HA-ZrO2生物复合材料的制备

钇稳定的二氧化镐中分别掺杂1％,5％,15％的羟基磷灰石来制备生物性能良好,且具有较好的机械强度和断裂韧性的生物复合材料以满足承载方面的需要。对其力学性能、微观结构和生物性能进行了研究,用扫描电镜（SEM）、x射线衍射仪（XRD）等对复合材料进行了分析。结果表明掺杂羟基磷灰石的复合材料的维氏硬度远远高于单一羟基磷灰石的硬度,几乎接近于二氧化镐的硬度。最大的抗弯强度为976.21MPa,K1c为5.2—10.4MPa·m^1/2。生物模拟试验表明该种复合材料具有良好的骨传导作用,具有生物活性,是一种较理想的骨植入材料。     

羟基磷灰石／壳聚糖生物复合材料研究进展

羟基磷灰石基人工骨作为最有前途的生物医用材料之一,在生物医用材料和医学研究领域有着广泛的应用和研究.羟基磷灰石/壳聚糖复合材料因其生物相容性和合适的力学性能逐渐成为骨修复生物材料研究的热点.本文综述了羟基磷灰石/壳聚糖复合材料的研究现状,探讨了其特点、制备和性能.另外对羟基磷灰石/壳聚糖复合材料的研究发展前景予以展望.     

多元羟基磷灰石纳米生物复合材料研究进展

本文综述了羟基磷灰石基纳米生物复合材料研究进展,总结分析羟基磷灰石与壳聚糖、明胶、聚酰胺等组分的二元生物复合材料,以及羟基磷灰石-壳聚糖-明胶、羟基磷灰石-壳聚糖-聚酰胺等三元生物复合材料的制备方法、组织结构特征和相关性能。     

PEEK/HA生物复合材料的热稳定性

缩聚合成聚醚醚酮,与纳米羟基磷灰石混合,制成聚醚醚酮/羟基磷灰石生物复合材料,用热重分析法研究其热稳定性.研究表明,该材料热分解起始温度在500℃以上,热稳定性好;升温速率对热重曲线有重要影响,随着升温速率加快,热失重曲线向高温区平移,起始分解温度和最大热分解速率温度提高,反应临近结束的拐点温度也提高;随着羟基磷灰石含量的增大,该复合材料的最大分解速率逐渐降低,热稳定性优于聚醚醚酮.细胞毒性试验显示,该复合材料对Hela细胞无明显毒性,对细胞生长有促进作用,生物相容性良好.     

纳米羟基磷灰石复合陶瓷生物摩擦学行为研究

采用沉淀法合成了纳米羟基磷灰石（HA）粉体，无压烧结工艺制备了HA／PSZ陶瓷复合材料．利用材料试验分析系统（MTS）和纳米硬度分析测试系统（Triboindenter）测定了复合材料的宏观和微观力学性能，用销盘式摩擦磨损试验机考察了血浆润滑条件下复合材料的生物摩擦学性能，探讨了力学性能与摩擦学性能之间的关系．结果表明，无压烧结HA／PSZ复合陶瓷材料断裂韧性比纯HA陶瓷提高近2．7倍，弯曲强度提高近1倍．纳米硬度最高值为10．6GPa，纳米弹性模量为156．OGPa．血浆润滑条件下，HA／PSZ陶瓷和UHMWPE摩擦副的摩擦系数与HA的含量有关，UHMWPE的磨损率与HA／psz复合陶瓷摩擦副的硬度和断裂韧性存在反比关系．     

锶磷灰石@壳聚糖-聚氧化乙烯@明胶复合支架制备及其生物性能探究

为了模拟自然骨的成分以及进一步提高材料的生物活性,制备羟基磷灰石@壳聚糖@明胶和锶磷灰石@壳聚糖@明胶复合支架,并对两种材料的生物性能进行表征。通过同轴电纺制备核壳结构的壳聚糖@明胶纤维;并采用化学沉积方法,在壳聚糖@明胶纤维表面沉积羟基磷灰石或锶磷灰石颗粒。结果显示:沉积锶磷灰石后,支架仍然能保持利于细胞生长的网状结构;细胞毒性实验和增殖实验结果表明,MG-63细胞在支架材料上的存活率均超过70%;与羟基磷灰石@壳聚糖@明胶复合支架相比,锶磷灰石@壳聚糖@明胶复合支架的细胞存活率更高,表明该材料确实促进细胞的生长和活性。因此锶磷灰石@壳聚糖@明胶复合支架有良好的骨组织工程应用前景。     

有机泡沫浸渍法制备多孔羟基磷灰石生物支架的研究

以聚氨酯海绵为模板,采用浸渍法合成了孔隙率可控的羟基磷灰石(hydroxyapatite, HAP)生物支架。首先自制了羟基磷灰石粉体, 并借助X射线衍射对其进行了物相组成的分析;其次,利用聚氨酯海绵自身均匀的孔隙结构,采用浸渍法制备了多孔羟基磷灰石支架。支架孔隙率的高低与浸渍次数有关, 可达45％～90％。支架的扫描电子显微镜(SEM)分析显示,多孔支架孔形状近似为圆形,尺寸400μm左右。随浸渍次数的增加,支架的抗压强度会相应增高,浸渍5次可达3。51MPa,满足临床要求。最后还对支架的生物亲和性进行了研究,结果表明制备的羟基磷灰石支架在人体环境中具有一定的生物亲和性。     

钙磷陶瓷表面类骨磷灰石形成的Ca2+浓度阈值研究

通过对双相磷酸钙陶瓷材料表面在静态模拟体液中和动态模拟体液中的形成类骨磷灰石的钙离子浓度的阈值的测定,表明双相磷酸钙陶瓷材料表面在静态模拟体液中形成类骨磷灰石的Ca^2 浓度阈值是0．2459g／L,其阈值比标准模拟体液低10％;双相磷酸钙陶瓷材料表面在模拟体液以生理流率流动时形成类骨磷灰石的Ca^2 浓度阈值是0．3392g,／L,其阈值比标准模拟体液高22％;动态模拟体液的Ca^2 浓度阈值比静态的Ca^2 浓度阈值高37．8％。     

C／C＋HA骨植入材料对杂交波尔山羊生理生化机能的影响

碳／碳复合材料＋羟基磷灰石涂层（C／C＋HA）骨植入材料具有与人体骨组织十分接近的弹性模量和优良的表面生物活性,是一种具有重要临床应用价值的骨替换材料、采用杂交波尔山羊作为动物实验模型,开展了C／C＋HA复舍材料骨内植入实验,并从呼吸、心跳、消化、血液和免疫等方面考察了该植入材料对实验动物生理、生化指标的影响．进而探讨了该材料的生物安全性．结果表明：在植入手术后61d的观察期内,虽然实验动物出现轻度贫血和消化吸收功能下降,但未发现C／C＋HA复合材料引起的热源性反应、急性感染和免疫功能下降,说明该材料具有较好的生物安全性．     

模拟体液中纳米羟基磷灰石／壳聚糖的制备及表征

从仿生合成的思路出发．分别以模拟体液和含有壳聚糖的模拟体液为反应介质，通过磷酸和硝酸钙反应合成了羟基磷灰石（HAp）和HAp／壳聚糖复合粉体，利用TG-DTA、XRD、FT-IR和TEM等对HAp和HAp／壳聚糖的形成过程、结构及其微观形貌进行了研究．结果表明，在模拟体液中合成的HAp粉体呈现出球状和短棒状形态；HAp／壳聚糖复合粉体呈现出不规则形状．粒度〈100nm．主要晶相为羟基磷灰石．体外生物活性实验结果表明，HAp／壳聚糖复合材料比纯HAp具有更好的生物活性．具有较强的诱导磷灰石沉积能力．     

Microstructure and Erosion Resistance of in-situ SiAlON Reinforced BN-SiO_2 Composite Ceramics

BN-SiO_2-SiAlON composite ceramics were successfully prepared by the means of hot pressed sintering.Xe plasma flow generated by HallThruster was used for sputtering the surface of the samples in order to evaluate the plasma erosion resistance.XRD,TEM,SEM,and LSCM were used to characterize the phase composition and morphologies of as-made composite ceramics before and after Xe plasma erosion.The ceramics were composed of h-BN,fused silica,and SiAlON,which maintained structuralstability during the process of Xe plasma sputtering.In conclusion,comparing with BN-SiO_2 composite ceramics,the plasma erosion rate of BN-SiO_2-SiAlON composite ceramics decreases significantly at first then rises with the increase of AlN addition.Erosion pits can be observed by using SEM on the surface after plasma sputtering,which demonstrates that the BN grains have dropped off the surface.In addition,mechanicaldenudation by high-speed Xe ions is recognized as the injury mechanism for the BN-matrix composite materials.     

高性能Si3N4基可加工复合陶瓷的快速制备

采用SPS在1600～1650℃烧结5min可以获得致密的Si_3N_4-BN复相陶瓷,实验结果表明,随着BN体积分数的增加,BN聚集生长导致Si_3N_4-BN复相陶瓷强度总体均呈缓慢下降趋势,但仍然维持在很高的强度水平,BN体积分数为30%时三点弯曲强度接近900 MPa,而且拥有优异的可加工性能,SEM分析表明,借助SPS可以在实现Si_3N_4-BN复相陶瓷快速致密化基础上进行相组成及显微组织的调控和优化,从而改善材料的性能。     

Effect of CaO doping on mechanical properties and thermal shock resistance of 10NiO-NiFe2O4 composite ceramics

The CaO doped 10NiO-NiFe2O4 composite ceramics were prepared by the cold isostatic pressing-sintering process, and the effects of CaO content on the phase composition, mechanical property and thermal shock resistance of 10NiO-NiFe2O4 composite ceramics were studied. The results show that the samples mainly consist of NiO and NiFe2O4 when content of CaO is less than 4%（mass fraction）, bending strength increases obviously by CaO doping. Bending strength of the samples doped with 2% CaO is above 185 MPa, but that of the samples without CaO is only 60 MPa. Fracture toughness is improved obviously by CaO doping, the samples doped with 2% CaO have the maximum fracture toughness of 2.12 MPa·m^1/2, which is about two times of that of the undoped ceramics. CaO doping is bad to thermal shock resistance of 10NiO-NiFe2O4 composite ceramics.     

抗菌功能陶瓷材料的研究

将稀土复合磷酸盐无机抗菌材料按一定比例添加到陶瓷中制备抗菌功能的陶瓷材料,研究抗菌陶瓷的生产工艺方法,抗菌性能及抗菌机理,结果表明：在陶瓷中加入稀土复合磷酸盐无机抗菌材料不会降低陶瓷表面质量,且对金黄色葡萄球菌的6h杀抑率可达到94．8％。     

Microstructure and erosion resistance of in-situ SiAlON reinforced BN-SiO<Subscript>2</Subscript> composite ceramics

BN-SiO₂-SiAlON composite ceramics were successfully prepared by the means of hot pressed sintering. Xe plasma flow generated by Hall Thruster was used for sputtering the surface of the samples in order to evaluate the plasma erosion resistance. XRD, TEM, SEM, and LSCM were used to characterize the phase composition and morphologies of as-made composite ceramics before and after Xe plasma erosion. The ceramics were composed of h-BN, fused silica, and SiAlON, which maintained structural stability during the process of Xe plasma sputtering. In conclusion, comparing with BN-SiO₂ composite ceramics, the plasma erosion rate of BN-SiO₂-SiAlON composite ceramics decreases significantly at first then rises with the increase of AlN addition. Erosion pits can be observed by using SEM on the surface after plasma sputtering, which demonstrates that the BN grains have dropped off the surface. In addition, mechanical denudation by high-speed Xe ions is recognized as the injury mechanism for the BN-matrix composite materials.     

MICROSTRUCTURE AND INFRARED EMISSIVITY AT NORMAL TEMPERATURE IN TRANSITIONAL METAL OXIDES SYSTEM CERAMICS

The fabrication of Fe_2O_3—MnO_2—Co_2O_3—CuO system ceramics, and the com posite system ceramics of transititmal metal oxides-cordierite and transitional metal oxides-kaolinit are presented in this work. The research was carried out with the main attention to the infrared emissivity in the band of 8～14p'm at room temperature, the microstructure of the ceramics and the relation between them. High infrared emissivities exceeding 0.9 in the band of 8～14pm at room temperature were gained in the transitional metal oxide ceramics and the composite system ceramics. It is suggested that the formation of inverse spinels and partially inverse spinels, such as Fe_3O_4, CoFe_2O_4, CuFe_2O_4 and CuMn_2O_4, is beneficial to the enhancement of the infrared emissivity of the transitional metal oxide ceramics. The transitional metal oxides play an important role in determining the infrared emissivity of the composite system ceramics.     

纳米TiC对Si3N4基复合陶瓷材料性能和微观结构的影响

用热压法制备了纳米TiC增韧补强的Si₃N₄基复合陶瓷材料,研究了不同TiC含量对复合陶瓷材料力学性能与微观结构的影响.结果表明：纳米TiC颗粒的添加对复合材料的力学性能的提高是有利的,当纳米TiC的质量分数为15%时,复合材料具备较优的力学性能,其抗弯强度、断裂韧性、HV硬度分别达到895MPa,8.03MPa.m1/2,15.06GPa;不同尺寸的Si₃N₄晶粒形成双峰结构,有利于复合材料性能的提高;其断裂机制为沿晶断裂和穿晶断裂的混合类型.     

Ba（Fe0．5Nb0．5）O3／Ni复合陶瓷材料介电性能的研究

在氮气气氛中采用传统固相法制备了（1-x）Ba（Fe0.5Nb0.5）O3／xNi（x=0．1,0．2,0．3;BFN／Ni）复相陶瓷,并研究了Ni含量对复相陶瓷晶体结构、显微组织、渗流阈值及介电性能的影响．研究结果表明：在高温烧结过程中,Ni含量为30wt％时,BFN和Ni没有发生化学反应．BFN／Ni复合陶瓷的电阻率随着Ni含量的增加而下降,且在渗流阈值附近,复合材料从绝缘体逐渐变为导体．BFN／Ni复合陶瓷的介电常数会随着Ni含量的增加而急剧增大．在室温下1kHZ条件下,当Ni含量为30wt％时,复合陶瓷材料的介电常数约为1670000,这是由于在导体和绝缘体的相界面处积累了大量的空间电荷,并由此产生界面极化,导致介电常数显著增大,且随着导体含量的增加,这种界面效应更加明显．对于介电常数的增加,可以借助Maxwell—Wagner极化模型来给予解释．     

烧结温度对Al_2O_3-SiC复合陶瓷力学性能的影响

以Al2O3和SiC为原料,利用热压烧结法制备了Al2O3-SiC复合陶瓷.采用三点弯曲法、单边切口梁法等手段和SEM方法分别测定和分析了该复合陶瓷的抗弯强度、断裂韧性、致密度和断口形貌.结果表明,Al2O3-SiC10wt%复合陶瓷的致密度随热压烧结温度的提高而逐渐提高,最高可达98.42%;抗弯强度随烧结温度的升高而呈上升趋势,在1 800℃时抗弯强度最大为623MPa;断裂韧性明显是随温度的升高加强,特别是在1 850℃烧结时达到最高值7.9MPa·m1/2.材料的断裂方式主要为沿晶断裂,随着烧结温度升高,穿晶断裂所占的比例增大.