用铅同位素特征研究中国古代铅(钡)玻璃

研究了我国出土的一些早期古代铅（钡）玻璃,尤其是先秦时期铅（钡）玻璃的铅同位素比值特征,总结了我国铅矿床铅同位素组成特征,并将两者进行对比研究,从原料来源的角度判定了我国出土的先秦铅（钡）玻璃等是中国本土制造的．     

塑料热稳定剂的无铅化技术发展趋势

介绍了国内外塑料热稳定剂行业及市场的无铅化进程和现状,针对国内聚氯乙烯（PVC）用塑料热稳定剂生产与应用中存在的问题和低铅化趋势进行了分析和探讨,并根据不同类型塑料热稳定剂的毒性类别,提出无毒或低毒性的钙、锌复合稳定剂、无重金属元素有机热稳定剂和有机锡稳定剂是国内塑料热稳定剂行业的无铅化技术发展趋势。     

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。     

低速雾锡镀浴中微量铅沉积研究

通过验证镀液中微量铅沉积行为,为制程无铅化管控提供依据。通过作业参数间接控制产品中的铅含量, 以达到无铅化制程(Lead-free)Pb<1×10-3的要求。探讨了产品(即镀层)中铅含量与镀液中铅含量的对应关系,并研究了电流密度、温度对镀层中铅含量的影响。     

3座日产12t铅玻璃电熔窑的总结

总结了作者设计的3座日产12t铅玻璃的电熔窑经验,分析了数家工厂运行中铅玻璃电熔窑出现故障的原因,提出了改进意见。简要介绍了铅玻璃电熔窑的一些设计原则和操作经验。     

铅晶质玻璃在不同环境下的铅析出性能研究

铅水晶玻璃具有折射率高、透过率高等优异性能,被广泛应用于工艺品、高档餐具、首饰等,但其中氧化铅成分存在潜在析出的风险,因此对使用者的健康有一定的影响。通过制备3种不同Pb_3O_4质量分数的铅水晶玻璃样品,分别研究了80℃条件下样品在白酒、洗洁精中浸泡后的铅析出情况,并通过失重法、光学显微镜以及元素分析(ICP)测试,对铅水晶玻璃在侵蚀过程中的铅析出速率和表面形貌等进行了测定。研究结果表明,铅水晶玻璃在不同溶液中长时间浸泡会导致铅析出,析出量和析出速率与其Pb_3O_4质量分数有关,其中低、中铅玻璃相对稳定,高铅玻璃的铅析出量大幅提升。     

无铅化稳定剂应用研究进展

本文介绍了无铅化稳定剂的应用现状,重点介绍了无铅化稀土复合稳定剂的作用特性及在UPVC制品中的应用,对稀土化合物的稳定机理进行了探讨。研究表明WWP稀土/钙/锌复合稳定剂无毒、高效、多功能,属新一代绿色环保产品,是具有中国特色的值得大力发展的PVC无铅化热稳定剂。     

汽油无铅化将促进我国甲醇市场的发展

为了改善我国的大气环境,国家有关部门决定在北京、上海、广州三城市试行汽油无铅化。北京市政府宣布从1997年6月1日起城近、效区禁售有铅汽油,1998年1月1日起,全市禁售有铅汽油。北京燕山石化公司已从1997年4月1日起停止生产有铅汽油。汽油中加入一定量的“四乙基铅”是为了提高汽油的辛烷值,从而提高汽油的燃烧性能,但是,有铅汽油燃烧后的废气会给大气造成严重的污染。汽油无铅化是发展的必然趋势。为了保证无铅汽油的辛烷值,在汽油中需加入一定量的“甲基叔丁基醚”(MTBE)。甲醇是生产 MTBE 的主要原料,目前,国际上约有20%的甲醇用于生产 MTBE。无铅汽油中添加 MTBE     

汽油无铅化将促进我国甲醇的发展

为了改善我国的大气环境，国家有关部门决定在北京、上海、广州三城市试行汽油无铅化。北京市政府宣布1998年4月1日起停止生产有铅汽油。     

古彩颜料研究状况及无铅化

介绍了古彩的发展和特点,对传统古彩颜料的制备、所用原料及陶瓷颜料的无铅化研究状况进行了叙述,并分析了古彩装饰存在的问题,提出了古彩颜料的改良及无铅化所要解决的主要技术关键。     

Properties and Structure of Lead Halosilicate Glasses

The glass transformation temperature, thermal expansion coefficient, dc electrical conductivity, and IR transmission have been measured for four series of lead halosilicate glasses of the general composition (65– x )PbO· x PbX₂·35 SiO₂ (X=F, Cl, Br, I). Although results of these and other measurements suggest that the halide ions play similar structural roles in the glass, there appear to be significant differences in physical property behavior between glasses containing F⁻ anions and those containing the other three halide anions. These results are explained by a proposed model incorporating both bridging and nonbridging halide species.     

Thermally Stimulated Polarization and Depolarization in Halogen-Containing Lead Silicate Glasses

Thermally stimulated polarization and depolarization current (TSPC/TSDC) measurements were made on lead halide silicate glasses having compositions (65 − x )PbO· x PbX₂·35SiO₂ where x = 0, 0.1, 2, 10 and X = F, CI, Br, and I. The addition of halogen ions to lead silicate glasses gives rise to a new high-temperature TSDC peak in the vicinity of the peak previously observed in binary lead silicate glasses. The integrated area of the new peak is dependent on the amount and type of halogen ion present in the glass and does not saturate in the temperature range of our measurements. This new peak is attributed to space charge polarization of halogen ions.     

Infrared Spectroscopy of Lead and Alkaline-Earth Aluminosilicate Glasses

Infrared spectroscopic studies of lead and alkaline-earth aluminosilicate glasses in the series x MO- x Al₂O₃ (1 - 2 x )SiO₂ M = Mg, Ca, Sr, Ba, and Pb; 0.05 x 0.275] were carried out in the range 2000 to 200 cm⁻¹. Three major absorption bands were observed in the 1100-, 800-, and 500-cm⁻¹ regions. The frequency and the intensity of the 1100-cm⁻¹ band varied linearly with composition. For a specific value of x , the changes in the frequency, intensity, and bandwidth of this band decreased in the order Mg > Ca > Sr > Pb > Ba and the apparent disorder in the glass structure, effected by the substitution of aluminum, increased in the direction Mg < Ca < Sr < Ba, with Pb in between Mg and Ca. The force constants and the bond orders of the Si-O and Al-O stretching vibrations in each of the glasses increased monotonically as Al/(Al + Si) decreased.     

Electrochemical Fingerprint of Archeological Lead Silicate Glasses Using the Voltammetry of Microparticles Approach

The application of a solid‐state electrochemical technique, voltammetry of microparticles (VMP), for studying archeological lead glass is described. Upon attachment to graphite electrodes immersed into aqueous acetate buffer, characteristic voltammetric profiles were obtained for submicrosamples of archeological glasses dated between the 9th and 19th centuries. Bivariate and multivariate chemometric analyses of the VMP data allowed us to characterize individual workshops/provenances which enabled a clear discrimination between soda‐rich and potash‐rich glasses. An analysis of the VMP data, combined by XRF, FESEM, AFM and ATR‐FTIR and Micro‐Raman spectroscopies, denoted the presence of Pb(IV) centers accompanying network‐former and network‐modifier Pb(II).     

Solubility of Ruthenium Dioxide in Lead Borosilicate Glasses

The solubility of RuO₂ in a lead borosilicate glass was measured in the range of 700° to 1000°C. The effect of dissolved alumina in the glass was studied in the same range using 2%, 4%, 6%, and 10% dissolved alumina. The solubility showed an exponential dependence on temperature, and the dissolved alumina decreased the solubility at any given temperature; however, the solubility was essentially the same in all of the alumina-containing glasses. The Kelvin equation was used to deduce the concentration of RuO₂ in glass as a function of the curvature of the RuO₂ particles, and the dependence was found to be quite small. The implications of the results in processing thick-film resistors using RuO₂ as the conductive phase and these glasses as insulating phases on an alumina substrate are discussed.     

Microseparation in Lead Borate Glasses

The microstructure of a series of lead borate glasses was studied by electron microscopy and small-angle X-ray scattering techniques. Although the glasses were optically homogeneous, microheterogeneities of the order of 2000 to 3000 A were detected in glasses with compositions near the region of two-liquid stability. The size of these heterogeneities increased as the composition approached the region of immiscibility.     

Leaching of Lead and Connectivity of Plumbate Networks in Lead Silicate Glasses

The formation of a plumbate network in binary lead silicate glasses was examined based on the leaching behavior of Pb²⁺ in lead silicate glasses over a wide composition region. The effective diffusion coefficient of Pb²⁺ at 40°C was on the order of 10⁻¹⁷ m²/s for PbO<35 mol% glasses, and increased three orders of magnitude for 35–50 mol% PbO contents. Such a steep composition dependence is considered to be because of changes in the medium or longer range structure. That is, it is proposed that the plumbate network forms a percolative 3D network in the composition region to form diffusion paths for the lead ions. In addition, the present results indicate that the lead ion exists as a network former over the entire glass forming composition range of the binary silicate glasses.     

Gamma-Ray Interaction with Lead Borate and Lead Silicate Glasses Containing Manganese

The optical absorption of high lead borate and lead silicate glasses containing manganese before and after γ-ray irradiation was studied. To separate the absorption due to manganese from the intrinsic absorption, blank glasses were prepared and measured. The results showed that the visible absorption band before and after irradiation exhibited changes with the radiation dose and chemical composition of the glass. The response of the glasses to gamma irradiation was related to the creation and spread of defect "color centers," the approach of a saturation condition, and the possible photochemical effect on the transition metal.     

Color and Light Scattering of Platinum in Some Lead Glasses

The coloration and light scattering of sodium lead silicate, borate, and phosphate glasses containing platinum, introduced as PtCl₄, have been studied. Under the normal atmosphere of a furnace heated by silicon carbide elements, the platinum is retained in the colloidal state in the sodium lead silicates and borates, producing gray glasses. In the phosphate glasses yellow to orange ionic colors as well as grays are produced. Lead oxide increases the stability of platinum ions in the phosphate glasses. Under strong oxidizing conditions, ionic platinum also can be obtained in the borate and silicate glasses. Tyndall scattering can be detected in what appear to be clear, colorless glasses. This light scattering has been observed in some glasses containing as little as 1 p.p.m. platinum.     

Structural Study of PbO–B2O3 Glasses by X-ray Diffraction and 11B MAS NMR Techniques

The structure of PbO–B₂O₃ glasses has been investigated in the composition range of 25–80 mol% PbO by using X-ray diffraction and ¹¹B NMR techniques. The well-separated peaks due to Pb–O and Pb–Pb pairs were first observed in the radial distribution function, and peak deconvolution was performed by using a pair function method. The average coordination number of lead atoms was determined to be about 6 in the low-PbO-content region and about 3 in the high-PbO-content region. With an increase of PbO content, the peaks at 0.24 and 0.40 nm shifted to shorter distances, and especially the latter peak drastically increased in intensity in the composition range >50 mol% PbO. It was suggested that PbO is a main glass former in the high-PbO-content region. Based on the results obtained, we propose structural models of lead borate glasses.