泡沫复制法制备多孔钛及表面水热碱处理改性

采用聚氨酯泡沫复制法成功的制备出孔径可控、孔隙率高且三维贯通的多孔钛.采用水热碱处理法对多孔钛进行表面改性,以提高其生物活性.改性后多孔钛的表面形貌发生了改变,呈均匀分布的三维网状微纳米结构.将改性后的多孔钛浸泡在SCPS中检测其矿化能力.研究结果表明,改性后的多孔钛能加速磷灰石的矿化,其中三维网状微纳米结构是加速矿化的主要因素.同时考察了改性后的多孔钛表面大鼠颅盖骨成骨细胞(MC3T3-E1)的黏附铺展情况.细胞培养表明细胞在改性后的多孔钛表面能较好的黏附铺展.上述研究结果表明水热碱处理改性后的多孔钛具有较好的生物活性及生物相容性.     

超级电容器用高性能石油焦基多孔炭的制备及改性（英文）

以石油炼制副产品石油焦为原料,采用KOH活化法制备高比面积多孔炭,通过氨水水热处理对多孔炭进行表面渗氮改性。系统考察了KOH/石油焦比例(碱/炭比)对多孔炭孔结构及电化学性能的影响。结果表明多孔炭的比表面积、孔结构和电化学性能可以通过碱/炭比有效地调控。随着碱/炭比的增大,多孔炭的孔道逐渐增大,当碱炭比为3∶1时最大比表面积达到2 964 m~2·g~(-1)。当碱/炭比为5∶1时,多孔炭的比表面积和中孔率分别高达2 842 m~2·g~(-1)和67.0%,其在50 m A·g~(-1)电流密度下的比电容达到350 F·g~(-1)。氨水水热处理多孔炭,可以有效地在多孔炭表面引入氮原子,从而提高了多孔炭电极的电化学性能,尤其提高其在高电流密度下的比电容值。KOH活化以及氨水水热处理为制备高性能低成本石油焦基超级电容器电极材料提供了一种简单有效的方法。     

去合金化制备孔径可控纳米多孔金属研究进展

纳米多孔金属具有三维连通、双连续的纳米级孔结构,使其具有超高比表面积、高强度、低密度等独特理化性能,在力学、催化、传感、拉曼散射等领域具有广阔的应用前景,而且纳米多孔金属的性能表现出一定的尺寸效应,因此研究孔结构调控对纳米多孔金属的实际应用具有重要意义。目前,去合金化制备孔径可控的纳米多孔金属主要集中在调节去合金化工艺(腐蚀方式、腐蚀温度、腐蚀电解质、腐蚀添加剂等)和去合金化后处理过程(热处理粗化、溶液浸泡)两方面,探索纳米多孔金属在不同工艺条件下孔结构的成孔机制、孔结构演变规律为制备孔结构呈特征规律分布(如梯度分布、分级分布、均匀分布)的纳米多孔金属块材或薄膜奠定了夯实的基础。     

直流电化学腐蚀法制备多孔硅的表面形貌研究

采用正交实验，直流电化学腐蚀法制备多孔硅。用原子力显微镜对表面进行观察，研究电化学腐蚀参数对其表面形貌的影响。氢氟酸浓度（CHF）升高，使临界电流密度（JPS）增大，有利于多孔硅的形成。电流密度（J）增大，多孔硅的孔隙率和孔径随之变大，而其纳米粒径将变小。腐蚀时间（t）越长，孔径越大，孔越深。     

纯钛微弧氧化膜的性能评价

采用微弧氧化-碱热处理复合的方法,在纯钛表面制备出较大表面积且成分单一的TiO2陶瓷膜,并在模拟体液中对膜层的生物活性予以评价。结果表明,纯钛微弧氧化膜层主要由锐钛矿型的TiO2构成,其表面孔径均匀,孔隙率达到12%;经碱热处理后,与模拟体液和去离子水的润湿角实验证明膜层具有较好的亲水性;碱热处理后的膜层置于模拟体液中培养14d后,膜层表面被生长出的类骨磷灰石完全覆盖,证明其具有良好的生物活性,且生长出的缺钙型磷灰石与人体自然骨成分相似。     

适用于微型燃料电池扩散层的多孔硅的可控制备工艺研究

多孔硅以其多孔结构及大的表面体积比等特点被认为是可在基于MEMS技术的微型燃料电池中代替碳 纸、碳布作为扩散层的材料. 本文考虑传统碳纸、碳布作为扩散层的要求, 并结合多孔硅材料的特点, 选用n<100>(0.04～0.15 Ω·cm)单晶硅进行了多孔硅制备工艺的研究; 考察了腐蚀液的浓度、电流密度和氧化处理时间对多孔硅的孔隙率、孔深度及氧化速率 的影响, 实现了多孔硅的可控制备. 孔隙率为40%、孔径为350～700nm、厚度为60μm的多孔硅膜电极经循环伏安测定, 在0.5mol/L H₂SO₄溶液中, 表现出与碳纸相近的电活性, 显示了潜在的应用价值.     

表面改性对介孔硅酸钙镁/聚醚醚酮复合材料性能的影响

实验制备了介孔硅酸钙镁/聚醚醚酮复合骨修复材料, 采用砂纸打磨及喷砂对其表面进行改性。结果表明: 表面改性明显提高了复合材料表面的粗糙度和亲水性(水接触角降低), 喷砂在复合材料表面暴露出大量的介孔硅酸钙镁, 形成了多孔结构, 粗糙度和亲水性提高最大。表面改性复合材料在模拟体液中浸泡7 d后, 表面都形成了大量磷灰石; 表面改性促进了MC3T3-E1细胞在复合材料表面粘附、增殖和分化。喷砂比砂纸打磨更明显地提高了复合材料的生物学性能。     

MEMS中多孔硅绝热技术

主要介绍了多孔硅的制备方法(化学法、电化学法及原电池法等)、多孔硅导热系数测试的几种常用手段(温度传感器法、显微拉曼散射法及光声法等)、导热系数的理论模型及影响因素．此外,采用不同方法制备了多孔硅样品,分析了其表面形貌并用显微拉曼光谱法测定了导热系数．结果发现,化学法制备的多孔硅孔径尺寸大于微米量级,而利用大孔硅电化学和原电池法得到的样品孔径尺寸小(约20nm),属于介孔硅．由于腐蚀条件的不同,多孔硅的孔隙率和厚度也不同,多孔硅的导热系数随孔隙率和厚度的增大而迅速减小．     

多孔Al-Si12合金的制备与性能研究

采用真空—压力烧结—溶解工艺制备出了孔隙率44%～76%、平均孔径30～110μm的多孔Al-Si12合金,对多孔Al-Si12合金的制备、孔结构、抗弯强度及渗透性能进行了研究。结果表明,真空环境下的压力烧结可明显提高多孔Al-Si12合金的抗弯强度,最佳的制备工艺为压制压力500MPa、烧结温度565℃、烧结时间2h以及烧结压力150～200MPa;多孔Al-Si12合金的相对渗透系数随其孔隙率和平均孔径的提高而增大;多孔Al-Si12合金的抗弯强度高于相近孔结构的多孔铝,渗透性能优于相近孔结构的多孔不锈钢及多孔铝。     

新型可降解钙磷骨水泥多孔支架研究

采用一种特殊的方法制备了孔径、孔隙率和孔形状可控的多孔羟基磷灰石骨水泥支架. 材料的抗压强度可达4MPa, 孔隙率可达70%, 孔与孔之间互相贯通, 大孔壁富含微孔. 细胞在材料表面黏附铺展且增殖良好, 体外模拟实验显示材料的降解速度随孔隙率的增加和Ca/P比的降低而加快, 多孔支架有优良的生物降解性和生物相容性. 该材料可用于修复骨组织缺损和作为支架材料用于组织工程.     

In vitro corrosion resistance of Lotus-type porous Ni-free stainless steels

The corrosion behavior of three kinds of austenitic high nitrogen Lotus-type porous Ni-free stainless steels was examined in acellular simulated body fluid solutions and compared with type AISI 316L stainless steel. The corrosion resistance was evaluated by electrochemical techniques, the analysis of released metal ions was performed by inductively coupled plasma mass spectrometry (ICP-MS) and the cytotoxicity was investigated in a culture of murine osteoblasts cells. Total immunity to localized corrosion in simulated body fluid (SBF) solutions was exhibited by Lotus-type porous Ni-free stainless steels, while Lotus-type porous AISI 316L showed very low pitting corrosion resistance evidenced by pitting corrosion at a very low breakdown potential. Additionally, Lotus-type porous Ni-free stainless steels showed a quite low metal ion release in SBF solutions. Furthermore, cell culture studies showed that the fabricated materials were non-cytotoxic to mouse osteoblasts cell line. On the basis of these results, it can be concluded that the investigated alloys are biocompatible and corrosion resistant and a promising material for biomedical applications.     

激光熔化镁合金凝固组织及腐蚀行为

采用Nd:YAG毫秒脉冲激光器,在高纯氩气保护下扫描AZ91D镁合金样品,采用X射线衍射仪(XRD),光学显微镜,扫描电镜(SEM),原子力显微镜(AFM)等对处理后镁合金表面形貌、组织、成分进行研究。使用模拟改性体液和质量分数为3.5%的NaCl溶液对实验样品进行腐蚀,观察腐蚀表面并计算材料腐蚀率。结果表明:在相同腐蚀时间下,与未被处理样品相比,激光处理后镁合金由于其显微组织中细化的α-Mg相与β-Mg_(17)Al_(12)相,及选择性气化现象和基体合金化学成分共同导致表面Al元素富集提高了表层的抗腐蚀性能;通过测算激光熔化区枝晶晶胞尺寸与冷却速率的关系得到其凝固方程。     

Electrochemical behaviour of Ti–25Nb–3Mo–3Zr–2Sn biomedical alloy in different simulated physiological environments

The electrochemical corrosion behaviour of biomedical Ti–25Nb–3Mo–3Zr-2Sn (TLM) alloy was investigated in various simulated body fluids at 37±0·5°C utilising potentiodynamic polarisation and current–time curves. The Ti–6Al–4V (TC4) alloy was also investigated to make a comparison. The different simulated body fluids comprised of 0·9%NaCl saline, Hank’s and Ringer’s solution were employed. The effect of heat treatment on the electrochemical behaviour of the TLM alloy was also considered. It was discovered that all the test specimens were passivated once immersed into the simulated body fluids. It was also found that the TLM alloy has poorer corrosion resistance in Hank’s solution, due to the chemical composition of the Hank’s. After different heat treated, the TLM alloy had different phases and microstructure, and the corrosion behaviour of the TLM alloy was different. In this study, after the heat treatment of 760°C/1 h/AC+550°C/6 h/AC, the TLM alloy had better corrosion resistance. Owing to the corrosion resistance of the TLM alloy was influenced by numerous factors, such as microstructure and the chemical composition of electrolyte, the corrosion behaviour of the TLM alloy is complex. By comparing with the corrosion behaviour of the TC4 alloy, the TLM alloy has poorer corrosion resistant than the TC4 alloy under the same conditions. But the current–time curves of the TLM alloy were more stable than these of the TC4 alloy with further experiments, because of the more passivation film on the surface of the TLM alloy.     

钛阳极氧化膜的着色研究

TA2型纯钛植入材料在葡萄糖酸钠电解液中阳极氧化可得到丰富的色彩,增强了钛植入体的美观性和功能性.分析表明:工艺参数对氧化膜质量有着重要的影响.电压是影响膜层色彩的最主要的因素,颜色随着电压的变化而发生规律性的改变.经X射线衍射分析,纯钛表面经阳极氧化处理后,其表面生成了一层非晶态的氧化钛薄膜,并且钛晶体的各个表面沿不同结晶方向的腐蚀速率不相同.通过对氧化膜层显微观察和耐蚀性研究,证明阳极氧化及热处理可大大提高钛氧化膜在模拟体液中的热力学稳定性和耐蚀性,且适当的热处理可使非晶态的钛氧化膜转化为稳定的二氧化钛.     

Synthesis and electrochemical characterization of porous niobium oxide coated 316L SS for orthopedic applications

Niobium oxide was prepared using sol–gel process and coated on 316L stainless steel (SS) substrate via dip-coating technique. The surface characterization results after a thermal treatment revealed that the coated surface was porous, uniform and well crystalline on the substrate. The corrosion resistance and bioactivity of the porous niobium oxide coated 316L SS in simulated body fluid (SBF) solution was evaluated. The in vitro test revealed a layer of carbonate-containing apatite formation over the coated porous surface. The results indicated that the porous niobium oxide coated 316L SS exhibited a high corrosion resistance and an enhanced biocompatibility in SBF solution.     

医用镁合金降解及其对人体的影响

镁合金具有比高分子更高的强度、比陶瓷材料更好的韧性,与人体自然骨的密度、弹性模量和力学性能也更为接近。更重要的是,其植入人体后将会逐步腐蚀降解,既无毒副作用也无需二次手术,是一种极具潜质的新型可降解生物金属材料。但镁在人体生理环境中腐蚀速度太快,可能导致镁离子、氢气、局部pH值和腐蚀沉淀物在体内发生堆积,同时镁合金的机械完整性和力学性能也会因此丧失,达不到预期的治疗目的,甚至引起不良反应和治疗失败。从镁在人体的腐蚀机理和降解产物对人体造成的影响进行综述,并分析了镁合金在未来的发展方向和挑战。     

镁合金微弧氧化陶瓷膜的组织结构及耐腐蚀性能

为了提高镁合金的耐蚀性,采用氢氧化钠-六偏磷酸钠-醋酸钙电解液,利用微弧氧化技术在AZ91D镁合金表面原位生长含有钙、磷的陶瓷膜,研究了醋酸钙浓度对陶瓷膜的厚度、表面粗糙度、形貌、成分、相组成及其在模拟体液中耐蚀性的影响。结果表明:陶瓷膜主要为MgO相,且含有Ca和P;膜层表面具有多孔结构;增加电解液中醋酸钙浓度,膜层变厚,粗糙度先增大后减小,Ca含量增多;陶瓷膜使镁合金的耐蚀性提高;电解液加入醋酸钙后,制得的膜层耐蚀性下降,含0.4 g/L醋酸钙的电解液制得的膜层的耐蚀性在含Ca膜层中最好。     

Corrosion process of pure magnesium in simulated body fluid

The chemical and physical processes of magnesium in simulated body fluid (SBF) were investigated. The corrosion rate of magnesium was measured after 3, 5, 7, 14 and 21 days of immersion, respectively. It was found that the corrosion rate decreased with increasing immersion time, while the pH of SBF changed inversely. Network-like cracks and pits were the main damages resulting from corrosion, and the localized buildup of chloride ions was the major cause of pit formation.     

Microstructure evolution and corrosion mechanism of dicalcium phosphate dihydrate coating on magnesium alloy in simulated body fluid

Dicalcium phosphate dihydrate (DCPD) coating was deposited on the substrate surface of magnesium alloy with solution treatment. The microstructures and corrosion behaviors of the DCPD-coated samples before and after immersion in simulated body fluid (SBF) for different times were investigated. It is important to note that DCPD was not only transformed into hydroxyapatite (HA) but also induced HA precipitation after immersion in SBF. An HA-like coating was generated on the substrate surface in a two step process involving an initial coating with DCPD, resulting in the corrosion resistance increasing along with the corrosion mechanism changing with increase to soaking time.     

Corrosion degradation of surface modified bio–magnesium materials by heat–self–assembled monolayer

将Mg和Mg--Ca合金进行热--自组装单分子膜表面改性, 并将其试样浸泡在SBF中和植入动物体内进行比较试验, 用LKII98B测试腐蚀电流密度, 用原子吸收光谱测定溶液中的镁离子浓度, 测量试样的质量和溶液pH值的变化, 用SEM、XRD, FTIR、EDS等分析其表面形貌、物相组成和成分变化, 研究了材料的腐蚀降解特性. 结果表明, 热自组装膜改善了镁基生物材料的腐蚀抗力和生物活性. 纯Mg的腐蚀速率由0.11 mm/y下降到0.05 mm/y, Mg--Ca合金的腐蚀速率由 0.38 mm/y下降到0.32 mm/y. 植入动物12周后, 直径的减小由0.97 mm下降到0.20 mm, 界面新类骨质层厚度由2.56 mm增加到3.14 mm.