Al2O3／TiO2纳米复相陶瓷的增韧机理研究

纳米结构与纳米添加剂对陶瓷体的增韧是多种增韧方式共同存在的。对于1350℃烧结的ATZ陶瓷,其增韧机理为相变增韧和纳米颗粒增韧;对于1450℃的ATZ陶瓷烧结体,增韧机理主要为纳米颗粒增韧和微裂纹增韧。而且ATZ陶瓷体在1450℃烧结时的增韧效果优于1350℃烧结时的增韧效果。     

Preparation and antibacterial activity of Ag/TiO2-functionalized ceramic tiles

An Ag/TiO₂ coating was deposited onto glazed ceramic tiles by a sol-gel and spraying method at high temperatures. The coating was characterized by X-ray diffraction, scanning electron microscopy, and atomic force microscopy. The results showed that silver was present in rutile-TiO₂, and the temperature did not change the phase composition of the samples. The Ag/TiO₂ coating had a higher roughness than the TiO₂ coating. The tape test (D 3359–08) showed that the coatings prepared at 950 °C and 1000 °C had good adhesion to the ceramic tile substrate. The antibacterial activity of the coating was tested by photocatalytic sterilization experiments. The results showed that the Ag/TiO₂ coating had a higher antibacterial activity than the TiO₂ coating, and the sterilization efficiency of Escherichia coli, Staphylococcus aureus, Shigella, and Salmonella exceeded 99.655% under 2 h of visible light irradiation. This research provides a method to create Ag/TiO₂ coatings with good thermal resistance, adhesion, and antibacterial activity. This improves the low photocatalytic activity caused by the anatase-to-rutile transformation of TiO₂ at high temperatures and the poor adhesion at low temperatures.     

原位合成的ZrO2/TiB2复合陶瓷材料摩擦磨损特性研究

对原位合成的ZrO2/TiB2复合陶瓷材料进行了室温下的摩擦磨损性能试验研究,利用扫描电镜对其磨损表面进行观察.结果表明:复合材料随着TiB2含量的增加摩擦系数减小,其抗磨损能力增强.磨损机理为微观切削和机械冷焊.     

聚丙烯/纳米TiO_2复合材料的性能研究

研究了PP/纳米TiO2 、PP/普通TiO2 复合材料的流变行为、力学性能和抗菌性能。结果表明 :在PP中加入TiO2 后 ,熔体的表观粘度增大 ,PP/纳米TiO2 复合材料尤其明显 ;熔体流变性对温度的敏感性降低 ,PP的加工温度范围变宽。纳米TiO2 对PP的增韧作用比普通TiO2 更好 ,在 0～ 4%的范围内 ,材料的冲击强度随用量的增加而增大 ;而对材料拉伸性能的影响甚微。PP/纳米、普通TiO2 复合材料都是有抗菌作用 ,PP/纳米TiO2 的抗菌作用相对较强。     

纳米TiO2/HPMC-PMMA-PBMA复合粒子的制备及表征

先用非离子型高聚物羟丙基甲基纤维素(HPMC)和阴离子表面活性剂十二烷基硫酸钠(SDS)对纳米TiO2进行表面处理，得到表面吸附有HPMC-SDS的纳米TiO2粒子，然后在其上接枝了甲基丙烯酸甲酯(MMA)和甲基丙稀酸丁酯(BMA)。通过正交实验，得出了吸附和接枝的最佳条件。采用透射电子显微镜(TEM)和红外光谱仪(FTIR)对复合粒子的性质进行了表征，利用热重分析仪对复合粒子的耐热性能进行了研究。     

Al2O3/TiO2纳米复相陶瓷的增韧机理研究

纳米结构与纳米添加剂对陶瓷体的增韧是多种增韧方式共同存在的.对于1350℃烧结的ATZ陶瓷,其增韧机理为相变增韧和纳米颗粒增韧;对于1 450℃的ATZ陶瓷烧结体,增韧机理主要为纳米颗粒增韧、微裂纹增韧.ATZ陶瓷体在1 450℃烧结时的增韧效果优于1 350℃烧结时的增韧效果.     

Al_2O_3/TiO_2纳米复相陶瓷的增韧机理研究

纳米结构与纳米添加剂对陶瓷体的增韧是多种增韧方式共同存在的.对于1350℃烧结的ATZ陶瓷,其增韧机理为相变增韧和纳米颗粒增韧;对于1450℃的ATZ陶瓷烧结体,增韧机理主要为纳米颗粒增韧、微裂纹增韧.ATZ陶瓷体在1450℃烧结时的增韧效果优于1350℃烧结时的增韧效果.     

V掺杂TiO2纳米粒子的制备及其光催化研究

溶胶-凝胶法制备5at.％V掺杂的TiO2和纯TiO2,然后在500℃煅烧6 h。 XRD谱图显示,样品均是锐钛矿型TiO2,还有一些无定型成分,平均晶粒大小分别为6.8 nm和9.7 nm。 TEM照片显示的纳米粒子大小分别在8.0-18.7 nm和21.6-30.2 nm范围内,比XRD计算结果大,这是因为样品未能充分分散所造成。 EDS谱图显示V的掺杂量是6.5at.％,红外光谱也证实V元素的存在。拉曼光谱表明, V元素均匀地分散在TiO2中。 Rh. B的光催化降解实验表明, V掺杂TiO2的光催化效率比纯TiO2低,这是由于较高的掺杂浓度导致电子-空穴复合中心增加,从而降低光催化效率。     

Construction of g-C3N4/TiO2/Ag composites with enhanced visible-light photocatalytic activity and antibacterial properties

In this study, the multifunctional carbon nitride based composite graphitic-C₃N₄ (g-C₃N₄)/TiO₂/Ag was prepared through a simple and efficient vacuum freeze-drying route. TiO₂ and Ag nanoparticles were demonstrated to decorate onto the surface of g-C₃N₄ sheet. In the ultraviolet–visible absorption test, a narrower band gap and red-shift of light absorption edge were observed for g-C₃N₄/TiO₂/Ag compared to pristine g-C₃N₄ and single-component modified g-C₃N₄/TiO₂. The photodegradation property of g-C₃N₄/TiO₂/Ag was investigated toward the degradation of methylene blue (abbreviated as MB) under the irradiation of visible light. These results indicated that the degradation performance of organic dyes for g-C₃N₄/TiO₂/Ag was obviously improved compared with g-C₃N₄/TiO₂ and g-C₃N₄. The reaction rate constant of MB degradation for g-C₃N₄/TiO₂/Ag was 4.24 times higher than that of pristine g-C₃N₄. In addition, such rationally constructed nanocomposite presented evidently enhanced antibacterial performance against the Gram-negative Escherichia coli. Concentration dependent antibacterial performance was systematically investigated. And 84% bacterial cell viability loss had been observed at 500 μg/mL g-C₃N₄/TiO₂/Ag within 2 h visible light irradiation.     

TiO2/N-琥珀酰壳聚糖复合材料的制备及表征

以N-琥珀酰壳聚糖与TiO2复合制备了TiO2/N-琥珀酰壳聚糖复合材料。采用透射电镜(TEM)、傅里叶红外光谱(FTIR)、紫外-可见光谱(UV-Vis)、X射线衍射(XRD)、粒径及Zeta电位分析对复合材料进行表征。结果表明,TiO2表面羟基与N-琥珀酰壳聚糖分子中的羟基、酰胺、羧基相互作用形成了稳定的复合材料;复合材料中TiO2晶型呈锐钛矿型;复合材料平均粒径为50nm,Zeta电位达39mV;紫外-可见光谱显示,复合材料的光响应范围拓宽到可见光区,且对光的吸收能力显著增强,但在模拟太阳光下其光催化效率较TiO2有所下降。     

Synthesis of Magnetite Nanoparticles with PDLLA Corona

The ring-opening polymerization (ROP) of D,L-lactide (DLLA) initiated by tin(II) 2-ethylhexanoate (Sn(Oct)₂) on the surface-initiated magnetite (Fe₃O₄) nanoparticles was performed at 130 °C. Effects of the polymer molar mass and concentration on the amount of polymer on the surface were investigated. The number average molecular weights, M _n , that we obtained by both nuclear magnetic resonance (NMR) and gel permeation chromatography (GPC) methods fit well within the accuracy of the applied methods, and range from 1,100 g · mol⁻¹ to 4,040 g · mol⁻¹. The surface functionalization density for up to 3,900 initiation sites per particle was obtained. The composition of various particles with poly(D,L-lactide) (PDLLA) corona is by means of thermogravimetric analysis (TGA), and indicates magnetite (Fe₃O₄) content between 17 wt.% and 59 wt.%. An erratum to this article can be found at     

Morphological and photoelectrochemical propertiesof porous, superimposed Au/TiO2 layers

Porous semiconducting ceramics deposited on a porous metallic film acting both as catalyst and electronic collector gave large photocurrents and considerably enhanced electrooxidation currents when irradiated in the presence of small amounts of alcohol vapours. The morphological properties of these layered materials, was studied by electron (SEM, ESEM) and atomic force (AFM) microscopy in order to observe the modification in shape and size of the precursor particles because such knowledge is helpful to the preparation of suitable anodes for photo-assisted processes in the gas-phase.     

CdS/TiO2复合纳米粒子的制备及其产氢性能研究

采用化学沉淀法制备了CdS包覆TiO2（CdS/TiO2）复合纳米粒子,利用XRD、TEM、SEM、UV-vis吸收光谱等对其进行了表征分析,并以可见光分解水制氢为探针反应考察了复合纳米粒子的活性。结果表明,CdS/TiO2 复合纳米粒子的颗粒大小约为40nm,TiO2 以锐钛矿型存在,CdS以六方相存在;复合纳米粒子的吸收光谱较TiO2 发生“红移”,大幅拓宽了对可见光区的吸收范围。光解水制氢实验表明,CdS/TiO2 复合纳米粒子具有良好的可见光释氢活性和光学稳定性。     

Preparation and characterization of SiO2/polydopamine/Ag nanocomposites with long-term antibacterial activity

Silver nanoparticles (Ag NPs) with diameter of approximately 10 nm were prepared by the reduction of silver nitrate using green synthesis, an eco-friendly approach. The synthesized Ag NPs were homogeneously deposited on silicon dioxide (SiO₂) particles modified with dopamine, leading to the formation of SiO₂/polydopamine (PD)/Ag nanocomposites (NCs) with a core–shell–satellite structure investigated by transmission electron microscopy. The Ag content of SiO₂/PD/Ag NCs determined by inductively coupled plasma optical emission spectrometry was approximately 5.92 wt%. The antibacterial properties of both Ag NPs and SiO₂/PD/Ag NCs against Vibrio natriegens (V. natriegens) and Erythrobacter pelagi sp. nov. (E. pelagi) were investigated by bacterial growth curves and inhibition zone. Compared to Ag NPs, the SiO₂/PD/Ag NCs exhibited superior long-term antibacterial activity, attributed to its controlled release of Ag⁺ ions.     

TiC-TiB2复合陶瓷制备及性能研究

TiC-TiB2复合陶瓷因具有高硬度、高断裂韧性及优异的耐磨性,目前已成为工程陶瓷的研究热点。但是TiC-TiB2复合陶瓷的难以制备与难于致密,又使其应用受到极大限制。本文介绍了国内外TiC-TiB2复合陶瓷合成与制备方法、显微组织与力学性能等,特别提到了军械工程学院先进材料研究所采用超重力下燃烧合成技术,制备出大尺寸、高致密性的TiC-TiB2共晶复合陶瓷,从而为以后的更广泛应用提供了支持。     

表面引发活性聚合SiO2/PMMA核壳复合纳米粒子的制备及表征

在乙醇介质中,通过在窄粒径分布SiO2胶体粒子表面上接枝的α-溴代物引发甲基丙烯酸甲酯的原子转移自由基聚合,制备了具有核壳结构的SiO2/PMMA复合纳米粒子.采用FTIR、TGA和Acoustosizer等表征了该核壳结构粒子的结构与性能、粒径和粒径分布.结果表明:PMMA已经成功接枝到SiO2表面,并且其链长约为8...     

硅酸盐矿物/TiB2复相陶瓷涂层的制备及耐蚀性能研究

本文采用热化学反应法在Q235钢基体表面分别制备了硅酸盐矿物陶瓷涂层和添加Al-TiO2-B2O3反应体系复相陶瓷涂层,用XRD分析其相结构,并研究了涂层的耐蚀性。结果表明,硅酸盐矿物/TiB2复相陶瓷涂层有TiB2、FeNi3、CaNi0.5Si1.5等新相产生。耐酸、碱、盐性相对基体分别提高8.6倍,4.4倍,6.2倍,耐蚀性优于纯硅酸盐矿物涂层。     

银负载二氧化钛(Ag/TiO_2)复合材料的光催化及润湿性能

通过光还原法合成了银负载二氧化钛(Ag/TiO2)复合材料,测定了其作为光催化剂降解罗丹明B的性能。考察了不同煅烧温度处理对其光催化性能以及润湿性能的影响。结果表明适当温度下的热处理不但可以改善样品的润湿性能,同时可以提高其光催化降解污染物的性能。     

Synthesis and Characterization of Core-shell ZrO2/PAAEM/PS Nanoparticles

This work demonstrates the synthesis of core-shell ZrO₂/PAAEM/PS nanoparticles through a combination of sol–gel method and emulsifier-free emulsion polymerizaiton. By this method, the modified nanometer ZrO₂ cores were prepared by chemical modification at a molecular level of zirconium propoxide with monomer of acetoacetoxyethylmethacrylate (AAEM), and then copolymerized with vinyl monomer to form uniform-size hybrid nanoparticles with diameter of around 250 nm. The morphology, composition, and thermal stability of the core-shell particles were characterized by various techniques including transmission electron microscopy (TEM), X-ray diffractometer (XRD), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and thermal-gravimetry analyzer (TGA). The results indicate that the inorganic–organic nanocomposites exhibit good thermal stability with the maximum decomposition temperature of ~447 °C. This approach would be useful for the synthesis of other inorganic–organic nanocomposites with desired functionalities.     

掺杂ZrO2纳米线的CaTiO陶瓷电极材料制备方法及性能测试

探讨影响陈化库设计的诸专业因素,以找到最适合工程项目的设计。