HAP粉体的制备及其性能

以P2O5和Ca(NO3)2.4H2O为原料,采用溶胶-凝胶法合成羟基磷灰石粉体,研究了不同合成温度条件下羟基磷灰石粉体的性能,结果表明,493℃煅烧时羟基磷灰石开始形成,600℃煅烧时羟基磷灰石粉体完全晶化,颗粒形貌为球形,尺寸约为50nm.煅烧温度进一步升高,粉体团聚倾向加剧,颗粒之间互相连接而导致粒径增大.     

掺炭煅烧法制备α-磷酸三钙粉体

以四水硝酸钙和磷酸氢二铵为主要原料,采用湿化学合成法制备了α-磷酸三钙(-αTCP)粉体,研究了煅烧过程中添加分散剂活性炭防止磷酸三钙在高温煅烧时发生团聚的作用。采用X射线衍射仪、扫描电子显微镜和激光粒度分析仪对样品的物相、显微结构及粒度分布进行观察与分析。结果表明,当煅烧温度为1 320℃时,晶型完全转变,能够制备纯度较高的α-磷酸三钙粉体。活性炭掺量煅烧对α-磷酸三钙的粉体形貌和粒度有很大影响,当m(粉末)∶m(活性炭)=1∶0.5时,煅烧后的α-磷酸三钙粉体颗粒的形态分布更均匀,颗粒的中粒径更小,粒径分布主要集中在1.46μm左右。     

液相水解法制备高纯石英粉体团聚状态的控制

采用多晶硅副产物SiCl4液相水解法制备高纯合成石英粉,通过激光粒度分析、SEM等研究了水解反应、干燥、高温煅烧过程中粉体颗粒团聚体的形成机理及控制技术,并利用XRD和IR分析了合成石英粉的结构形态及羟基含量。结果表明:在水解反应过程中,添加合适分散剂(如聚乙二醇、十六烷基三甲基溴化铵)有助于防止水解产物SiO2颗粒的团聚;在干燥前,用去离子水洗涤水解产物多次后再用无水乙醇脱水,可减少干燥过程颗粒的团聚;干燥温度不宜过高,以水分易于均匀地排除即可;随着烧结温度的升高,粉体羟基含量逐渐减少,从1 250℃开始非晶态的SiO2颗粒逐步转变为α-方石英,在1 300℃时衍射峰形尖锐,但高温下SiO2颗粒之间形成了坚实的烧结颈,产生了硬团聚体,需粉磨和筛分以得到所需粒径的石英粉体。     

温度对纳米氧化锆粉体结构的影响

以ZrOCl2.8H2O为原料,加入3%的Y2O3为稳定剂,采用湿化学法制备出稳定的纳米ZrO2粉体,分别在200℃、400℃、600℃、800℃和900℃下煅烧,研究煅烧温度对纳米ZrO2粉体的物相组成、粒径大小、比表面积及粉体分布特征的影响,并讨论了分散时间对纳米粉体团聚现象的影响.研究结果表明:当温度从200℃升至900℃,粉体经历了由无定形向四方相、单斜相晶体的转变,对应相变温度分别是400℃、800℃;随着煅烧温度的不断升高,ZrO2粉体的粒径不断增大,比表面积不断减小;分散时间的延长可以减少纳米ZrO2粉体中颗粒之间的软团聚,改善颗粒分布的均匀性.     

SiCp/Al复合材料的凝胶法混料工艺研究

采用凝胶法研究了SiCp/Al复合材料制备中原料混合工艺的影响因素。实验结果表明,经湿法腐蚀超声处理可得到粒径集中分布的SiC颗粒;经表面涂覆后的SiC颗粒能降低颗粒的团聚程度;通过向凝胶体系添加分散剂,并以去离子水为分散介质,聚乙烯吡咯烷酮(PVP)能够使SiC颗粒完全均匀分布于复合粉体中。     

化学沉淀法制备HA粉体过程中水中分散效果的试验研究

选用聚乙二醇2000、六偏磷酸钠和BK Giulini公司提供的粉体分散剂LoponR 885对化学沉淀法制备的HA进行水中分散性试验研究. 用粒度分布仪、X射线衍射仪（XRD）和透射电子显微镜（TEM）对分散体系进行粒度分布、形貌和物相分析. 对粉末HA颗粒的团聚及分散机理进行了探讨. 结果表明，采用这种方法得到的粉体的组成相以羟基磷灰石（HA）为主,且颗粒具有近似球形的微观形貌. (NaPO3)6和LoponR 885对HA颗粒团聚的消弱作用明显. 可以认为合理选用分散剂是在不影响HA粉体品质前提下消除HA颗粒团聚现象的有效方法.     

化学沉淀法制备HA粉体过程中水中分散效果的试验研究

选用聚乙二醇2000、六偏磷酸钠和BK Giulini公司提供的粉体分散剂Lopon 885对化学沉淀法制备的HA进行水中分散性试验研究。用粒度分布仪、X射线衍射仪（XRD）和透射电子显微镜（TEM）对分散体系进行粒度分布、形貌和物相分析。对粉末HA颗粒的团聚及分散机理进行了探讨。结果表明，采用这种方法得到的粉体的组成相以羟基磷灰石（HA）为主，且颗粒具有近似球形的微观形貌。（NaPO3）6和Lopon 885对HA颗粒团聚的消弱作用明显，可以认为合理选用分散剂是在不影响HA粉体品质前提下消除HA颗粒团聚现象的有效方法。     

纳米羟基磷灰石制备的实验研究

采用NaP作为分散剂,共沸蒸馏脱水来制备纳米羟基磷灰石（HA）颗粒.通过X射线衍射仪、透射电子显微镜（TEM）、和粒度分布仪等设备分别表征所制取的粉末的物相、形貌、粒度分布.主要观察NaP和共沸蒸馏方法的效果.实验结果表明,NaP作为分散剂有一定效果且在20%附近有一个最佳分散点,但是会降低羟基磷灰石（HA）粉体的热稳定性,并且,共沸蒸馏能够有效的防止团聚的发生.     

纳米羟基磷灰石制备的实验研究

采用NaP作为分散剂，共沸蒸馏脱水来制备纳米羟基磷灰石(HA)颗粒.通过X射线衍射仪、透射电子显微镜(TEM)、和粒度分布仪等设备分别表征所制取的粉末的物相、形貌、粒度分布.主要观察NaP和共沸蒸馏方法的效果.实验结果表明，NaP作为分散剂有一定效果且在20％附近有一个最佳分散点，但是会降低羟基磷灰石(HA)粉体的热稳定性，并且，共沸蒸馏能够有效的防止团聚的发生.     

直接沉淀法制备纳米TiO2粉体的研究

以工业偏钛酸为原料,在添加特殊分散剂并进行冷水浴的情况下,用直接沉淀法制备出了纳米TiO2粉体。实验研究了硫酸氧钛溶液的浓度,分散剂的添加量,以及煅烧温度对产物的影响。实验结果表明：硫酸氧钛的浓度为0．4mol／L时可得到粒径约为40nm的前驱体（TiO（OH）2）粉体;分散剂的最佳加入量是TiOSO4的2‰（质量比）;TiO2向金红石相转变的温度是850℃。本实验还确定了TiOSO4溶液制备中的一些参数。     

不同Ca/P比粉末对宽带激光熔覆梯度生物陶瓷涂层组织结构的影响

采用梯度设计思想,利用宽带激光熔覆技术,在TC4合金表面分别熔覆Ca/P为1.4和1.5的CaH-PO4.2H2O+CaCO3混合粉末制备含羟基磷灰石[Ca10(PO4)6(OH2),简称HA]、β-磷酸三钙[β-Ca3(PO42),简称β-TCP]的度生物陶瓷涂层.采用XRD、SEM等表征手段,研究不同Ca/P粉末配比对生物陶瓷涂层组织结构的影响.研究表明:由于P在激光条件下存在烧损现象,当Ca/P为1.5的粉末经激光熔覆后所生成的陶瓷组织较Ca/P较1.4结晶状态更好.不同Ca/P粉末以及CeO2的添加量对催化合成HA+β-TCP有着深刻的影响.当Ca/P=1.4,CeO2的添加量为0.4wt%时,催化合成HA+β-TCP的数量最多;而当Ca/P=1.5,CeO2的添加量在0.2～0.4wt%范围内,催化合成HA+β-TCP的量最多.     

热喷涂HA复合涂层的组织分析

为了制备羟基磷灰石（HA）复合涂层,采用化学沉淀法制备羟基磷灰石粉末,对制备的超细粉末加入PVA溶液充分搅拌、干燥、研磨和过筛,制备出微米级、近似球状的、在等离子送粉器中容易流动的羟基磷灰石粉末.利用等离子喷涂和电弧喷涂的复合喷涂方法制备出羟基磷灰石不锈钢复合涂层和氧化铝不锈钢复合涂层,并通过扫描电镜分析了涂层的组织形态.结果表明,羟基磷灰石粉末比重很轻,不易进入等离子弧中心而被融化,等离子弧将羟基磷灰石粉末加热并载入电弧喷涂气流中,由不锈钢雾化液滴一并打在基体上形成复合涂层.对于氧化铝/不锈钢涂层和复合涂层,2种粒子虽然分布不均匀,但却获得了良好的冶金结合.     

粉体结构对羟基磷灰石生物涂层组织结构的影响

采用亚音速火焰喷涂方法及涂层处理技术,以Ti6Al4V为基体喷涂不同结构粉体,制备HA生物涂层,并引入Ti/G过渡层缓解应力,涂层经700℃晶化处理.结果表明：粉体结构对HA涂层结构影响较大.化学沉淀法制备的HA粉体,涂层孔洞稀少、致密,喷雾干燥法制备的HA粉体,涂层疏松、多孔.涂层经700℃晶化处理后,主相为晶态HA,同时含有少量CaO与焦磷酸钙Ca2P2O7相,保证了涂层的生物性能.     

Morphologies of hydroxyapatite nanoparticles adjusted by organic additives in hydrothermal synthesis

Properties of hydroxyapatite (HA, Ca₁₀(PO₄)₆(OH)₂), including bioactivity, biocompatibility, solubility and adsorption could be tailored over wide ranges by the control of particle composition, particle size and morphology. In order to satisfy various applications, well-crystallized pure HA nanoparticles were synthesized at moderate temperatures by hydrothermal synthesis, and HA nanoparticles with different lengths were obtained by adding organic additives. X-ray diffractometry (XRD) and Fourier transform infrared (FTIR) spectrometry were used to characterize these nanoparticles, and the morphologies of the HA particles were observed by transmission electron microscopy (TEM). The results demonstrate that shorter rod-like HA particles can be prepared by adding cetyltrimethylammonium bromide (CTAB), as the additive of CTAB can block the HA crystal growth along with c-axis. And whisker HA particles are obtained by adding ethylenediamine tetraacetic acid (EDTA), since EDTA may have effect on the dissolution-reprecipitation process of HA.     

Preparation and Behaviour of New Materials for Percutaneous Access

1Introduction HAbioceramicsarewidelyusedinclinic,buttheir applicationsaresometimeslimitedowingtolowstrengthof thematerial.Ontheotherhand,theimplantedmaterial ofpercutaneousaccessandbodytissueswillreactmutual lyintheextremelycomplicatedphysiologycircumstan…     

超声波辅助下纳米羟基磷灰石的制备

为有效控制纳米羟基磷灰石粉体的团聚,以硝酸钙和磷酸氢二铵为原料,超声波辅助下合成了纳米羟基磷灰石粉体,并对其进行了900℃的热处理。借助X射线衍射(XRD)、红外吸收光谱(FTIR)、扫描电子显微镜(SEM)、热重差热分析(TG-DTA)对合成的羟基磷灰石进行了物相组成、化学组成、微观形貌、热稳定性的研究。结果表明合成的羟基磷灰石为50nm左右均匀分散的等轴晶,超声处理有效控制了纳米粉体的团聚,热处理能显著提高羟基磷灰石晶粒的结晶度。     

镁合金表面HA/CNTs涂层的制备及电化学性能研究

为了提高生物镁合金羟基磷灰石(HA)涂层的耐蚀性能,在微弧氧化电解液中加入羟基磷灰石/碳纳米管(HA/CNTs)复合粉体添加剂,制备HA/CNTs复合涂层。分别对制备的HA/CNTs复合粉体和HA/CNTs复合涂层进行表面形貌和物相组成分析,并对HA/CNTs复合涂层在模拟体液(SBF)中的耐腐蚀性能进行了研究。结果表明,HA/CNTs复合粉体在微弧氧化过程中能均匀地沉积在镁合金表面,结晶良好且无任何杂质;与HA涂层相比,HA/CNTs涂层具有较小的腐蚀电流密度值和较大的阻抗值。此外,在SBF中浸泡4d后,HA/CNTs复合涂层表面出现大量的亚微米级颗粒产物且没有任何腐蚀裂纹。     

Surface Modification of Hydroxyapatite by Using γ-aminopropyl Silane

Surface modification of hydroxyapatite( HA) powder was performed with r-aminopropyi silane in toluent solvent. The modification effects were characterized by using XPS and FT-IR methods . The results indicated that the P2p electron binding energy of the modified HA decreases 0.4 eV compared to that of HA . Furthermore , a new peak, 998cm-1 absorption appeared in IR differential spectra of modified HA and HA, which is due to a stretching vibration of structure P-O-Si, meaning that a direct covalent bonding between hydroxyl group on HA surface and the organic silane molecule was realized after modification, and the chemical bonding type was P- O-Si. The formation of the above structure suggested that the more effective interfacial adhesion between the modified HA and polymer matrix could be carried out.     

Surface Modification of Hydroxyapatite by Using γ-aminopropyl Silane

Surface modification of hydroxyapatite(HA) powder was performedwith r-aminopropyl silane in toluent solvent. The modification effects were characterized by using XPS and FT-IR methods. The results indicated that the P2p electron binding energy of the modified HA decreases 0.4eV compared to that of HA. Furthermore, a new peak, 998cm-1 absorption appeared in IR differential spectra of modified HA and HA, which is due to a stretching vibration of structure P-O-Si, meaning that a direct covalent bonding between hydroxyl group on HA surface and the organic silane molecule was realized after modification, and the chemical bonding type was P-O-Si. The formation of the above structure suggested that the more effective interfacial adhesion between the modified HA and polymer matrix could be carried out.     

CuO-containing multi-wailed carbon nanotubes: a novel catalyst for the catalytic ozonation of humic acid in water

CuO particles were attempted to fill in the channel of multi-walled carbon nanotubes(MWCNTs)as novel catalytic materials CuO@MWCNTs used for ozonation of humic acids(HA)in aqueous solution.Catalyst samples were characterized by transmission electron microscopy(TEM),X-ray diffraction(XRD),thermogravimetric analysis(TG)and X-ray photoelectron spectroscopy(XPS).The removal efficiency of HA was promoted in the presence of CuO@MWCNTs compared with that of Al2 O3-supported CuO catalyst(CuO/Al2O3)and CuO-coating MWCNTs catalyst(CuO/MWCNTs).The strong synergetic effect in the confinement environment on CuO nanoparticles can attribute to the locally higher pressure due to the lower potential energy of reactants in the channels.Strong interaction happened between the catalyst and reactants,which promoted the decomposition of ozone and the generation of OH.The results of experimental and theoretical investigation confirmed that CuO@MWCNTs promotes the initiation and generation of OH,hence accelerating the degradation of organic pollutants.