钠钙铝镁硅酸盐玻璃和碱铅硅酸盐玻璃的风化

本文采用了AAS、IRRS、XPS、EPM、SEM和EPMA研究了影响两种钠钙铝镁玻璃(浮法和压延玻璃)及两种铅玻璃(高铅光学和中铅器皿玻璃)风化的因素(温度、湿度、时间)。在相同的风化条件下,含碱量较高的中铅器皿玻璃最易风化。求出四种玻璃风化析碱量与温度和时间的经验式,并得出高铅玻璃风化前后表面桥氧、非桥氧和自由氧的比例。对钠钙玻璃和铅玻璃的风化机理也进行了讨论。     

钠钙玻璃分相对风化性能的影响

钠钙玻璃分相和未分相玻璃的加速风化试验在75％相对湿度和70℃静止条件下进行。详细研究了抗风化能力的变化,结果表明:如果分相导致富硅连通结构,则风化速率降低;分相导致富硅滴状结构,则易风化。风化产物用波长色散谱仪检验。     

Na2O-CaO-Al2O3-B2O3-SiO2-TiO2体系分相过程中两相组成的变化

研究了Na2O-CaO-Al2O3-B2O3-SiO2-TiO2体系分相过程中两相组成的变化。采用扫描电镜测试、能谱分析和X射线衍射等手段对在不同温度下热处理的试样进行测试。实验结果表明,试样发生相分离后,分离成富碱硼相和富硅相,两相的化学组成随分相温度呈现一定的变化。当热处理温度从700℃升高至850℃时,富碱硼相量增加,玻璃分相程度增大。分相温度较低时,富碱硼相中的网调整氧化物只有氧化钙,而网调整氧化物氧化钠集结在富硅相中。随分相温度的升高,氧化钙仍保持在富碱硼相中,而氧化钠则由在富硅相中集聚逐步转移至在富碱硼相中。在分相过程中二氧化钛在分相界面处集聚并析出。     

氟硅碱钙石微晶玻璃快速微晶化机理研究

以34.8SiO_2、15.0 CaF_2、13.6 CaO、9.4 Na_2O、1.4 K_2O、3.5 ZnO、4.7 TiO_2(重量百分比)组成玻璃为基础制备具有快速微晶化特性的R_2O-CaO-SiO_2-F系微晶玻璃。采用差热分析(DTA)技术、X射线衍射(XRD)技术、场发射扫描电镜(FESEM)研究了微晶玻璃分相的成因、分相对析晶的影响和作用规律、机理。XRD分析得出微晶玻璃中的晶相为硬硅钙石、氟化钙和氟硅碱钙石,证实低温放热峰为分相峰。分相峰温度为611℃,析晶峰温度为725℃。分相处理降低了析晶活化能,从而缩短了析晶的时间。扫描电镜观察到玻璃样品的分相微观形貌为花瓣状,析出的晶粒的形貌为堆叠在一起的小球颗粒,并连通在一起为"蠕虫"状。说明分相使结晶成分偏聚于某一相,有利于基础玻璃的快速析晶;析晶过程是在分相基础上,球形相的有序化和聚集生长。     

硅酸盐玻璃表面析碱的研究

对硅酸盐平板玻璃进行恒温恒湿培养,采用原子吸收分光光度计法测定了玻璃的MgO和Na2O的析出量,采用荧光X-射线分光计法测定了玻璃风化后的表面成分。研究结果表明:该玻璃的总析碱性能随恒温恒湿处理的温度、湿度和时间的增加呈增加趋势,Na2O的析出量对温度敏感,MgO的析出对Na2O的析出有抑制效应。     

P_2O_5影响Na_2O-B_2O_3-SiO_2系玻璃结构与性质的特殊性

本文通过不混溶温度的确定,分相玻璃沥滤速率的测定以及NMR定量分析,研究了P_2O_6对Na_2O-B_2O_3-SiO_2系统玻璃结构和沥滤性质的影响。结果表明,P_2O_5在很大程度上促进钠硼硅分相玻璃的沥滤并非压抑“硼反常”所致,而是由以下三种因素综合作用的结果:(1)P_2O_5促进了钠硼硅玻璃的分相,使连通富硅相骨架尺寸增大;(2)P_2O_5的加入使富硅相骨架间隙中沉积的SiO_2量减少,减小了可溶相扩散阻力;(3)P_2O_5也使可溶相的溶解速率加快。     

稀土掺杂对平板玻璃耐水性及抗风化性能的影响

利用传统的熔融冷却法制备了镧、铈和钕等稀土掺杂的钠钙硅平板玻璃,利用光学显微镜、电感耦合等离子体发射光谱仪、扫描电子显微镜和能谱仪等研究了该玻璃的耐水性和风化过程。测定了玻璃样品在去离子水中的质量损失及浸出液中的离子浓度。结果表明:镧、铈和钕等轻稀土的掺杂提高了该玻璃的耐水性,降低了硅的浸出量。人工加速风化实验结果表明:平板玻璃、掺镧平板玻璃和掺铈平板玻璃的表面形成白色片状结晶物,该结晶物中Na的相对含量较高;掺钕平板玻璃表面形成一层膜,其中Na,Ca和Si的相对含量较高。     

水淬渣的胶凝活性及其形成机理

采用重新熔融水淬的方法制备不同水淬矿渣样品,综合进行净浆强度实验和碱溶出实验研究,借助XRD,DTA, TEM, SEM和EDX等分析手段,研究了矿渣形成过程、形成结构和胶凝性能之间的关系,并在此基础上探讨了矿渣潜在胶凝活性的形成机理. 研究表明,在合适的排渣温度和冷却速度条件下,水淬渣能够形成分相结构,对水淬渣胶凝活性产生重要影响. 分相矿渣具有富钙相和富硅相,富钙相的迅速溶解和富硅相的缓慢溶解是水淬渣水化过程中产生足够早期强度和发挥稳定后期强度的主要原因. 由于玻璃分相的影响,排渣过程存在最佳工艺条件,即最佳的排渣过程能使水淬渣形成玻璃分相结构,从而具有最好的活性.     

复合晶核剂（MoO3＋CaF2）对铝硅酸盐玻璃析晶行为的影响作用研究

采用ＤＴＡ，ＳＥＭ，ＥＤＡＸ，ＳＡＤＰ和ＸＲＤ等测试方法研究了含复合晶核剂（ＭｏＯ３＋ＣａＦ２）的铝硅酸盐玻璃的分相与析晶行为。实验结果表明，含单一晶核剂ＣａＦ２或ＭｏＯ３的玻璃仪产生表面析晶，而ＣａＦ２和ＭｏＯ３共同引入时能诱导玻璃的体内核化，ＣａＦ２和ＭｏＯ３均能降低基玻璃的析晶温度，整体析晶的机理是ＣａＦ２促进了玻璃的分相，ＭｏＯ３富集子分相玻璃的富钙相中，热处理过程中优先析出了ＣａＭｏＯ４     

钡磷酸盐光学玻璃风化的研究

本文采用了红外反射光谱，扫描电镜，Ｘ射线波长色谱仪和椭圆偏光仪测定了钡磷酸盐玻璃的风化能力。研究了温度，湿度和时间对钡磷酸盐玻璃风化的影响。     

EFFECT OF STORAGE CONDITIONS ON WEATHERING OF COMMERCIAL GLASS CONTAINERS*

Important factors in the weathering of commercial flint glass containers were determined by the storage of empty bottles, capped and uncapped, of ten different compositions for periods up to thirteen months at (1) 100°F., 80% relative humidity, (2) 12OoF., 15% relative humidity, and (3) normal room conditions. The effect of storage was determined by visual inspection, tests of the alkali extraction by water at elevated temperatures and photomicrographs of the weathered surfaces. The results obtained indicate that the most important factor in the weathering conditions used is the humidity. Although the weathering produced depends on several factors, the important weathering effect of high humidity may be significantly controlled by the chemical composition of the glass. Storage for the periods used at low relative humidity or at normal room conditions was relatively ineffective for weathering any of the bottles tested. Photomicrographs of representative weathered internal and external bottle surfaces are shown. A microscopic examination of these surfaces revealed the presence of calcite     

一件战国时期八棱柱状铅钡玻璃器的风化研究

利用三维视频显微镜、偏光显微镜、X射线衍射仪(XRD)、激光拉曼光谱(Raman)和扫描电子显微镜/能谱仪(SEM-EDX)等分析测试仪器,分析了一件战国时期淡绿色八棱柱状玻璃饰品,确定其为铅钡玻璃,主要显色元素为Cu。发现碱性环境中,Pb析出形成碳酸铅是导致其层状风化结构形成的关键。本研究分析和探讨了该件八棱柱状物的风化产物、风化形貌和元素迁移情况。     

玻璃分相结构形态与MgO/CaO摩尔比的相互关系

本文研究MgO/CaO比值不同的两种玻璃的分相结构。结果发现高MgO/CaO比的玻璃在热处理的过程中分相液滴由连通结构逐渐长大而转变为孤立的液滴结构。而低MgO/CaO比的玻璃在热处理的过程中分相液滴则由小尺度的连通结构长大为大尺度的连通结构。     

THE WEATHERING OF GLASS CONTAINERS1

Stability in storage is a requisite of commercial glass. A white film or surface spotted with white patches is frequently observed on glass that has been in storage for some time. These weathering effects can be produced artificially by several methods which are given. Several factors, including humidity, have been found to influence the rate at which weathering takes place. Dipping in hydrochloric acid before packing retards weathering and paper properly used in packing is effective in decreasing the tendency to weather. Three classes of weathering effects are given and illustrated with microphotographs. Experiments show that continued boiling removes the weathered surface. The products of weathering consist of crystals of soluble salt or salts, principally sodium carbonate, and an insoluble film. The lime, soda, and silica are found to have the same relative values in the weathered material as in the original glass, with the addition of certain amounts of carbonate, moisture, and dirt and organic material. Weathering is largely dependent on solubility. Glass showing the greatest resistance to weathering proves equally resistant to action of water at temperatures and pressures above normal. Condition of surface appears to influence the solubility. Alumina increases the resistance of glass to weathering. Sodium carbonate may exist in glass after manufacture and assist in weathering.     

Heat of Annealing in Simple Alkali Silicate Glasses

The enthalpy changes associated with annealing of glass were studied in simple and mixed alkali silicate glasses. The data indicate that during prolonged annealing the glass comes to a metastable equilibrium state and has a unique heat of solution which depends on its fictive temperature. The heats of solution of these glasses show a linear dependence on fictive temperature, and the magnitude of this dependence is related to the molar volume of the glass. The significance of these heat effects is discussed. The maximum heat effects which can occur on annealing sodium silicate glasses were measured and were approximately half as large as the enthalpy changes associated with the structural arrangements that occur during crystallization of these glasses.     

Dielectric response and polarization mechanism of alkali silicate glasses in gigahertz to terahertz frequency range

Oxide glasses are dielectric materials with potential applications in high-frequency communications; hence, their dielectric properties in the gigahertz to terahertz frequency range should be investigated. In this study, the dielectric properties of silica glass and five single alkali silicate glasses were measured at 0.5–10 THz using terahertz time-domain spectroscopy and far-infrared spectroscopic ellipsometry. At 0.5–10 THz, the silica glass exhibited low dielectric dispersion with a low dielectric constant and loss. By contrast, the alkali silicate glasses exhibited high dielectric dispersion, and the dielectric constant and loss were higher than those of the silica glass. The shape of the dielectric dispersion profile depended on the alkali-metal ions; it was broader for lighter ions such as Li ions and sharper for heavier ions such as Cs ions. The peak dielectric loss shifted toward a lower frequency as the weight of the alkali-metal ions in the alkali-silicate glass increased. To understand the dielectric dispersion, the complex permittivity was calculated using molecular dynamics simulations. The theoretical results qualitatively agreed with the experimental data. Ion dynamics analysis revealed that alkali-metal ions vibrate and migrate under an applied electric field, which affects the dielectric constant and loss of alkali-silicate glasses at gigahertz to terahertz frequencies. To fabricate filter devices at low temperatures, alkali metals should be added to silicate glass; therefore, a minimum amount of light alkali metals should be used to minimize the dielectric loss of the glass materials while maintaining productivity.     

玻璃中离子注入研究的现状与发展趋势

早期的论文报道了离子注入对机械性能的改性是由于离子碰撞和辐照损伤的结果，近期工作指出注入离子与玻璃基片相互作用，造成结构变化，化合物形成，分相，纳米粒子的聚集，所以离子注入影响玻璃的风化，化学稳定性，非线性光学，电导率和晶体，离子注入引起玻璃性能改变，取决于玻璃成分，注入离子种类，注入参数（能量和剂量）以及热处理制度，离子注入已应用于改善玻璃显微硬度，风化能力，耐水性和晶体形貌，在不影响玻璃其他性能条件下，用离子注入可以提高磷酸盐光学玻璃的化学稳定性，降低电极玻璃电阻率，金属离子注入玻璃导致玻璃基片表面纳米簇的形成，这些纳米粒子呈现的等离子体激元震荡导致玻璃的非线性光学性质增强，因此离子注入的玻璃可以应用于全光学开关器件，本文还指出了离子注入今后研究的方向和应用前景。     

Ionic Conduction in Alkali and Thallium Silicate Glasses

Electrical conductivities of binary alkali and thallous silicate glasses have been measured as a function of composition, temperature, and frequency. The best approximation to the activation energy for dc conduction can probably be obtained by extrapolating its frequency dependence to zero frequency, although values obtained at frequencies below 2500 hz do not differ greatly from the dc values. The plot of activation energy for conduction against modifier content consists of two straight lines of different slope. For all the alkali silicate glasses the break in slope occurs near 25 mole % alkali oxide and at an activation energy near 14.7 kcal/mole. The slope of the line below 25 mole % alkali oxide is proportional to the alkali ion radius. The behavior of thallous silicate glass is similar but not identical to that of the alkali silicates. It is concluded that (1) the reported conduction behavior does not result primarily from phase separation, (2) the principal contribution to the activation energy is probably the work required for a mobile ion to pass through the glass network rather than to leave its initial position, and (3) a structural change independent of the nature of the modifier cation occurs near a modifier content of 25 mole %.     

Molecular Dynamics Simulations of Silicate Glasses and Melts

The application of molecular dynamics to the modeling of glasses is reviewed. Several examples are used to illustrate the value of these computer simulations in advancing our understanding of the structure of silicate glasses. The mixed alkali effect is explained in terms of structural variations in going from single alkali to mixed alkali glasses that lead to distinct environments for each type of alkali ion and also result in the smaller alkali ion becoming more tightly bound to the network. Some recent results on the structure of silicate melts are presented, and the relationship between the structures of glass and melt are discussed.