纯钛阳极氧化及表面薄层羟基磷灰石形成技术的研究Ⅲ.蒸汽温度及Ca2+浓度对氧化膜表面析出晶体性能的影响

目的：了解蒸汽温度及Ca^2 浓度对氧化膜表面析出晶体性能的影响。方法：将钛片分别在六种不同Ca^2 浓度的电解质溶液中进行电解（β-磷酸甘油钠：醋酸钙=0.04M:0.15M,0.04M:0.20M,0.04M;0.25M,0.04M:0.30M,0.04M:0.35M,0.04M:0.40M)和在三种不同蒸汽温度下进行水热处理（200℃，250℃，300℃）。结果：随着水热温度的增高，钛片表面晶体开始析出并增多，在200℃水热处理时，钛片表面几乎无晶体析出，300℃为较理想的水热温度的增高，钛片表面晶体开始析出并增多，在200℃水热处理时，钛片表面几乎无晶体析出，300℃为较理想的水热处理温度，随着Ca^2 浓度的增加，钛片表面晶粒逐渐变细，增多，形状逐渐规则，Ca/P比则从1-3不等，结论：蒸汽温度以及Ca^2 浓度对于氧化膜表面结晶物和HA的析出有重要的影响。HA在高温下生成，因而较稳定，此外，在贫钙状态，析出晶体较为粗大，而在富钙状态，析出晶体较为细小。     

纯钛阳极氧化及表面薄层羟基磷灰石形成技术的研究——Ⅰ.氧化膜的制备及羟基磷灰石涂层的形成

目的：初步了解制备纯钛表面阳极氧化膜和沉积HA薄涂层的技术路线。方法：商业纯钛片经抛光、除油、酸洗后,置于电解槽中进行阳极氧化,采用β－磷酸甘油钠和醋钙作为电解质,阳极化条件为直流电压200V－400V,电流密度≤50mA/cm^2,时间15分钟,阳极氧化完毕后将钛片经高温水热处理2小时（180℃－300℃）。结果：在阳极化后的钛片表达出现蜂窝状孔隙,孔径约1μm-3μm,周围为较规则的突起;X射线衍射图谱（XRD）显示钛表面有金红石和锐钛矿两种氧化钛形态,能谱分析（EDAX）表明钛表面氧化膜内含Ca、P元素;水热处理后,在钛表面出现了结晶物,XRD证明其为HA。结论：阳极氧化可以在纯钛表面形成呈蜂窝状孔隙的、含Ca、P的氧化膜,经水热处理后,在氧化膜表面沉积了HA薄涂层。     

电解液钙磷比对微弧氧化法制备含钙磷氧化物膜结构的影响

目的:探讨在不同钙磷比的电解液中,利用微弧氧化技术在纯钛表面形成含钙磷氧化物膜的组成。方法:根据电解液中钙磷浓度比的不同,将纯钛试件分成A、B、C和D共4组,采用微弧氧化技术对各个试件作处理,使用扫描电镜(SEM)观察试件的表面形貌和X射线能谱仪(EDS)对试件的表面氧化层进行成分分析。结果:微弧氧化处理后,纯钛表面生成微孔结构的氧化膜,表面沉积物的元素组成主要是Ti、O、Ca、P等。经相关系数分析,电解液的钙磷浓度比与氧化膜的Ca、P含量相关,有统计学意义(P<0.05)。随电解液中Ca浓度的增加,表现为Ca和P元素的上升。除A组Ca/P比为1.26外,其它3组Ca/P比均在1.42～1.44之间。结论:利用微弧氧化技术能形成含钙磷的多孔氧化物薄膜,氧化物薄膜中钙磷含量与电解液中钙磷含量有关。     

微弧氧化电压处理钛表面后对钛瓷结合强度的影响

目的：观察钛试样在微弧氧化处理过程中，电源电压不同，形成的氧化膜对钛瓷结合强度的影响。方法：电解液由去离子水和Na2SiO3溶液组成，占空比和频率为0．04、500Hz，时间3min，电压分别为Ⅰ组300V；Ⅱ组350V；Ⅲ组400V，分别对钛试样表面进行处理，扫描电镜（SEM）观察膜表面形貌；对不同组别试件进行瓷粉烧结，再采用三点弯曲试验测量钛与瓷的结合强度。结果：随电压的升高，钛试件表面形貌变化较大，微孔直径增大，微孔的数量明显减少，表面变得粗糙不平，氧化膜的厚度也随之增加，从5μm增加到10μm；钛与瓷的结合强度随电压增大逐渐降低，但微弧氧化组的结合强度明显高于未行微弧氧化组（P〈0.01）。结论：钛在烤瓷前经微弧氧化处理有利于钛与瓷的结合，且微弧氧化过程中不同处理电压对钛瓷结合强度有影响。     

微弧氧化法在纯钛表面生成含羟基磷灰石陶瓷膜的研究

目的：利用微弧氧化法在纯钛表面直接生成含羟基磷灰石的陶瓷膜。方法：通过微弧氧化技术,采用双相脉冲电源,以0．4mol／L醋酸钙和0．2mol／L磷酸二氢钠为电解液体系,设定脉冲频率为60Hz,正相电流密度为20A／dm^2,处理时间分别为5rain、10min、20min、30min、60min,在纯钛表面制备陶瓷膜。利用扫描电镜观察膜层的表面形貌,能谱仪分析氧化膜的元素组成,X射线衍射仪分析膜层的相组成,电涡流涂层测厚仪测量膜层的厚度。结果：以0．4mol／L醋酸钙和0．2mol／L磷酸二氢钠为电解液体系,经微弧氧化处理后,在纯钛表面形成含有Ti、O、Ca和P元素的微孔结构的氧化膜,该膜由锐钛矿型TiO2、金红石型TiO2及羟基磷灰石组成。随微弧氧化反应时间的延长,膜层增厚,膜层表面微孔孔径增大,数量减少,粗糙度增大。钛元素的相对含量减少,Ca、P元素相对含量增加,O元素变化不明显。钛、锐钛矿型TiO2和金红石型TiO2的衍射峰逐渐减弱,羟基磷灰石的衍射峰逐渐增强。结论：应用微弧氧化技术,以0．4mol／L醋酸钙和0．2mol／L磷酸二氢钠为电解液体系,在纯钛表面能直接生成含有羟基磷灰石成份的微孔结构的陶瓷膜。     

阳极氧化促进钛表面生物矿化的研究

目的：用阳极氧化法在纯钛表面制备纳米二氧化钛管（TiO2nanotube）以及TiO2纳米管诱导羟基磷灰石（HA）沉积的能力。方法：用扫描电子显微镜（SEM）观察钛片在不同氧化时间和电压下,在含0．1mol／LNaH2PO4和0．1mol／LNH4F的电解液中阳极氧化后的表面形貌。经阳极氧化后的样本在SBF溶液中进行体外矿化处理,矿化后的试样用SEM、X射线衍射分析仪（XRD）观察分析羟基磷灰石（HA）的形貌和晶形。结果：在20V电压下,氧化2h,钛表面形成孔径均一、排列规整的纳米二氧化钛管;在20V电压下氧化2h的试样（实验组）与末经阳极氧化的试样（对照组）在仿生体液中浸泡7d后,实验组表面沉积的HA晶体更多。结论：阳极氧化时间、电压对钛表面的TiO2纳米管形貌及结构产生影响,TiO2纳米管可以加速诱导HA在其表面沉积。     

纯钛表面阳极氧化电压对成骨细胞早期黏附及伸展的影响

目的:通过成骨细胞离体培养试验,观察不同阳极氧化电压对成骨细胞早期黏附及伸展的影响。方法:分别在电压为140V、200V及260V,电流密度为70A/m2等条件下,在0.03mol/L甘油磷酸钙(Ca-GP)和0.15mol/L醋酸钙混合电解液中,对纯钛样本表面进行阳极氧化处理。对阳极氧化后样本的平均粗糙度进行测量,并在其表面进行人成骨细胞培养,对早期细胞黏附及伸展等情况进行研究。采用SPSS13.0forWindows统计分析软件中的单因素方差分析进行统计学处理。结果:纯钛表面平均粗糙度为0.17μm,经阳极氧化后,随电压升高,平均粗糙度分别为0.23μm、0.26μm及0.33μm,统计学分析表明有显著性差异(P<0.05)。经过2h细胞培养后,阳极氧化处理后,纯钛表面细胞骨架发生形态学改变,且随阳极氧化电压的增高,细胞形态不规则呈现升高的趋势。统计分析结果表明,260V电压阳极氧化组,细胞黏附数显著高于对照组(P<0.05)。结论:阳极氧化处理可改善纯钛表面特性,成骨细胞在其表面的黏附及伸展等早期细胞行为受阳极氧化电压的影响。     

二种阳极氧化电解液对钛表面细胞相容性的影响

目的:研究纯钛表面阳极氧化过程中电解液成份对其细胞相容性的影响。方法:在电流密度为70A/m2及200伏电压等条件下分别在0.03M甘油磷酸钙(Ca-GP)与0.15M醋酸钙混合液(混合组)及0.2M磷酸溶液中对纯钛样本表面进行阳极氧化处理。在阳极氧化及纯钛样本表面进行人类成骨细胞培养,以观察细胞毒性、细胞增殖及分化等细胞行为的改变。结果:细胞毒性试验结果表明,本研究中所用的电解液不会对阳极氧化后纯钛样本产生细胞毒性。所有样本表面经过1d、2d或4d细胞增殖培养后磷酸组与纯钛组之间没有显著性差异,而在0.03M甘油磷酸钙(Ca-GP)与0.15M醋酸钙混合液中进行阳极氧化处理后的纯钛样本,经过2d及4d成骨细胞培养后细胞增殖数量较纯钛组及磷酸组显著增高。细胞分化试验结果表明,除在4d时混合液组碱性磷酸酶活性较纯钛组及磷酸组显著性降低外,其余各组间无显著性差异。结论:对纯钛表面的阳极氧化处理过程中,电解液成份可对阳极氧化后纯钛表面的细胞相容性产生影响。     

阳极氧化及模拟体液沉积后的铌金属表面特性研究

目的 评价纯铌(Nb)金属在DL-α磷酸甘油与醋酸钙阳极氧化处理后的表面特性.方法 所有Nb试件在模拟体液(SBF)沉浸30 d.用扫描电镜观察膜层的表面形态,用X射线光电子能谱(XPS)分析膜层的电子结合能元素分布.结果 Nb试件电镜观察结果,阳极氧化处理的表面呈现多孔重叠的微孔,阳极氧化及300℃高温蒸汽压下2 h热处理,SBF沉积后的表面呈现微细的结晶,其微孔逐渐减少.XPS分析所有Nb试样上观察Nb、Ca、C、O谱及微量的P谱.结论 阳极氧化及热处理可诱导Nb金属表面形成氧化膜层,提高其生物活性.     

占空比和脉冲频率对钛微弧氧化表面处理后与瓷结合强度的影响

目的:观察钛试样在微弧氧化处理过程中,不同的占空比和脉冲频率对钛瓷结合强度的影响。方法:电解液由去离子水和Na2SiO3溶液组成,电压为300V,时间3min,占空比和频率分别为Ⅰ组0.2,500Hz;Ⅱ组0.2,1000Hz;Ⅲ组0.04,1000Hz;Ⅳ组0.04,500Hz;Ⅴ组0.12,750Hz。对钛试样表面进行处理后,用扫描电镜(SEM)观察表面形貌,并对不同组别试件进行瓷粉烧结,用三点弯曲试验测出钛与瓷的结合强度。结果:频率在1000Hz时比500Hz的膜层表面的微孔直径小,膜层厚度增加;结合强度Ⅳ组明显高于Ⅲ组(P<0.01),Ⅰ组高于Ⅱ组(P<0.05);占空比由0.04增加至0.2时,氧化膜表面分布的微孔直径无明显变化,结合强度Ⅲ组明显高于Ⅱ组(P<0.01),Ⅳ组高于Ⅰ组(P<0.01)。微弧氧化组膜层与基底间无明显界线,结合强度明显高于未行微弧氧化组(P<0.01)。结论:钛在烤瓷前经微弧氧化处理有利于钛与瓷的结合,且微弧氧化过程中不同处理参数对钛瓷结合强度有影响。     

阳极氧化法制备的二氧化钛纳米管在钛表面改性中的研究进展

采用阳极氧化法在钛基体表面原位制备高度有序的二氧化钛（TiO2）纳米管阵列,探讨阳极氧化电压、次数、电解液种类、电解液浓度和电解液温度等对二氧化钛纳米管表面形貌的影响。相对于微米级表面,TiO2纳米管具有更好的促进体外矿化和促进成骨性,同时可作为生物载体负载生长因子和抗生素等载体。本文就此作一综述。     

阳极氧化法制备的二氧化钛纳米管在钛表面改性中的研究进展

采用阳极氧化法在钛基体表面原位制备高度有序的二氧化钛(TiO2)纳米管阵列,探讨阳极氧化电压、次数、电解液种类、电解液浓度和电解液温度等对二氧化钛纳米管表面形貌的影响.相对于微米级表面,TiO2纳米管具有更好的促进体外矿化和促进成骨性,同时可作为生物载体负载生长因子和抗生素等载体.本文就此作一综述.     

阳极氧化处理后的新型钛合金表面成骨细胞OPG、RANKL基因表达研究

目的:新型钛合金Ti-24Nb-4Zr-7.9Sn(TNZS)经过阳极氧化(anodic oxidation,AD)技术处理后,分析其表面的人成骨样MG63细胞骨保护素(osteoprotegerin,OPG)、细胞核因子-κB受体活化因子配体(RANKL)基因表达水平.方法:将人成骨样MG63细胞接种于Ti-6Al-4V、TNZS、AD-TNZS表面,采用半定量RT-PCR法检测OPG、RANKL mRNA的表达量.结果:人成骨样MG63细胞在AD-TNZS表面的OPGm RNA表达量有所提高,而RANKL mRNA的表达量3组材料间无明显差异.结论:阳极氧化处理的TNZS钛合金可能通过影响骨保护素、细胞核因子-κB受体活化因子配体调节成骨细胞、破骨细胞的平衡,从而促进种植体植入后的骨重建.     

Determination of trace vanadium(V) by adsorptive anodic stripping voltammetry on an acetylene black paste electrode in the presence of alizarin violet

A sensitive and simplified voltammetric method is developed for the determination of trace amounts of vanadium(V) by adsorptive anodic stripping voltammetry using an acetylene black (AB) paste electrode. The method is based on the preconcentration of the V(V)–alizarin violet (AV) complex at open circuit while stirring the solution for 90 s in 0.15 mol dm⁻³ hexamethylenetetraamine–hydrochloric acid buffer (pH 4.4), the adsorbed complex is then oxidized, producing a response with a peak potential of 564 mV when scanning linearly from 0 to 1000 mV. For voltammetric determination of V(V), the parameters influencing the peak current have been optimized. Under the selected conditions, the peak current and concentration of V(V) accorded with linear relationship in the range of 8.0 × 10⁻¹⁰ mol dm⁻³–1.0 × 10⁻⁷ mol dm⁻³ (c_AV = 2.0 × 10⁻⁶ mol dm⁻³) and 1.0 × 10⁻⁷ mol dm⁻³–8.0 × 10⁻⁶ mol dm⁻³ (c_AV = 2.0 × 10⁻⁵ mol dm⁻³), the detection limit (three times signal to noise) was estimated to be 6.0 × 10⁻¹⁰ mol dm⁻³ for 90 s accumulation. The relative standard deviation (RSD) is 1.9% and 2.3% for V(V) concentrations of 1.0 × 10⁻⁷ mol dm⁻³ and 1.0 × 10⁻⁸ mol dm⁻³ respectively. Finally, this proposed method was successfully applied to the determination of V(V) in natural water samples.     

Numerical simulations of linear scan anodic stripping voltammetry at a modified square array of hemispherical microelectrodes located in a thin-layer cell

The finite element method has been used to simulate LSASV measurement at a loosely packed square array of recessed microdiscs and of hemispherical mercury microelectrodes located in a thin-layer cell. The mercury volume (radius=7.5 μm), the protective gel (thickness=300 μm) and the solution medium (thickness=200 μm) have been meshed. The concentrations of the reduced and oxidised species were linked both by the Nernst equation and the equality of the fluxes at the mercury|gel interface. Both overlapping of adjacent diffusion layers and depletion occurring in this finite box decrease the amount of species being reduced during the deposition step. However, the peak width (W^1/2=39 mV) and peak potential (E_p?E^′0=?34.6±1 mV) of the resulting stripping current are independent of the deposition time. During the stripping step, the metal concentration at the surface of the electrode is much higher than the initial concentration. The time to reach a uniform concentration in the gel again after the voltammetric reoxidation step has been determined, for both single microelectrode and a square array, as a function of the deposition time, thus giving the maximum frequency of successive measurements that should be used. Agreement between simulated and experimental results confirms that diffusion is the predominant transport process occurring in such thin-layer cell. In addition, comparison with analytical expressions has been done whenever possible.     

A stannum/bismuth/poly(p-aminobenzene sulfonic acid) film electrode for measurement of Cd(II) using square wave anodic stripping voltammetry

In the present work, a new method for a trace analysis of metal cadmium ion has been developed on the stannum/bismuth/poly(p-aminobenzene sulfonic acid) film electrode in combination with square wave anodic stripping voltammetry. This new electrode was prepared by in situ depositing stannum, bismuth and target metal on the poly(p-aminobenzene sulfonic acid)(p-ABSA) coated glassy carbon electrode. Some key factors including the pH of measure solution, the proper proportion between Bi(III) and Sn(II), the preconcentration time and the preconcentration potential have been studied and optimized. Compared with the traditional bismuth-film electrode, the stannum/bismuth/poly(p-ABSA) film electrode displayed higher stripping current response. In addition, it has the advantages of better stability and less toxicity. Under the optimum conditions, the linear calibration graph for Cd(II) in the concentration range of 0.5–55 μg L⁻¹ was obtained and the detection limit was 0.32 μg L⁻¹. The method was applied to the analysis of cadmium ion in tap water sample with satisfactory results.     

Surface analysis of anodic oxide films containing phosphorus on titanium

PURPOSE: To examine the effect of phosphoric acid solution on the anodic oxide film of titanium. MATERIALS AND METHODS: Commercially pure grade 2 titanium specimens were prepared and anodized in phosphoric acid solution at a constant current density (70 A/m2). Specimens were evaluated by means of scanning electron microscopy, x-ray diffraction analysis, electron probe microanalysis, energy-dispersive spectroscopy, profilometry, and atomic force microscopy. RESULTS: The anodic oxide film was observed to consist of a porous or non-uniform layer and a dense or uniform layer. X-ray diffraction and energy-dispersive spectroscopic analyses indicated that the film consisted of a mixture of anatase and amorphous oxide, with the incorporation of phosphorus. DISCUSSION: The degree of oxide crystallinity was observed to increase with an increase in voltage but decreased as the electrolyte concentration was increased. In addition, the concentration of phosphorus also increased as the electrolyte concentration and voltage increased. CONCLUSIONS: Electrolyte concentration and voltage play an important role in governing the anodic oxide thickness, composition, and degree of oxide crystallinity.