Influence Of Surface Treatment Research Articles

The Influence of Removal of Secondary Phases and Dissolution By-Product from the Surface of Cu2ZnSnS4 Film on the Photoelectrochemical Response of This Film

The influence of surface treatment of as-synthesized Cu2ZnSnS4 (CZTS) thin films on the photocurrent response in the photoelectrochemical cell with Eu3+ contact has been studied. With our work we are the first, to our knowledge, to show that in order to achieve the maximal photocurrent response of CZTS, dissolution of copper sulfide in a KCN solution and subsequent dissolution of ZnS in a HCl solution is insufficient. An additional treatment in a KCN solution for only 10 s can results in the highest photocurrent density. XPS, photoelectrochemical and the Mott-Schottky measurements reveal a negatively charged layer of surficial chlorides on the CZTS film. This layer was captured during removal of the ZnS secondary phase from CZTS film surface in a HCl solution. It has been shown that this layer is the reason why it was impossible to reach the maximum photocurrent. XRD, SEM and XPS measurements demonstrated the dissolution of copper sulfide in a KCN solution, zinc sulfide in a HCl solution and removal of a thin layer of copper chloride during a short (10 s) additional treatment in a KCN solution.

Influence of Surface Treatment and Resin Cements on the Bond Strength between the Y-TZP Zirconia and Composite Resin Interface

AbstractThe evolution of dental materials and the improvement of ceramic systems stimulated the increased use of Y-TZP zirconia-based ceramics. Despite the excellent mechanical performance, this material has low adhesion potential. The objective of this work was to evaluate the surface treatments and resin cements influence on bond strength between Y-TZP zirconia and composite resin interface. A total of 60 blocks of Y-TZP zirconia (3x8x8mm) were prepared and divided into 3 groups according to the surface treatments: (C) control - extra fine diamond bur, (J) sandblasting with Al2O3 and (JP) sandblasting with Al2O3 + ceramic primer. Each group was subdivided into two groups according to type of resin cement used for cementing composite resin discs (2mm thick x 5mm diameter): self-adhesive and conventional (n=10). The samples were stored in distilled water for 24 hours at 37±1°C in a incubator and subsequently submitted to the shear bond test to determine the bond strength (RU). There was no significant difference in RU among the surface treatments when using conventional resin cement. For the self-adhesive resin cement, Al2O3 blasting and Al2O3 + primer blasting increased the RU but did not present significant differences between them (p<0.05). Comparing the cements, it was observed that regardless of the surface treatment, the highest values were for the self-adhesive resin cement (p<0.05). Application of the primer after blasting with Al2O3 did not increase RU. Keywords: Dental Prosthesis. Ceramics. Dental cements. Shear Strength. ResumoA evolução dos materiais odontológicos e o aprimoramento dos sistemas cerâmicos impulsionaram o aumento da utilização da cerâmica a base de zircônia Y-TZP. Apesar do excelente desempenho mecânico, este material apresenta baixo potencial de adesão. O objetivo deste trabalho foi avaliar a influência dos tratamentos de superfícies e dos cimentos resinosos na resistência de união entre a interface zircônia Y-TZP e resina composta. Foram confeccionados 60 blocos de zircônia Y-TZP (3x8x8 mm) e divididos em 03 grupos de acordo com os tratamentos de superfícies que receberam: (C) controle - ponta diamantada extrafina, (J) jateamento com Al2O3 e (JP) jateamento com Al2O3 + primer cerâmico. Cada grupo foi subdividido em dois novos grupos de acordo com tipo de cimento resinoso utilizado para cimentação de discos de resina composta (2mm de espessura x 5mm de diâmetro): autoadesivo e resinoso convencional (n=10). As amostras foram armazenadas em água destilada por 24 horas a 37±1°C em estufa e posteriormente submetidas ao teste de cisalhamento para averiguar a resistência de união (RU). Não houve diferença significativa na RU entre os tratamentos de superfície quando utilizado o cimento resinoso convencional. Para o cimento resinoso autoadesivo o jateamento com Al2O3 e o jateamento de Al2O3 + primer aumentaram a RU porém não apresentaram diferenças significativas entre si (p<0,05). Comparando os cimentos observou-se que, independente do tratamento de superfície, os maiores valores foram para o cimento resinoso autoadesivo (p<0,05). A aplicação do primer após o jateamento com Al2O3 não proporcionou aumento da RU. Palavras-chave: Prótese Dentária. Cerâmica. Cimentos Dentários. Resistência ao Cisalhamento.

Application of surface modifiers in ceramic tile to improve adhesion strength with mortars

Nowadays, ceramic floor or wall tiles have been composed mainly of large ceramic tiles with low water absorption, which requires a greater need for bond strength between the tile and the adhesive mortar. Some researchers argue that adhesion is obtained mainly by mechanical interlocking, while othersclaim that adhesion is obtained mainly by increasing the contact surface. To provide this increase in the contact surface, some studies indicate the use of surface modifiers on the back of the ceramic plate. Thus, this research aimed to evaluate the influence of surface treatment on tensile strength. The research showed that factors such as the polymer content of the adhesive mortar, the absorption and the roughness of the ceramic back were more influential in the tensile strength than the use of the mentioned surface treatments.

Does the application of surface treatments in different sintering stages affect flexural strength and optical properties of zirconia?

To investigate the influence of surface treatments conducted in presintering and postsintering stages on flexural strength and optical properties of zirconia. Specimens were milled from partially sintered zirconia blocks in different geometries and divided into three main groups as presintered, postsintered, and control groups. Test groups were further divided into three subgroups (n = 10) according to the surface treatments conducted (grinding, Er,Cr:YSGG laser irradiation, air-borne particle abrasion [APA]). Four-point flexural strength (σ) test and Weibull analysis were conducted. Color differences (ΔE00 ) and translucency parameter (TPab ) were calculated with a spectrophotometer. Surfaces of specimens were scrutinized under FESEM. Data were statistically analyzed. Postsintered groups exhibited higher σ values (P < .05). Within all groups, highest and lowest σ values were detected at postsintered and presintered APA groups, respectively (P < .05). All ΔE00 values were above the perceptibility threshold (ΔE00 > 0.8). Higher TPab values were obtained and deeper scratches were observed in presintered groups. Surface treatments performed at postsintering stage had a favorable effect on the flexural strength of all specimens. Surface treatments performed before sintering increased translucency and caused higher ΔE00 values. Surface treatments performed at different sintering stages can alter mechanical and optical properties of zirconia.

Influence of surface treatments on composite resin cores

Influence of surface treatments on composite resin cores

Physical-mechanical properties of bamboo fibers-reinforced biocomposites: Influence of surface treatment of fibers

The composition and the morphology of most plant fibers allow their use as reinforcement of biocomposites. In this study, the effect of the modification of the surface of the fibers on the physical and mechanical properties of biocomposites reinforced with bamboo fibers is analyzed. For the experimental procedure, three treatments were carried out: mercerization, ozone, and plasma. The influence of the treatments on the modification of the surface of the fibers was evaluated using X-ray diffraction (XRD), infrared spectroscopy (FTIR), atomic force microscopy (AFM), and scanning electron microscopy (SEM-EDS). The analysis of the properties of the fibers was focused on the determination of the tensile strength, modulus of elasticity, density, moisture content, and absorption capacity. The evaluation of physical properties of biocomposites consisted in the determination of the density, effective absorption, and dimensional stability. The determination of the mechanical properties focused in the evaluation of their behavior under compression and static bending. The results obtained were compared with the results for biocomposites made with untreated fibers, and they demonstrate that by using treated fiber it is possible to increase both the dimensional stability of the panels and their mechanical strength by more than 50%.

Influence of surface treatment on the fluorescence of composite resins subjected to in situ bleaching.

Use fluorescence analysis to evaluate the effect of polishing and surface sealant on the color of composite resin bleached with carbamide peroxide and subjected to staining. Forty-eight composite resin specimens (Z250/Z350XT) were fabricated. After 24 hours stored in distilled water, all specimens were submitted to in situ bleaching with 16% home peroxide for 8 hours daily for a period of 14 days. Subsequently specimens were separated in three groups according to surface treatment proposed (group 1-polishing Sof-Lex; group 2-BisCover; group 3-control). After this, all the specimens were stained with red wine. A spectrofluorometer was used to evaluate the fluorescence in two readouts (L0-after surface treatment and L1-after staining).Data were analyzed by applying ANOVA using a statistical software program. No differences were shown for the factor treatment and other interactions. The lowest mean fluorescence value was found for Z350XT resin (1759.18 ± 0.13) when compared with Z250 (6863.92 ± 0.13). There was significant difference in the mean fluorescence values for all surface treatments between the two different readouts L0 (4820.93 ± 0.05) and L1 (3802.17 ± 0.05). The results suggested that all surface treatments proposed did not influenced the results of wine staining of bleached resins when compared with the control evaluated by the fluorescence method. The purposes of this research was to find solutions, by means of surfaces treatment, to achieve restorations with a satisfactory and similar final aspect in relation to the teeth, and avoid discrepancies related to the esthetics and longevity of the restoration.

Evaluation of Nano-Mechanical Behavior on Flax Fiber Metal Laminates Using an Atomic Force Microscope

The application of plant fiber-reinforced composite (PFRC) is limited due to its relatively low mechanical properties. The hybridization of a thin metal layer with plant fiber into a fiber metal laminate can largely improve the mechanical performance and the brittle fracture behavior of PFRC. However, both plant fiber and metal have difficulty bonding with the polymer matrix. In this paper, several different surface treatment methods were applied on Al alloy sheets, and the influence of surface treatments on the surface morphology and nano-mechanical properties of Al alloy were studied using an atomic force microscope (AFM). After the preparation of flax fiber–metal laminates (FFMLs) with a vacuum-assisted resin transfer molding (VARTM) technique, the nanomechanical properties of different modified FFMLs were also evaluated with an AFM. It was found that the surface treatment combination of the sulfuric acid-ferric sulfate-based treatment (P2 etching) and the silane coupling agent provided the best adhesion force and modulus for Al alloy sheets at nanoscale resolution, which contributed to the surface energy increasing and strong covalent bonds between metal and polymer matrix. The resulting manufactured FFMLs also exhibited the highest nano-mechanical properties due to the great improvement of interfacial properties between metal and matrix, which was caused by mechanical interlocking mechanism and covalent bonds between metal/fiber and resin. Macromechanical performance, including tensile and flexural properties of these modified FFMLs, was also investigated. Comparison of the modulus at the nanoscale and macroscale showed reasonable agreement, and it revealed the tough interlaminar mechanisms of these types of FFMLs.

Influence of surface treatment on marginal bone loss–5‐years prospective clinical trial

Influence of surface treatment on marginal bone loss–5‐years prospective clinical trial

Influence of surface treatment on microstructure of stainless steels studied by Mössbauer spectrometry

Examination of surface microstructure of stainless steels is presented. Transmission Mossbauer spectrometry and Conversion Electron Mossbauer Spectrometry which provide information from the bulk and surface regions, respectively, were used. We concentrate on structural modifications that were caused by surface treatments including grinding, polishing, and electrolytic etching. Scanning Electron Microscopy with Energy Dispersive Spectrometry was adopted for visualization of surface differences. Formation of magnetic phases was revealed in the surface regions of X6CrNiTi1810 steel while no substantial effect of surface treatment was found in the ATABOR steel. Bulk regions in both steels are not affected by surface treatment.

Influence of Surface Treatment on the Interfacial and Mechanical Properties of Short S-Glass Fiber-Reinforced Dental Composites.

The influence of interfacial shear strength (IFSS) between processed short S-glass fibers (250 and 350 μm in length, 5 μm in diameter) and the dental resin (a mixture of urethane dimethacrylate and triethylene glycol dimethacrylate monomers) on the mechanical properties has been studied experimentally. The surface profile of short S-glass fibers was modified using a selective atomic level metal etching process and simple silanization process to enhance the interfacial properties. The S-glass fibers were etched in acid solutions to increase the surface roughness and selectively remove Al3+ and Mg2+ ions, which promoted the mechanical and chemical interfacial bonding reactions. The single glass fiber tensile and microdroplet pull-out tests were performed to investigate the effects of interfacial properties on the flexural strength of the resultant composites. The surface modified S-glass fibers showed an increase of 11-40% in IFSS compared to untreated glass fibers. Composites reinforced with 350 μm length glass fibers (AR-70), which were treated in piranha solution for 4 h, showed the highest improvement in overall mechanical properties, flexural strength (34.2%), modulus (9.7%), and breaking energy (51.9%), compared to the untreated fiber-reinforced composites. The modified Lewis-Nielsen equation was developed using the effective fiber length factor to accurately predict the modulus of the short fiber-reinforced composites and validated with experimental results.

Influence of Surface Treatment of Recycled Aggregates on Mechanical Properties and Bond Strength of Self-Compacting Concrete

In the last decade there has been a massive growth for development of concrete infrastructures all around the world. Take into account environmental concerns, concrete technology should direct efforts toward assuring development and fabrication of sustainable and resilient concrete. For this purpose, incorporation of recycled concrete aggregate in concrete products particularly self-compacting concrete (SCC) for structural and non-structural application would be significant achievement. In this study the fresh and hardened properties of SCC prepared by substituting natural aggregates (NA) with recycled coarse aggregates (RCA). In addition, bonding behaviour of reinforced RCA-SCC for structural application was investigated. Moreover, surface treatment of RCA using lithium silicate solution was proposed to investigate its feasibility to improve the fresh and hardened properties of SCC as well as its bonding strength. The mechanical properties including compressive strength, tensile strength and elastic modulus of SCC mixes using untreated RCA and treated RCA (TRCA) were investigated. The results showed an improvement in performance of SCC mixes made with TRCA in compare with the untreated samples. The bond behaviour between SCC made with RCA and steel reinforcement was studied and the relationship between the brittleness and bonding of SCC mixes using untreated RCA and TRCA determined. The effect of surface treatment on the interfacial transition zone (ITZ) between adhered mortar and RCA studied using scanning electron microscope (SEM). It was determined that the treatment of RCA improved the bond at the ITZ through densification. The results gave experimental evidence of the suitability of RCA-SCC for structural use and application in reinforced concrete.

Influence of surface treatments in flexural strength and superficial topography of a lithium disilicate ceramic

The aim of the study was to evaluate the influence of different surface post-etching treatments in flexural strength, contact angle and surface roughness of a lithium disilicate ceramic. 60 bars (16x2x4mm) were divided in six groups (n=10): C, no treatment; HF, hydrofluoric acid for 20s (HF) + washing (60s), drying (30s); HFL, HF + washing (60s), drying (30s) and luting; HFNL, HF + washing (60s) + neutralization with sodium bicarbonate (SB) for 40s + washing (5s), drying (30s) and luting; HFUL, HF + washing (60s) + ultrasonic bath (UB) for 4 min, drying (30s) and luting; HFNUL, HF + washing (60s) + SB (40s) + UB (4 min) and luting. The bars were submitted to three-points flexural strength test. To analyze roughness and contact angle 25 ceramic blocks (12x7x7 mm) were divided into five groups (n=5): C - no treatment; HF - HF ; HFU - HF and UB for 5 min ; HFN - HF and SB; HFNU - HF, UB and SB. A scanning electron microscope (SEM) analysed the surface of the samples. ANOVA one-way statistical analysis was done for comparison of results. There was no statistical difference for flexural strength (p-value=0.15) and for surface roughness (p-valor=0.15). However, it was obtained statistically significant difference for contact angle (p-valor=0.00). SEM images showed precipitates after the acid etching, which were removed by post-etching treatments. It can be concluded that the different post-etching surface treatments did not increase the flexural strength, surface roughness and ceramic wetting, but it influenced the SEM images.

The Influence of Surface Treatment of PVD Coating on Its Quality and Wear Resistant

The article deals with a determination of the influence of a cutting edge preparation on the quality and wear resistance of coated cutting tools. Cutting inserts made from a sintered carbide with a deposited layer of PVD coating were selected for measurement. Non-homogeneity caused by the creation of droplets arises in the application layer during the process of applying the coating by the PVD method. These droplets make the surface roughness of the PVD coating worse, increase the friction and thereby the thermal load of the cutting tool as well. Also, the droplets could be the cause of the creation and propagation of droplets in the coating and they can cause quick cutting tool wear during machining. Cutting edge preparations were suggested for the improvement of the surface integrity of deposited layers of PVD coating, namely the technology of drag finishing and abrasive jet machining. After their application, the areal surface roughness was measured on the surface of coated cutting inserts, the occurrence of droplets was tracked and the surface structure was explored. A tool-life test of cutting inserts was carried out for verification of the influence of surface treatment on the wear resistance of cutting inserts during the milling process. The cutting inserts with a layer of PVD coatings termed as samples A, B, and C were used for the tool-life test. The first sample, A, represented the coating before the application of cutting edge preparations and samples B and C were after the application of the cutting edge preparation. A carbon steel termed C45 was used for the milling process and cutting conditions were suggested. The visual control of surface of cutting inserts, intensity of wear and occurrence of thermal cracks in deposited PVD layers were the criterion for the evaluation of the individual tests.

The Influence of Surface Treatment on Wettability of TiNi-Based Alloy

The results of an investigation of surface wettability of TiNi-based alloys by water and DMEM-medium are presented. A comparative analysis of the wetting angle is performed after processing the specimens by grinding, sand blasting, oxidation in air, etching in a solution of acids, processing by vapor, hydrogen peroxide, and detergent solution in an ultrasonic bath. It is shown that oxidation in air and etching in acids increase the surface hydrophilic property of TiNi-based alloys. The highest hydrophilic value with the water wetting angle about 30° is achieved in the case of vapor treatment following sand blasting and treatment of the oxidized specimens with hydrogen peroxide. The differing influence of treatments on the wetting angle is attributed to variations in the surface energy of TiNi-based alloy specimens, which is affected by the microrelief and structural-chemical characteristics of the surface.

In Vitro Corrosion and Bioactivity Performance of Surface-Treated Ti-20Nb-13Zr Alloys for Orthopedic Applications

The influence of surface treatments on the microstructure, in vitro bioactivity and corrosion protection performance of newly fabricated Ti-20Nb-13Zr (TNZ) alloys was evaluated in simulated body fluid (SBF). The TNZ alloy specimens were treated with separate aqueous solutions of NaOH and H2O2 and with a mixture of both, followed by thermal treatment. The nanoporous network surface structure observed in H2O2-treated and alkali-treated specimens was entirely different from the rod-like morphology observed in alkali hydrogen peroxide-treated specimens. XRD results revealed the formation of TiO2 and sodium titanate layers on the TNZ specimens during surface treatments. The water contact angle results implied that the surface-treated specimens exhibited improved surface hydrophilicity, which probably improved the bioactivity of the TNZ specimens. The in vitro corrosion protection performance of the surface-treated TNZ specimens was analyzed using electrochemical corrosion testing in SBF, and the obtained results indicated that the surface-treated specimens exhibited improved corrosion resistance performance compared to that of the bare TNZ specimen. The in vitro bioactivity of the treated TNZ specimens was assessed by soaking in SBF, and all the investigated treated specimens showed numerous apatite nucleation spheres within 3 days of immersion in SBF.

Temperature Regulation in Colored Infrared-Transparent Polyethylene Textiles

Summary Effectively regulating heat flow between the human body and its environment not only increases thermal comfort but also presents a novel and potentially cost-effective approach to reducing building energy consumption. Infrared property-engineered textiles have been shown to passively regulate radiative heat dissipation for effective cooling and warming of the human body. However, a lack of dyes that can tune the textile color without compromising the infrared properties remains a major impediment to textile commercialization. Here, we report a new strategy utilizing inorganic nanoparticles as a coloring component for scalable brightly colored, infrared-transparent textiles. The as-fabricated composite textiles not only show a high infrared transparency of ∼80% and a passive cooling effect of ∼1.6°C–1.8°C but also exhibit intense visible colors with good stability against washing. This facile coloration approach will promote the commercialization of radiative cooling textiles in temperature-regulating wearable applications for effective energy savings.

The influence of surface treatment and activation of thin film composite membranes with plasma discharge and determination of their physicochemical properties

In this paper we have focused on the surface treatment and activation of membranes (73 AC and 82 V) with plasma discharge, and on the determination of their physicochemical properties. The surface morphology, wettability, zeta potential of pristine and plasma-treated membranes were tested and compared. Our study is focused on how plasma treatment may be used to tailor the membrane properties. The reactive plasma with functional groups can actively improve the interfacial properties (OH groups for hydrophilicity, NH2 groups for interaction with CO2) and increase separation efficiency of the membrane process. The surface morphology is also significantly affected in the case of membrane 82 V, and rather globular structures appeared on the surface of the plasma-exposed membrane. This change of morphology is also accompanied by a decrease of surface area difference, for both plasma-treated membranes 73 AC and 82 V. Membrane 82 V is more sensitive to the plasma treatment at both of the tested plasma power levels and exposure times. In all cases, the zeta potential changes due to the presence of polar groups on the surface. Plasma modification effects on wettability of both types of membranes revealed that water contact angles (CAs) of membranes 73 AC modified for short times (20 and 60 s) are lower than CAs of the membranes 82 V modified under the same conditions. X-ray photoelectron spectroscopy demonstrated an increase in atomic oxygen concentration upon plasma treatment, which then gradually decreased as a function of time. When the composite membranes are exposed to water, the active layers of the membranes become dense and the transport no longer follows the Knudsen mechanism. These swollen membranes follow a solution-diffusion mechanism and the membranes are much more selective and less permeable for all the measured gases. The permeability reduction is much stronger for H2 compared to CO2. The selectivity increases a lot, especially for the CO2/CH4 pair, from 0.3 up to 13.

Characterization of Highly Filled PP/Graphite Composites for Adhesive Joining in Fuel Cell Applications

In order to evaluate the suitability of graphite composite materials for use as bipolar plates in fuel cells, polypropylene (PP) was melt compounded with expanded graphite as conductive filler to form composites with different filler contents of 10–80 wt %. Electrical resistivity, thermal conductivity, and mechanical properties were measured and evaluated as a function of filler content. The electrical and thermal conductivities increased with filler content. Tensile and flexural strengths decreased with the incorporation of expanded graphite in PP. With higher graphite contents, however, both strength values remained more or less unchanged and were below the values of pure PP. Young’s-modulus and flexural modulus increased almost linearly with increasing filler content. The results of the thermogravimetric analysis confirmed the actual filler content in the composite materials. In order to evaluate the wettability and suitability for adhesive joining of graphite composites, contact angle measurements were conducted and surface tensions of composite surfaces were calculated. The results showed a significant increase in the surface tension of graphite composites with increasing filler content. Furthermore, graphite composites were adhesively joined and the strength of the joints was evaluated in the lap-shear test. Increasing filler content in the substrate material resulted in higher tensile lap-shear strength. Additionally, the influence of surface treatment (plasma and chemical) on surface tension and tensile lap-shear strength was investigated. The surface treatment led to a significant improvement of both properties.

Theoretical and Experimental Studies on Tribological Behavior of Luffa Fiber Reinforced Polyester under the Influence of Surface Treatment

Abstract In the present study, the influence of surface modification treatments such as alkali, silane and Ca(OH)2 on luffa fiber reinforced composites has been investigated. In addition, the design of experiment and Taguchi method were used for optimizing the wear resistance of composites. Statistical regression analysis was also used to develop mathematical model for specific wear rate and coefficient of friction. The dry sliding wear tests were conducted through pin-on-disc equipment as per ASTM G99 for the varying sliding velocity. Surface modifications of luffa fiber reinforced composites such as NaOH, Silane and Ca(OH)2 cause an increase wear resistance. It was observed that the Ca(OH)2 treatment to luffa fiber improves wear resistance significantly compared to NaOH and silane treatment. In particular, luffa fiber (with 30 wt.%) reinforced composites at a normal load of 10 N have higher wear resistance among other Ca(OH)2 treated composites. Depending upon load, velocity of sliding and sliding distance, fiber weight percentage used in this study, wear resistance can be ranked as Ca(OH)2&gt; Silane &gt;NaOH&gt; untreated luffa fiber reinforced composites. The worn surface morphologies of composites with different condition are discussed. The developed statistical regression mathematical equations predictions were in good agreement with experimental data. It is noted that the developed model may be used to successfully predict the tribological behavior of luffa fiber reinforced composites.