溶胶-凝胶法制备含氟羟基磷灰石生物涂层的特点及研究进展

含氟羟基磷灰石(FHA,Ca10(PO4)6(OH2-xFx),0＜x＜2)涂层由于比羟基磷灰石(Ca10(PO4)6-(OH)2,HA)涂层的溶解度低、热膨胀系数小且生物活性好在临床医学中有着更加广泛的应用前景.介绍了FHA的结构特点、FHA涂层的制备工艺,并重点陈述了溶胶-凝胶技术在制备FHA涂层中的应用.最后在综述国内外研究进展的基础上,提出了目前研究中存在的不足,并展望了FHA涂层今后的研究和发展趋势.     

FHA的热物性能及生物活性研究

采用沉淀-煅烧法制备了F掺杂HA的FHA(Ca10(PO4)6(OH)2-2xF2x,0≤x≤1)粉末。通过X射线衍射(XRD)、热重分析(TG)、高温膨胀仪,扫描电镜(SEM),能谱仪(EDS)以及模拟体液浸泡实验研究了F掺杂对FHA高温热稳定性,高温烧结性能,热膨胀系数和生物活性的影响。结果表明,F掺杂能够提高FHA的高温热稳定性,且随F掺杂量增加,其稳定性逐渐提高;少量F(x=0.25)掺杂提高了HA基体的烧结致密度,随F含量增加(x0.25),烧结致密度下降;F掺杂能降低FHA高温热膨胀系数(CET),随着F含量的增加,FHA的CET值减小。类骨磷灰石在块体表面的生长能力为FHAHAFA,其中x=0.5和0.75的FHA具有最好的生物活性。     

氟化钠处理对炭/炭复合材料磷灰石生物活性涂层的影响

通过声电沉积工艺在炭/炭复合材料表面制备钙磷生物活性涂层, 采用扫描电镜、 X射线能谱仪、 X射线衍射仪、 红外光谱等方法研究了氟化钠处理前后钙磷生物活性涂层的形貌、 结构和组成。实验结果表明: 氟化钠能促进磷酸三钙转化为含氟羟基磷灰石(FHA), 并提高涂层结晶度; 经氟化钠处理后, 羟基磷灰石(HA)的(112)、 (300)衍射峰明显增强, 涂层是HA和FHA的混合物。氟化钠处理前后涂层表面形貌均为片状晶体, 但处理后其颗粒尺寸增大; 氟化钠处理后涂层与基体的结合强度略有增强, 结合强度可达4.08MPa, 涂层氟的含量为4.59wt％。分析了炭/炭复合材料表面HA转变为FHA的反应机制。采用氟化处理HA制备FHA涂层时, 应加入磷酸盐保持整个反应过程的pH值不变。      

碳/碳复合材料表面的含氟磷灰石生物活性涂层

用超声电沉积与离子交换相结合的方法在碳/碳复合材料表面制备含氟磷灰石(FHA)生物活性涂层,研究了离子交换时间和氟化钠浓度对含氟磷灰石(FHA)生物活性涂层的形貌、结构和组成的影响.结果表明:离子交换后的涂层是羟基磷灰石(HA)和含氟磷灰石(FHA)混合物,离子交换前后其表面形貌均呈片状晶体.随着离子交换时间的延长或氟化钠浓度的增加,HA含量降低,FHA含量升高,涂层的晶粒尺寸和致密性均发生变化.离子交换后其涂层与基体的结合强度略有增强,其原因是FHA的热膨胀系数与碳/碳复合材料基体更为匹配,涂层的残余应力减小.     

射频磁控溅射含氟羟基磷灰石涂层的研究

本文采用射频磁控溅射技术在钛合金(Ti6Al4V)基体上制备出含氟羟基磷灰石(FHA)生物涂层,探讨该涂层组织结构,不同氟含量和温度对涂层晶化程度的影响.利用扫描电镜(SEM)观察FHA生物涂层的表面形貌,采用X射线衍射仪(XRD)分析涂层相结构,利用能量分散谱仪(EDS)分析涂层的Ca/P比.结果表明,随着氟含量的增加可大大提高涂层的晶化程度,制备的FHA涂层致密、均匀.700℃晶化处理的涂层结晶度较高.     

声电沉积-氟化钠处理复合工艺制备C/C含氟磷灰石涂层

通过声电沉积和氟化钠处理相结合的方法在碳/碳复合材料(C/C)表面制备含氟磷灰石生物活性涂层,采用SEM、EDAX、XRD、FTIR研究氟化钠处理前后以及氟化钠处理时间对含氟磷灰石生物活性涂层形貌、结构和组成的影响.结果表明,氟化钠处理能促使磷酸三钙向含氟磷灰石的转化,并能提高涂层的结晶度;经氟化钠处理后的涂层是HA和含氟磷灰石(FHA或FA)不同比例的混合物.随着氟化钠处理时间的延长,磷灰石(211)、(300)的衍射峰向高衍射角漂移;HA含量降低,而FHA或FA的含量升高.氟化钠处理前后其表面形貌均呈片状晶体,但涂层颗粒尺寸发生变化.当浸泡时间达48h,涂层致密,涂层氟含量为5.85%(质量分数).氟化钠处理后涂层与基体的结合强度略有增强的趋势,其结合强度最大为4.08MPa.     

电泳沉积制备BG／BG—FHA复合涂层

采用电泳沉积在Ti6A14V钛合金表面制备了以生物玻璃（BG）为中间层,BG与氟取代磷灰石（FHA）复合粉末为表层的BG／BG—FHA涂层。通过XRD、SEM、EDS和电子万能力学试验机对BG／BG—FHA复合涂层的物相结构、微观形貌和涂层结合力进行了分析,优化了涂层的热处理制度,并通过模拟体液浸泡实验研究了涂层的体外...     

Ti-6Al-4V合金基体等离子喷涂生物活性羟基磷灰涂层的研究进展

系统阐述了在钛合金(Ti-6Al-4V)表面等离子喷涂羟基磷灰石(HA)涂层的研究进展.描述了等离子喷涂制备HA涂层的工艺过程、微观形貌和化学组成.综述几种综合性能较高的复合型涂层:HA/BG(生物活性玻璃)复合涂层,HA/ZrO2复合增强型涂层,HA/Ti涂层,HA/Ti-6Al-4V梯度涂层;并对HA涂层发展趋势进行了展望.     

梯度结构羟基磷灰石生物活性涂层的性能

采用等离子喷涂系统在Ti6Al4V钛合金基体表面制备出真有梯度结构的羟基磷灰石生物活性梯度涂层,利用纳米硬度计等手段分析了生物活性涂层的梯度结构．结果表明：金属基体与陶瓷界面区域的弹性模量和硬度呈梯度变化;生物活性功能涂层的表面具有典型的多孔结构特征,整个涂层沿垂直基体方向从底层致密结构向表面层多孔结构过渡;涂层的成分从生物稳定性的底层至生物活性的表面层呈梯度变化,涂层表面成分为具有生物活性的羟基磷灰石．涂层的这种结构特征保持了涂层的生物活性,提高涂层与基体的结合强度（48．6MPa）。     

CaB_6对激光熔覆生物陶瓷涂层组织和生物学性能的影响

为了提高医用钛合金表面激光熔覆羟基磷灰石(HA)涂层的植入稳定性和生物活性,将HA与CaB_6粉末充分混合,采用激光熔覆工艺制备了含硼元素的生物陶瓷涂层。通过X射线衍射仪(XRD)、扫描电镜(SEM)、电化学腐蚀和体外模拟体液(SBF)浸泡实验,对涂层的物相组成、组织形貌、耐腐蚀性和生物活性进行了研究。结果表明,添加CaB_6后熔覆层中产生了物相B_2O_3和CaB_2O_4,同时熔覆层中部组织呈现有序分布的二次枝晶;腐蚀电位下降了294.46 mV,电流密度是未添加CaB_6的4.28倍;在体外SBF浸没实验中,添加CaB_6后,涂层表面沉积的磷灰石均匀分布,浸泡7 d后,形成的矿化磷灰石沉积量最大,涂层表现出较强的矿化作用。CaB_6的添加可以细化晶粒,显著提升生物陶瓷涂层的耐腐蚀性,加强涂层表面的矿化能力。     

载钛(Ⅳ)锌(Ⅱ)纳米羟基磷灰石的制备及抗菌性能研究

以硝酸钙、硫酸钛、磷酸和氨水等为原料, 通过共沉淀水热合成和离子交换法, 制备了钛(Ⅳ)与锌离子共掺杂的羟基磷灰石(Ca₁₀(PO₄)₆(OH)₂, HAp)白色纳米粒子(TiZnHAp). 采用XRD、TEM、EDS、UV Vis和ESR测试对样品的结构、形貌、组成、吸光性能以及催化氧化活性进行了表征. 针对大肠杆菌和金黄色葡萄球菌进行了抗菌实验测试, 研究材料在黑暗和室内弱紫外光下的抗菌活性. 结果表明, 钛(Ⅳ)的掺杂没有明显改变HAp晶粒的形态和尺寸, 而钛(Ⅳ)的掺杂能够提高HAp的吸光性能和紫外光催化氧化能力. 相对于ZnHAp和TiHAp颗粒, 在室内弱紫外光下钛(Ⅳ)的光催化分解细菌与锌离子抗菌协同作用使TiZnHAp具有优良的抗菌效果. 同时, 离子溶出测试实验结果表明, TiZnHAp具有长效抗菌性.     

TA2纯钛微弧氧化陶瓷膜层的颜色和性能

在添加乙酸铜、乙酸镁的磷酸-氟锆酸钾电解液中对纯钛TA2基体进行微弧氧化处理,制备出颜色均匀的浅棕色陶瓷膜层。通过X射线衍射分析(XRD)、扫描电子显微分析(SEM)及附带的能谱(EDS),研究了陶瓷膜的表面和截面形貌、元素分布、相组成;用分光光度计测量了膜层的颜色,根据热震试验和三点弯曲法评价了膜层与基体的结合强度。结果表明:随着微弧氧化时间的延长,膜层中铜镁元素的含量增加,膜层的颜色随之发生变化,膜层与基体的结合强度降低。热震实验结果表明,膜层与基体有较高的结合强度。     

用冰模板法制备羟基磷灰石多孔陶瓷

使用水基羟基磷灰石(HA,Ca5(PO4)3OH)浆料,用冰模板法制备定向层状多孔HA陶瓷,研究了浆料中HA陶瓷颗粒含量和冷端温度的影响.结果表明:随着浆料中HA陶瓷颗粒含量的提高,浆料的粘度值增大,层状多孔结构的层厚度相应增加,孔道层间距减小甚至消失,多孔材料的抗压强度从1.4 MPa提高到5.7 MPa,孔隙率从7...     

Sol-gel prepared β-TCP/FHA biphasic coatings

β-tricalcium phosphate/fluoridated hydroxyapatite (β-TCP/FHA) biphasic coatings were prepared on titanium alloy substrate by means of sol-gel method. The coatings combine the initial dissolution of β-TCP with the long-term stability of FHA to create a high quality bioactive coating. Ca(NO₃)₂, P₂O₅ and HPF₆ were dissolved in ethanol respectively and mixed in designed sequence and Ca : P : F ratios to form a sol. After the sol was refluxed for 24 h, the as-refluxed sol was used for FHA coating. β-TCP powders were dispersed into the sols to form colloidal sols for β-TCP/FHA biphasic coatings. The as-refluxed sols with different Ca : P : F ratios only resulted in apatite coatings with low F content. Biphasic coatings were prepared with the colloidal sols. The β-TCP contents of the coatings could be tailored by varying the amount of the powders in the colloidal sols. The surface morphology of the coatings becomes rougher with increasing amount of the powders, which favors cell attachment. However, excessive amount of powders results in powder agglomeration, leading to more cracks in the coatings. Fine powders and good dispersion are essential factors for good biphasic coatings.     

Coatings of needle/stripe-like fluoridated hydroxyapatite on H2O2-treated carbon/carbon composites prepared by induction heating and hydrothermal methods

A hydroxyapatite (HA) coating was achieved on H₂O₂-treated carbon/carbon (C/C) composite through hydrothermally treating and induction heating deposited CaHPO₄ coating in an ammonia solution under ultrasonic water bath. Then, this HA coating was placed in a NH₄F solution and hydrothermally treated again to fabricate fluorinated hydroxyapatite (FHA) coatings for 24 h at 353, 373, 393 and 413 K, respectively. The structure, morphology and chemical composition of the HA and FHA coatings were characterized by SEM, XRD, EDS and FTIR, and the adhesiveness and chemical stability of these FHA coatings were examined by a scratch test and an immersion test, respectively. The results showed that the as-prepared FHA coatings contained needle-like or stripe-like crystals, different from those of the HA coating. As the fluoridation temperature rose, the adhesiveness of the FHA coating first increased from 34.8 to 40.9 N at a temperature between 353 and 393 K, and then decreased to 24.2 N at 413 K, while the dissolution rate of the FHA coating decreased steadily. The reasons for the property variation of the FHA coatings were proposed by analyzing the morphology, composition and structure of the coatings.     

Interfacial study of magnesium-containing fluoridated hydroxyapatite coatings

Magnesium-containing fluoridated hydroxyapatite (Mg_xFHA) coatings have been developed to improve the biological performances of fluoridated hydroxyapatite (FHA) coatings. The coatings are deposited on Ti6Al4V substrates via a sol-gel process. The interface between the coating and substrate is characterized by scanning electron microscopy, glow discharge optical emission spectroscopy and X-ray photoelectron spectroscopy for coating thickness, elemental distribution and chemical states. Pull-off test is used to evaluate the adhesion strength. The results show that the interdiffusion of elements happens at the coating/substrate interface. The incorporation of Mg ions into FHA coatings enhances the pull-off adhesion strength between the coating and the substrate, but no significant difference is observed with different Mg concentrations.     

The hydrothermal synthesis of beta-Ni(OH)(2) nanoflakes on carbon cloth and their electrochemical properties北大核心CSCD

Carbon cloth (CC) coated with beta-Ni(OH)(2) nanoflakes was prepared by a hydrothermal method using nickel nitrate, urea and ammonium fluoride as the reaction system, and was characterized by SEM, XPS and XRD. Results indicated that the acid treatment of the CC introduced more active functional groups on its surface, which was beneficial to the coating of the beta-Ni(OH)(2). The beta-Ni(OH)(2) nanoflakes were of high purity; and their formation mechanism on the CC was investigated by observing their morphology at different reaction times. It was revealed that the beta-Ni(OH)(2) were initially present in the form of discrete nanoparticles and nanoflakes and after 6 h formed a continuous and well-crystallized beta-Ni(OH)(2) nanoflake with diameter and thickness of 1 mu m and 10 nm, respectively. Nanoflakes continued to form, grow and overlap and after 12 h the thickness had increased to 200 nm. The sample at 6 h had the highest specific capacitance of 815. 67 F.g(-1) at a current density of 1 A.g(-1) and retained 98. 1% of its initial capacitance after 4 000 cycles.     

乙醇胺添加剂对AZ91D镁合金表面磷化膜微观结构的影响研究

以锌系磷酸盐化学转化膜为研究体系,采用SEM,XRD分析方法及检测手段,研究乙醇胺(MEA)添加剂及其浓度对AZ91D镁合金锌系磷酸盐化学转化膜微观结构的影响.研究发现由于锌系磷化液中乙醇胺的添加:(1)改变了AZ91D镁合金锌系磷化膜晶体层的微观结构,促进了晶核的形成和晶粒细化,晶簇间隙中晶核的形成对晶体膜层完整性和致密度起着关键作用;(2)对(Zn_3(PO_4)_2·_4H_2O)晶体的取向有影响,有控制晶簇尺寸使磷化结晶组织更均匀的作用;(3)MEA在1.2g/L时磷化膜层平整致密、晶簇的尺寸均匀缺陷最少;(4)锌系磷化膜有两层结构:(Zn_3(PO_4)_2·_4H_2O)晶体外层和非晶态内层;(5)MEA的不同添加量对晶体层孔隙的影响有3种类型:表面浅孔(a型),晶簇间缝隙或微裂纹(b型),开放缺陷(c型).