Chemical etching of micro-plasma oxidized titania film on titanium alloy and apatite deposited on the surface of modified titania film in vitro

TiO₂ film was deposited on titanium alloy by micro-plasma oxidization (MPO) in an electrolyte containing (NaPO₃)₆ and NaOH. A chemical etching (NaOH aqueous solution) was used to modify the surface of the MPO film to form specific surface structure favorable for apatite deposition. The surface of the MPO film was mainly composed of anatase, while that of the chemically etched MPO (CE-MPO) film shows anatase phase containing Na, Ti and O. Moreover, ribbon-like products with an interlaced morphology were found on the surface of the CE-MPO film. During the chemical etching process, phosphorus of the surface of the MPO film dissolved into the NaOH aqueous solution. Negatively charged HTiO₃⁻ ions are formed on the MPO film surface due to the attack of OH⁻ ions on TiO₂ phase of the MPO film. The negatively charged HTiO₃⁻ ions could incorporate sodium ions from the NaOH aqueous solution to form sodium titanate. When incubated in a simulated body fluid (SBF) for 7 and 14 days, the MPO film does not exhibit apatite-forming ability; however, apatite was deposited on the CE-MPO film probably due to the formation of hydroxyl functionalized surface via an ionic exchange between Na⁺ ions of the CE-MPO film and H₃O⁺ ions of the SBF.     

Eu5（PO4）3OH的粉末结构测定,计算及描述

本文对以水解法合成的Ｅｕ５（ＰＯ４）３ＯＨ的结构进行了测定及计算，计算结果表明，该物质属于六方晶系，空间群为Ｐ６３／ｍ，晶胞参数ａ０＝０．９７６４ｎｍ，ｃ０＝０．７６２７ｎｍ，Ｖ＝０．６０００ｎｍ＾３，Ｚ＝２。此外，提出了Ｅｕ５（ＰＯ４）３ＯＨ的结构模型，并对其结构进行了详细的描述。     

碱处理多孔钛制备磷灰石涂层的研究

采用碱处理法对多孔钛表面改性,在钛基体上产生晶体钛酸钠和无定形金红石,在模拟体液中形成含有羟基磷灰石和磷酸八钙的磷灰石涂层。研究表明：经碱处理的多孔钛二周后显示较强生物活性。     

磷灰石结构电解质La_(10-x)Si_6O_(27-1.5x)的合成及电性质

以La_2O_3和SiO_2为原料,采用凝胶注模工艺合成了具有磷灰石结构晶相的固体电解质材料La_(10-x)Si_6O_(27-1.5x)(x=0,0.5).通过X射线衍射光谱法(XRD)对所得化合物的结构进行表征.在300～800 ℃的温度范围内,利用电化学阻抗谱详细研究了La_(10-x)Si_6O_(27-1.5x)陶瓷的烧结温度和La元素的含量对La_(10-x)Si_6O_(27-1.5x)电导率的影响.结果表明:陶瓷样品的烧结温度对其电导率的影响较大,La_(10)Si_6O_(27)的电导率随着陶瓷样品烧结温度的上升而提高,1 650 ℃烧结的La_(10)Si_6O_(27)在800℃电导率为3.46×10~(-2) S/cm,约是1 550 ℃烧结样品的6倍.La_(9.5)Si_6O(26.25)的电导率随着陶瓷样品烧结温度上升呈先上升后下降的变化趋势,当烧结温度高于1 600℃时,晶粒和晶界内有大量未知相析出,这可能是导致其电导率反而下降的直接原因.     

Journal. Effects of Composition Changes on the Crystallization Behavior of MgO-CaO-SiO2-P2O5 Glass-Ceramics

The effects of composition changes on the crystallization behavior of apatite-containing glass-ceramics in the system MgO-CaO–SiO₂–P₂O₅ were studied. The eutectic composition of 40 wt% 3CaO-P₂O₅–60 wt% CaO MgO 2SiO₂ was selected as the base glass. Several parameters were quantitatively or qualitatively derived from thermal analysis, X-ray diffraction, and microstructural observations. These parameters can be divided into two groups according to their variation with glass composition. The parameters in the first group depend mainly on the apatite nucleation rate, which increases with an increase in CaO or PiO₅, and with a decrease in MgO or SiO₂. The parameters in the second group are closely related to the extent of deviation of the glass composition from the eutectic. The classical theory for nucleation employed to explain the observed phenomena is discussed.     

酸浸泡处理软玉仿鸡骨白沁色的实验探索

在分析前人研究古玉材质的资料和调研市场上常见仿古玉材质的基础上,选用主要矿物成分为透闪石的软玉为实验样品,通过无机酸性试剂浸泡实验,初步得出酸处理软玉仿鸡骨白实验是可行的。结果表明,用含有HF的酸性溶液处理样品后对其"白化"程度的影响最明显,不同的HF系列溶液组合对样品"白化"外观的影响不同。     

Yttrium silicate and oxonitridosilicate luminescent materials from a silicone resin and nano-sized fillers

Yttrium silicate and oxonitridosilicate ceramic powders have been successfully prepared by heat treatment, at 1300–1400 °C, of a silicone resin embedding Y₂O₃ nano-sized particles as reactive fillers. Nano-sized RE-oxides (Eu₂O₃, CeO₂), used as secondary additives, promoted the development of apatite phase, in both air and N₂ atmosphere. For treatments in nitrogen, the only crystal phase consisted of yttrium nitrogen apatite, mixed with amorphous silicon oxycarbide (SiOC). Eu-doped and Ce-doped yttrium silicates were characterized by means of UV–visible luminescence and ion beam induced luminescence (IBIL). Strong luminescence features were observed, depending on the conditions of thermal treatment.     

RE2Zr2O7-RETaO4体系中RE50TaxZr50-xO175+0.5x热障涂层氧化物的抗CMAS腐蚀特征(英文)

研究RE₂Zr₂O₇-RETaO₄体系中富稀土RE₅₀Ta_xZr_50-xO_175+0.5x氧化物在1300℃下抗钙镁铝硅酸盐(CMAS)腐蚀特征,并讨论RE³⁺和Ta⁵⁺离子对CMAS熔体腐蚀化学反应和反应结晶的影响。结果表明,伴随着热化学反应,磷灰石、烧绿石、再沉淀的萤石和过剩的Yb(Y)TaO₄相是主要的反应产物。磷灰石相和烧绿石相的形成能力与稀土离子半径成正比。Ta⁵⁺含量的增加能减少形成磷灰石相的稀土原子的有效数目。此外,RE₅₀Ta_xZr_50-xO_175+0.5x热障涂层氧化物的抗CMAS腐蚀能力由磷灰石相和烧绿石相共同决定。紧密混合的磷灰石和烧绿石相在腐蚀反应的前端产生致密的反应层,该结构能够抑制CMAS的继续渗透。萤石和RET...