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.     

钛涂覆多孔羟基磷灰石/氧化铝生物陶瓷涂层的性能研究

通过电泳沉积的方法在生物医用钛基体表面制备羟基磷灰石(HA)/Al/壳聚糖(CS)复合涂层,通过高温烧结分解CS颗粒并制备钛基多孔HA/Al_2O_3复合生物陶瓷涂层。通过粘结-拉伸实验测定涂层与基材的结合强度;XRD和SEM对涂层的物相组成和形貌进行表征;CHI660C电化学工作站测试涂层在模拟体液中的耐蚀性能。研究表明,经过热处理后的涂层为表面可形成平均孔径为5μm的多孔HA/Al_2O_3,涂层厚度可达25μm,涂层中的HA颗粒致密粘连,Al在高温条件下反应成Al_2O_3从而使涂层与基体的结合强度最高可达30.5MPa,涂层的涂覆使Ti金属在人体模拟体液中具有良好的耐腐蚀能力。     

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.     

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。     

多孔钛支架表面羟基磷灰石的仿生生长

以纯钛粉为原料,采用选区激光烧结(SLS)技术制备不同孔隙率仿生人工骨试样。测试烧结试样表面抗压强度,将试样表面处理后,在4倍模拟体液(SBF)中浸泡,利用X射线衍射、扫描电子显微镜和能谱分析表面涂层的物相组成,观察多孔试样的表面、纵切面及孔内涂层形貌,计算表面涂层的钙磷比。讨论了激光扫描速率和扫描间距对试样孔隙率的影响。结果表明:SLS可以获得内部连通微孔结构的试样。经过4倍模拟体液中浸泡8 d,在2组试样外表面及孔内均产生类骨磷灰石涂层,实现了HA钙磷涂层的三维生长。孔隙率较高的试样抗压强度为117 MPa,其表面诱导羟基磷灰石沉积的能力更强,且表面涂层的钙磷比与自然骨更接近,涂层的综合性能更好。     

在非水溶液体系中电泳沉积Ti6Al4V/BG/HA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 ,提高涂层的结合强度及稳定性 .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 ,在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 .     

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。     

电化学沉积制备多孔羟基磷灰石泡沫复合材料

以多孔聚氨酯泡沫为基体,经过预处理、电化学沉积等工艺制备了具有三维多孔网状结构的、高空隙率的羟基磷灰石泡沫复合材料,将羟基磷灰石涂层浸泡在模拟体液SBF中进行浸泡实验,通过扫描电子显微镜(SEM)、X射线衍射(XRD)和红外分析仪(FTIR)等技术对羟基磷灰石涂层进行了表征。实验结果表明:在合适的条件下可得到纯羟基磷灰石涂层;随着温度的升高,晶体端面边长和长度逐渐增大;涂层在模拟体液SBF中浸泡24h后,涂层表面生成了很多球状磷灰石颗粒相互堆积,磷灰石颗粒尺寸明显增大。     

仿生法在AZ91D镁合金表面制备羟基生物涂层

镁基表面制备羟基磷灰石可以使材料同时具备镁良好的力学性能以及羟基磷灰石的耐腐蚀性、生物相容性等特点。本课题通过酸洗、碱洗、活化的处理活化镁合金表面,试样经碱热处理后置于SBF溶液中仿生生成羟基磷灰石。结果表明:随浸泡的Na OH溶液浓度升高,试样表面沉积物质量增加,经15%Na OH浸泡后,试样在SBF中沉积得到的羟基磷灰石量最多。沉积3天后,镁合金表面得到均匀性较好的生物涂层。     

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。     

A duplex coating composed of electrophoretic deposited graphene oxide inner-layer and electrodeposited graphene oxide/Mg substituted hydroxyapatite outer-layer on carbon/carbon composites for biomedical application

A duplex coating composed of electrophoretic deposited graphene oxide (GO) inner-layer and electrodeposited GO/Mg substituted hydroxyapatite (MH) outer-layer was prepared on carbon/carbon composites (CC). The morphology and microstructure of GO-GO/MH coating were researched by Scanning electron microscopy, energy dispersive X-ray spectroscopy, X-ray diffraction, Raman spectroscopy and X-ray photoelectron spectroscopy. The bonding strength between GO-GO/MH coating and CC substrate was investigated by shear test. The in-vitro bioactivity of GO-GO/MH coating was analyzed by simulated body fluid (SBF) immersion test. The results demonstrated that electrophoretic deposited GO inner-layer was successfully introduced on CC and could serve as an interlayer between CC and following electrodeposited GO/MH outer-layer. GO/MH outer-layer presented a flake morphology with 150–250?nm in thickness and 1.5–2.5?µm in width, exhibiting porous three-dimensional networks structure uniformly. The shear test showed that the bonding strength between the duplex coating and CC reached 7.4?MPa, which was 80.49% higher than that of single-layered MH coating without GO. The duplex coating could induce the formation of flocculent and chapped apatite after SBF immersion, which demonstrated the in-vitro bioactivity of the duplex coating. These results suggested that GO-GO/MH coating might be a promising candidate in the field of biomaterials, especially for implant coatings.     

医用钛合金微弧氧化膜的制备及其生物相容性研究

利用微弧氧化技术在Ti合金表面制备了医用羟基磷灰石(HA)膜,研究了HA膜在模拟体液中的生物相容性,通过SEM观察了HA膜在模拟体液中浸泡不同时间的表面形貌,并利用EDs测试了HA膜浸泡前后的Ca、P原子分数.结果表明,HA膜在模拟体液中浸泡后,体液的pH变化不大,而经过溶解-重结晶,新生成的HA晶粒发育更完整,更利于...     

多孔双相钙磷钛合金微弧氧化膜层的制备及生物相容性

为克服钛合金生物膜层单一相的缺陷,以Ti6A14V合金为基体,用微弧氧化法制得具有双相钙磷复合陶瓷膜层(BCP)的钛合金器件.通过控制工作液成分制得由不同比例的β-磷酸三钙(β-TCP)和羟基磷灰石(HA)组成的多孔性复合膜层.研究了电源占空比对BCP膜孔隙率和孔径大小的影响.采用能谱仪和X射线衍射仪分析了BCP膜层的...     

Effect of suspension medium on the electrophoretic deposition of hydroxyapatite nanoparticles and properties of obtained coatings

The suspensions of hydroxyapatite (HA) nanoparticles were prepared in different alcohols. The zeta potential of HA nanoparticles was the highest in butanolic suspension (65.65 mV) due to the higher adsorption of RCH₂OH₂⁺ species via hydrogen bonding with surface P3OH group of HA. Electrophoretic deposition was performed at 20 and 60 V/cm for different times. Deposition rate was faster in low molecular weight alcohols due to the higher electrophoretic mobility of HA nanoparticles in them. The coating deposited from butanolic suspension had the highest adhesion strength and corrosion resistance in SBF solution at 37.5 °C. The surface of this coating was covered by apatite after immersion in SBF solution for 1 week.     

Long-term corrosion resistance and fast mineralization behavior of micro-nano hydroxyapatite coated magnesium alloy in vitro

To improve the long-term corrosion resistance of biodegradable AZ31 magnesium alloy, the micro-nano structural hydroxyapatite (HA) coating was fabricated on AZ31 substrate by hydrothermal treatment. The compact and high crystallinity HA coating prepared at 120 °C had excellent electrochemical properties. Moreover, the cell viability experiment revealed that the micro-nano structure coating was conducive to the viability and proliferation of MC3T3-E1 osteoblasts. The immersion experiment in simulated body fluid (SBF) solution showed that the micro-nano structural HA coatings could quickly induce the production of HA mineralization, and then the mineralization evolved into a compact mineralized layer on the surface of coated sample, which provided a long-term protection for the specimen. Even after 147 days of immersion, the coated samples remained the relatively complete macroscopic shape, the corrosion rates were lower than 0.500 mm/y and the pH values of the SBF solution maintained in the range of 7.10–7.80, suggesting when these coated AZ31 magnesium alloys were used as degradable biomaterial implants, they could provide a long-term mechanical support during the healing of damaged bones.     

Development of HA-CNTs composite coating on AZ31 Magnesium alloy by cathodic electrodeposition. Part 2: Electrochemical and in-vitro behavior

The carbon nano-tubes (CNTs) reinforced hydroxyapatite (HA), with various functionalized CNTs concentration ranging from 0 to 1.5?wt%, were deposited on AZ31 magnesium alloy by direct and pulse cathodic electrodeposition methods. The corrosion resistance of the coatings was tested in simulated body fluid (SBF) using different electrochemical methods such as open circuit potential, polarization and electrochemical impedance spectroscopy. The in-vitro behavior, changes in solution pH as well as the amount of evolved hydrogen of these coatings were also evaluated during five days immersion in SBF. The results indicated that the pulse deposited HA having 1% CNTs coating was the optimum condition which decreased the corrosion current density of AZ31 magnesium alloy from 44.25?µA/cm² to 0.72?µA/cm². Moreover, it stabilized the alkalization behavior of AZ31 alloy and caused a tenfold decrease in the amount of hydrogen generation in SBF. Additionally, the formation of new hydroxyapatite layer on the surface of the pre-exist coatings after five days immersion in SBF was confirmed by SEM characterization.     

等离子喷涂硅灰石涂层结构和性能的研究

采用等离子喷涂技术，在Ti-6Al-4V基体上制备了硅灰石涂层，利用SEM和XRD分析技术对涂层的形貌，结构和相组成进行了研究，按ASTMC－633标准对涂层的结合强度也进行了测试，将涂层试样浸泡于模拟体液中以评估其生物活性，利用SEM及配备的能谱仪（EDS），XRD和IR对浸泡后涂层表面产物的形貌，结构和相组成等进行了分析，结果表明，等离子喷涂硅灰石涂层具有粗糙的表面和层状结构，涂层内部存在一些气孔和微裂纹，涂层的主晶相是三斜晶系硅灰口，也存在玻璃相，硅灰石涂层和Ti-6Al-4V基体热膨胀系数相近，因此涂层和T-6Al-4V基体具有较高的结合强度，其值可达约39MPa，模拟体液浸泡试验显示，硅灰石涂层表面能形成含有碳酸根的羟基磷灰石层，这表明硅灰石涂层会有良好的生物活性，可作为生物活性涂层的候选材料。     

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.     

Influence of a hard transition layer on the microstructure and properties of diamond-like carbon/hydroxyapatite composite coating prepared by magnetron sputtering

The nanostructured diamond-like carbon/hydroxyapatite composite coating (DLC/HA) was deposited using magnetron sputtering technique with a densely packed columnar cross-sectional structure and a uniform granular surface morphology. After heat treatment, the amorphous structure of the coating was transformed into a crystal structure. Nanohardness and scratch tests results demonstrated the DLC transition layer significantly enhanced the nanohardness of Ti6Al4V substrates from 4.8 GPa to 10.4 GPa, and increased critical load from 16.6 N (pure HA layer) to 26.5 N (DLC layer) without obvious brittle fracture, flaking and delamination. Electrochemical and immersion tests results demonstrated that DLC/HA composite coatings with a dense gradient transition interlayer had better corrosion resistance and could prevent harmful metal ions being released into the SBF solution more effectively than single HA coatings. Furthermore, active Ca²⁺ ions can be rapidly released from the coating surface during initial immersion in the SBF solution, and facilitated the formation of bone-like apatite.