在非水溶液体系中电泳沉积Ti6Al4V/BG/IIA梯度涂层

本工作的目的是探索制备钛合金表面生物活性梯度涂层的新方法,提高涂层的结构强度及稳定性,通过诱导羟基磷灰石（HA）在生物玻璃（BG）颗粒表面的结晶,改变了生物玻璃表面的带电特性;采用电泳沉积（EPD）法,大非水溶液体系中实现了BG和HA在阴极Ti6Al4V基体上的共沉积,经烧结获得了生物活性梯度陶瓷涂层,得到了一种制备生物活性梯度陶瓷涂层的新工艺,用XRD对涂层的相组成进行了定性分析,结果表明涂层由HA,榍石和玻璃组成;采用粘结拉伸法测定的涂层与基体结合强度大于18MPa,用SEM观察涂层表面及断面的形貌,可见涂层表面较为平整,没有明显的裂纹;涂层与基体结合紧密,且存在一明显的界面梯度区域。     

冰醋酸介质中电泳共沉积制备生物玻璃/羟基磷灰石涂层

通过研究生物玻璃(bioglass，BG)微粉和羟基磷灰石(hydroxyapatite，HA)微粉在水和非水介质中的分散及带电特性，选择冰醋酸为介质，使分散在其中的BG颗粒和HA颗粒表面均带上正电荷，为电泳共沉积提供了前提条件。通过对BG颗粒和HA颗粒在冰醋酸介质中电泳共沉积以及后续低温快速热处理，在钛合金基体上成功地制备出了底层致密而表层附近多孔的BG／HA涂层。并对所制备的BG／HA涂层的力学性能和微观结构及组成进行了测试分析。     

电泳沉积和反应结合制备羟基磷灰石/氧化铝复合涂层

在金属表面用电泳沉积(electrophoretic deposition, EPD)法制备羟基磷灰石(hydroxyapatite, HA)涂层的主要问题是结合强度较低.为了提高HA涂层与基体的结合强度,先采用EPD在钛表面制得羟基磷灰石/铝(hydroxyapatite/aluminum, HA/Al)复合涂层,然后采用反应结合方法(reaction bonding process)制备羟基磷灰石/氧化铝(hydroxyapatite/aluminum oxide, HA/Al2O3)复合涂层,并与相同条件下制备的HA单一涂层进行比较研究.用扫描电镜表征涂层的表面和横截面形貌.用能量散射X射线衍射(X-ray diffraction, XRD)谱分析HA/Al2O3复合涂层的化学组成.用XRD仪研究涂层的物相组成和热稳定性.通过黏结-拉伸实验测定HA涂层与基体的结合强度.结果表明:通过850℃热处理,HA/Al复合涂层中的Al粉发生氧化反应生成Al2O3,经反应结合得到HA/Al2O3复合涂层;反应结合提高了HA涂层的致密化程度且降低了基底钛表面的氧化程度;与单一HA涂层相比,HA/Al2O3复合涂层与基底间的结合强度得到明显提高.     

水热电沉积法制备羟基磷灰石/氧化钛复合涂层的研究

采用水热电沉积法．在钛金属基体￡：成功制备了羟基磷灰石(hydroxyapatite,HA)氧化钛(HA／TiO2)复合涂层．对涂层的表面形貌、相组成、TiO2共沉积量、热稳定性和结合强度进iir研究。实验结果表明：复合涂层具有较均匀的微观结构。TiO2的加入明显改善了涂层与基体的结合强度．涂层中TiO2含量越高．结合强度的提高也越显著。在200℃．100g／L TiO2条件下．电沉积制备的HA／TiO2复合涂层的结合强度为21.0MPa,约为纯HA涂层的2倍。TiO2共沉积量随电解液中TiO2浓度的提高逐渐增加;随电解液温度的提高先增后降,在160C达到最大。涂层经800℃热处理后,TiO2促使HA部分分解为β-磷酸钙(β-tricalciumphosphate,β-TCP)和CaO;经1200℃热处理后,HA和TiO2发生相互作用生成α-TCP和CaTiO3。     

医用Ti合金表面生物玻璃涂层的制备与研究

在医用Ti合金表面涂覆一层生物玻璃涂层可阻止金属离子的溶出并且提高其生物活性。本文采用溶胶-凝胶法在Ti合金基体上制备了SiO2-CaO-MgO-P2O5系生物玻璃涂层。利用差示量热扫描仪(DSC)、扫描电镜(SEM)、拉伸试验和模拟体液(SBF)浸泡等手段系统研究了涂层的表面形貌、粘附性能及生物活性。结果表明:热处理温度为800℃时涂层与基体间的粘附强度最大,涂层越薄涂层与基体间的粘附强度越大;在模拟体液中浸泡30天后,材料表面生成了大量磷灰石。用溶胶-凝胶法可在Ti合金基体上制备出SiO2-CaO-MgO-P2O5系生物活性高的生物玻璃涂层。     

溶胶凝胶法制备羟基磷灰石/TiO2复合生物活性涂层的研究

通过溶胶凝胶法在纯钛基体上制备了羟基磷灰石/TiO2复合生物活性涂层.HA可以提高钛基的生物活性,TiO2可以提高涂层与基体的物理、化学相容性和结合强度.HA和TiO2溶胶由前驱体制得,按不同物质的量比直接混合两种溶胶来制备复合溶胶.使用XRD、SEM研究了不同温度下热处理后涂层的组成和结构.实验结果表明HA的结晶度和晶粒随着温度的升高而提高和变大;涂层表面为连续多孔结构.粘结拉伸结果表明复合涂层与基体结合良好,较纯HA涂层与基体的结合强度有较大提高.复合涂层试样于SBF中浸泡2d、7d和14d的SEM分析结果表明复合涂层表面的磷灰石形成量较高.电位动力学曲线分析表明复合涂层可以提高基体的耐蚀性.     

微弧氧化和电泳沉积复合制备羟基磷灰石/TiO2复合涂层及其生物学特性

采用微弧氧化和电泳沉积复合的方法,在钛样品表面沉积了羟基磷灰石(hydroxyapatite,HA)/TiO2复合涂层.用扫描电子显微镜,能量散射X射线能谱分析和X射线衍射对复合涂层的表面形貌、形成过程、元素组成及含量变化、相组成进行了观察和分析.通过剪切粘结实验确定了复合涂层与基体的结合强度,并在高温消毒后,将成骨样细胞MC-3T3-E1接种于试件表面进行培养以评估HA/TiO2复合涂层的生物学性能.结果表明形成的复合涂层由内层致密的TiO2层、中间HA/TiO2混合过渡层和外层HA层构成,其中HA含量呈梯度变化,使TiO2层逐渐向HA层过渡.HA/TiO2复合涂层和基体间的结合强度约为(19.3±2.5)MPa.通过细胞免疫荧光染色观察到细胞在培养3 h就可附着于复合涂层表面并形成良好的铺展,而且随着培养时间的延长,细胞的形态更加舒展,附着在复合涂层表面的细胞数量亦逐渐增加,初步表明复合涂层具有较好的生物学和力学性能.     

C/C复合材料表面羟基磷灰石/聚丙烯酰胺梯度复合涂层的制备与表征(英文)

以丙烯酰胺单体和声化学法制备的纳米羟基磷灰石(hydroxyapatite,HAp)粉为原料、异丙醇为分散介质,采用水热电泳聚合沉积法在C/C复合材料表面制备HAp/聚丙烯酰胺(polyacrylamide,PAM)梯度复合涂层。用电导率仪、X射线衍射仪、扫描电子显微镜、能谱仪、Fourier变换红外分析仪和万能材料试验机等对悬浮液的电导率以及涂层的物相组成、结构、断面微观形貌和结合强度进行了研究,结果表明:异丙醇中碘的浓度为8g/L时,所制备的涂层由HAp和PAM两相组成;HAP被包裹在黏度较大的PAM中,涂层表面均匀,涂层与基体之间结合紧密,未发现明显的裂纹;涂层中元素沿基体–界面方向呈梯度分布;涂层与基体结合强度最大值达到19.10MPa。     

热处理对钛基体表面电泳沉积GO/HA生物活性涂层的影响

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。     

以葡萄糖为造孔剂制备多孔羟基磷灰石涂层

采用电泳沉积方法在钛基材表面制得羟基磷灰石(hydroxyapatite,HA)/葡萄糖复合涂层,经烧结处理得到多孔HA涂层。采用红外光谱仪、扫描电镜、X射线衍射和热重分析表征了涂层的组成、表面形貌、物相组成及热稳定性,黏结-拉伸实验测定涂层与基体的结合强度,人体模拟体液(simulated body fluid,SBF)浸泡测定涂层的生物亲合性。结果表明:经700℃烧结处理,复合涂层中的葡萄糖微粒热分解得到多孔HA涂层,孔径为2～20μm,涂层与基体的结合强度可达17.6MPa;在1.5倍SBF(各离子浓度为SBF的1.5倍)中浸泡5d后,多孔HA涂层表面碳磷灰石化,呈现良好的生物亲合性。     

两步电化学法制备羟基磷灰石/氧化铝复合生物涂层的研究

研究旨在开发一种可应用于医用金属表面生物学改性的复合生物陶瓷涂层。通过先阳极氧化、再电沉积的两步电化学方法成功制备了羟基磷灰石(hydroxyapatite,HA)／Al2O3复合生物涂层。利用扫描电子显微镜(SEM)研究了阳极氧化Al2O3(anodic aluminum oxide,AAO)膜的表面形貌与HA／Al2O3复合涂层的表面及截面形貌结构;用X射线衍射仪(XRD)、Fourier变换红外光谱仪(FT-IR)与能谱仪(EDS)表征了复合涂层的物相组成;用等离子原子发射光谱仪(ICP-AES)和粘接拉伸试验分别测定涂层在模拟体液(SBF)中的体外行为和浸渍后涂层间的结合强度,结果表明：所制备的HA含有少量碳酸根,在SBF中呈现优良的稳定性并能诱导新的磷灰石层的形成;HA底部嵌入AAO膜的孔洞中形成互锁界面,经模拟体液处理后两者之间结合强度为3．2MPa。     

钛合金表面TiO2-FHA-HA梯度生物陶瓷涂层的制备

采用溶胶-凝胶工艺在经过微弧氧化预处理的钛基体表面制备二氧化钛(TiO2)-含氟羟基磷灰石(FHA)-羟基磷灰石(HA)梯度结构的生物陶瓷涂层.采用X射线衍射检测了涂层的相组成,采用扫描显微镜观察了梯度涂层的形貌,采用划痕法测定了涂基结合力,结果表明:所制备的涂层是均匀和致密的具有梯度结构的TiO2-FHA-HA涂层;与单一的HA涂层相比梯度的引入显著提高了涂基结合力.生物溶解性实验结果显示了溶解速度FHA小于HA,这就表明了可以通过梯度设计来提高涂层的植入寿命.     

Post-hydrothermal treatment of hydrothermal electrodeposited CaHPO4 on C/C composites in sodium silicate-containing solution at various temperatures

Direct deposition of hydroxyapatite (HA) coatings on carbon/carbon(C/C) composites through hydrothermal electrochemical deposition (HED) were limited by the poor bonding strength. To overcome this problem，in this work, CaHPO₄ (monetite) coating was firstly deposited on C/C using HED, and then converted into HA coating in a sodium silicate–containing solution by post-hydrothermal treatment. Effects of post-treatment temperatures on the chemical composition, structure, and bonding strength of the coatings were investigated. The results showed that obtained monetite showed a compact microstructure, and could react with the solution to produce a well-crystallized HA as well as amorphous silicate which contained some calcium and sodium ions. All the coatings were composed of rod-like crystals. The diameter of these crystals increased when the post-hydrothermal temperature was changed from 110?℃ to 140?℃, and then decreased at 155?℃. The Si contents and the adhesive strength of the HA coatings showed a similar temperature dependence to the crystal size of the HA. 140?℃ is determined to the optimal treatment temperature, at which the HA coating reached the highest critical load of 24.02?N, corresponding to the shear strength of 82.83?MPa. The bioactivity of the HA coating on C/C increased with the increasing post-treatment temperature.     

Fabrication of Ti/TiO2(Ca)/hydroxyapatite bioceramic material by micro-arc oxidation and electrochemical deposition

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.     

Effect of transition layer on the performance of hydroxyapatite/titanium nitride coating developed on Ti-6Al-4V alloy by magnetron sputtering

A gradient transition multilayer hydroxyapatite/titanium nitride (HA/TiN) coating was prepared on the Ti-6Al-4V alloy by magnetron sputtering. The composition, surface topography, microstructure, adhesion strength and electrochemical properties of the as-deposited coatings were characterized by SEM/EDS, AFM, XRD, FT-IR and electrochemical workstation. The experimental results showed that the single TiN coating deposited at a partial pressure of nitrogen (N₂) of 0.08?Pa had the best internal stress and tribological performance, and its volume loss was only 0.89% of that of Ti-6Al-4V alloy. The introduction of the TiN transition layer greatly improved the wear resistance of the Ti-6Al-4V alloy, and the adhesion strength of the HA layer to the substrate increased from 6.50?±?0.5?N to 11.70?±?1.2?N, an increase of 56%. The HA/TiN coating surface consisted of uniform hemispherical particles with dense structure and invisible defects (micro-cracks and pores). For the HA surface layer, the crystal structure and active hydroxyl (-OH) group was restored after heat treatment. Potentiodynamic polarization experiments indicated that the HA/TiN coating achieved the lowest corrosion current density and the most positive corrosion potential compared to the single TiN layer and Ti-6Al-4V alloy. In summary, it can be conclude that the gradient transition layer can well improve the mechanical properties and electrochemical behavior of the titanium alloy, and largely ensuring the stability of the surface bioactive coating.     

Nano-Sized Hydroxyapatite Coatings on Ti Substrate with TiO2 Buffer Layer by E-beam Deposition

A nano-sized hydroxyapatite (HA) layer was coated on a Ti substrate with a titanium oxide (TiO₂) buffer layer by the electron-beam deposition method. The morphological features as well as the mechanical and biological properties of the HA/TiO₂-layered coating were noticeably different from those of a conventional HA coating on Ti. The HA on the TiO₂ layer replicated the fine grain structure of the TiO₂ layer, with grain sizes of just a few tens of nanometers. The TiO₂ buffer layer was highly effective in preserving the adhesion strength of the coating layer following the heat treatment at 500°C, which was necessary to crystallize the structure. Moreover, in contrast to the HA single coating wherein severe cracking was observed under moist conditions, the HA/TiO₂ coating retained its mechanical stability under the same conditions. The dissolution of the HA/TiO₂ coating in a physiological saline solution exhibited a more favorable pattern than that of the HA single coating, with a reduced initial burst and a subsequent steady release rate. Preliminary in vitro cellular tests showed that osteoblastic cells expressed a significantly higher alkaline phosphatase level on the HA/TiO₂ coating than on the HA single coating. Conclusively, the nano-sized HA coating with the TiO₂ buffer layer holds great promise as a bioactive coating system.     

医用钛合金表面羟基磷灰石/二氧化锆梯度复合涂层的制备

用恒电流沉积方法分别在ZrO(NO3)2电解液和由Ca(NO3)2及NH4H2PO4组成的电解液中制备出羟基磷灰石/二氧化锆(HA/ZrO2)梯度医用复合涂层.通过扫描电镜观察,研究了沉积电流和沉积时间对涂层形貌的影响.结果表明,当沉积电流为11.1 mA,沉积时间为400 s时,在锆电解液中可获得均匀的钛基Zr(OH...     

Mechanical and histological evaluation of a plasma sprayed hydroxyapatite coating on a titanium bond coat

To improve the biological stability of hydroxyapatite-coated implants, the use of an appropriate commercial pure titanium bond coat (CP-Ti) is an effective method for significant improvement in the interface bonding and stress reduction of the plasma-sprayed HA coating and Ti-alloy system. The purpose of this study was to determine the effect of plasma-sprayed CP-Ti on the in vivo properties of the HA coating on Ti6Al4V. According to the experimental results, samples with an HA coating on the CP-Ti (Ti-HA coating) display a lower and ineffective residual stress than samples without the bond coat. The CP-Ti provides a very rough surface and results in a higher adhesive strength between the HA and CP-Ti. In the in vivo test, after the intramedullary implantation, the histological observation showed the apposition of the new bone tissue directly onto the HA coating. The shear strength between the bone and the Ti-HA coating was higher than that without CP-Ti after 12 weeks of implantation (5.15 vs. 1.41 MPa). The failure mode analysis showed the failure mainly occurring at the surrounding bone, with some failure at the HA/CP-Ti interface. The excellent bio-durability and mechanical properties of the HA coating in this study contributed to the reduction of the compressive residual stress in the HA coating and to the enhancement of interface adhesive strength by introducing the commercial pure titanium bond coat.     

Porous Hydroxyapatite Scaffolds Coated With Bioactive Apatite–Wollastonite Glass–Ceramics

The objective of this study was to fabricate porous hydroxyapatite (HA) scaffolds coated with bioactive A/W glass–ceramics and to examine their mechanical and biological properties. Firstly, the HA scaffolds were prepared by the polymeric sponge replication method, and then A/W glasses were coated on the surface of the struts. All of the scaffolds had a highly porous structure with well-interconnected pores. It was observed that the bioactive glass coating markedly increased the strength of the HA scaffolds. This enhancement was attributed to the formation of a dense and strong coating layer on the weak HA struts. The in vitro bioactivities of the scaffolds were markedly improved by the coatings. When the coated scaffolds were soaked in a simulated body fluid (SBF), the bone-like apatite crystals were well mineralized on their surfaces. Osteoblast-like cells (MC3T3) adhered, spread, and grew well on the porous scaffolds. The cells placed on the glass-coated HA scaffold showed a higher proliferation rate and alkaline phosphatase (ALP) activity than those on the pure HA scaffold. These results demonstrate that the bioactive glass coating is effective in improving the strength and bioactivity of the porous HA scaffolds.