Thin Film X-ray Diffractometer Research Articles

Conductive polyurethane nanofiber membrane prepared through high-power impulse magnetron sputtering using brass alloy

In this work, a copper-rich α-phase brass alloy was deposited on the surface of polyurethane nanofiber membranes with different densities using high-power impulse magnetron sputtering technology. The microstructural and electrical properties of the brass-coated membranes were investigated using a cold field emission scanning electron microscope with an energy dispersive spectrometer, atomic force microscope, a multipurpose thin-film X-ray diffractometer, and low impedance meter with a four-point probe. A network analyzer with a coaxial tube was used to analyze the resistance characteristics and electromagnetic shielding effectiveness of the samples. Results indicated that the brass alloy was evenly deposited on the surface and inner layers of the nanofiber membrane. Brass nodules were stacked on the surface of nanofibers and had a granular structure. The nanofibers of all membranes were neither damaged nor degraded after deposition. The brass-coated membrane provided a good conductive path on the surface. When the deposition time increased, the deposition of brass nodules on the membrane was more complete and uniform, which reduced the surface resistance and improved the electromagnetic shielding performance of the membrane.

Plasma electrolytic oxidation of Ti-6Al-4V alloy in electrolytes containing bone formation ions

In this study, plasma electrolytic oxidation of Ti-6Al-4V alloy in electrolytes containing bone formation ions was examined using various instruments. Here, a Ti-6Al-4V ELI disk is used for PEO treatment. A pulsed DC power of 280 V was applied to all specimens for 3 min. The electrolytes used for PEO were prepared by mixing of calcium, prosperous, silicon, strontium, zinc, magnesium, and manganese ions. Additionally, MC3T3-E1 mouse osteoblasts were cultured on the specimens for the cell proliferation assay. The morphology of the attached cells was observed using field-emission scanning electron microscopy (FE-SEM). The surface characterization of the PEO-treated surface was performed by FE-SEM and energy dispersive X-ray spectroscopy. The surface area of the pores was measured using an image analyzer. Furthermore, the phase of the specimen was analyzed with a thin film X-ray diffractometer (XRD).The PEO films, except the specimen containing manganese element, exhibit a uniform porous surface. The porous structure displays a very rough surface, and Mn easily precipitates around pores in the process of original and new pore formation. A high amount of Mn was detected in the precipitate inside the pores, whereas high amounts of calcium, phosphorus, strontium, titanium, and oxygen were detected around the pores. The XRD peak of HA on PEO-treated surface in the electrolyte containing the ions of five elements is lower, broader and shifted toward the left side. The pores were covered with MC3T3-E1 cells and extended well. Cells exhibit a spinning form of filopodia in lamellipodia and grow in association with the cells on PEO-treated surface in an electrolyte containing five ions. The cell differentiation and bone formation ability of ions of five elements doped surface were significantly increased compared to bulk surface.

Morphology changes and bone formation on PEO-treated Ti-6Al-4V alloy in electrolyte containing Ca, P, Sr, and Si ions

In this study, morphology changes and bone formation on plasma electrolytic oxidation (PEO)-treated Ti-6Al-4V alloy in electrolyte containing Ca, P, Sr, and Si ions were researched using various experimental instruments.Ti-6Al-4V ELI disk was used as the specimens. The specimen was used as the anode and the carbon rod as the cathode. Pulsed DC power of 280 V was applied to all specimens for 3 min. at 25 ℃. The electrolyte used for PEO was produced by mixing up Ca(CH3COO)2·H2O, C3H7NaCaO6P, Sr(CH3COO)2·0.5H2O, and Na2SiO3·9H2O. To investigate the bioactivity, PEO-coated specimens and untreated Ti-6Al-4V specimens were immersed in simulated body fluid (SBF) for 12 h at 36.5 ℃. The phase and surface morphology of the specimen were analyzed by a thin film X-ray diffractometer, field–emission scanning electron microscopy, Energy dispersive X-ray spectroscopy, and surface roughness tester.The pore size decreased, while the number of pores increased, as the content of Sr increased. In the case of the amount of 5Si addition, the size of the pores decreased whereas the number of pores increased as the content of Sr increased. Ca, P, Sr, and Si ions were uniformly distributed on the surface and, in the case of Sr and Si addition, the contents of Ca, P, and Sr significantly increased. The cell proliferation and bone-like apatite increased as the content of Sr and Si.

Effects of Organo-Modified Clay Addition and Temperature on the Water Vapor Barrier Properties of Polyhydroxy Butyrate Homo and Copolymer Nanocomposite Films for Packaging Applications

Polymer nanocomposites, based on bacterial biodegradable thermoplastic polyester, poly(hydroxy-butyrate) (PHB), poly(hydroxyl-butyrate-co-hydroxy-valerate) (PHBHV), and commercial organo-modified montmorillonite (OMMT-Cloisite 10A) were prepared by solution casting method. This work aims to investigate the effect of Cloisite 10A type clay addition on the water vapour permeability properties of PHB/OMMT, and PHBHV/OMMT nanobiocomposite films. Temperature dependence of water vapor permeabilities of the films were also evaluated at various temperatures, and semi empirical permeability models were used to predict the permeability of polymer systems as a function of clay concentration and aspect ratio of nanoplates. Moreover, thermal, optical, and mechanical properties of the composites were examined by using varieties of techniques including differential scanning calorimeter (DSC), thermogravimetric analyzer (TGA), scanning electron microscope (SEM), and thin-film X-ray diffractometer (TF-XRD) respectively. Test results indicated that addition of highly intergallery swollen Cloisite 10A to the PHB/PHBHV, reduced the water vapor permeability up to 41 and 25% compared to native PHB and PHBHV films, respectively. Regarding the all mechanical properties measured, the maximum improvement was achieved for 3 wt% clay loaded samples for both PHB and PHBHV polymer composites. An increase of about 152 and 73% in tensile strength and of 77 and 18% in strain at break was achieved for PHB and PHBHV polymers, respectively. As a result of X-ray diffraction analysis, exfoliated structure was achieved at low clay loaded sample (1% w/w), however at higher concentration (3% w/w) the structure found as intercalated. Therefore, it is an evident that enhancement of characteristic properties highly depend on the dispersion level of clay particles in polymer matrix. The results obtained in this study show the feasibility of improvement of the properties of PHB based polymers with incorporation of nanoclay.

Bone-like apatite formation on manganese-hydroxyapatite coating formed on Ti-6Al-4V alloy by plasma electrolytic oxidation

In this study, bone-like apatite formation on manganese-hydroxyapatite (Mn-HA) coatings formed on Ti-6Al-4V by plasma electrolytic oxidation (PEO) has been investigated by several techniques. Ti-6Al-4V ELI disks were used as substrates for PEO treatment. Test specimens were used as anodes, and a Pt rod was used as the cathode in an electrolytic solution containing Mn. The applied voltage was 280V, and the deposition time was 3min. To examine the bioactivity, the PEO films formed on Ti-6Al-4V were immersed in SBF for 12h. The PEO films and the Ti-6Al-4V surface after immersion in SBF were characterized by a thin-film X-ray diffractometer, field-emission scanning electron microscopy, and energy dispersive X-ray spectroscopy.The PEO surface presented large and irregular pores, and the number of pores increased as the Mn content increased. For the PEO-treated samples, anatase peaks were detected by X-ray diffraction, and the HA peak intensity increased as the Mn content increased. The Ca/P ratio decreased, whereas the (Ca+Mn)/P ratio increased, as the Mn content increased. The coatings without Mn on the micropores had a small granular shape, and the pores were covered with HA after the immersion in SBF. As the Mn concentration increased, all Mn-HA coating surfaces became more dense, and microcracks appeared on the coating surface.

Optimization of poly(ε‐caprolactone) surface properties for apatite formation and improved osteogenic stimulation

A biodegradable polymer with surface properties that promotes cell attachment and host integration is widely recognized as a useful three-dimensional construct for bone tissue engineering applications. In this work, studies were carried out to correlate surface properties of modified polycaprolactone (PCL) films with cell-material interactions. PCL film substrates were subjected to various degrees of chemical hydrolysis using different pretreatment solutions to introduce different densities of carboxylate groups onto the surfaces. The extent of hydrolysis on the films was optimized to allow the deposition of a dense and uniform bone-like apatite layer by an alternate soak treatment, followed by subsequent incubation in simulated body fluid (SBF). The hydrolyzed and apatite-coated PCL films were investigated using scanning electron microscopy, thin film X-ray diffractometer (TF-XRD), water contact angle, and Alizarin red staining. Surface wettability, roughness, and chemistry of various PCL substrates were correlated with cell attachment, proliferation, viability, and alkaline phosphatase activity. Results demonstrated that cell attachment increased with increasing surface hydrophilicity and roughness. The apatite-coated films showed significantly improved surface wettability and enhanced surface roughness, which subsequently led to better cell attachment potential, high-cell viability, and enhanced bone formation capability. Thus, surface modification with an apatite coating layer is a promising approach for enhancing the efficacy of the polymeric scaffold for bone tissue engineering applications.

Ultra-fast boriding of nickel aluminide

In this study, we explored the possibility of ultra-fast electrochemical boriding of nickel aluminide (Ni 3Al) in a molten borax electrolyte. Electrochemical boriding was performed at 950 °C for 15 min and at current densities ranging from 0.1 to 0.5 A/cm 2. The boride layers formed on the test samples were 50 to 260 μm thick depending on the current density. The mechanical, structural, and chemical characterization of the boride layers was carried out using a Vickers micro-hardness test machine, optical and scanning electron microscopes, and a thin film X-ray diffractometer. The hardness of boride layer was in the range from 800 to 1200 ± 50 HV depending on the load and the region from which the hardness measurements were taken. X-ray diffraction studies confirmed that the boride layers were primarily composed of Ni 3B, Ni 4B 3 and Ni 20AlB 14 phases. Structurally, the boride layer was very homogenous and uniformly thick across the borided surface area.

Blood responses to titanium surface with TiO2 nano‐mesh structure

The goal of this study was to enhance the blood responses to titanium (Ti) surfaces used for dental implant application through the formation of a TiO2 nano-mesh surface layer produced by a fast electrochemical anodization treatment. Electrochemical anodization treatments with different anodization currents and temperatures in an alkaline solution were used to create a nano-mesh oxide layer on polished Ti surface. Surface characterizations of the mesh structure were carried out using thin-film X-ray diffractometer, field-emission scanning electron microscope, and atomic force microscope. The blood responses, including the blood-clotting ability and platelet adhesion morphology, to the test Ti surfaces were evaluated. The blood-clotting ability, in terms of optical density of blood, was statistically analyzed using a nonparametric method, Kruskal-Wallis test, for the factor of anodization treatment. A multilayer TiO2 nano-mesh structure was rapidly formed on the polished Ti surface using a simple electrochemical anodization treatment in an alkaline solution. The TiO2 nano-mesh had an average mesh size between 34 and 93 nm, depending on the anodization current and temperature. The features on the TiO2 nano-mesh structure on the anodized Ti surface were of a similar size scale as blood proteins, giving the material better blood clot ability (P<0.05) and improved platelet activation and aggregation as compared with an untreated polished Ti surface. The formation of TiO2 nano-mesh on the Ti surfaces was shown to enhance blood responses, which we expect to promote cell growth in the application of dental implants.

Low-Temperature Metal Induced Crystallization of Amorphous Silicon Using Nano-Nickel Particles

A simple method was presented to conduct the low-temperature metal induced crystallization of an amorphous silicon (a-Si) film using nano-sized nickel particles. The effects of the annealing temperature and the duration on the morphology and the crystallized size of the induced polycrystalline silicon (poly-Si) film were investigated using a field emission scanning electron microscope (FE-SEM), a twin thin-film X-ray diffractometer (XRD), a Raman spectrometer, and an energy dispersive spectrum (EDS). In addition, the residual nickel and the I-V characteristics of the poly-Si film were measured using a secondary ion mass spectrometer and a semiconductor parameter analyzer, respectively. The crystalline peak of Si (311) was obviously detected even at an annealing temperature of 400°C and the duration of 1 h. The crystallization temperature was lowered due to the high activity of the nano-nickel particles. Therefore, this study supports the feasibility of applying nano-nickel particles to crystallize the a-Si film.

Effects of UV-irradiation on in vitro apatite-forming ability of TiO2 layers

Abstract Titanium and its alloys are employed as artificial joints, bone plates, wires, screws and bone prostheses in orthopedic and dental fields, because of their high corrosion resistance, good mechanical properties, and biocompatibility. Since they cannot directly bond to living bone–tissue through stable chemical interactions, a few surface modification techniques have been proposed for giving materials apatite-forming ability that secures bone–tissue bonding, such as chemical treatment with H 2 O 2 or NaOH, electrochemical oxidation, electrophoretic apatite particle deposition, and UV-irradiation of surface titanium oxide layer. This study examined how the combination of H 2 O 2 chemical treatment and UV-irradiation affected in vitro apatite-formation on TiO 2 (anatase phase) layers as UV was irradiated under a few different conditions. TiO 2 layer was prepared by the chemical treatment with H 2 O 2 solution and subsequent heat-treatment (CHT). CHT samples were irradiated with UV-light for 1 h in air or in ultra-pure water. They were then soaked in Kokubo's simulated body fluid (SBF; pH 7.4) at 36.5 °C for 1 day. Their surface structure and morphology were examined by using a thin film X-ray diffractometer (TF-XRD), and a scanning electron microscope (SEM). The UV-irradiation of CHT in air reduced the number of active sites for apatite nucleation. On the contrary, however, the UV-irradiation in water increased them. These opposite results indicate that environmental factors of the UV-irradiation are important for controlling the in vitro apatite-forming ability of anatase layer.

Formation of TiO 2 nano-network on titanium surface increases the human cell growth

Objectives This study was to improve human cell growth on titanium (Ti) used for dental implants through formation of a nano-network surface oxide layer created by an electrochemical anodization treatment. Methods An electrochemical anodization treatment was used to produce a network oxide layer on Ti surface. Surface characterization of the network layer was carried out using thin film X-ray diffractometer and field emission scanning electron microscopy. Human bone marrow mesenchymal stem cells (hMSCs) were made to express green fluorescent protein (GFP) by retroviral transduction. The GFP signal was measured in situ to assess in vitro and in vivo cell growth on Ti surfaces. In vivo experiments on Ti-supported cell growth were carried out on the back skin of nude mice. Alizarin red staining and immunofluorescent staining were used to observe cell differentiation. Results A multilayer TiO 2 nano-network was produced rapidly on Ti surface using a simple electrochemical anodization treatment. The TiO 2 nano-network layer on the anodized Ti surfaces significantly improved in vitro and in vivo hMSC growth, as assessed by measurement of GFP fluorescence, relative to hMSC growth on untreated Ti surface. The TiO 2 nano-network layer on the anodized Ti surfaces can also induce the differentiation of hMSCs after 28-day in vivo test. Significance The formation of TiO 2 nano-network on the Ti surfaces can increase the hMSC growth in vitro and in vivo.

Nano/submicron-scale TiO 2 network on titanium surface for dental implant application

In this study, a fast electrochemical anodization treatment, applying different anodic currents, was used to produce a nano/submicron-scale network oxide layer on Ti metal surface for biomedical implant application. The anodized Ti surface was analyzed using thin film X-ray diffractometer, X-ray photoelectron spectrometer, and field emission scanning electron microscope. The whole blood coagulation and human bone marrow stem cells (hBMSCs) adhesion on the anodized Ti surface were evaluated. Results showed that a nano/submicron-scale TiO 2 network layer with a lateral pore size of 20–160 nm could be rapidly produced on Ti surface through electrochemical anodization treatment. Increasing the applied anodic current led to an increase in pore size of TiO 2 network. The nano/submicron-scale TiO 2 network layer significantly enhanced the whole blood coagulation and hBMSCs adhesion on Ti surface.

Effect of mold temperatures on interface between primary and secondary castings of cast-on method for precision metal frameworks

The purpose of the present study was to obtain fundamental data for application of the cast-on method by evaluating the effect of mold temperatures on the interface between primary and secondary castings in detail. Silver-palladium-gold alloy (Ag-Pd-Au), type-4 gold alloy (Type4), and chromium-cobalt alloy (Cr-Co) were used in the present study. A polished flat, square metal plate, 10.0 mm x10.0 mm x 1.0 mm, was used as the primary casting. A wax pattern, 2.0 mm in diameter and 2.0 mm thick, was prepared for the secondary casting and invested together with the primary casting. The mold was heated at 600, 700 and 800 degrees C for Ag-Pd-Au and Type4, and 700, 800 and 900 degrees C for Cr-Co. After casting, the mold was embedded and sectioned. The cross-section was observed using a scanning electron microscope (SEM) and analyzed using energy dispersive X-ray spectroscopy (EDS). The gaps between the primary and secondary castings were analyzed for each alloy by analysis of variance and Tukey's honestly significant difference test. The significance level was set at 0.05. The heated primary casting without the secondary casting was examined using a thin film X-ray diffractometer (XRD). Gaps were observed between the primary and secondary castings in all examined conditions. The primary casting surface was covered with oxide layers such as CuO and Cr(2)O(3), and became rough with an increase of the mold temperature. The results suggested that the cast-on method was influenced by the mold temperature.

Dynamic mechanical properties and in vitro bioactivity of PHBHV/HA nanocomposite

Biopolymer composite materials for potential medical applications are of current research interest. In this study, a nanocomposite based on bioresorbable polymer-poly(3-hydroxybutyrate- co-3-hydroxyvalerate) (PHBHV) was prepared by the incorporation of nano-sized hydroxyapatite (nano-HA) using a solution casting method. Homogeneous distribution of nanoparticles in the polymer matrix was validated by the observation of field emission scanning electron microscope (FE-SEM). The dynamic mechanical properties, thermal properties, and bioactivity of the nanocomposite were examined by using varieties of techniques including dynamic mechanical analyser (DMA), differential scanning calorimeter (DSC), thermogravimetric analyzer (TGA), scanning electron microscope coupled with energy dispersive X-ray analysis detector (SEM + EDXA), Fourier transforms infra-red spectrometer (FT-IR) and thin-film X-ray diffractometer (TF-XRD). The results indicated that the storage modulus ( E′) of PHBHV was considerably improved with the introduction of nano-HA. For an instance of examination at 1 Hz, the PHBHV/HA (100/30) nanocomposite showed an increment of 41.2% at −50 °C and 99.1% at 75 °C in E′ as compared with the polymer matrix. It was also found that higher testing frequencies used induce more elastic-like behavior. With the increase in the amount of nano-HA, both the glass transition temperature ( T g) and the activation energy (Δ E) for the glass transition increased, while the tangent of loss angle (tan δ) decreased due to the hindrance of the nanofillers to the mobility of the polymer segments. The thermal experiments revealed that, when incorporating HA nanoparticles, the decomposition of the polymer matrix was accelerated at the initial stage but postponed thereafter. The addition of nano-HA also resulted in a decrement in the melting enthalpy of PHBHV. The in vitro investigation indicated that the nanocomposite has an improved bioactivity over the conventional one.

In vitro apatite formation and its growth kinetics on hydroxyapatite/polyetheretherketone biocomposites

The formation of biologically equivalent carbonate-containing apatite on the surface of synthetic hydroxyapatite (HA) is an important step leading to good bone healing. In this study, HA-reinforced polyetheretherketone (PEEK) composites were prepared by homogeneous mixing of HA and PEEK powders, compaction, and pressureless sintering. The bioactivity of HA/PEEK composite with 10, 20, 30 and 40vol% HA was evaluated by immersing the composite disks in the simulated body fluid (SBF) for up to 4 weeks. The surface of composite with 40vol% HA was covered by a layer of bone-like apatite just after 3 days of immersion, while 10vol% HA was covered only after 28 days. This apatite layer was characterized by SEM, thin film X-ray diffractometer, attenuated total reflectance–Fourier transform infrared spectrometer (FTIR)/FTIR. Introducing a concept called apatite-forming capacity of SBF, growth kinetics of the apatite layer on the surface of the composite disks was carried out. The growth rate constant increased with HA volume fraction of the composite, suggesting that the bioactivity of the HA/PEEK composite increases with increasing HA volume fraction in the composite.

Activity of plasma sprayed yttria stabilized zirconia reinforced hydroxyapatite/Ti–6Al–4V composite coatings in simulated body fluid

Hydroxyapatite (HA)/yttria stabilized zirconia/Ti–6Al–4V bio-composite coatings deposited onto Ti–6Al–4V substrate through a plasma spray technique were immersed in simulated body fluid (SBF) to investigate their behavior in vitro. Surface morphologies and structural changes in the coatings were analyzed by scanning electron microscopy, thin-film X-ray diffractometer, and X-ray photoelectron spectroscopy. The tensile bond strength of the coatings after immersion was also conducted through the ASTM C-633 standard for thermal sprayed coatings. Results showed that carbonate-containing hydroxyapatite (CHA) layer formed on the surface of composite coatings after 4 weeks immersion in SBF solution, indicating the composite coating possessed excellent bioactivity. The mechanical properties were found to decrease with immersion duration of maximum 56 days. However, minimal variation in mechanical properties was found subsequent to achieving supersaturation of the calcium ions, which was attained with the precipitation of the calcium phosphate layers. The mechanical properties of the composite coating were found to be significantly higher than those of pure HA coatings even after immersion in the SBF solution, indicating the enhanced mechanical properties of the composite coatings.

Bioactive modification of titanium by coating bioactive glasses

Two different bioactive glasses, 55SF (55.1SiO2-3.4P2O5-9.2Na2O-27.8CaO-4.5CaF2; mol%) and 50SB (50.1 SiO2-3.4P2O5-9.2Na2O-32.3CaO-5B2O3; mol.%), were used to coat titanium metal in order to make it bioactive. The bonding characteristics between titanium substrate and bioactive glass were examined and then the hydroxyapatite formation on the coated specimen was studied after its reaction in a simulated body fluid (SBF). A thin film X-ray diffractometer and scanning electron microscope were employed for the examination of the coated layer surface. Ionic concentrations in the reacted solution were also measured. When the 55SF glass was coated with a ground coat, a Ti5Si3 crystal was formed at the interface between the titanium and the glass coat. There was no hydroxyapatite found on this layer when reacted in a SBF. 50SB glass was used as a cover coat and fired at various temperatures. An amorphous phase was observed when fired at 800°C, while oxyapatite crystal was obtained when fired at 900°C. When those samples were reacted in a SBF, hydroxyapatite crystal was deposited only on the sample that had an amorphous phase.