改进酸碱联合处理法制备钛基羟基磷灰石活性涂层(英文)

为了制备理想的钛基羟基磷灰石(hydroxyapatite,HA)生物活性涂层,对钛合金表面分别采用酸处理、碱处理和酸碱联合处理,经过预钙化和热处理后,于模拟体液中进行HA沉积试验.采用X射线粉末衍射仪分析HA涂层的化学组成,以扫描电镜观察所得涂层的表面形态.结果表明:酸碱联合处理法是理想的钛合金表面处理法,所得表面呈多孔状,表面粗糙,对HA涂层沉积和结合强度的改善极为有利;模拟体液法所得涂层主要由HA组成,沉积物为云团状或球状;与相关文献比较,涂层HA含量高,没有裂纹,并且在钛基金属表面形成了片状晶体,均匀覆盖于金属表面,球状颗粒间有空隙存在,有利于新骨形成和牢固的结合.     

仿生法制备钛合金/羟基磷灰石复合涂层的研究

本研究了仿生溶液中钛合金表面沉积羟基磷灰石的技术路线。钛合金经抛磨、清洗．进行酸碱活化处理后，置于模拟体液(SBF)中，最终在钛合金基体上生成羟基磷灰石涂层。     

通过仿生法在纯镁表面制备羟基磷灰石涂层的研究

在纯镁表面自组装单分子层,用CaCl2和K2HPO4溶液对其进行预钙化处理,将处理过的纯镁试样浸泡于钙磷饱和溶液,仿生沉积得到羟基磷灰石涂层。利用X射线衍射和扫描电子显微镜对形成的涂层进行表征。试验结果表明,6天后即在镁基体表面得到了均匀致密、以羟基磷灰石（HA）为主晶相的羽毛状涂层。     

预钙化加速类骨磷灰石在镍钛合金表面生长的电化学阻抗谱

通过酸碱处理活化NiTi合金表面,在模拟体液中仿生生长类骨磷灰石层以改善其生物相容性.采用电化学阻抗谱研究了预钙化对加速磷灰石沉积的影响,并基于双层模型建立了电子等效电路.结果表明:随着在模拟体液中浸泡时间的延长,化学处理的NiTi合金表面类骨磷灰石不断生长,并且添加预钙化试样浸泡3 d,即可在合金表面生长出均匀完整的类骨磷灰石层,而未预钙化试样表面沉积物稀少.对应电子等效电路中,预钙化试样电阻值明显大于未预钙化试样的,显示预钙化促进了活化NiTi合金表面类骨磷灰石的生长.     

AZ91D镁合金表面诱导矿化磷灰石层的研究

通过金属螯合剂EDTA在基体表面自组装成膜,在基体表面大量引入活化基团,并利用活化基团诱导磷灰石矿化层的沉积。用GaCl2和溶液和K2HPO4溶液沉淀反应预钙化,在基体表面预沉积出大量的钙磷盐晶核,该钙磷盐晶核可诱导矿化出含有羟基磷灰石相的磷灰石矿化层。实验证明经过自组装、预钙化的基体可在8天内沉积出比较致密、均厚度的磷灰石矿化层。     

乙二胺四乙酸二钠对镍钛合金表面电沉积羟基磷灰石涂层的影响

先用10mol/L的NaOH溶液处理镍钛片,随后采用电沉积法制备羟基磷灰石涂层。电沉积工艺参数为:硝酸钙0.042mol/L,磷酸二氢铵0.025mol/L,EDTA-2Na1.5×10-4mol/L,温度65℃,pH4.5,电流密度1mA/cm2,时间1h。采用扫描电镜、红外光谱仪和能谱仪对所得涂层进行表征。NaOH溶液处理有利于羟基磷灰石的生长。溶液中EDTA-2Na的存在不影响羟基磷灰石的生成,只是促使羟基磷灰石末端聚拢,使羟基磷灰石之间的空隙扩大,并减少涂层的CO3-2含量,增加OH-,有效减少了涂层的镍含量。     

电沉积HA/Ti复合涂层的研究

采用复合电沉积-水热法在钛基体上形成羟基磷灰石／钛复合涂层。讨论了电沉积工艺条件对涂层中钛微粒含量的影响。用扫描电子显微镜(SEM)、X射线衍射(XRD)、傅立叶变换红外光谱(FTIR)等手段对处理后的涂层进行了表征。实验结果表明：在[Ca^2 ]0．00525～0．042mol/L、J0.1～0．3mA/cm^2、T313～353K、t60～180min条件下能制备得到羟基磷灰石和钛微粒两相分布均匀的复合涂层，涂层中Ti微粒的含量为64.3％～88．7％(质量分数)。涂层经500℃烧结8h，羟基磷灰石和钛没有发生化学反应。     

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。     

两种电化学方法对制备羟基磷灰石涂层的差异性研究

通过恒电流和脉冲电流技术在钛基表面制备磷酸钙,然后经热碱处理得到羟基磷灰石(HAP)涂层。利用X射线衍射(XRD)、红外光谱(FT-IR)和扫描电镜(SEM)等手段对涂层的结构及形貌进行了表征,并对涂层的耐腐蚀性进行了研究。结果表明,恒电流与脉冲电流技术均可在钛基表面电沉积羟基磷灰石涂层,所得的2种涂层均具有良好的生物相容性;与恒电流方法制得的涂层相比,脉冲电流技术制得的涂层更均匀、致密,与基体结合强度较高,在模拟体液中表现出较好的耐腐蚀性。     

电沉积制备羟基磷灰石-碳化硅复合涂层

采用电沉积技术在碳/碳复合材料表面制备出羟基磷灰石-碳化硅复合涂层,通过扫描电镜、x.射线衍射仪、能谱仪、傅里叶红外光谱仪研究了电解液浓度与电流密度对复合涂层形貌与组成的影响,采用粘接拉伸法测试羟基磷灰石-碳化硅涂层、羟基磷灰石涂层与基体的结合强度.结果表明:随着电解液浓度的降低,涂层的组成由磷酸氢钙转变为羟基磷灰石,晶体从大尺寸的片状逐渐转变为纳米级球状.随着电流密度的升高,涂层的钙、磷摩尔比逐渐升高,晶体向疏松的针状转变.选取适当的工艺参数,羟基磷灰石-碳化硅与基体结合强度高于羟基磷灰石涂层.     

Pulsed laser deposition of hydroxyapatite-diamondlike carbon multilayer films and their adhesion aspects

We have developed a layered hydroxyapatite/diamondlike carbon/functionally gradient diamondlike carbon-silver/titanium carbide/titanium carbonitride/titanium nitride composite film using pulsed laser deposition. A diamondlike carbon interlayer between a hydroxyapatite coating and the Ti-6Al-4V alloy can serve several purposes, including preventing corrosion of Ti-6Al-4V alloy, overcoming poor adhesion between the hydroxyapatite coating and the titanium oxide surface, and reducing inflammation at the implant/tissue interface. Titanium nitride, titanium carbonitride (TiC _x N _y ), titanium carbide and functionally gradient diamondlike carbon-silver layers were used to improve the adhesion of diamondlike carbon films to Ti-6Al-4V alloy. We envision several potential medical applications for these multilayer materials, including use in orthopedic and dental devices.     

Design of Experiments (DOE) for the Optimization of Titania–hydroxyapatite Functionally Graded Coatings

Titania–hydroxyapatite functionally graded coatings were deposited on titanium alloy substrates by plasma spraying. Because it was necessary to spray together the titania and the hydroxyapatite powders to obtain the graded system, the first target of the present study was to optimize the process parameters in order to obtain a high-quality coating. A 2³ Design of Experiments was applied to define the optimal values of plasma torch power, hydrogen flux, and spraying distance. This defined set of parameters (38 kW, 5 SLPM, and 90 mm, respectively) was used to spray the most promising graded coating, which was characterized and postheat treated.     

Hybrid Process of Microarc Oxidation and Hydrothermal Treatment of Titanium Implant

A duplex process was proposed with which a titania containing calcium and phosphate on the surface of titanium alloy was formed by microarc oxidation in aqueous electrolytes, and finally converted to bioactive layer containing hydroxyapatite by subsequent hydrothermal synthesis. The layer is porous in micro scale and composed of crystals in nanometer size. There was no distinct interface between the hydroxyapatite layer and the substrate.     

Preparation and bioactivity of apatite coating on Ti6Al4V alloy by microwave assisted aqueous chemical method

To improve the bioactivity of titanium and its alloys, dense and uniform apatite coatings were prepared on Ti6Al4V titanium substrates using microwave assisted aqueous chemical method. The influence of the pretreatment to the titanium substrates and the Ca/P molar ratio of the microwave solution on the coating deposition and morphology, as well as the bioactivity of the coated samples were studied. Results showed that during the microwave process, alkali treatment followed by heat treatment to the titanium substrates would promote the rapid deposition of hydroxyapatite to form coating. And the morphologies of the apatite coatings could be adjusted by the Ca/P molar ratio of the microwave solution. After immersion test in simulated body fluid (SBF), the coated titanium alloy exhibits a good bioactivity by inducing the formation of apatite depositions.     

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...     

溶胶凝胶法制备钛基羟基磷灰石涂层的研究

混合硝酸钙乙醇溶液和磷酸三甲酯水溶液作为羟基磷灰石(HA)前驱体,利用旋转涂膜技术在钛片表面制备羟基磷灰石涂层.研究了溶胶陈化时间和凝胶热处理温度对涂膜的影响,同时对涂层的生物活性进行了研究.样品利用X射线衍射仪(XRD)和扫描电子显微镜(ESEM)进行表征.结果表明:利用经过24 h陈化的溶胶涂膜的样品在500℃热处...     

Hydrothermal nucleation of hydroxyapatite on titanium surface

Titanium plates were submitted to nucleation and growth of hydroxyapatite (HAp) under hydrothermal conditions. A group of these plates were submitted to nucleation without any previous treatment and another group was treated with NaOH 1 M at 130°C inside an autoclave followed by heat-treatment at 600°C. The nucleation were performed by soaking all these titanium pieces, in a simulated body fluid (SBF) solution, containing calcium, phosphate and other ions, in order to promote the nucleation and growth of hydroxyapatite under hydrothermal conditions on the titanium surface. The results show that hydrothermal nucleation and growth of HAp occurs even on the non-treated titanium surface at 150°C. However, a better uniformity of the hydroxyapatite layer was observed on the pre-treated titanium surface, at 80°C, with the renewal of the SBF solution.     

羟基磷灰石/TiO2复合涂层在模拟脑脊液中生物相容性（英文）

应用阳极氧化法在Ti-6Al-4V钛合金（TC4）表面制备了多孔TiO2涂层,在TiO2涂层表面电沉积制备了羟基磷灰石（hydroxyapatite,HA）/TiO2复合涂层,用实验用人工脑脊液（artificial cerebrospinal fluid,ACSF）体液模拟人体的脑脊液,以TC4和TiO2涂层为对比,研究了HA/TiO2涂层在浸泡过程中发生的物理化学变化,考察了HA/TiO2复合涂层抑制钛合金中元素Al和V的析出情况。结果表明：3种样品随浸泡时间的延长遵循的生长规律为：HA成核→HA晶粒长大→HA晶粒相互团簇形成一体→涂层逐渐扩大覆盖到整个基体表面;TC4,TiO2以及HA/TiO2涂层在ACSF中都能够诱导HA的生成,表现出了良好的生物活性。检测浸泡后溶液中Al和V的浓度可知,阳极氧化法制备的TiO2涂层对于Al,V元素的析出起到了一定的抑制作用,能够进一步提高钛合金的生物相容性。

Abstract：

Porous TiO2 coating was prepared on Ti-6Al-4V titanium alloy （TC4） substrate by the potentiostatic anodic oxidation method,and hydroxyapatite （HA） coating was prepared on the surface of TiO2 coating by the electrodeposition method to form HA/TiO2 composite coating. By using artificial cerebrospinal fluid （ACSF） to simulate human cerebrospinal fluid,the physicochemical changes of the HA/TiO2 coatings when soaked in ACSF were studied and compared with TC4 and TiO2 coating. Its inhabitation effects on Al and V were also studied. The results show that these three samples follow such a growth pattern：HA nucleation forma-tion,crystal growth,agglomeration,coatings formation. The bioactivity of TC4,TiO2 coating and TiO2/HA composite coating can be induced by the formation of HA in ACSF. According to the concentration of Al and V in ACSF,the TiO2 coating formed by anodic oxidation could inhibit the element precipitation more or less,and enhance the biocompatibility of titanium alloy.