Commercial Surface Treatment Research Articles

Assessment of a novel electrochemically deposited smart bioactive trabecular coating (SBTC®): a randomized controlled clinical trial

ObjectivesA randomized controlled clinical trial of dental implants was conducted to compare the clinical properties of a novel electrochemically deposited calcium phosphate coating to those of a common marketed surface treatment.Material and methodsForty implants of the same brand and type were placed in 20 fully edentulous participants requiring mandibular implantation. The two study groups were defined by the surface treatment of the implants. 20 implants in the control group were coated via a commercial electrochemical surface treatment that forms a mixture of brushite and hydroxyapatite, while the remaining 20 in the test group were coated with a novel electrochemical Smart Bioactive Trabecular Coating (SBTC®). A split-mouth design was employed, with each participants receiving one control implant in one mandibular side and a test implant in the other. To mitigate potential operator-handedness bias, control and test implants were randomly assigned to mandibular sides. All cases underwent digital planning, implant placement with a static surgical guide, and participants received locator-anchored full-arch dentures. The primary outcome was implant stability (measured using Osstell ISQ) assessed at insertion, loading, and then 3 months, 9 months, and 2 years post-insertion. The secondary outcome was bone level change (in millimeters) over the 2-year observation period. Oral health-related quality of life (OHRQL) was monitored using the OHIP-14 questionnaire. Complications and adverse events were recorded.ResultsSuccessful osseointegration and implant stability were achieved in all cases, allowing loading. ISQ values steadily increased throughout the observation period. While no significant differences were observed between the SBTC® and control coatings, the test group exhibited a higher ISQ gain. Bone resorption was somewhat lower in the SBTC® but not significantly so. Patients' OHRQL significantly improved after denture delivery and remained stable throughout the follow-up. No complications or adverse events were observed.ConclusionsBased on the study results, we conclude that the new surface treatment is a safe alternative to the widely used control surface, demonstrating similar osseointegrative properties and time-dependent bone level changes. Further research may explore the broader implications of these findings.Trial registrationThe study is registered on clinicaltrials.gov under the identifier ID: NCT06034171.

Design and evaluation of an innovative composite silicate-based surface treatment agent of concrete

Silicate-based surface treatment agent is a sustainable material to provide a sealing coat on the surface of Portland cement concrete to improve its hardness, impermeability, chemical durability, and abrasion resistance. A type of composite surface treatment agent of concrete is introduced in the paper, using potassium silicate and lithium silicate as main agents and different contents of lithium sulfate, urea, triethanolamine, organosilicon polyether surfactant, and fluorocarbon surfactant as additives. An orthogonal test was conducted to evaluate the effects of different proportions of the two main agents and five additives. The gelation time and viscosity of the agent and the rebound value and penetration depth of the tested concrete samples were tested to evaluate the performance of the designed composite material. The results showed that the two main agents had significant influences on the viscosity, while potassium silicate had the greatest influence on the rebound value. For penetration depth, urea, triethanolamine, organosilicon polyether nonionic surfactants, and fluorocarbon surfactants all had significant effects. The proper ingredients were selected based on the test results, and the optimum proportion of the designed surface treatment agent was determined based on variance analysis of the test results. Two representative commercial inorganic surface treatment agents were selected to compare with the optimum proportion of the designed material, and the effects of the material on the microstructures of the concrete specimens were analyzed by scanning electron microscope (SEM). The mechanism is that Calcium Silicate Hydrate (CSH) gel and ettringite generated can effectively improve surface properties of concrete. The results showed that the optimum proportion of the designed material can effectively block micropores in the surface layer, thus significantly decreasing the concrete porosity, which is conducive to the rapid improvement of concrete strength and compactness.

Mixing and Comparative Properties of NR Compounds Filled with Different Types of Reinforcing Fillers

Mixing behaviors of the compounds filled with different reinforcing fillers were studied in correlation with compound and vulcanizate properties. Four filler systems were used including: 1) silica plus small amount of silane coupling agent; 2) carbon black; 3) pre-modified silica; and 4) silica+silane-carbon black mixed one. The results have shown that silica provides longer optimum cure time and shorter cure rate than carbon black due to accelerator adsorption on silica surface. In addition, owing to highly polar nature on silica surface the silica-based compounds show rather high viscosity, attributed to stronger filler-filler interaction as can be confirmed by Payne effect and reinforcement index. However, the commercial surface treatment or pre-modified form of silica shows superior properties than in-situ modification of silica by silane during mixing, while it gives comparable properties to carbon black-based compound. Tensile properties of vulcanizates show a good correlation with the basic properties of their compounds.

Microwave induced hierarchical nanostructures on aramid fibers and their influence on adhesion properties in a rubber matrix

Several commercial surface treatments are used to increase the adhesion between aramid fibers and the matrix material in composite structures but each of these has some limitations. The aim of this study is to address some of these limitations by developing a surface treatment method for aramid fibers that would not affect mechanical properties of the fibers negatively, could be used with any matrix material and that could withstand handling of the fibers and ageing. The method used is microwave assisted surface treatment that uses microwave radiation together with dry reactive chemicals to create hierarchical structures to the fiber surface and so makes it possible to control the adhesion properties of the fibers. SEM and AFM imaging, fiber tensile tests and modified bundle pull-out test were used to investigate the outcome of the surface treatment and measure adhesion between aramid fiber bundles and rubber. SEM and AFM imaging revealed that nanoscale deposits are formed on to the fiber surface which enable mechanical interlocking between the fiber and the matrix material. Fiber tensile tests showed that the surface treatment does not influence the tensile properties of the fiber negatively. Results from the bundle pull-out tests confirmed that this kind of method can lead up to 259% improvement in adhesion when compared to untreated aramid fibers in the rubber matrix.

IMPROVING THE INTERFACIAL PROPERTIES OF GLASS FIBRE REINFORCED AND UNREINFORCED WASTE SOURCED LOW DENSITY POLYETHYLENE/ACRYLONITRILE BUTADIENE STYRENE/POLYSTYRENE COMPOSITES

This work is focused on compatibilization of immiscible waste sourced low density polyethylene (LDPE), acrylonitrile butadiene styrene (ABS), and polystyrene (PS) blends by different surface modifying routes. To reach better mechanical properties of the given reused waste blends 20% glass fibre was used. The ratio of waste LDPE/ABS/PS was 3.6/2.0/1.0 both in the presence and absence of glass fibre, while the applied concentration of the surface modifying routes was 1% in each case. Blends of raw materials had been manufactured by two roll mill, and specimens were obtained by the press moulded plates. The properties of samples were studied by mechanical testing. Results show that blending of the three kinds of waste polymers without compatibilizers resulted immiscible blends with poor mechanical properties. This could be significantly improved by the application of the commercial and synthetic surface treatment additives. Generally, favourable properties were found in the presence of 20% glass fibre. Especially AD-1 and AD-2 experimental and commercial γ-aminopropylsilane additives showed the best results.

Influence of the carbon fiber surface microstructure on the surface chemistry generated by a thermo-chemical surface treatment

Carbon fibers made of textile and aerospace grade polyacrylonitrile precursor fibers were surface treated by a continuous gas phase thermochemical treatment. The surface chemistry generated by the surface treatment was characterized by X-ray photoelectron spectroscopy. The surface and the average entire microstructure of the fibers were characterized by Raman spectroscopy and X-ray diffraction, respectively. Depending on the grade of the precursor, the final surface concentration of oxygen was comprised between 14% and 24%, whereas the typical commercial electrochemical surface treatments led to concentrations of around 8% with the same fibers. The final concentration of oxygen was directly correlated to the size of the crystallites which was a function of the grade of the polyacrylonitrile precursor and to the corresponding surface microstructure. The thermochemical surface treatment enabled a better control of the nature of the oxygen-containing functionalities as well. Whatever the grade of the precursor, desired hydroxyl groups and carboxylic acid functionalities were preferably generated, which is observed to be difficult with electrochemical surface treatments.

Surface engineering to improve the durability and lubricity of Ti–6Al–4V alloy

► Oil-lubricated friction and wear tests of both commercial and experimental coatings and surface treatments for titanium alloy Ti–6Al–4V were conducted to determine which held promise for applications in diesel engines. ► Eighteen materials and surface treatment combinations were tested against Type AISI 52100 bearing steel under reciprocating sliding and in engine-conditioned formulated diesel oil. ► Eight of eighteen candidates passed the friction criteria (friction coefficient less than 0.15) and wear criteria (stable sliding with minimal vibration). ► The eight treatments that passed our criteria included a nitriding treatment, a titanium nitride coating, an oxygen diffusion treatment, a diamond-like coating, and a commercial chromium-nitride coating. The fuel efficiency of ground vehicles, like heavy trucks, can be improved by reducing engine weight. While primarily known for its use in aerospace structures, titanium alloy Ti–6Al–4V has the potential to replace heavier steel in certain friction and wear-critical diesel engine components like connecting rods, intake valves, movable turbocharger vanes, and pistons. While Ti–6Al–4V exhibits excellent corrosion resistance, good fatigue strength, and acceptable fracture toughness, it has poor sliding characteristics. Titanium alloys have a propensity to fail by galling, and often exhibit high and unstable friction coefficients. In the current work, selected surface engineering techniques were compared to determine which best enhance the tribological performance of Ti–6Al–4V alloy and another alloy, 60Ni–40Ti. Candidate treatments included diffusion treatments, hard coatings (TiN and CrN), a soft coating (Cu–Ni–In), titanium-matrix TiB 2 in situ-formed composite, and shot peening. Diffusion treatments included oxygen diffusion, nitriding, and carburizing. In addition to studying the effects of individual surface engineering approaches, some were combined in an attempt to maximize their effects, but at the same time retain the mechanical properties of the titanium alloy achieved by proper heat treatment. Both dry and lubricated friction and wear tests were conducted using ASTM G133 (linearly reciprocating ball-on-flat). The ball specimens were AISI 52100 bearing steel. Lubricated tests were performed in engine-conditioned diesel engine oil. Test coupons were characterized using microindentation, stylus and optical interferometry, and metallographic examination. Surface engineering methods significantly improved the wear performance of Ti–6Al–4V alloy, but their relative rankings varied significantly between oil-lubricated and non-lubricated conditions.

Evaluation of Coatings Applied to Flexible Substrates to Enhance Quality of Ink Jet Printed Silver Nano-Particle Structures

Different types of the commercial surface treatment InkAid have been evaluated as a surface treatment to enhance print quality of silver nano-particle ink structures printed on polyimide and polyethene substrates. Originally these coatings were designed to be applied on substrates for graphical ink jet printing. On the coated polyimide and polyethene substrates lines of different widths have been printed using a Dimatix materials printer together with silver nano-particle ink manufactured by Advanced Nano-Products. The prints have then been evaluated in terms of print quality and resistivity before and after sintering. The results show that the application of these coatings can improve the print quality considerably, making it possible to print lines with a good definition, which is not otherwise possible with this type of ink on this substrate types. It has been found that the semi-gloss coating provides the best results, both in terms of print quality as well as the lowest resistivity. The resistivity on polyethene is 3.5×10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-7</sup> Ωm at best when sintered at 150°C and for polyimide 8.9×10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-8</sup> Ωm sintered at 200°C. This corresponds to a conductivity of about 4.5% and 18% of bulk silver, respectively. It can be concluded that applying such polyvinylpyrrolidone (PVP)-based coatings to polyethene and polyimide will increase the print quality quite substantially, making it possible to print patterns with requirements of smaller line widths and more details than what is possible without coating.

Heterojunction solar cells on multi‐ crystalline silicon: surface treatments

AbstractIn this work we present the results we obtained by processing 1 Ωcm p and n‐type, multi‐crystalline silicon wafers when a double hydrogenated amorphous/crystalline silicon heterojunction is applied to sandwich the substrate, at the sunward surface to form the emitter and at the rear side to act as back surface field. We have investigated the role of the multi‐crystalline silicon surface conditioning, on the base of illuminated and dark current‐voltage characteristic, quantum efficiency measurements, and overall photovoltaic solar cell performance. In particular, a comparison between an acidic isotexturing and a chemical polishing treatment is presented and discussed in detail. We have found that the morphology of the multi‐crystalline silicon surface plays a tough role in the a‐Si:H properties when used as surface passivating layer. The commercial acidic surface treatment, commonly used in diffused junction mc‐Si solar cell fabrication, requires a level of passivation which is not easily achievable using the very thin a‐Si:H film, needed in heterojunction technology. The deposition of a uniform thickness over a whole textured silicon surface of a thin amorphous layers still requires further investigation and improvement. Nevertheless the high Voc obtained on p‐type doped mc‐Si (625 mV) remarks the effectiveness of a‐Si:H/mc‐Si technology in achieving high photovoltaic efficiency using low thermal budget manufacturing process. (© 2011 WILEY‐VCH Verlag GmbH &amp; Co. KGaA, Weinheim)

Osteoconductivity of hydrophilic microstructured titanium implants with phosphate ion chemistry

This study investigated the surface characteristics and bone response of titanium implants produced by hydrothermal treatment using H 3PO 4, and compared them with those of implants produced by commercial surface treatment methods – machining, acid etching, grit blasting, grit blasting/acid etching or spark anodization. The surface characteristics were evaluated by scanning electron microscopy, thin-film X-ray diffractometry, X-ray photoelectron spectroscopy, contact angle measurement and stylus profilometry. The osteoconductivity of experimental implants was evaluated by removal torque testing and histomorphometric analysis after 6 weeks of implantation in rabbit tibiae. Hydrothermal treatment with H 3PO 4 and subsequent heat treatment produced a crystalline phosphate ion-incorporated oxide (titanium oxide phosphate hydrate, Ti 2O(PO 4) 2(H 2O) 2; TiP) surface approximately 5 μm in thickness, which had needle-like surface microstructures and superior wettability compared with the control surfaces. Significant increases in removal torque forces and bone-to-implant contact values were observed for TiP implants compared with those of the control implants ( p < 0.001). After thorough cleaning of the implants removed during the removal torque testing, a considerable quantity of attached bone was observed on the surfaces of the TiP implants.

Estudo da resposta termicamente estimulada do compósito LDPE/CB por meio da técnica de corrente de despolarização termicamente estimulada (TSDC)

The thermally stimulated depolarization current (TSDC) in a range of temperature from 84 to 373 K, has been applied to study the depolarization current of polyethylene and polyethylene composites in form of film and filled with commercial or oxidative surface treatment carbon black. The diagrams of TSDC obtained show that the composite in which the carbon black had received oxidative surface treatment reducing on an average depolarization current intensity in a magnitude order if compared to the composite with commercial carbon black. Therefore in the area between α and β transitions the difference is accentuated by reaching a peak 55 times in a temperature of 240 K. The difference in results is explained in terms of molecular interactions neighboring of carbon black particles.

Effectiveness of admixtures, surface treatments and antimicrobial compounds against biogenic sulfuric acid corrosion of concrete

Abstract In situ failure of laboratory tested coatings against biogenic sulfuric acid (BSA) corrosion of concrete in sewers has lead to new approaches that affect microbial activity. This paper reports on the performance of concrete surfaces containing antimicrobial polymer fibers or metal-zeolites in preventing BSA corrosion. Additionally, the effectiveness of commercial surface treatments and admixtures was measured by means of accelerated chemical exposure and microbiological simulation tests. The biocidal effect of antimicrobial additives was quantified by means of incubation tests on mortar specimens. The presence of antimicrobial compounds resulted in a 3–12-fold decrease of the bacterial activity, as observed from ATP measurements. The largest deterioration from the accelerated tests was noticed for a cementitious coating. The antimicrobial and silicates admixtures did not result in a protective effect towards degradation under the given test conditions. The best protection was obtained with a polyurea lining and an epoxy coating. No loss of coating integrity could be observed after 8 and 10 cycles of microbiological and chemical testing, respectively.

Effect of surface oxygen content and roughness on interfacial adhesion in carbon fiber–polycarbonate composites

The effect of surface chemistry and rugosity on the interfacial adhesion between Bisphenol-A Polycarbonate and a carbon fiber surface subjected to surface treatment to add surface oxygen groups was investigated. The surface oxygen content of PAN based intermediate modulus IM7 carbon fibers was varied by an oxidative surface treatment. The oxygen content of the carbon fiber surface increased from 4 to 22% by changing the degree of surface treatment from 0 to 400% of nominal commercial surface treatment levels. The oxidative surface treatment also causes an increase in surface roughness by creating pores and fissures in the surface by removing carbon from the regions between the graphite crystallites. To decouple the effects of surface roughness and the surface oxides on the interfacial adhesion, the oxidized fiber surface was passivated via hydrogenation at elevated temperature. Thermal hydrogenation removes the oxides on the surface without significantly altering the surface topography. The results of interfacial adhesion tests indicate that an increase in the oxygen content of the fiber does not increase the fiber-matrix interfacial adhesion significantly. Comparing adhesion results between oxidized and hydrogen passivated fibers shows that the effect of the surface roughness on the interfacial adhesion is also insignificant. Overall, dispersive interactions alone appear to be the primary factor in adhesion of carbon fibers to thermoplastic matrices in composites.

Evaluation of Four Commercially Produced Surface Treatments

The paper reports the results of characterization of four commercial surface treatments on M2 tool steel substrates. The treatments characterized were (a) TiN deposited by physical vapor deposition (PVD), (b) TiCN/TiN multilayer also deposited by PVD, (c) diamond-like carbon (DLC) deposited by an ion-assisted technique, and (d) vanadium carbide (VC) produced by a thermal diffusion process. The surface treatments were evaluated for characteristics relevant to their tribological performance, such as thickness, roughness, chemical composition, micro- and nanohardness, coating-substrate adhesion, and wear resistance. In addition, a hardness model developed at the University of Newcastle upon Tyne (United Kingdom) to correct for substrate effects was successfully applied. Nanohardness tests also yielded the elastic modulus values of the surface treatments, while scratch testing used for determining coating-substrate adhesion provided qualitative information on their ductility.

X-ray Photoelectron Spectroscopic Studies of Carbon Fiber Surfaces. 22. Comparison between Surface Treatment of Untreated and Previously Surface-Treated Fibers

IM7 PAN-based carbon fibers, with a proprietary surface treatment applied by the manufacturer, were analyzed by X-ray photoelectron spectroscopy (XPS). The surface treatment applied by the manufacturer was removed by heating in a vacuum. The fibers detreated in this manner were then subjected to electrochemical treatment. The electrochemical behavior of the as-received fibers and detreated fibers were measured and analyzed. When the same electrochemical treatment was applied to the as-received fibers with their commercial surface treatment intact, a different surface chemistry was observed for the detreated fibers. This study shows that the surface chemistry of treated fibers depends closely on the initial surface chemistry of the fibers and its detreatment. This work shows the importance of using untreated or detreated fibers as precursors for applying reproducible surface treatment so that one can understand and control the surface chemistry of fibers and their interfacial interaction in composites.

Application of advanced surface treatment technologies in the modern plastics moulding industry

The advantages of surface treatment, which are very well known for cutting tools, are almost unexplored for plastics-moulding tools. Several factors contribute to this situation, including the use of relatively soft and/or low-tempered steels or soft aluminium and copper alloys as tool materials, the wide usage of spark-eroding technology, the high tolerances and the residual plastics material embedded in the tool surface. Nevertheless, advanced surface treatments like PVD coatings and ion implantation are slowly gaining ground in this uncommon and difficult market. In the following paper, the major problems connected with tooling in the plastics-moulding industry are described along with the appropriate surface treatments for solving or reducing these problems; examples from commercial surface treatment at the DTI Tribology Centre are given.

An experimental and numerical investigation into the single-fibre fragmentation test: stress transfer by a locally yielding matrix

Single-fibre fragmentation tests on carbon/epoxy microcomposites were performed using carbon fibres with surface treatment levels varying from 0 to 200% of the commercial fibre surface treatment, i.e. 100%. Polarized light microscopy showed substantial local matrix yielding near the fibre-matrix interface in the case of good fibre-matrix adhesion. The level of fibre surface treatment proved to have a large influence on both the final fragment length distribution and the debonded length. The experimental fragment length distributions were compared to predicted fragment length distributions resulting from a numerical simulation of the fibre fragmentation test, based on stress transfer through a yielding matrix and frictional shear stress. Good agreement between the experimental results and the predictions was observed for the case of little debonding. Because of the observed stress transfer through a locally yielding matrix, the classical stress transfer theories for the fibre fragmentation test do not determine a realistic value for the strength of the fibre-matrix interface.

Measurement of Adhesion Between Carbon Fibers and Bismaleimide Resins

Abstract The adhesion between carbon fibers and bismaleimide resins was evaluated using the microbond single fiber pull-out test. A commercially-available, methylene dianiline-based bismaleimide resin and a novel phosphorus-containing bismaleimide were tested with as-received and plasma-treated polyacrylonitrile-based carbon fibers. The surface chemical composition, topography, tensile strength, and surface free energy of the carbon fibers were studied using x-ray photoelectron spectroscopy, scanning electron microscopy, single fiber tensile tests, and dynamic contact angle analysis. The carbon fiber-bismaleimide adhesion improved when the carbon fiber received an oxidative commercial surface treatment or was exposed to an air or ammonia plasma prior to bonding.

Studies of the effect of size on carbon fiber surfaces

The effect of size on carbon fiber surfaces was examined by x-ray photoelectron spectroscopy and scanning electron and x-ray wavelength dispersive microscopies. The fibers studied had been subjected to various levels of commercial surface treatment before the commercially applied size was added. The removal of the size from the fiber surface was examined both by using solvents and by heating the sized fibers. The surface chemistry of the sized fibers was dominated by the sizing and indicated that more sizing was often found on the fibers that received greater prior surface treatment. The study suggests that some significant interaction occurs between the size and the surface treated fiber surface, and this interaction leads to a greater stability of the size on the fiber surface.

The relevance of the surface structure and surface chemistry of carbon fibres in their adhesion to high-temperature thermoplastics

The surface structure and morphology of several high strength polyacrylonitrile (PAN) based carbon fibres was studied with the scanning electron microscope (SEM) on the micrometre scale and the scanning tunnelling microscope (STM) down to the atomic scale. In addition, active surface area measurements were made to determine the number of bonding sites/unit area. Prior to the observations, the surfaces of some of the samples were subjected to either the commercial surface treatment or to oxidation in air or ozone in our laboratory. The roughness and number of bonding sites on each fibre surface was determined. These values will be correlated with the mechanical properties of composites made with these fibres and thermoplastic polymers in Part III of this study