Type Of Surface Treatment Research Articles

Effect of Luting Agent and Surface Treatment Type on Bond Strength to a Zirconia-Based Ceramic

Effect of Luting Agent and Surface Treatment Type on Bond Strength to a Zirconia-Based Ceramic

EFFECT OF TWO DIFFERENT SURFACE TREATMENTS ON MICRO-SHEAR BOND STRENGTH OF CAD/CAM AND HEAT PRESSED GLASS CERAMICS

Objective: The aim of this study was to evaluate the micro-shear bond strength between a dual cured resin cement and five different types of ceramics in composition and techniques of construction, using two different surface treatments.Materials & methods: A total of 50 ceramic disks were made and divided into 5 equal groups according to material type IPS Empress CAD, IPS e.max Press, IPS e.max CAD, Vita Suprinity and PM9 (n = 10). Each group was subdivided into 2 subgroups according to surface treatment they will be subjected to (n=5). Subgroup I: Bonding surfaces were etched with 5% HF acid, then coated with Monobond S. Subgroup II: Monobond Etch & Prime was applied on the bonding surfaces. For standardization of bonding surface area, 5 plastic tubings distributed on the bonding surface of each disk were used to place the dual resin cement. The samples were then subjected to micro-shear bond strength.Results: Results showed insignificant difference in micro-shear mean values between the IPS Empress CAD subgroups while significant differences were found between the other subgroups within the same group. Monobond Etch & Prime surface treatment resulted in higher micro-shear bond strength compared with HF surface treated subgroups for all the tested materials except for the PM9 and IPS e.max CAD. Conclusions: It was found that ceramic microstructure as well as the fabrication technique affects the selection surface treatment type. Also, Monobod Etch and Prime as a single step surface treatment produced clinically accepted and comparable results to that of HF treatment.

Anti-bacterial and anti-mold efficiency of silver nanoparticles present in melamine-laminated particleboard surfaces

Laminated surfaces of wooden composites are created from decorative papers and impregnation thermosetting resins, mainly melamine-formaldehyde (MF). This type of surface treatment is not always resistant to microorganisms, especially when polluted with organic substances. Bioactive additives are often needed to improve the microbial resistance. In this study, silver nanoparticles (Ag-NPs), in amounts of 0.15  10-3 wt.%, 0.5  10-3 wt.%, 1.5  10-3 wt.%, 5  10-3 wt.%, 15  10-3 wt.%, and 50  10-3 wt.% were added to MF resin. The presence of Ag-NPs in the laminated surfaces of the particleboards improved their anti-bacterial and anti-mold resistances. Growth of gram-positive bacterium Staphylococcus aureus on the sterilized surfaces decreased by approximately 53.7% at most, while the growth of gram-negative bacterium Escherichia coli decreased by up to 100%. The anti-mold resistance of the polluted laminated surfaces containing Ag-NPs increased against Penicillium brevicompactum by up to 62.5%, but there was almost no improvement against Aspergillus niger. The Ag-NPs did not affect the resistance of the laminated surfaces towards aggressive chemicals and only minimally towards dry heat at 180 °C. This inorganic biocide decreased the abrasion resistance of the laminated surfaces by up to 12.6%.

Surface activation of High Impact Polystyrene substrate using dynamic atmospheric pressure plasma

Over the last decade, the number of researches has increased in the field of bonding technologies. Researchers attempt to improve surface adhesion properties by surface treatments. Adhesive bonding is one of these bonding techniques, where it is important to see what surfaces will be bonded. One such surface property is wetting, which can be improved by several types of surface treatment. In recent years, atmospheric pressure plasmas have appeared, with which research is ongoing on surface treatments. In our research, we will deal with the effects of plasma surface treatment at atmospheric pressure and its measurement. In addition, we summarize the theoretical background of adhesion, surface tension and surface treatment with atmospheric pressure plasma. Our goal is to improve adhesion properties and thus the adhesion quality.

Comparison of Adhesive Properties of Polyurethane Adhesive System and Wood-plastic Composites with Different Polymers after Mechanical, Chemical and Physical Surface Treatment.

The cost of most primary materials is increasing, therefore, finding innovative solutions for the re-use of residual waste has become a topic discussed more intensely in recent years. WPCs certainly meet some of these demands. The presented study is focused on an experimental analysis of the effect of surface treatment on the adhesive properties of selected WPCs. Bonding of polymer-based materials is a rather complicated phenomenon and modification of the bonded area in order to improve the adhesive properties is required. Two traditional types of surface treatments and one entirely new approach have been used: mechanical with sandpaper, chemical with 10 wt % NaOH solution and physical modification of the surface by means of a MHSDBD plasma source. For comparison purposes, two high-density polyethylene based products and one polyvinyl-chloride based product with different component ratios were tested. A bonded joint was made using a moisture-curing permanently elastic one-component polyurethane pre-polymer adhesive. Standardized tensile and shear test methods were performed after surface treatment. All tested surface treatments resulted in an improvement of adhesive properties and an increase in bond strength, however, the MHSDBD plasma treatment was proven to be a more suitable surface modification for all selected WPCs.

Studies on the influence of surface treatment type, in the effectiveness of structural adhesive bonding, for carbon fiber reinforced composites

Primary intent of the present paper is to correlate the effectiveness of surface preparation type (pre-bonding), such as solvent cleaning, sanding (mechanical abrade), chemical etching (alkaline and acid), and peeling of sacrificial surface layer (peel ply) of carbon fiber reinforced composite (CFRC) test specimens, with the corresponding effect to the final strength of adhesive bonding. The analysis was performed by means of several spectroscopic and microscopic techniques, such as XPS, SEM, AFM, and a contact angle measurement technique which provides a direct, fast and easy measurement of the surface energy of the fiber composites. The adhesively bonded carbon fiber composites based on the different surface treatments were mechanically tested by employing the ASTM D 5528-0 (reapproved 2007) standard. The double cantilever beam (DCB) specimen geometry was used to evaluate the value known as opening Mode I inter-laminar fracture toughness (GIC) in adhesive bonds of carbon fiber composite materials. The results were varying between 1 and 1.8 kJ/m2 for GIC analysis and around 50 mm for delamination lengths. The mechanics of the linear elastic fracture is considered a tool for the failure of the laminate in composite materials with cracks or cuts in the plane, due to the presence of damaged zones in the tip of the crack; which is therefore applied to the study of delamination or fracture toughness.

Effect of Surface Treatment with CO2 Laser on Bond Strength in Composite Resin Restorations.

Objective: Evaluate the bond strength of repairs made on composite resin following the treatment of the surface of the flaw with different bonding agents and/or CO2 laser. Background: The influence of CO2 laser and its interaction with other bonding agents on the surface of the flaw is not yet known. In this study, CO2 laser was chosen to treat the surface of the flaw due to its capacity to promote irregularities on the surface that enhance mechanical micro-retention. Methods: A block was created with Vitra APS nanohybrid composite resin (color: A3; FGM, Joinville, Brazil) measuring 5 mm in width, length, and depth (volume: 125 mm3). The surface of the flaw was treated before the repair with an adhesive, silane bonding agent, and/or CO2 laser. Six specimens were created in composite resin for each group (total: n = 36): G1: resin+resin; G2: adhesive+resin; G3: laser+adhesive; G4: laser+silane+adhesive; G5: silane+adhesive; G6: laser+silane. After the repair, the surfaces of the fracture of all specimens, which were submitted to the microtraction test, were analyzed under an optical microscope. Bond strength values obtained according to the type of surface treatment were tabulated and submitted to the Kruskal-Wallis test. Dunn's test was used to compare means. Results: G3 and G4 had significantly higher bond strength values compared to all other groups tested. Adhesive fractures predominated in all groups. However, G3 and G4 had a higher percentage of cohesive fractures compared to the other groups. Conclusions: The application of CO2 laser as a surface treatment led to greater bond strength of composite resin repairs in comparison with the groups that only received treatment with a burr and silanization. The groups submitted to CO2 laser also had a significantly lower number of adhesive failures when submitted to the microtraction test.

Effect of surface treatments on the localized corrosion resistance of the AA2198‐T8 aluminum lithium alloy welded by FSW process

In this work, the effect of eight types of surface treatments on the corrosion resistance of friction stir welded samples of an AA2198‐T8 Al‐Cu‐Li alloy were tested and compared in an attempt to find suitable alternatives to toxic and carcinogenic hexavalent chromium treatments. All the samples were anodized and subjected to different post‐anodizing treatments. The post‐anodizing treatments were (1) hydrothermal treatment in Ce (NO3)3 6H2O solution; (2) hydrothermal treatment in Ce (NO3)3 6H2O solution with H2O2; (3) hydrothermal treatment in boiling water; (4) hexavalent chromium conversion coating; and (5) immersion in BTSE (bis‐1,2‐(triethoxysilyl) ethane. The corrosion resistance of the treated samples was evaluated by immersion tests in sodium chloride solution (0.1 mol L−1 NaCl) and electrochemical impedance spectroscopy (EIS) of the friction stir weldment. The results showed that among the alternative treatments, the Ce‐containing solutions presented the best corrosion resistance, especially when used without peroxide.

Influence of Surface Treatment Method and Type of Bonding System on the Adhesion of Polyetherketoneketone

Influence of Surface Treatment Method and Type of Bonding System on the Adhesion of Polyetherketoneketone

EFFECT OF AGING ON THE SHEAR BOND STRENGTH OF ZIRCONIA CERAMIC WITH DIFFERENT SURFACE TREATMENTS

Statement of the problem: Zirconia is an acid etching resistant ceramic and may cause difficulty in obtaining a safe bond with it. The aim of this study is to evaluate the effect of aging on the shear bond strength of zirconia ceramic after being subjected to different surface treatments. Materials & Methods: Forty zirconia samples were constructed in the form of discs by copy milling. All the samples were 5mm in diameter and 1mm in thickness. The samples were divided into four groups according to the type of surface treatment they were subjected to, group1: control, group 2: subjected to etching using hydrofluoric acid 9% , group 3: sandblasting using 50µm Al2O3 particles and group 4 : silica coating using 50µm Al2O3 and 50 µm SiO2 particles. The samples were cemented on the occlusal surface of molar teeth using Rely XTM U200. Each group was further subdivided into two subgroups according to the type of test: shear bond strength before aging, shear bond strength after aging. The samples of the second subgroups were thermocycled (5– 55 °C/5,000 cycles) as aging procedure. Shear bond strength was measured. Data were tabulated and statistically analyzed using one-way analysis of variance (ANOVA).Result: Results showed that the highest shear bond strength before aging was recorded by the silica coated samples while the lowest shear bond strength was recorded with the hydrofluoric acid etched samples. There was no statistical significant difference between all the tested different surface treated samples regarding shear bond strength before aging except the silica coated samples. After aging, the most affected samples with decrease in the shear bond strength were the control samples while there was no significant difference for the tested surface treatments.Conclusion: Silica coating recorded the highest shear bond strength. Hydrofluoric acid etching and sandblasting are not reliable methods of surface treatment for production of safe and strong bond with zirconia. Aging has a significant effect on the control zirconia samples which showed decrease in the shear bond strength.

Change of Surface Texture Parameters of Ground Surfaces after Application of Hard and Abrasion Resistant Layers

The paper deals with the change of selected 3D parameters of the surface texture of ground steels after application of diffusion technologies. The steel CSN 41 2050 and 34CrNiMo6 after nitriding and ferritic nitrocarburizing in gas and plasma were evaluated. Selected 3D surface texture parameters were measured by the coherence correlation interferometer Talysurf CCI Lite. The change in surface texture parameters is influenced by the preparation of the substrate, i.e. the grinding parameters and the used diffusion technology, as well as the chemical composition of the used steels (2), (3). The steels were ground with SiC abrasive papers with grain sizes of 120, 220, 600 and 1000 according to FEPA. Steel CSN 41 2050 showed the reduction of the observed surface texture parameters almost all types of surface treatments - roughness decreased. Only in the case of ferritic nitrocarburizing in gas occurred to the deterioration of surface roughness. Similar results were achieved at 34CrNiMo6 steel - ferritic nitrocarburizing in gas led to an increase of surface roughness. For other surface treatments the roughness decreased. Applied diffusion technologies increase the hardness of functional surfaces, corrosion resistance, fatigue strength, wear resistance and reduce coefficient of friction (4). The above-mentioned advantages of applied diffusion layers along with the reduction in surface roughness can contribute to wider use of these technologies in technical practice.

The effect of cataphoretic and powder coatings on the strength and failure modes of EN AW-5754 aluminium alloy adhesive joints

The aim of this study is to determine the effect of cataphoretic and powder coatings and also the method of application the primer on the adherends surface on the strength and failure modes of EN AW-5754 aluminium alloy adhesive joints. The study is performed on lap joints made of EN AW-5754 aluminium alloy, subjected to three different types of surface treatment; namely a) polyurethane cataphoretic coating, b) powder coating based on black mat RAL 9005 UL polyester resin and c) no coating. The tested adhesive joints were made using a one-component polyurethane adhesive Terostat 8596, which was dedicated for automotive and cured under a constant load of 0.018 MPa at 20 ± 2 °C. In addition, this study investigates the effect of the application of Terostat 8519P adhesion promoter which is a liquid polyurethane-based primer containing solvents and which is corresponding to Terostat 8596 polyurethane adhesive. Terostat 8519P adhesion promoter was applied in two different ways: a) to one substrate and b) to both substrates. The produced adhesive joints were subjected to strength tests using the Zwick/Roell Z150 testing machine. The examination of fracture in the tested adhesive joints was performed in accordance with the EN ISO 10365 standard. The shear strength results have demonstrated that both the method of application of the adhesion promoter (Terostat 8519 P) and the presence of cataphoretic coating had an influence on adhesive joints strength. The use of the adhesion promoter significantly affects the strength of both uncoated EN AW-5754 aluminium alloy adhesive joints and the adhesive joints subjected to powder coating. The use of the adhesion promoter has a less significant effect on the cataphoretic-coated samples.

Estimation the surface roughness after mineralceramic smoothing of electrophysical coating

Roughness is an important factor in the working properties of instruments. Roughness determines such working properties as durability, wear resistance from detritions, density of combinations, chemical fortitude and appearance. A method for evaluating the roughness of wear–resistant electric-spark coatings on a metal cutting instrument and a specimen of fast-cutting steel is a complex parameter of roughness (Δ). Complex parameter of roughness (Δ) allows more accurately estimating the surface roughness after smoothing the mineral ceramics of an electrophysical coating and others types of surface treatment.

Comparative cytotoxicity of respirable surface-treated/untreated calcium carbonate rock dust particles in vitro

Calcium carbonate rock dust (RD) is used in mining to reduce the explosivity of aerosolized coal. During the dusting procedures, potential for human exposure occurs, raising health concerns. To improve RD aerosolization, several types of anti-caking surface treatments exist. The aim of the study was to evaluate cytotoxicity of four respirable RD samples: untreated/treated limestone (UL/TL), untreated/treated marble (UM/TM), and crystalline silica (SiO2) as a positive control in A549 and THP-1 transformed human cell lines. Respirable fractions were generated and collected using FSP10 high flow-rate cyclone samplers. THP-1 cells were differentiated with phorbol-12-myristate-13-acetate (20 ng/ml, 48 h). Cells were exposed to seven different concentrations of RD and SiO2 (0–0.2 mg/ml). RD caused a slight decrease in viability at 24 or 72 h post-exposure and were able to induce inflammatory cytokine production in A549 cells, however, with considerably less potency than SiO2. In THP-1 cells at 24 h, there was significant dose-dependent lactate dehydrogenase, inflammatory cytokine and chemokine release. Caspase-1 activity was increased in SiO2- and, on a lesser scale, in TM- exposed cells. To test if the increased toxicity of TM was uptake-related, THP-1 cells were pretreated with Cytochalasin D (CytD) or Bafilomycin A (BafA), followed by exposure to RD or SiO2 for 6 h. CytD blocked the uptake and significantly decreased cytotoxicity of all particles, while BafA prevented caspase-1 activation but not cytotoxic effects of TM. Only TM was able to induce an inflammatory response in THP-1 cells, however it was much less pronounced compared to silica.

PLGA-amoxicillin-loaded layer formed on anodized Ti alloy as a hybrid material for dental implant applications

In this paper, the preparation of a functional hybrid coating loaded with a drug (amoxicillin) on a promising titanium alloy – Ti-15Mo alloy is presented. The titanium alloy surface was anodized in solution with bioactive compounds to obtain a porous oxide layer favorable for MG-63 osteoblast-like cell adhesion. Then, a poly(lactide-co-glycolide) (PLGA) loaded with amoxicillin layer was formed using a dip-coating technique to cover the oxide layer, without filling in all of the pores. The morphology of the surface was evaluated using scanning electron microscopy supported by 3D Roughness Reconstruction software. The surface treatment of the Ti-15Mo alloy surface caused the surface roughness to increase up to 1.71 μm. The anodization process caused the Ti-15Mo alloy surface to become slightly more hydrophilic; however, the formation of the PLGA layer loaded with drug increased the contact angle to 96.5° ± 2.2°, respectively. After 4 weeks of polymer layer degradation, the registered signals on the 1H NMR spectrum were identical to the signals registered for lactic acid (LAc), which confirms that the polymer layer was degraded within a short period of time. The concentration of drug released into the artificial saliva was investigated using high-performance liquid chromatography (HPLC) up to 12 h of coatings immersion. During the first hour of coating degradation in artificial saliva, and the concentration of the drug (13 μg/ml) was enough to inhibit bacterial growth of S. aureus and S. epidermidis. These results were confirmed by agar plate diffusion method and evaluation of the minimal inhibitory concentration (MIC). The cytocompatibility of the materials was determined using the osteoblast-like cells MG-63, and the viability and cell morphology (live/dead staining) were also evaluated. The results showed that amoxicillin influences the osteoblast-like MG-63 cells' behavior during cell culture, especially for the first few hours. The influence on the type of surface treatment on MG-63 cell behavior during 7 days of culture is discussed in this paper. To the best of our knowledge, this is the first time that a fast-degrading layer with amoxicillin has been deposited on previously anodized Ti surface. The formation of functional coating may find application as a cytocompatible coating to prevent bacterial adhesion on long-term implant surfaces.

Investigation of Quantum Dot–Metal Halide Interactions and Their Effects on Optical Properties

Quantum dots (QDs) are a class of important light-emitting nanomaterials, which have shown considerable potential for a range of applications. Here, we report detailed studies of the interactions between cadmium halide salts and II–VI-based quantum dots affecting their optical properties. A specific set of experiments have been utilized to better understand these effects using a range of core and core–shell quantum dots as model systems, examining CdSe, CdS, CdS/CdSe, CdTe/CdSe, CdSe/CdS, CdSe/ZnS QDs, and CdSe/CdS dots in rod nanostructures. In our studies, we have demonstrated that significant increases in photoluminescent (PL) and photoluminescent quantum yields (PLQY) can be achieved, producing a 1.5–4-fold increase for CdSe QDs and 1.4–1.8-fold increase for a number of other Cd-based core–shell nanostructures. To explain these phenomena, the interaction’s efficiency for three alternative ligand-capped CdSe QDs have been examined, with results showing a weak dependency on capping ligand. By contrast, we have demonstrated that variation of the halide anion of the cadmium salt shows a strong dependence, with decreasing effectiveness found when comparing Cl– to Br– and I–. In addition, we have been able to show a large increase of PLQY for reverse type I (CdS/CdSe) and type II (CdTe/CdSe) QDs, both nanostructures which display strong surface-sensitive PL properties, while type I (CdSe/CdS) nanostructures showed a weaker effect, with an inverse relationship relative to shell thickness. Finally, it was also found that ZnS or ZnS-shelled QDs show the onset of cation exchange, causing PL red shifting and a significant reduction of PLQY. Therefore, the culmination of these results can be best explained using standard covalent ligand classification, and points to this treatment working via a three-pronged approach, in which surface passivation takes place through the presence of the L-type ligand oleylamine, the Z-type ligand, Cd(oleylamine), and the X-type ligand Cl– anion, the combination of which produces the total optimal effect observed. Overall, this study presents important approaches to increase quantum yields in a range of widely utilized QDs and provides important insights into the underlying interactions of this type of surface treatments as means to improve the resulting optical properties.

Analysis of Multiaxial Near-Surface Residual Stress Fields by Energy- and Angle-Dispersive X-ray Diffraction: Semi- Versus Nondestructive Techniques

Abstract Under laboratory conditions while applying angle-dispersive X-ray diffraction, the information depth in steel is usually restricted to less than 10 μm. Access to residual stresses induced by mechanical, chemical, or both types of surface treatment in deeper regions requires either the application of the layer removal method or an analysis with highly penetrating X rays and synchrotron radiation, respectively. Successive layer removal yields the actual residual stress depth profiles σij(z) up to any depth below the surface, but this is time consuming and semidestructive. High-energy X-ray diffraction performed in the energy-dispersive mode avoids these drawbacks, but it provides only the Laplace stresses, σij(τ), which have to be transformed back into the real space in order to obtain the actual stress-depth profile σij(z). Using an example of a uniaxially ground steel specimen, it is shown that the layer removal method and the energy-dispersive diffraction method for X-ray stress analysis when performed in reflection geometry yield comparable results in the case of the in-plane stress components σ11 and σ22. However, significant differences were observed concerning the out-of-plane stresses, which can be attributed to the boundary conditions that the σi3 components must satisfy at the free surface. It is demonstrated that stress redistribution at the newly generated surfaces after successive layer removal leads to an underestimation of the shear stresses σ13. The analysis of the out-of-plane normal stress component σ33 is shown to require nondestructive measurements.

Investigation of the Influence of Various Kinds of Hardening on the Surface Structure EI893

The paper presents data on investigation of the microstructure of the surface of EI893 alloy samples on a Jeol JSM-6390A scanning electron microscope after different types of processing: annealing, thermoplastic hardening and surface plastic deformation. The change of structure and thickness of the hardened layer is shown, depending on the type of surface treatment

Probe the micro arc softening phenomenon with pulse transient analysis in plasma electrolytic oxidation

Soft sparking can be utilized to dismiss the intrinsic porosity problem of plasma electrolytic oxidation (PEO) coatings on aluminum alloy, since this type of surface treatment generates a dense inner layer. Researchers usually recognize soft sparking through the anodic voltage drop, along with the decline in light and acoustic emissions. Analysis of V-I transients in the anodic pulse of bipolar DC current reveals the decline in RC time constant is a forerunner, which reflects the transition in micro arc state prior to the conventional definition. In studying the negative current dependence and the current frequency dependence of soft sparking, the results suggest the time constant may serve as an auxiliary indicator, monitoring growth activity variations and further assuring the dense inner layer. The role of time constant is exemplified in the soft sparking experiments at 500 Hz and duty 40%. Microstructure analysis reveals three relatively dense stacks separated by two layers of pores and loose grains. The porous layer is attributed to the micro arc state of less intense microdischarges, marked as a substantial drop in the R2C2 value. Matching between stratified layers and R2C2 rises-and-falls is verified in two electrolytic solutions with and without chromia inclusions. Thus, we suggest time constant as a probing tool of microdischarges softening to help analyze the events prior to voltage drop.

Influence of surface treatment on the surface energy of an aluminium substrate

The mechanisms by which adhesion occurs are known. In all cases, the search for an adequate surface condition is decisive in achieving a good adhesion. For this reason, the researches usually work on modifying the surface roughness or improving the thermodynamic characteristics of the surface. The objective on this work is to analyse influence of different attack types (chemical, mechanic, with laser …) which are used to improve surface finish, roughness and surface energy. We have analysed the effects that have produced in the contact angle, measuring the surface energy by the Zisman method. The results revealed that the method of attack has more influence on the value of surface energy than the values of roughness obtained, which can make rethink the type of surface treatment to improve adhesion.