喷砂酸蚀处理促进Ti6Al7Nb表面钙磷沉积

研究了Ti、Ti6Al4V和Ti6Al7Nb 3种钛基材料在喷砂酸蚀处理后成骨细胞在其表面生长的生物活性。通过Al2O3喷砂和盐酸、硫酸混合物酸蚀的表面改性方法,在Ti、Ti6Al4V和Ti6Al7Nb3种钛基材料表面进行喷砂酸蚀处理,通过SEM观察样品的表面形貌,样品的表面呈现出微米级多孔形貌;将样品浸入模拟体液(simulated body fluid,SBF)中浸泡7,14和21 d后通过SEM、X射线衍射仪(XRD)分析样品表面沉积物的形貌、物相,样品浸入SBF 14 d后,Ti6Al7Nb表面最先观察到表面覆盖的羟基磷灰石涂层;样品浸入SBF 21 d后,Ti、Ti6Al4V和Ti6Al7Nb表面都观察到羟基磷灰石涂层。羟基磷灰石涂层有利于促进钛基植入体与体内骨组织的骨结合,喷砂酸蚀处理的Ti6Al7Nb表现出良好的生物活性。     

Ti、Ti6Al4V和Ti6Al7Nb对成骨细胞生物活性影响的研究

研究Ti、Ti6Al4V和Ti6Al7Nb 3种钛金属表面经喷砂酸蚀处理后的表面形貌、亲水性及对成骨细胞生物活性的影响。在Ti、Ti6Al4V和Ti6Al7Nb 3种钛金属表面进行Al2O3喷砂和盐酸、硫酸混合物酸蚀的表面改性处理(SLA),通过扫描电子显微镜(scanning electron microscope,SEM)观察样品的表面形貌,通过接触角测量仪在显微镜下测量接触角的大小;将SD大鼠成骨细胞以1×104cells/m L密度接种于Ti、Ti6Al4V和Ti6Al7Nb表面后通过MTT活性实验观察成骨细胞在样品表面的增殖,通过SEM观察细胞在样品表面生长的形态,通过碱性磷酸酶(AKP)活性实验,检测成骨细胞的分化能力。Ti、Ti6Al4V和Ti6Al7Nb在经过喷砂酸蚀处理后,表面均呈现出微米级多孔形貌,3种样品均为亲水性表面;细胞在SLA处理后的Ti、Ti6Al4V和Ti6Al7Nb表面增殖良好,细胞伸展显著;其中在Ti6Al7Nb表面细胞的增殖、黏附、分化能力最强。大颗粒喷砂酸蚀技术的表面处理方法能够促进Ti、Ti6Al4V和Ti6Al7Nb的生物活性;经SLA处理的Ti6Al7Nb比Ti和Ti6Al4V表现出更好的生物学活性,成骨细胞在其表面呈现出更好的增殖、黏附及分化能力。     

阳极氧化对钛合金表面HA-TiO2复合涂层的影响

对钛合金表面进行阳极氧化预处理,然后用水热电化学方法在其上沉积羟基磷灰石-二氧化钛(HA-TiO2)复合涂层,研究了阳极电压对基体表面的物相、形貌、润湿性和粗糙度的影响,以及对HA的物相、形貌及生物活性的影响。结果表明:阳极氧化电压高于110 V时在钛基体表面出现金红石型和锐钛矿型TiO2,孔径尺寸随阳极电压的增加而增大。在120 V预处理的钛合金试样表面具有好的润湿性,粗糙度Ra达到0.56μm。HA涂层沿c轴方向择优生长,并呈现分层生长,HA的结晶度随着阳极氧化电压的提高先增大后减小,在120 V取得最大值。在120 V氧化处理的试样具有较好的生物活性。     

钛合金表面Nb-C复合渗层摩擦磨损性能的研究

为提高钛合金表面的耐磨性能,采用等离子表面合金化技术在Ti6A14V(TC4)合金表面形成含Nb的梯度改性层,然后进行渗C复合处理,得到Nb-C复合改性层,研究了改性层的显微组织形貌、成分分布、相结构特征及硬度分布,并进行了球盘摩擦磨损实验.结果表明,Nb、C元素呈梯度分布,合金层主要由Ti、TiC、Nb2C、NbC等...     

钛合金微弧氧化膜成分特性分析

钛合金微弧氧化膜层硬度大、耐蚀性好、电绝缘性好,可用于耐磨、耐蚀零件的处理.介绍了钛合金微弧氧化技术现状,采用引进设备,通过控制电压、电流密度、电解液浓度等参数在Ti6Al4V表面生成了膜层;测试了膜层的厚度、粗糙度、显微硬度及绝缘电阻值;采用X射线衍射及扫描电镜并结合能谱仪研究了膜层的结构、形貌及元素;分析了膜层的形成机理.结果表明,膜层厚度为22 μm,粗糙度Ra为2.0 μm,显微硬度为HV 2 200,绝缘电阻值为5 MΩ,包含非晶相和晶相-钛组织,是由膜层基体和大量的直径只有几微米的孔洞组成,主要包含O,Si,Ti和Al元素.     

钛合金表面等离子体电解氮碳共渗的研究

在含有硝酸铵、甘油、乙醇的水溶液中,利用等离子体电解渗入技术在Ti6Al4V钛合金表面制备了氮碳共渗层.利用SEM、XRD、GDS以及显微硬度计分析了渗层的形貌、成分、组织和显微硬度,探讨了渗层形成的机理和过程.结果表明:(1)以300V的电压经45min处理制备的渗层总厚度约为100μm,其中化合物层约为20μm,主要由Ti(C,N)相组成;(2)渗层最高显微硬度超过2000HK0.0025.等离子体电解渗入技术可以较快地在钛合金表面制备出厚度大、硬度高的氮碳共渗层.     

热氧化处理对铋薄膜光学性能的影响

对通过蒸发获得的金属铋薄膜经热氧化处理并与直接蒸发氧化铋获得的薄膜比较和进行不学性能测量，发现都能获得β相氧化铋薄膜。     

酸洗和热氧化对氮化硅粉料表面特性与浆料流变性能的影响

选用四种商业氮化硅粉料(其中FD1、FD2和M11均由硅粉直接氮化法合成但后处理工艺不同, 而UBE粉的合成采用亚胺基硅热分解法), 系统研究了酸洗和热氧化处理对其表面特性和水基浆料流变特性的影响. 研究表明, 表面基团的种类和数量、可溶性高价反离子浓度以及离子电导率是影响氮化硅粉料在水中分散性能的关键因素. FD1粉料分散性能差的原因是可溶性高价反离子浓度太高, FD2粉料分散性能差的关键是颗粒表面存在Si-O-C-R憎水基团, M11粉料分散性能不好源于离子电导率过大, 而UBE粉料表面的大量Si-O-Si基团是其分散性能差的限制性因素. 经表面改性处理的四种氮化硅水基浆料具有良好的流变特性.     

热氧化处理对铋薄膜光学性能的影响

对通过蒸发获得的金属铋薄膜经加热氧化处理并与直接蒸发氧化铋获得的薄膜比较和进行光学性能测量，发现都能获得β相氧化铋薄膜。但是由于热氧化与蒸发的过程或速率不同，出现化学计量偏离，薄膜结构和光学性能变化。热氧化不够或低速率蒸发形成薄膜富铋，出现无定型或其它相结构，光学吸收限变宽，移向低能处。过氧化则会使薄膜富氧，同样使结构变化，吸收限变宽而向高能方向移动。实验表明蒸发金属铋薄膜然后经３５０℃，３小时热氧化是比较合适的制备氧化铋薄膜的条件。     

An interfacial study of sol-gel-derived magnesium apatite coatings on Ti6Al4V substrates

Magnesium apatite coatings on Ti6Al4V substrate were synthesized by the sol-gel dip-coating method. Magnesium was incorporated in the coating according to the formula (Ca_10−xMg_x)(PO₄)₆(OH)₂, where x = 0, 0.50, 1.00, 1.50 and 2.00. Approximately 2-μm-thick apatite coatings were derived after five cycles of dip-drawing-drying-firing process. A transitional region (R_t) was formed between substrate and coating during the firing process. Adhesion tests show that the adhesion strength between substrate and apatite coating is enhanced by the incorporation of magnesium in the coating. The quantity of magnesium incorporated appeared to correspond to the Mg-Ti-O chemical bonds formed in the transitional region, which contributed to the adhesion strength of the coatings.     

Ti-2Al-2.5Zr合金在300℃碱性水中氧化的表面分析

利用原位 AES深度分析 ,XRD,和 XPS方法研究了 Ti- 2 Al- 2 .5 Zr合金在 30 0℃碱性水中氧化 130 0 0 h所形成的氧化膜的结构、成分和价态 ,及其随深度的变化。结果表明 ,氧化膜是由板钛型 Ti O2 、Al2 Ti O5(Ti O2 ·Al2 O3) ,Ti3O5,Ti2 O3和 Ti O所组成 ,氧化膜由表面到基体基本是按以上顺序交迭构成。通过 XPS和原位 AES分析发现钛合金表面形成由 Ti O2 ,Al2 Ti O5(Ti O2 ·Al2 O3) ,Ti3O5组成的较为稳定的厚约 80 0 nm的 Ti4 + (Ti O2 )层 ,随深度的增加出现了 Ti3+ (Ti3O5,Ti2 O3)和 Ti2 + (Ti O) ,直至基体 ,氧化膜总厚度约 30 0 0 nm。     

Surface State of Carbon Fibers Modified by Electrochemical Oxidation

Surface of polyacrylonitrile (PAN)-based carbon fibers was modified by electrochemical oxidation. The modification effect on carbon fibers surface was explored using atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD). Results showed that on the modified surface of carbon fibers, the carbon contents decreased by 9.7% and the oxygen and nitrogen contents increased by 53.8% and 7.5 times, respectively. The surface roughness and the hydroxyl and carbonyl contents also increased. The surface orientation index was reduced by 1.5% which decreased tensile strength of carbon fibers by 8.1%, and the microcrystalline dimension also decreased which increased the active sites of carbon fiber surface by 78%. The physical and chemical properties of carbon fibers surface were modified through the electrochemical oxidative method, which improved the cohesiveness between the fibers and resin matrix and increased the interlaminar shear strength (ILSS) of carbon fibers reinforc     

Characterization of ultra-thin TiO2 films grown on Mo(112)

Ultra-thin TiO₂ films were grown on a Mo(112) substrate by stepwise vapor depositing of Ti onto the sample surface followed by oxidation at 850 K. X-ray photoelectron spectroscopy showed that the Ti 2p peak position shifts from lower to higher binding energy with an increase in the Ti coverage from sub- to multilayer. The Ti 2p peak of a TiO₂ film with more than a monolayer coverage can be resolved into two peaks, one at 458.1 eV corresponding to the first layer, where Ti atoms bind to the substrate Mo atoms through Ti-O-Mo linkages, and a second feature at 458.8 eV corresponding to multilayer TiO₂ where the Ti atoms are connected via Ti-O-Ti linkages. Based on these assignments, the single Ti 2p_3/2 peak at 455.75 eV observed for the Mo(112)-(8 × 2)-TiO_x monolayer film can be assigned to Ti³⁺, consistent with our previous results obtained with high-resolution electron energy loss spectroscopy.     

Biological Multi‐layer Systems as Implant Surface Modification

In living organisms the natural contact areas between cells are the cell membranes. These membranes separate the individual cells or build reaction compartments in an aqueous environment. Beside their structural role they also have specific functions that are due to the great variety of their components which are lipids (about 40 %) and proteins (about 60 %). In terms of implant development the next neighbors of the cells are artificial materials which do not belong to the natural cellular environment. Therefore, a biocompatible implant surface is needed which is achieved by either the correct choice of the material and surface roughness or a functionalization of the surface. To date little is known of the role lipids could play in this context. However, from literature we know that phospholipids can cause calcification and that modified phosphorylcholine polymers ('MPC polymers') are used to decrease cell adhesion and to improve blood compatibility. In the last few years it became obvious that the lipid contribution in the membrane is not only important as support for proteins but that the lipid membrane itself can also be a target for drug design and its structure can influence the function of the proteins. We therefore focused our interest on this class of amphiphilic molecules. In this work we present initial observations on the modification of metallic implant surfaces of Ti‐6Al‐7Nb (in mass percent) by phospholipid multilayers, using contact angle measurements and surface sensitive characterization techniques such as scanning electron microscopy (SEM) and scanning force microscopy (SFM). Preliminary data concerning cell adhesion experiments are also presented.     

The oxidation kinetics of magnesium at low temperatures and low oxygen partial pressures

The initial oxidation of magnesium at oxygen partial pressures between 1.3 × 10^− 8 Pa and 1.3 × 10^− 5 Pa and at temperatures just above room temperature has been investigated in situ with X-ray photoelectron spectroscopy (XPS) and ellipsometry. Quantitative analysis of the XPS spectra showed that the initially formed oxide has a higher Mg/O ratio (> 1.3) than bulk MgO. Ellipsometry measurements indicated that the band gap values of the oxide layers are considerably smaller than the value expected for bulk MgO ( 2.5 eV vs. 7.8 eV). From the XPS and ellipsometry data recorded as a function of oxidation time the oxidation kinetics have been determined. The kinetics has been described quantitatively with a coupled currents model, involving simultaneous transport of electrons and ions through the oxide layer.     

Characterization by optical emission spectroscopy of an oxygen plasma used for improving PET wettability

Polymers have excellent bulk physical and chemical properties but usually poor surface properties. For wettability improvement plasma technology is one of the most promising techniques. Several studies about surface modifications of polyethylene terephthalate (PET) exposed to an oxygen plasma have been already carried out. In this work an analysis of the plasma phase by optical emission spectroscopy (OES) has been employed in order to establish a correlation with the surface effects induced by plasma exposition on PET chemical composition and wettability, investigated by X-ray photoelectron spectroscopy (XPS) and water contact angle measurements, respectively. The treatment has been carried out for a time of 60 s at a constant pressure (15 Pa) and at different process powers ranging from 20 to 200 W. As expected, the best performance has been obtained at a power of 200 W due to the larger presence of oxygen radicals (OI) with the assistance of ionic species (OII, O₂⁺) which create dangling bonds on the substrate surface.