence of 74.29 (19.7)% vs. 18.9 (12.3)% for the control (p < 0.05). In addition, after 30 min exposure to acidified saline with pepsin, Esophacare shows a protective effect on the oesophageal mucosa, detectable histologically: preserved integrity and structure of the apical layers was observed, as well as reduced permeability to the washing solution. Esophacare shows an adhesive strength close to 100%, irrespective of the washing solution applied or the oesophageal region studied. Histologically, it reduces the abrasive effects of the acidic solution on the oesophageal epithelium, reducing permeability to the washing solution. The results in this ex vivo model of gastro-oesophageal reflux disease (GERD) support its therapeutic potential. Investigar la fuerza mucoadhesiva y el efecto barrera de Esophacare® (Atika Pharma SL, Las Palmas de Gran Canaria) en un modelo ex vivo con reflujo gastroesofágico. Se realizó una evaluación ex vivo mediante la técnica falling liquide film con esófagos porcinos, en comparación con un control positivo (Ziverel®, Norgine, Ámsterdam, Países Bajos), después de diferentes periodos de lavado con solución salina, solución salina acidificada (pH 1,2) y solución salina acidificada con pepsina (2.000 U/mL). La fuerza media de adhesión en la mucosa esofágica de Esophacare fue del 94,7% (6,0%), en comparación con el 27,6% (19,1%) del control positivo (p < 0,05). Estos resultados fueron homogéneos en los diferentes lavados y en todo el tejido. También se evaluó el área cubierta por 1 mL de Esophacare y su respectiva persistencia tras el lavado: se obtuvo una persistencia global media del 74,29% (19,7%) frente al 18,9% (12,3)% del control (p < 0,05). Además, tras 30 minutos de exposición a una solución salina acidificada con pepsina, Esophacare muestra un efecto protector sobre la mucosa esofágica, detectable histológicamente, con la conservación de la integridad y la estructura de las capas apicales, así como con reducción de la permeabilidad a la solución de lavado. Esophacare muestra una fuerza adhesiva cercana al 100%, independientemente de la solución de lavado aplicada o de la región esofágica estudiada. Histológicamente, reduce los efectos abrasivos de la solución ácida sobre el epitelio esofágico y reduce la permeabilidad a la solución de lavado. Los resultados en este modelo ex vivo de enfermedad de reflujo gastroesofágico apoyan su potencial terapéutico.

Evaluation of adhesion strength, corrosion, and biological properties of the MWCNT/TiO2 coating intended for medical applications.

Multi-wall carbon nanotube (MWCNT) coatings are gaining increasing interest because of their special properties used in many science fields. The titania coatings are known for their improvement of osteoblast adhesion, thus changing the surface architecture. Bi-layer coatings comprising 0.25 wt% of the MWCNTs and 0.30 wt% of titania (anatase structure) were synthesized in a two-stage procedure using the electrophoretic deposition method (EPD). The MWCNT and TiO2 coatings were deposited with voltage and time parameters, respectively, of 20 V and 0.5 min, and 50 V and 4 min. EDS, AFM, SEM, Raman spectroscopy, nano-scratch test, potentiodynamic corrosion tests, wettability studies, and cytotoxicity determined with MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) test on human dermal fibroblasts (HDF) and mouse osteoblast precursors (MC3T3), and lactate dehydrogenase (LDH) activity test were carried out on examined surfaces. The prepared MWCNT/TiO2 coating is uniformly distributed by MWCNTs and agglomerated by TiO2 particles of size ranging from 0.1 to 3 μm. Raman spectroscopy confirmed the anatase structure of the TiO2 addition and showed typical peaks of the MWCNTs. The MWCNT/TiO2 coating had higher roughness, higher adhesion strength, and improved corrosion resistance compared to the MWCNT basic coating. The results of biological tests proved that physicochemical properties of the surface, such as high porosity and wettability of MWCNT/TiO2-coated material, would support cell adhesion, but toxic species could be released to the culture medium, thus resulting in a decrease in proliferation.

Evaluation of interlaminar adhesion strength of carbon fiber reinforced plastics with different molding pressure and fiber volume fraction by a laser spallation technique

Evaluation of interlaminar adhesion strength of carbon fiber reinforced plastics with different molding pressure and fiber volume fraction by a laser spallation technique

Photostabilization, Adhesion Strength and Solubility Evaluation of Novel Acrylic Acid Based Copolymers

Photostabilization, Adhesion Strength and Solubility Evaluation of Novel Acrylic Acid Based Copolymers

AN INDENTATION METHOD FOR ADHESIVE STRENGTH EVALUATION OF POLYMER COATINGS

An indentation method was developed for adhesive strength evaluation of a polymer coating using the example of an epoxy composition with titanium alkoxide deposited on the surface of low-carbon steel. The method is based on the numerical implementation of the fracture mechanics approach in experimental data processing. It was found that the penetration of a Rockwell indenter perpendicular to the coating surface causes annular delamination buckling of the coating around the indentation, which is due to adhesive bond breaking as a result of radial shear when the coating material is forced out from under the indenter. A controlled parameter in finite element modeling was the experimentally determined width of the coating delamination zone at a fixed indentation depth at which delamination occurred. The adhesive contact conditions were set using the bilinear law of the cohesive zone model, which describes the relationship between the adhesive shear stress and adhesive bond stretching during shear of interacting surfaces in the contact plane. The limiting specific surface energy of adhesive failure was used as a quantitative evaluation criterion for adhesive strength. The optimal value of the limiting specific surface energy of adhesive coating failure was determined for the cohesive zone model parameters that provide the best convergence of the numerical and experimental data.

Evaluation of tensile adhesion strength in mortar for coating with incorporation of crushing sand

The use of crushed sand, a by-product generated in quarries during the process of manufacturing crushed stone used in civil construction, can reduce the consumption of natural sand, reducing the environmental impact of the extraction of this material. In this sense, this research aims to evaluate the influence of replacing natural sand with crushed sand on the tensile bond strength of mortars. Mortars were made with crushed sand from quarries in the region of Bauru/SP, performing 3 percentages of substitution, in mass, of natural sand by crushed sand: 10%, 20% and 30%, plus a reference with 100% sand natural, totaling 4 strokes. All mortars were made in accordance with ABNT NBR 13276/2005. The performance of the mortars was evaluated through the tensile bond strength test, as recommended by the ABNT NBR 13528/2019 standard. In the end, it can be said that it is feasible to use crushed sand to replace natural sand in the percentage of up to 20% for making mortars for coating external walls, which showed the best adhesion results. It was also found that, for internal coating, it is possible to use up to 30% of crushed sand, without compromising the performance of the mortar.

Comparative Evaluation of Adhesive Bond Strength of Conventional GIC and Cention N to Enamel and Dentin of Primary Teeth: An In Vitro Study.

The aim of this in vitro study was to evaluate and compare the adhesive bond strength of conventional glass ionomer cement (GIC) and Cention N to the primary enamel and dentin using an accelerated fatigue test. A total of 30 sound human primary molars were collected and were mounted on a metal cylindrical block using acrylic resin, embedding the root up to cemento-enamel junction (CEJ). Proximal box was prepared on both mesial and distal surfaces, one of the cavity was restored with GIC (Type 9) and the other proximal cavity with Cention N. A nonretentive cavity design was followed for both the materials so as to maintain the uniformity between the two specimens were then placed under a universal testing machine (Instron) and subjected to accelerated cyclic loads till a separation fracture occurs at the tooth-restoration interface. The number of endured cycles a particular restoration could withstand before getting fractured was registered. Cention N resisted significantly more number of endured cycles before separation from the cavity as compared to GIC (p < 0.001). Within the limitations of the study, it can be concluded that newly developed material Cention N is preferred alternative over conventional GIC for the restoration of proximal cavities in primary molars. Dhull KS, Dutta B, Pattnaik S, et al. Comparative Evaluation of Adhesive Bond Strength of Conventional GIC and Cention N to Enamel and Dentin of Primary Teeth: An In Vitro Study. Int J Clin Pediatr Dent 2022;15(4):412-416.

Ex vivo evaluation of adhesive strength and barrier effect of a novel treatment for esophagitis

AimTo investigate the mucoadhesive strength and barrier effect of Esophacare® (Atika Pharma SL, Las Palmas de Gran Canaria) in an ex vivo model of gastro-oesophageal reflux. MethodsAn ex vivo evaluation through the Falling Liquide Film Technique with porcine esophagi was performed, compared to a positive control (Ziverel®; Norgine, Amsterdam), after different washing periods with saline, acidified saline (pH 1.2) and acidified saline with pepsin (2000U/mL). ResultsThe adhesive mean strength on the oesophageal mucosa of Esophacare was 94.7 (6.0)%, compared to 27.6 (19.1)% of the positive control (p<0.05). These results were homogeneous across the different washes and throughout the tissue. The area covered by 1mL of Esophacare, and its respective persistence after washing was also assessed, yielding a mean global persistence of 74.29 (19.7)% vs. 18.9 (12.3)% for the control (p<0.05). In addition, after 30min exposure to acidified saline with pepsin, Esophacare shows a protective effect on the oesophageal mucosa, detectable histologically: preserved integrity and structure of the apical layers was observed, as well as reduced permeability to the washing solution. ConclusionsEsophacare shows an adhesive strength close to 100%, irrespective of the washing solution applied or the oesophageal region studied. Histologically, it reduces the abrasive effects of the acidic solution on the oesophageal epithelium, reducing permeability to the washing solution. The results in this ex vivo model of gastro-oesophageal reflux disease (GERD) support its therapeutic potential.

Evaluation of Viscoelastic Adhesion Strength and Stability of Composite Waterproofing Sheet Using Non-Hardening Viscoelastic Synthetic Polymer-Based Rubber Gel

Recently, a non-hardening type synthetic polymerized rubber gel (hereinafter referred to as NHV-SPRG) composite waterproofing sheet has been used on construction site as a new waterproofing technology. In this study, a test method is proposed in which a composite waterproof sheet is attached to an area of 150 mm in length and 100 mm in width on the mortar-based substrate specimen, and subsequently peeled off at 180 ° vertically to measure the “peel load (N)” at 10 points of 10 mm intervals (P1~P10, from 30 mm point to 120 mm point). Value obtained by dividing the average value of the measured peeling load by a width of 100 mm was defined as “viscoelastic adhesion strength (N/mm)”. The viscoelastic adhesive strength evaluated for the NHV-SPRG composite waterproof sheet of 4 types (VG-1, VG-2, VG-3, VG-4) was an average of 1.99 N/mm. To examine the effectiveness of the viscoelastic adhesive strength, the adhesion stability was evaluated based on the peel load’s coefficient of variation, grade of the linear regression line of the peel load, and peel load percent relative range in peel load for each section of the composite waterproofing layer. As a result, the VG-2 type was measured to have the highest viscoelastic adhesive strength, but the VG-1 type was confirmed to have the highest adhesive stability. Considering these results, it is judged that even a product with high adhesion can have varying stability in terms of performance that can affect construction precision. The test method and performance standard value for the viscoelastic adhesion strength proposed as an evaluation index through this study are expected to be used as a quality control standard to secure the on-site adhesion stability of the NHV-SPRG composite waterproof sheet.

Adhesive Joints of Additively Manufactured Adherends: Ultrasonic Evaluation of Adhesion Strength.

Adhesive joints are widely used in the construction of machines and motor vehicles. Manufacturers replace them with the welding and spot-welding methods due to the lack of damage to the material structure in the joint area. Moreover, it is aimed at reducing the weight of vehicles and producing elements with complex shapes. Therefore, additive manufacturing technology has been increasingly used in the production stage. This fact has not only changed the view on the possibilities of further development of the production technology itself, but it has also caused an intense interest among a greater number of companies in the advantages of structural optimization. There is a natural relationship between these two areas in the design and production, allowing for almost unlimited possibilities of designing new products. The main goal of the research described in this article was to determine the correlation between the strength of the adhesive joint of elements produced using additive technology and the parameters of the ultrasonic wave propagating in the area of the adhesive bond. The tests were carried out on samples made of AlSiMg0.6 material and a structural adhesive. Strength tests were performed to determine the shear force which damaged the joint. Furthermore, an ultrasonic echo technique enabling the determination of a nondestructive measure of the quality and strength of the joint was developed. The samples of the adhesive joints had a strength of about 18.75–28.95 MPa, which corresponded to an ultrasonic measure range of 4.6–7.8 dB. The determined regression relationship had a coefficient of determination at the level of 0.94. Additional ultrasonic tests of materials made with the additive technology confirmed its different acoustic properties in relation to aluminum produced with the standard casting or extrusion process. Designated dependence combining the mechanical strength and the decibel difference between the first and second impulses from the bottom of the joint may constitute the basis for the development of a nondestructive technique for testing the strength of adhesive joints.

Evaluation of adhesion strength for oxide scale grown on low carbon steel

Adhesion strength between a substrate and its oxide scale grown on hot-rolled low carbon steel was evaluated by a hybrid numerical-experimental analysis of artificial spallation results. Interfacial fracture of the scale was reproduced by a scratch tester, in which the onset of interfacial fracture was identified by examining the mechanical responses along with microscopic observation. Critical traction at interface was solved quantitatively by numerical inverse analysis with finite element method. Influence of residual stress on adhesion strength was also investigated. Finally, validity of the identified adhesion strength was confirmed by analytical comparison with energy release rate reported in previous research.

Bacterial identification and adhesive strength evaluation based on a mannose biosensor with dual-mode detection

A biosensor integrated with mannose nano-surface was developed for the identification and adhesive strength evaluation of bacteria. Different bacteria were studied on the designed surface by both electrochemical impedance spectroscopy (EIS) and surface enhanced Raman spectroscopy (SERS). S. typhimurium and E. coli JM109 (type 1 pili) were found to be captured by the mannose nano-surface. SERS spectra were used to identify the species of captured bacteria by combing with partial least squares discriminant analysis (PLS-DA). Meanwhile, binding affinities of the two captured bacteria to mannose nano-surface were obtained by EIS measurements and Frumkin isotherm model analysis, which were 6.859 × 1023 M-1 and 2.054 × 1017 M-1 respectively. A higher binding affinity indicates a stronger adhesive strength. Hence the results show the S. typhimurium has a stronger adhesive strength to mannose. Normalized impedance change (NIC) was proved to have a positive relevant relationship with binding affinities, which could be used as an indicator for the adhesive strength of bacteria. It was demonstrated that 100% accuracy of bacteria species discrimination and good consistency of NIC and adhesive strength for blind samples. The developed biosensor can provide both qualitative and quantitative information of selective recognition between bacteria and mannose.

Evaluation of Interface Adhesion Strength of Unidirectional CFRP Using Numerical Material Test and Neural Network

Evaluation of Interface Adhesion Strength of Unidirectional CFRP Using Numerical Material Test and Neural Network