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1.
《Ceramics International》2021,47(19):27071-27081
In this work, ternary HA/chitosan/graphene oxide (GO) coating was applied via electrophoretic deposition on AZ91D magnesium alloy as bone implants, successfully. Subsequently, phase composition, surface morphology, hardness, corrosion behavior, bioactivity and antibacterial of the composite coatings were studied. Hardness and Young's modulus of the composite coatings increased from 40 ± 1.5 MPa and 3.1 ± 0.42 GPa to 60 ± 3.12 MPa and 8 ± 0.53 GPa for composite coatings with 0 and 2 wt% GO, respectively. The results of the SBF solution soaking of the composites after 24 days, indicated the improvement of HA growth due to the increasing of the GO addition in composite coating. New HA grains with leaf-like morphology grew uniformly at higher amounts of GO (1 and 2 %wt) in a perfectly balanced composition. Rate of the substrate corrosion significantly decreased from 4.3 to 0.2 (mpy), when the amount of GO increased from 0 to 2 wt% due to reduction of the surface cracks at the presence of the GO reinforcement. Also, there was no Escherichia coli and Staphylococcus aureus bacteria growth in broth medium after 24 h and OD600 results at 24 h post inoculation for the 2%wt GO addition in coating.  相似文献   

2.
Graphene oxide (GO) was firstly employed as nanoscale reinforcement fillers in hydroxyapatite (HA) coatings by a cathodic electrophoretic deposition process, and GO/HA coatings were fabricated on pure Ti substrate. The transmission electron microscopy observation and particle size analysis of the suspensions indicated that HA nanoparticles were uniformly decorated on GO sheets, forming a large GO/HA particle group. The addition of GO into HA coatings could reduce the surface cracks and increase the coating adhesion strength from 1.55 ± 0.39 MPa (pure HA) to 2.75 ± 0.38 MPa (2 wt.% GO/HA) and 3.3 ± 0.25 MPa (5 wt.% GO/HA), respectively. Potentiodynamic polarization and electrochemical impedance spectroscopy studies indicated that the GO/HA composite coatings exhibited higher corrosion resistance in comparison with pure HA coatings in simulated body fluid. In addition, superior (around 95% cell viability for 2 wt.% GO/HA) or comparable (80–90% cell viability for 5 wt.% GO/HA) in vitro biocompatibility were observed in comparison with HA coated and uncoated Ti substrate.  相似文献   

3.
采用电泳沉积法在钛基体表面制备氧化石墨烯(GO)/羟基磷灰石(Ca10(PO4)6(OH)2, HA)复合涂层,通过XRD和SEM等测试手段对不同热处理条件下得到的GO/HA涂层进行表征。研究结果表明,热处理有助于促进涂层中HA结晶度的提高,600 ℃和800 ℃的热处理温度并没有导致HA发生热分解,但有可能破坏了涂层中GO的有序晶体结构。GO/HA涂层具有优异的生物活性,但随热处理温度的升高,涂层的润湿性和生物活性下降。热处理过程有利于涂层致密,加强涂层与基体的结合,800 ℃热处理后的涂层结合强度高达25.31 MPa。  相似文献   

4.
《Ceramics International》2020,46(17):27021-27030
To explore a new approach for fabricating the load bearing implants with the combination of bioactivity, biocompatibility, and mechanical properties, mechanically mixed hydroxyapatite (HA) and titanium (Ti) powders containing 30, 50, and 70 wt% Ti were sprayed onto a 316L stainless steel substrate using a warm spray (WS) process. The microstructures, phase compositions, chemical structures, and mechanical properties of WS HATi composite coatings were comprehensively investigated and compared to those of WS HA coating. Experimental results indicate that the cross-sectional microstructures of WS HATi composite coatings present typical lamellar structures composed of curved stripes formed by well-deformed and oxidized Ti splats and limited deformed HA splats, and are significantly influenced by the Ti content in the original powders. Phase constitutions of the composite coatings mainly consist of HA, Ti, TiO2, and TiO. Chemical structures of HA in the composite coatings deposited using powders with Ti content less than 30% are similar to the structures in the original powder. The microhardness, elastic modulus, and bond strength of the coatings increased from 0.32 ± 0.15 GPa to 1.41 ± 0.31 GPa, from 1.37 ± 0.28 GPa to 23.28 ± 3.45 GPa, and from 17.3 ± 2.2 MPa to 34.8 ± 3.2 MPa, respectively. The abrasive wear weight loss of the coatings on Al2O3 abrasive paper decreased from 2.9 mg to 1 mg, as the addition of Ti particles in original powders increased from 0 to 70%.  相似文献   

5.
Hydroxyapatite (HA) coated carbon/carbon composites (CC) is a potential material for orthopedic application because of the combination of good biocompatibility and mechanical properties. In this work, we synthesize a tree-planting interface which is composed of holes formed by micro-oxidized CC substrates and carbon nanotubes (CNTs) to achieve a high bonding strength of HA coating. The holes include annular gaps between carbon fiber and pyrolytic carbon, as well as irregular holes formed by oxidized pyrolytic carbon. The CNTs can grow inside the holes and extend into the HA coating. As a result, the bonding strength of HA coating with tree-planting interface achieves 11.14 ± 0.78 MPa. It increases by 181.3% comparing with the HA coating on CC without interface (3.96 ± 0.30 MPa). The in-vitro bioactivity evaluated by the response of mesenchymal stem cells (MSCs) shows promotions of cell proliferation and cell activity with increasing culture time. After applied with tree-planting interface, the HA coating with strong bonding and good bioactivity may be applied in orthopedic field in the future.  相似文献   

6.
《Ceramics International》2016,42(14):15650-15657
Carbon nanotubes-hydroxyapatite (CNTs-HA) composite coatings, which behaved like single composites, were synthesized by a combined method composed of electrophoretic deposition and pulsed electrodeposition. The phase compositions and the microstructure of the composite coatings were studied by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Fourier transform infrared spectrometry (FTIR). Potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) studies showed that the CNTs-HA composite coatings protected the bare carbon/carbon composites from corrosion in simulated body fluid (SBF) solution. The adhesion strength of CNTs-HA composite coating prepared by the combined method is 14.57±1.06 MPa achieved at the CNTs EPD time of 10 min. Compared to the other CNTs-HA composite coatings with different content of CNTs, the CNT-HA composite coating with the electrophoretic deposition of 10 min showed the best corrosion resistance. The morphology of CNTs-HA composite coatings immersed in SBF solution rendered the formation of HA crystallites. In addition, in vitro cellular responses to the CNTs-HA composite coatings were assessed to investigate the proliferation and morphology of mouse cells 3T3 cell line.  相似文献   

7.
《Ceramics International》2022,48(7):9579-9594
In the field of orthopaedic implants, post-surgery infections and biocompatibility are the most challenging obstacles. Sustained and controlled antibiotic release is a key factor in novel drug delivery systems. A novel drug delivery system combined with vaterite microsphere, graphite oxide (GO), reduced graphene oxide (rGO) incorporated in a polycaprolactone (PCL) matrix on TiO2 nanotube coated Ti (TNT-Ti) is established. Anodization was employed to develop TiO2 nanotubular arrays on Ti. Ciprofloxacin hydrochloride (CPF–HCl) loaded vaterite microspheres were synthesized by in situ precipitation method. Deposition of vaterite/PCL, vaterite-GO/PCL and vaterite-rGO/PCL composite coating on TNT-Ti was carried out by dip coating method. The composite coatings were characterized for their phase content, morphological features and functional groups. Among the three types of composite coatings, vaterite-rGO/PCL composite coating is found to be capable of encapsulating CPF-HCl to a level of 75.14 μg. The drug release profile of CPF-HCl from the vaterite-rGO/PCL composite coating exhibits a controlled release amounting to only 35.02 % of release at the end of 120 h. The vaterite-rGO/PCL composite coating exhibits a low dissolution rate and possesses adequate bioactivity in HBSS and SBF solutions at 37 °C for 14 and 10 days, respectively. The in situ loaded CPF-HCL drug on vaterite microspheres, PCL polymer matrix and GO/rGO nanofillers does not affect the cytocompatibility and all the composite coatings supported cell viability and proliferation. The ability of vaterite-rGO/PCL composite coating to provide a slow and steady release of antibiotics with sufficient bioactivity and biocompatibility at the tissue implant interface makes it a promising for osteomyelitis infection of bone tissue implant materials.  相似文献   

8.
In this study, hydroxyapatite (HA) coatings containing carboxymethyl cellulose (CMC) and graphene (Gr) were developed on AZ31 magnesium alloy through two-step electrophoretic deposition method. The morphology and chemical bonding of coatings were characterized and also the phase identification was done using scanning electron microscopy, Fourier transform infrared spectroscopy, and X-ray diffraction, respectively. Moreover, the corrosion behavior of the applied coatings was compared with the bare AZ31 Mg alloy substrate in the simulated body fluid by the means of potentiodynamic polarization test and electrochemical impedance spectroscopy. Obtained results revealed that the novel HA-CMC-Gr coating possesses the highest corrosion resistance compared to the HA, HA-CMC, and HA-Gr coatings due to its uniform and compact structure. To investigate the mechanical properties and to elucidate the effect of CMC on the adhesion of coating-alloy interface, pull-off test was employed, where results demonstrated that the addition of CMC increases the adhesion force from 1.06 MPa to 1.62 MPa. Besides, the modulus of elasticity and the hardness of HA and HA-Gr composite coatings were compared by applying nanoindentation test. Interestingly, it is detected that the presence of Gr has considerably increased the elastic modulus of the coating by approximately 30% in comparison to the pure HA coating.  相似文献   

9.
《Ceramics International》2022,48(14):19937-19943
Titanium with a bioceramic hydroxyapatite (HA) coating has been widely used in biomaterials owing to its excellent mechanical characteristics and high osteoconductivity. However, the interfacial strength of Ti/HA prepared by electrochemical deposition (ED) is relatively low because the physical combination is typically inadequate. In this study, to improve the interfacial strength, a micro-arc oxidation (MAO) process with calcium was introduced for preparing a connecting interlayer known as the MAO coating. Pulsed ED was employed to synthesise the HA coating on the MAO surface using an electrolyte with 6 wt% H2O2. Sample characterisations revealed that the MAO coating comprised porous TiO2 (rutile and anatase) with Ca or CaTiO3. The formation of CaTiO3 depends on the current density, reaction time, and concentration of Ca2+, in addition to voltage. The MAO coatings exhibited a higher corrosion resistance than that exhibited by Ti substrates. Furthermore, the HA coating on the MAO coating was confirmed to be plate-like Ca-deficient HA. The final sample had a Ti/TiO2(Ca)/HA structure, and its adhesive strength was approximately double that of the Ti/HA sample. In particular, the MAO coating synthesised at a high Ca2+ concentration exhibited an improved adhesive strength (2.326 MPa). The application of the MAO coating containing Ca as a connecting interlayer is a promising strategy for improving the HA adhesion strength.  相似文献   

10.
The addition of bio-inert ceramics such as alumina and zirconia can significantly improve the mechanical properties of hydroxyapatite bioactive coatings and increase their biocompatibility. In the present study, the surface of a titanium substrate was coated by the electrophoretic deposition method (EPD). Moreover, the reaction bonding process has been used to precipitate the nanocomposite containing the hydroxyapatite (HA), alumina, yitteria-stabilized zirconia (YSZ). The coating process was performed by an electrical power supply and a suspension of hydroxyapatite, aluminum, and YSZ nanopowders. For preparing a suspension consisting of 50% isopropanol and 50% acetone, 0.6 g/L of iodine was used as a stabilizer. Green and sintered coatings were analyzed by FE-SEM and XRD. In addition, the mechanical properties such as bonding strength, hardness, and toughness were measured. The hardness, bonding strength, and toughness of the HA coating were 107 ± 10.3 HV, 10.8 ± 3.2MPa, and 0.72MPa√m, respectively, while those of the HA-Al2O3-YSZ nanocomposite coating were 213 ± 1.8 HV, 35 ± 1.6MPa, and 1.6MPa√m, respectively.  相似文献   

11.
《Ceramics International》2022,48(16):23314-23324
Magnesium (Mg)-based alloys have appealing properties as promising implants for medical applications. However, their clinical applications are hindered due to the rapid corrosion and degradation rate in the physiological environment. In this investigation, we reported a novel interfacial engineering approach for the fabrication of polymer/ceramic hybrid coating on Mg–Zn–Ca Mg alloy. Firstly, hydroxyapatite (HA) coating was fabricated on the Mg–Zn–Ca sample followed by an alkali treatment that was performed in 1 M NaOH solution at 60 °C. Finally, polycaprolactone (PCL) coating was synthesized using a dip-coating approach on the top of the HA-coated Mg–Zn–Ca specimen. Microhardness test and adhesion test revealed that PCL/HA hybrid coating significantly improved mechanical properties and enhanced biointerface property between the substrate and coating. The immersion tests showed that the hybrid coating considerably slowed down the degradation in the simulated body fluid (SBF) solution. In addition, in vitro electrochemical investigations confirmed that PCL/HA coating significantly improved corrosion resistance and greatly reduced corrosion rate by about 10 times compared to HA coating and about 900 times to untreated Mg–Zn–Ca sample. Moreover, cytotoxicity assessment exhibited PCL/HA hybrid coating enhanced biocompatibility and bioactivity due to adopting a suitable interfacial engineering approach.  相似文献   

12.
Graphene oxide (GO) was modified by 3-methacryloxypropyltrimethoxysilane (MPS) to obtain modified graphene oxide (MGO). MGO was dispersed in urushiol-formaldehyde polymer by mechanical mixing and ultrasonic dispersion, and MGO/urushiol-formaldehyde polymer (UFP) coatings with different MGO contents were fabricated. The microstructure, physico-mechanical properties, and electrochemical properties of the MGO/UFP composite coatings were investigated. The results indicated that the hardness, adhesion, and corrosion resistance of the MGO/UFP composite coatings were obviously enhanced compared with the pure UFP coatings. The hardness and the adhesion grade of the MGO/UFP composite coatings with 3.5 wt% MGO (GO, 1.5 wt%, and MPS, 2.0 wt%) reached 6H and 2, respectively. Additionally, GO connected with MPS by chemical bond and the well-dispersed MGO in UFP could significantly enhance the anticorrosion performance of the UFP coatings, which could result from bending the diffusion pathway of penetrant species in the UFP coating matrix.  相似文献   

13.
针对金属腐蚀问题,制备了以环氧涂层为底漆,溴代环氧涂层为面漆的溴代环氧/环氧复合涂层。研究结果表明:环氧树脂的极性为涂层提供良好的附着力,溴代环氧树脂的疏水性有效提高涂层的抗渗透性能。复合涂层具有低润湿性(吸水率:0.217%,接触角:93.6°)、高附着力(干:5.28 MPa,湿:2.52 MPa)和优异的耐盐水防腐性能(浸泡70 d后,|Z|0.01 Hz>108 Ω·cm2)。通过综合利用溴代环氧树脂和环氧树脂的优势,使复合涂层具有良好疏水性、屏蔽性,有效提高涂层的防护能力,实验结果表明,该涂层具有防腐的长效性和实用性。  相似文献   

14.
《Ceramics International》2020,46(6):7374-7387
Carbon/carbon (C/C) surface micropatterning is a method of modifying the surface into the complete and regular geometry. In this work, we introduce a positive effect on bonding strength between sprayed Ca–P coating and surface micropatterning C/C substrate. Interestingly, C/C substrate coated by Ca–P coating provides textured surface for a new bone ingrowth. The sprayed Ca–P coating is then subjected to microwave-hydrothermal (MH) treatment with the aim of eliminating surface defects and obtaining a uniform purity phase. These objectives were achieved in our previous study by the MH method. The molar ratio of Ca/P in the coatings is nearly close to 1, which is far below that of Ca/P for hydroxyapatite (Ca10(PO4)6(OH)2, HA, 1.67). The purpose of this article is to transform the phases in the sprayed Ca–P coating, which owns the better bioactivity and high corrosion resistance. In order to raise the molar ratio of Ca/P, the coatings are treated under high-temperature (around 700 °C). They are analyzed by scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and a fourier transform infrared spectra (FTIR). The bonding strength (coating/substrate), biological activity and corrosion resistance of the coatings are investigated. The resulting coatings own the different microstructures and phase compositions from the original sprayed Ca–P coating. Especially, results show that the shear strength of the sprayed Ca–P coating deposited on surface micropatterning C/C substrate increases by 61% which is more than that of the coating on non-surface micropatterning C/C substrate. Additionally, high-temperature treated coating presents a good biological activity and an excellent corrosion resistance of current density (1.3078 × 10-6 A/cm2) and potential (−0.17 VSCE).  相似文献   

15.
《Ceramics International》2016,42(9):10638-10644
In this study, ceramics containing mixed phases of hydroxyapatite/beta-tricalcium phosphate (HA/β-TCP) were fabricated by a solid-state reaction technique. The HA powder was synthesized from cockle shells while the β-TCP powder was synthesized from egg shells. Pure HA and β-TCP fine powders were successfully obtained. The HA and β-TCP were mixed and subjected to a thermal treatment up to 1100 °C. To form the mixed phase ceramics, the resulting powders were sintered at 1350 °C. Effects of HA concentration on the properties of the studied ceramic were investigated. X-ray diffraction analysis revealed that all samples presented multiphase of calcium phosphate compounds. Average grain size of the ceramics decreased with the HA additive content. The 75 wt% HA ceramic showed the maximum hardness value (5.5 GPa) which is high when compared with many calcium phosphate ceramics. In vitro bioactivity test indicated that apatite forming increased with the HA additive content. To increase antibacterial activity, selected ceramics were coated with AgNO3. Antibacterial test suggested that an Ag compound coating on the ceramics could improve the antibacterial ability of the studied ceramics. In addition, the antibacterial ability for the Ag coated ceramics depended on the porosity of the ceramics.  相似文献   

16.
《Ceramics International》2020,46(10):15882-15888
Hydroxyapatite (HA) was fabricated in microns as its basic size. The particle size distribution was controlled by mixing micron- and nano-sized HA to obtain the optimum amount of mixture to improve its properties. HA powder with a size of 2.5 μm was mixed with that with a size of 200 nm, with a variety of concentrations of up to 20 wt%. A green body was fabricated using the uniaxial pressing method at a pressure of 200 MPa. The sintering process was conducted at a temperature of 1200 °C, heating rate of 3 °C/min, and holding time of 2 h in air. The physical characteristics of the HA sintered body were determined using X-ray diffraction, scanning electron microscopy, linear shrinkage, and density testing. The mechanical properties of the HA sintered body were tested using compressive strength testing. The test results indicated that the mechanical properties of the HA sintered body increased with the addition of nano-sized HA. The mechanism of the increasing strength occurred because nano-sized HA particles filled the gaps between the micron-sized particles. In this study, the highest mechanical properties were obtained by adding 20 wt% nano-sized HA. The compressive strength in the sample without added nano-sized HA was 132.2 MPa and increased significantly to 208.6 MPa with the addition of nano-sized HA of 20 wt%. No change in the phase in HA was observed within a sintering temperature of 1200 °C.  相似文献   

17.
《Ceramics International》2023,49(6):9239-9250
Zinc oxide coatings were electrodeposited on Ti6Al4V substrates from a nitrate bath with and without 1 wt% BG nanoparticles at ?1.2 and ?1.4 VAg/AgCl, where the former voltage created a spherical morphology, the latter developed a flower-like one. The spherical morphology was modified through the incorporation of BG nanoparticles, where surface roughness, wettability, and adhesion strength of the coating were enhanced. The coatings with spherical morphology also revealed complete barrier property after immersion in PBS solution. However, fully adverse effects were found for the coatings deposited at ?1.4 VAg/AgCl. This indicates that morphology is the most important factor determining the properties of ZnO and ZnO-BG coatings. The highest corrosion barrier performance was achieved for the ZnO-BG composite coating with spherical morphology. Although the composite coating with flower-like morphology did not provide complete barrier property at short immersion times, it earned that at longer times due to the plugging supported by the BG nanoparticles. The bioactivity tests in SBF at long times showed that the formation of Ca-P deposits on the surface of the composite coatings was noticeably improved.  相似文献   

18.
The successful fabrication of hydroxyapatite‐bioactive glass scaffolds using honeycomb extrusion is presented herein. Hydroxyapatite was combined with either 10 wt% stoichiometric Bioglass® (BG1), calcium‐excess Bioglass® (BG2) or canasite (CAN). For all composite materials, glass‐induced partial phase transformation of the HA into the mechanically weaker β‐tricalcium phosphate (TCP) occurred but XRD data demonstrated that BG2 exhibited a lower volume fraction of TCP than BG1. Consequently, the maximum compressive strength observed for BG1 and BG2 were 30.3 ± 3.9 and 56.7 ± 6.9 MPa, respectively, for specimens sintered at 1300°C. CAN scaffolds, in contrast, collapsed when handled when sintered below 1300°C, and thus failed. The microstructure illustrated a morphology similar to that of BG1 sintered at 1200°C, and hence a comparable compressive strength (11.4 ± 3.1 MPa). The results highlight the great potential offered by honeycomb extrusion for fabricating high‐strength porous scaffolds. The compressive strengths exceed that of commercial scaffolds, and biological tests revealed an increase in cell viability over 7 days for all hybrid scaffolds. Thus it is expected that the incorporation of 10 wt% bioactive glass will provide the added advantage of enhanced bioactivity in concert with improved mechanical stability.  相似文献   

19.
《Ceramics International》2020,46(9):13539-13548
Hydroxyapatite (HA) coatings, reinforced with varied concentration (0–2 wt%) of Graphene nanoplatelets (GNPs) have been deposited on titanium alloys (Ti–6Al–4V) substrate using atmospheric plasma spraying. Present work studies the effect of GNP concentration on the electrochemical behaviour of the HA coatings in simulated body fluid (SBF). The HA coating exhibited 15% porosity, whereas reinforcement of 1 wt% GNPs in HA (HA-1G) shows 13% porosity, further addition of 2 wt% GNPs in HA reduced the porosity to 10%. Reduction in porosity was achieved as GNPs easily accessed the inter-lamellae to fill the gaps at inter splat region and minimized the occurrence of post-plasma spray defects such as porosity, voids, microcracks etc. These consequences nextward resulted in the significant enhancement in corrosion resistance of the matrix. HA-1G displayed a significant reduction by 67% in the corrosion rate in SBF solution, while this reduction came to 87% for HA-2G coatings. Randomly oriented wrinkles in the GNPs after corrosion process and their hydrophobic nature effectively hindered the SBF infiltration into the coating and resisted their movement towards the underlying substrate. This in turn improved the overall corrosion resistance of the system.  相似文献   

20.
《Ceramics International》2016,42(10):11876-11888
Bacterial infection are serious complications for biomedical implants in the orthopedic and dental fields, and the ideal implants should combine good antibacterial ability and bioactivity. In this paper, we have fabricated the strontium/copper substituted hydroxyapatite (SrCuHA) coating on the commercially pure titanium (CP-Ti) and studied their effect on antibacterial and in vitro cytocompatible properties. Cu was incorporated into HA in order to improve its antimicrobial properties. Sr was added as a second binary element to improve the biocompatibility. The structural and morphological characteristics of the SrCuHA coatings were investigated using various analytical techniques. The presence of Sr2+ and Cu2+ in solution led to reduced roughness of the coating and finer nucleus size formed. The results highlight that Sr2+ and Cu2+ were homogenously incorporated into HA lattice to form SrCuHA coatings. Inductively coupled plasma mass spectrometry (ICP-MS) was used for the leach out analysis of the samples. A low contact angle value revealed the hydrophilic nature. In vitro electrochemical corrosion studies indicated that the SrCuHA coating sustain in the stimulated body-fluid (SBF), exhibiting superior corrosion resistance with a lower corrosion penetration rate than the bare CP-Ti substrate. The SrCuHA coatings can kill Escherichia coli to a certain extent during the first few days, which might be due to the Cu substitution in the coating. An enhancement of in vitro osteoblast adhesion, proliferation, and alkaline phosphatase activity was observed, which could lead to the optimistic orthopedic and dental applications.  相似文献   

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