引氟量对钛表面电沉积含氟羟基磷灰石涂层的影响

根据电沉积磷灰石陶瓷技术,通过在含有Ca(NO3)2·4H2O、NH4H2PO4、NaNO3及H2O2的电解液中加入不同浓度的氟化钠作为引氟剂,在钛片表面进行电化学沉积,分别采用扫描电镜(SEM)、X射线衍射(XRD)、傅立叶变换红外光谱(FT-IR)、X射线光电子能谱(XPS)对所得涂层的表面形貌和理化性质进行分析.结果表明,通过上述方法可以在钛表面制备纳米晶含氟羟基磷灰石(FHA)涂层,涂层的含氟量与电解液中加入NaF的浓度有关.当NaF浓度低于0.012 mol/L时,随着引氟量的增加,所得FHA涂层的含氟量也相应增加;当NaF浓度高于0.012 mol/L后,涂层的含氟量不发生明显变化.     

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.     

钛合金表面电泳沉积氟羟基磷灰石涂层

采用沉淀法制备了氟掺杂的氟羟基磷灰石(FHA,Ca_(10)(PO_4)_6OH_(2–x)F_x(x=0~2))粉体,并采用电泳沉积在钛合金(Ti_6Al_4V)表面制备了FHA涂层。通过改变沉积电压、时间及电极间距获得不同沉积量的涂层,采用X射线衍射、扫描电子显微镜研究了电压、时间、电极间距以及热处理对涂层形貌、物相组成和涂基结合强度的影响,确定制备FHA涂层的最佳沉积工艺和热处理制度。结果表明:控制沉积电压15 V、沉积时间1 min、电极间距1 cm的条件下沉积涂层并在N_2气氛下900℃保温1 h热处理可制得涂层质量好,涂基结合强度高的FHA生物陶瓷涂层。     

羟基磷灰石和含氟羟基磷灰石涂层的制备技术

羟基磷灰石(HA)生物陶瓷涂层被认为是目前最好的用于替代人体硬组织的一种生物医用材料,具有很高的外科应用价值.含氟羟基磷灰石(FHA)涂层由于比羟基磷灰石涂层的溶解度低、热膨胀系数小且生物活性好,有着更为广泛的应用前景.对羟基磷灰石及其涂层的各种制备方法进行了概述,同时介绍了溶胶-凝胶法制备含氟羟基磷灰石涂层的技术特点,并对未来的发展前景进行了分析.     

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。     

含氟羟基磷灰石的性能及涂层制备技术

含氟羟基磷灰石（FHA,Ca10（PO）46F2～x（OH）x）涂层由于比羟基磷灰石涂层的溶解度低、线胀系数小且生物活性好等优点,受到生物学界的广泛重视。本文介绍了FHA的性能特点以及涂层的制备技术,并认为系统研究FHA涂层中的氟含量即F^-对OH^-的取代量对FHA溶解性能以及生物活性性能的影响,将决定FHA涂层的实际应用。     

氧化石墨烯/氟羟基磷灰石复合粉体表征

拟采用原位合成法制备氧化石墨烯/氟羟基磷灰石(GO/FHA)复合粉体,并通过扫描电子显微镜(FE-SEM)、能谱仪(EDS)及X射线衍射仪(XRD)进行表征。结果表明膨胀石墨制备的GO层间距更大,表面更平整。成功制备的GO/FHA复合粉体将在种植体材料领域具有广阔的应用前景。     

引氟量对含氟羟基磷灰石纳米晶结构的影响

采用Ca(NO_3)_2·4H_2O-P_2O_5-NH_4F-乙醇体系,利用溶胶凝胶法在600℃获得不同含氟量的纳米含氟羟基磷灰石(FHA)粉体。通过X射线衍射分析(XRD)对纳米粉体进行了表征,讨论了不同引氟量对衍射峰强度、晶面间距、晶格常数及粒度的影响,并从FHA形成机理及结构构成方面解释了原因。结果表明,FHA主晶相衍射峰强度随引氟量增加,呈先减少后增加的趋势,晶面间距(特别是(300)晶面)逐渐减小,而晶格常数及粒度在a轴方向上亦呈现逐渐减少的趋势。     

钛植入合金表面电化学沉积掺镁羟基磷灰石涂层

以Ca(NO3)2、(NH4)2HPO4和Mg(NO3)2为原料,采用电化学沉积法在医用钛合金表面制备了掺镁羟基磷灰石涂层,研究了电沉积工艺条件对掺镁羟基磷灰石涂层表面形貌的影响。结果表明,当电流密度为1.0mA/cm2,温度为65°C,pH为4.5,n(Mg):n(Ca)=1:3,电沉积时间为1300s时,得到了均匀致密的晶须状涂层。X射线衍射分析表明,烧结后的掺镁羟基磷灰石涂层中Mg2+取代了Ca2+,使HA涂层的晶格发生了变化。     

氧化铝基体上羟基磷灰石/氟羟基磷灰石双层涂层的制备及性能

通过涂覆-烧结法在氧化铝(Al_2O_3)表面制得羟基磷灰石(HA)/氟羟基磷灰石(FHA)双层涂层,HA和FHA重复沉积在氧化铝基体上形成均匀涂层,然后在1300 ℃进行热处理.在此过程中,如果没有FHA中间层,HA会和Al_2O_3发生严重的反应,形成磷酸三钙和钙铝化合物.SEM、XRD及粘接拉伸试验表明:FHA中间层能有效地抑制HA与Al_2O_3的反应,所获得的双层涂层具有多孔粗糙的表面,但与Al_2O_3基体结合紧密.涂层经1300 ℃热处理后,其结合强度约为30 MPa.     

Influence of ionic substitution in improving the biological property of carbon nanotubes reinforced hydroxyapatite composite coating on titanium for orthopedic applications

The present work is aimed for the development of carbon nanotubes (CNTs) reinforced single mineral (Sr, Mg, Zn) as well as multi minerals (Sr+Mg+Zn) substituted hydroxyapatite composite (M-HAP) coatings on titanium (Ti). The effect of different mineral ions substitution and CNTs reinforcement in HAP composite coating is discussed in detail. Fourier Transform Infrared spectroscopy (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM) equipped with energy dispersive X-ray analysis (EDX), and high resolution transmission electron microscopy (HRTEM) were used to characterize the structural and morphological behavior of the composite coatings. The corrosion resistance of the composite coatings in simulated body fluid (SBF) solution was evaluated by the potentiodynamic polarization and electrochemical impedance spectroscopic (EIS) studies. In addition, the biocompatibility of the composite coatings was evaluated by in vitro culture of human osteoblast MG63 cells on the composite coated Ti. All these results essentially suggest that CNTs/M-HAP composite coated Ti can be a potential candidate for orthopedic applications.     

微晶纤维素模板法制备纳米二氧化钛及表征

以TiCl4为原料,微晶纤维素为模板,制备了具有微晶纤维素特征形貌的纳米二氧化钛。借助透射电子显微镜、环境扫描电子显微镜、傅里叶变换红外光谱、X射线衍射、热重分析等分析方法对样品进行表征,探讨纳米二氧化钛的形成机理。结果表明:在500℃焙烧得到准球形锐钛矿纳米二氧化钛,粒径为15 nm;在700℃和900℃焙烧分别得到夹有金红石型的锐钛矿和红晶石型纳米二氧化钛,并且随着焙烧温度的升高,纳米二氧化钛晶型由锐钛矿逐渐转变成金红石型,其粒径增大,烧结加剧致使形貌变得更不规则。700℃焙烧产物在紫外光下对罗丹明B具有较佳的光催化降解性能。     

Correlation between microstructure and properties of biocomposite coatings

A SiO₂–CaO–Na₂O (SCN) based bioactive glass was used to prepare glass–matrix/Ti particle composite coatings (SCNT). The coatings were obtained by vacuum plasma spray (VPS) on Ti–6Al–4V substrates. Two different deposition methods have been compared: (a) VPS of powders obtained by ball milling of sintered composites; (b) in situ plasma spray of mixed titanium and glass powders. For comparative purposes, pure SCN glass coatings were produced. The coating morphology and microstructure were observed by optical and scanning electron microscopy, compositional analyses by energy dispersive X-ray spectroscopy (EDS), and X-ray diffraction (XRD). Comparative mechanical tests were carried out by shear tests and by Vickers indentations at the interface between the substrate and the coatings. The bioactivity of glass- and composite coatings was investigated in vitro by soaking them in a simulated body fluid (SBF) with the same ion concentration of the human plasma. All the layers retain their starting composition. The composite coatings obtained by VPS of the powdered presintered composites showed a better mechanical behaviour with respect both to the composite coatings obtained by the in situ method and to the pure glass coatings. Both the glass- and the two kind of composite coatings revealed to be bioactive by the growth of a thick apatite layer after 30 days of soaking in SBF. The electrochemical behaviour of the SCNT coatings was evaluated by means of potentiodynamic anodic polarization curves and free corrosion potential measurements in Ringer solution at 25 °C. For comparative purposes the same analyses were performed on analogous bioactive glass-matrix/Ti particle composite coated samples, based on the system TiO₂–SiO₂–CaO–B₂O₃ (TSCB), and obtained both by the in situ and by presintering method as well. The results of the electrochemical tests showed a better corrosion behaviour of the samples coated by VPS of powdered sintered composites with respect to those coated by in situ VPS composites.     

In-vitro corrosion inhibition mechanism of fluorine-doped hydroxyapatite and brushite coated Mg–Ca alloys for biomedical applications

Magnesium alloys have received great attention as a new kind of biodegradable metallic biomaterials. However, they suffer from poor corrosion resistance. In this study, Mg–Ca alloy was coated with nano-fluorine-doped hydroxyapatite (FHA), and brushite (DCPD); via electrochemical deposition (ED). Coatings were characterized by X-ray diffraction (XRD), Fourier-transformed infrared spectroscopy (FTIR), transmission electron microscopy (TEM), scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS). The results revealed that nano-fluorine-doped hydroxyapatite coating produced more dense and uniform coating layer, compared to the brushite coating. The compression tests of the ED-coated Mg alloy samples immersed in simulated body fluid for different time periods showed higher yield strength (YS) and ultimate tensile strength (UTS), compared to those of the uncoated samples. The degradation behavior and corrosion properties of the ED-coated Mg alloy samples were examined via electrochemical measurements and immersion tests. The results showed that FHA coating could effectively induce the precipitation of more Ca²⁺ and PO₄³⁻ ions than DCPD coating, because the nanophase can provide higher specific surface area. It was also found that FHA and DCPD coatings can significantly decline the initial degradation rate of the alloy. A corrosion mechanism of the ED-coated alloy is proposed and discussed in this paper.     

Anti-corrosive properties of waterborne polyurethane/poly(o-toluidine)-ZnO coatings in NaCl solution

The aim of this research was to prepare waterborne polyurethane (WPU) coating blended with a series of poly(o-toluidine)-nano ZnO composites and study its anti-corrosion performance after its application over carbon steel. The synthesized composites were characterized by X-ray diffractometry (XRD), Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), and scanning electron microscopy (SEM). The corrosion resistance of coatings with and without nano ZnO were studied in 3.5% NaCl solution at a temperature of 25?°C, by electro-chemical techniques such as potentiodynamic polarization measurements and electrochemical impedance spectroscopy (EIS). It was observed that the composite coating containing 7% poly(o-toluidine)-nano ZnO composite had higher corrosion resistance than poly(o-toluidine) and 14% poly(o-toluidine)-nano ZnO composite. The presence of appropriate amount of ZnO significantly improved the corrosion resistance, due to the formation of passive layer on steel surface and the synergistic effects of poly(o-toluidine) along with a suitable amount of nano-ZnO reduced the porosity of the coating surface.     

脉冲电沉积纳米镍-碳化硅复合镀层的性能

分别采用直流(DC)和换向脉冲电流(PRC)电沉积法制得纳米Ni-SiC复合镀层。采用X射线衍射仪、扫描电镜、能谱仪对比研究了纯Ni镀层和Ni-SiC复合镀层的微观结构、宏观残余应力、表面形貌及成分。用浸泡法研究了不同镀层在3.5%(质量分数)NaCl和10%(体积分数)H2SO4溶液中的腐蚀行为。结果表明,脉冲电沉积能改变镀层的微观结构,有效提高镀层硬度,降低宏观残余应力。脉冲电沉积所得到的纯Ni镀层和纳米Ni-SiC复合镀层在3.5%NaCl及10%H2SO4溶液中的耐蚀性均优于直流镀层。脉冲镀层在3.5%NaCl溶液中受腐蚀很轻,主要腐蚀形态为点蚀,而在10%H2SO4溶液中,SiC粒子作为增强相使镀层的耐腐蚀性进一步提高。     

Vacuum Plasma Spray Deposition of Titanium Particle/Glass-Ceramic Matrix Biocomposites

The vacuum plasma spray technique (VPS) has been successfully employed to coat Ti-6A1-4V substrates with bioactive glasses and Ti-particle/glass-ceramic matrix biocomposites. The composites were prepared by sintering, under an Ar flow, green bars of bioactive glass powders and 30% volume Ti particles. The bioactive glasses have the two following compositions: SCB (48.8SiO₂−48.8CaO−2.4B₂O₃) and TSCB (46.6SiO₂−48.7CaO−2.5B₂O₃−2.2TiO₂) (mol%). The VPS bioactive coatings were characterized by means of scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), and mechanical tests (Vickers indentations and tensile and shear tests). Their bioactivity was tested by soaking the samples in a simulated body fluid (SBF) and by analyzing the growth of hydroxylapatite (HA) by SEM, EDS, and XRD. Leaching tests of Ca, Si, and P in SBF were made by inductively coupled plasma-atomic emission spectroscopy (ICP-AES, Perkin-Elmer 5000) to study the in vitro bioactivity of the samples versus time. Each coating was found to be bioactive and well bonded to the substrate; the composites showed better mechanical properties than the pure glass matrices and the hydroxylapatite coatings deposited by the same VPS technique.     

The superlattice structure and self-adaptive performance of C–Ti/MoS2 composite coatings

To improve the self-adaptability of MoS₂ coating in different environments, the coatings were doped with functional C and Ti by unbalanced magnetron sputtering system. The clear superlattice structure with minimal modulation period was investigated by High Resolution Transmission Electron Microscope (HRTEM). The co-doped coatings have better mechanical properties due to the special structure and the formation of C–Mo, Ti–S and Ti–O bonds, and better lubrication performance in both high humidity and vacuum than those of the single-doped ones. The doped Ti not only facilitates the formation of the MoS₂ (002) basal plane, but also improves the oxidation resistance of the composite film. The degree of friction-induced graphitization on the wear tracks and the quality of transfer films on the wear scars are key factors affecting the lubrication performance of the composite film. In the high-humidity environment, the reasonable doping elements can promote the formation the high-quality transfer film by interacting with H₂O water molecules, which will benefit the lubrication of the coating better. Our findings deepen the understanding of MoS₂ composite coating and provide a new solution for improving the self-adaptability of the coating.     

The effect of lignin on the structure and characteristics of composite coatings electrodeposited on titanium

Composite coatings based on lignin, obtained by electrophoretic deposition (EPD) on titanium, were investigated. The aim of this work was to produce hydroxyapatite/lignin (HAP/Lig) coatings on titanium and to investigate the effect of the lignin concentration on microstructure, morphology, phase composition, thermal behavior and cytotoxicity of the HAP/Lig coatings. An organosolv lignin was used for the production of the composite coatings studied in this research. The properties of HAP/Lig coatings were characterized using X-ray diffraction (XRD) analysis, scanning electron microscopy (SEM), thermogravimetric analysis (TGA), attenuated total reflection Fourier transform infrared spectroscopy (ATR-FT-IR) and X-ray photoelectron spectroscopy (XPS), as well as the MTT test of cytotoxicity. The results showed that higher lignin concentrations protected the HAP lattice during sintering, thereby improving the stability of the HAP/Lig coatings. The cell survival of peripheral blood mononuclear cells (PBMC) after proliferation indicates that the HAP/Lig coating with 1 wt% Lig electrodeposited on titanium was non-toxic with significant promise as a potential bone-repair material.