乳浊玻璃（四）

３．２磷酸盐乳浊玻璃为了防止氟化物的污染和利用磷灰石（ａｐａｔｉｔｅ）等天然矿物原料，在工业生产中已广泛应用磷酸盐乳浊玻璃。磷酸盐乳浊玻璃是在硅酸盐和硼硅酸盐玻璃基础成分中析出磷酸盐的晶粒而乳浊的。理想的磷酸盐晶体应为小球状分布，如图９所示。但如温度...     

La（0.3）Ca（0.7）Mn（1–x）VxO3体系的电荷序和自旋序（英文）

通过对样品La0.3Ca0.7Mn1–xVxO3（x=0.05,0.10,0.134,0.20）的磁化强度–温度（magnetization–temperature,M–T）曲线、电阻率–温度（resistivity–temperature,ρ–T）曲线、电子自旋共振谱的测量,研究了Mn位V掺杂对La0.3Ca0.7MnO3体系电荷序和自旋序的影响。结果表明：当0.05≤x≤0.134时,体系存在电荷有序（CO）相,体系自旋序随温度降低发生顺磁（paramagnetism,PM）–电荷有序（charge ordering,CO）–反铁磁（antiferromagnetism,AFM）变化。当x=0.20时,电荷有序融化,体系出现再入型自旋玻璃行为。     

乳浊玻璃（五）

３．４分相乳浊玻璃正如乳浊玻璃机理中所阐述，分相乳浊玻璃是以与母体玻璃不同折射率的非晶态液滴而进行乳浊的。在研究硼硅酸盐玻璃分相过程中，发现分相而引起乳光，以后就有意识地利用此现象来制造乳浊玻璃。常用的分相乳浊玻璃的成分见表７。表７分相乳浊玻璃成分编...     

颜色玻璃（二）

颜色玻璃（二）袁怡松（中国轻工总会玻璃搪瓷研究所２０００５２）二、几种常见离子的着色１．钛在玻璃中的着色钛是第四周期过渡元素中第一个着色元素。根据玻璃基础成分和熔制条件不同，钛可能以Ｔｉ４＋和Ｔｉ３＋离子状态存在于玻璃中。前者在玻璃中是无色的，因为它...     

乳浊玻璃（二）

乳浊玻璃（二）王承遇陶瑛（大连轻工业学院玻璃及无机新材料研究所１１６００１）２玻璃乳浊的机理玻璃表面喷砂或氢氟酸侵蚀形成凹凸不平的毛面，使光线散射，导致玻璃表面呈半透明乳白的现象，已在玻璃表面装饰讲座中阐述过。此处我们研讨的是玻璃体中微粒引起光的散射...     

乳浊玻璃（三）

乳浊玻璃（三）王承遇陶瑛（大连轻工业学院玻璃及无机新材料研究所１１６００１）３乳浊玻璃的成分与制造工艺乳浊玻璃的成分与制造工艺必须根据品种、用途和性能的要求来制定。通常制定乳浊玻璃的成分与制造工艺时需符合下列要求：图５乳白玻璃的反射曲线⑴乳浊程度乳浊...     

玻璃掺杂（SrxBa1—x）TiO3陶瓷基压敏材料的制备,表征及性能

采用陶瓷工艺，制备了钙钛矿结构的（ＳｒｘＢａ１－ｘ）ＴｉＯ３粉体，利用溶胶－凝胶技术合成的Ｂ－Ｓｉ－Ｐｂ玻璃对（ＳｒｘＢａ１－ｘ）ＴｉＯ３进行掺杂，所制备的材料具非线性Ｖ－Ｉ特性，非线性系数在３～４之间，当ｘ≤０．３３时，其Ｖ１ｍＡ值低于２０Ｖ．ｍｍ＾－１，ｘ≥０．４０时，Ｖ１ｍＡ值急剧上升，材料制备不需要经过氧化－还原两步工艺过程，对于工业生产具有重要意义。     

乳浊玻璃（一）

乳浊玻璃（一）王承遇陶瑛（大连轻工业学院玻璃及无机新材料研究所１１６００１）乳浊玻璃指玻璃中含有大量高分散的微粒,由于其折射率与主体玻璃不同,光线照射后产生散射而呈乳浊。高分散的微粒可以是未熔透的砂粒、微小气泡、分相的液滴以及析出的晶粒。微粒尺寸大于...     

(AgSt)_(1-x)/(AgI)_x复合颗粒的制备及其性能研究

分别以碘化钾(KI)为碘源以及硬脂酸银(AgSt)为本体,用原位法合成了负载型的(AgSt)1-x/(AgI)x复合颗粒。利用红外光谱仪(FTIR)、扫描电子显微镜(SEM)、紫外-可见漫反射光谱仪(UV-Vis)、X射线衍射仪(XRD)以及差示扫描量热仪(DSC)对复合颗粒的微观结构、形貌、光吸收、晶型以及热相变行为进行了表征。结果表明,(1)(AgSt)1-x/(AgI)x复合颗粒由本体AgSt颗粒及其表面上负载的尺寸为30~50nm的AgI粒子构成;(2)相对于AgSt,(AgSt)1-x/(AgI)x复合颗粒的光谱吸光范围从265 nm拓展到425 nm左右,是由AgI的吸收造成;(3)(AgSt)1-x/(AgI)x复合颗粒在82~88℃左右就出现第一相变峰,显著低于本体AgSt的122.9℃,体现了AgSt与AgI两相界面的作用。     

Ethene/Ethane (C2H4/C2H6) Separation through an Inorganic–Organic Hybrid Membrane Containing Silver(I) Ions as Olefin Carriers, Using Poly(N-vinylpyrrolidone) as a Mediation Agent

Novel inorganic–organic membranes that contained Ag⁺ ions as olefin carriers were prepared using sol–gel and dip-coating processes. The permeance of the membranes for nitrogen, helium, ethane (C₂H₆), and ethene (C₂H₄) were evaluated using the single-gas permeation method at temperatures of 298, 373, and 423 K. The results showed that the selectivity of the membranes to C₂H₄ against C₂H₆ increased as the measurement temperature increased, because the decomplexation rate of C₂H₄ molecules from Ag⁺ sites is enhanced by increases in the temperature. Fourier transform infrared spectrophotometry of the hybrid membranes and the performance of the membranes at 373 and 423 K indicated that poly( N -vinylpyrrolidone) (PVP) had a role in increasing the flexibility of the inorganic network and also served as a mediation agent to fix Ag⁺ ions in the polymer segments, because of the coordination interaction between the Ag⁺ ions and the PVP.     

Removal of Ag(I) and Cr(VI) by Complexation-Ultrafiltration and Characterization of the Membrane by CFSK Model

Removal of Ag(I) and Cr(VI) by complexation-ultrafiltration, anionic polyacrylamide being the complexation agent, has been reported. Effects of operating variables such as initial metal ions concentration in feed, feed pH, polymer-to-metal ions ratio, and applied pressure on the removal of metal ions were studied at a constant feed flow rate of 15 L/min. Maximum rejection obtained were close to 100% for Ag(I) and 94% for Cr(VI) ions in single ion system; and for binary ions system it is 87% for Ag(I) and 76% for Cr(VI) ions. The membrane was characterized using the combined-film theory-Spiegler-Kedem (CFSK) model.     

Fluorescence-Responsive Detection of Ag(I), Al(III), and Cr(III) Ions Using Cd(II) Based Pillared-Layer Frameworks

Two Cd(II) based coordination polymers, {Cd₃(btc)₂(BTD-bpy)₂]∙1.5MeOH∙4H₂O}_n (1) and [Cd₂(1,4-ndc)₂(BTD-bpy)₂]_n (2), where BTD-bpy = bis(pyridin-4-yl)benzothiadiazole, btc = benzene-1,3,5-tricarboxylate, and 1,4-ndc = naphthalene-1,4-dicarboxylate, were hydro(solvo)thermally synthesized. Compound 1 has a three-dimensional non-interpenetrating pillared-bilayer open framework with sufficient free voids of 25.1%, which is simplified to show a topological (4,6,8)-connected net with the point symbol of (3²4²56)(3⁴4⁴5⁴6²8)(3⁴4²6¹⁹7²8). Compound 2 has a three-dimensional two-fold interpenetrating bipillared-layer condense framework regarded as a 6-connected primitive cubic (pcu) net topology. Compounds 1 and 2 both exhibited good water stability and high thermal stability approaching 350 °C. Upon excitation, compounds 1 and 2 both emitted blue light fluorescence at 471 and 479 nm, respectively, in solid state and at 457 and 446 nm, respectively, in the suspension phase of H₂O. Moreover, compounds 1 and 2 in the suspension phase of H₂O both exhibited a fluorescence quenching effect in sensing Ag⁺, attributed to framework collapse, and a fluorescence enhancement response in sensing Al³⁺ and Cr³⁺, ascribed to weak ion–framework interactions, with high selectivity and sensitivity and low detection limit.     

聚邻氨基苯酚(POAP)修饰电极的制备和银电沉积的研究

采用POAP为导电聚合物,制得了POAP修饰的铂电极,并研究了在POAP修饰铂电极上银的电沉积。同时用循环伏安,XPS和SES对膜进行了表征。研究发现pH≤3时,铂电极上可形成一层导电聚合物(POAP)膜且表现出电活性。该电极具有良好的稳定性和重现性,对银离子是一种敏感型电极。     

Kinetics of electroless silver deposition using cobalt(II)-ammonia complex compounds as reducing agents

The kinetics of electroless silver deposition from solutions containing Co(II)-ammonia complex compounds as reducing agents was studied at 20 and 50 °C. The process rate depends on the solution pH and the concentration of Ag(I), Co(II) and ammonia species. Under optimum operating conditions selected a silver deposition rate up to 1.2 m h^–1 can be obtained at 20 °C with high solution stability. At elevated temperature (50 °C) the rate increases and reaches 3 m h^–1. The silver coatings obtained are of high quality, compact and bright.     

溴化银晶体(110)表面上银原子簇的理论研究

本文采用量子化学半经验分子轨道法(CNDO方案),选取了三个晶面层数不同的AgBr晶体模型,对在这些晶体模型(110)表面上的银原子簇Ag_n(n=1,2,3,4)的电子结构及性质以及潜影机理作了量子化学研究。计算结果表明,晶体对银原子簇的性质有很大的影响,Ag_3和Ag_4优先取竖立晶面的结构。并且从Ag_3起,银原子簇的电荷分布成为上正下负的极性体。本文认为,这种极性是潜影的一个重要性质。Ag_3的热稳定性最强,又是银原子簇产生极性的转折点,故Ag_3是形成潜影的最小银原子簇。计算表明,银原子簇的增长是离子步骤先于电子步骤。     

Coating silver nanoparticles on poly(methyl methacrylate) chips and spheres via ultrasound irradiation

Ultrasound irradiation is used for anchoring silver nanoparticles with an average size of ～ 51 nm onto the surface of poly(methyl methacrylate) PMMA chips (2 mm diameter), and silver nanoparticles with an average size of ～ 20 nm onto the surface of the PMMA spheres (1–10 μm). The sonochemical reduction was carried out under argon atmosphere at room temperature. The silver nanoparticles were obtained by the irradiation of a mixture containing the PMMA, silver nitrate, ethylene glycol, ethanol, water, and 24% (wt) aqueous ammonia for 2 h, yielding a PMMA‐nanosilver composite. By controlling the atmosphere and reaction conditions, we could achieve the deposition of silver nanoparticles onto the surface of poly(methyl methacrylate). The silver‐deposited PMMA chips (loaded with 0.01–1.0 weight percent silver) were successfully homogenized in melt by extrusion and then injection molded into small, disc‐shaped samples. These samples were analyzed with respect to their directional spectral optical properties in UV, VIS, and IR spectroscopy. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007     

高介电陶瓷Ag0.9A0.1(Nb0.8Ta0.2)O3(A=Li,Na,K)的研究

采用传统的固相合成法制备了Ag（Nb0.8Ta0.2）O3（ANT）和Ag0.9A0.1（Nb0.8Ta0.2）O3（A=Li,Na,K）样品,并通过X射线衍射,扫描电镜和Raman光谱等手段对样品进行了表征。研究了Li^＋,Na^＋,K^＋取代Ag（Nb0.8Ta0.2）O3中的少量Ag^＋（摩尔比10％）对其介电性能的影响。结果表明：由于Li^＋,K^＋与Ag^＋半径差较大,它们的取代样品中出现了钙钛矿相以外的杂相峰,与未取代样品（ANT）相比介电常数（ε）和介电损耗（tgδ）变大;Na^＋取代样品的X射线衍射谱中只呈现单一的钙钛矿相特征峰．其ε,tgδ较未经取代样品（ANT）的值略有减小。     

Solvent extraction of silver(I) from nitrate media using thiourea derivatives

Liquid–liquid extraction of Ag(I) from nitrate solutions using N‐(N′,N′‐diethyl thiocarbamoyl)‐N″‐phenylbenzamidine (TCBA) and 1‐6,‐diethylcarbamoyl imino‐1,6‐diphenyl‐2,5 dithiahexane (TCTH) dissolved in cumene has been studied. The extraction of Ag(I) from 1 mol dm⁻³ NO₃⁻ solutions by TCTH and TCBA was investigated as a function of several variables: equilibration time, organic phase diluent, pH of aqueous phase, Ag(I) and NO₃⁻ concentration in aqueous phase as well as TCBA and TCTH concentrations. Experimental equilibrium data were analysed numerically using the programs LETAGROP‐DISTR and LETAPL and the results showed that Ag(I) extraction could be explained assuming the formation of AgL and AgNO₃HL with TCBA (HL) and AgNO₃S with TCTH (S). The metal extraction was not influenced significantly by the structures of the thiourea derivatives used as extractants. The back extraction of Ag(I) from loaded organic phase was performed using different strippants and 0.5 mol dm⁻³ NaSCN was found to be efficient for this purpose. © 2000 Society of Chemical Industry