Alkali Attack of Glass Surfaces by Molten Salts

The surface reaction of soda-lime-silica, sodium borosilicate, soda-zirconia-silica, and soda-alumina-silica glasses with pure molten sodium hydroxide and potassium hydroxide was investigated at 350° and 425°C, respectively. Chemical durability of these glasses is assessed in terms of an acid-base concept in which the glass network forms the acid function. Use of a mixture of sodium hydroxide in sodium nitrate resulted in a tenfold increase in the zirconia-silica glass durability at concentrations up to 60 mole % sodium hydroxide.     

Diffusion-Controlled Attack of Glass Surfaces by Aqueous Solutions

Simple binary alkali oxide silica glasses and some ternary glasses derived from the binary compositions by substituting alkaline earth oxides for silica were subjected to the action of water and various aqueous solutions (pH 1.4 to 10.9) and the kinetics of the reactions were studied. In every case a root-time relation of extraction, suggesting an ion-exchange controlled diffusion mechanism, was observed, followed by a time relation of extraction. The rate and duration of diffusion depended on the pH of the solution and the reaction temperature. Above a critical pH the hydrogen ion concentration of the attacking solution was so low that the surface sites began to be occupied preferentially by alkali ions, increasing their concentration at the leached layer-solution boundary and slowing the diffusion process. For potassium glasses only, where alkali ion distribution in the leached layer was exponential, the diffusion coefficients calculated from the concentration profiles agreed well with those calculated from the extraction of potassium ions by a diffusion mechanism.     

螯合剂的生产工艺研究进展

综述了螯合剂的品种和其在各行业中的主要用途;针对现有主要螯合剂产品进行了概述,详细研究了乙二胺四乙酸(EDTA)、二乙烯三胺五乙酸(DTPA)、氮川三乙酸(NTA)以及羟乙基乙二胺三乙酸(HEDTA)等传统螯合剂的生产工艺;同时针对易降解、无害的新型螯合剂进行了概述,重点阐述了谷氨酸N,N-二乙酸(GLDA)和葡庚糖酸(Glucoheptonate)的生产工艺以及突出优势;展望了螯合剂产品未来的发展趋势。     

Effects of Some Metals and Chelating Agents on Patulin Degradation by Ozone

The efficiency of ozone treatment for degradation of the mycotoxin patulin in the presence of various metal ions was evaluated in model systems. An initial patulin concentration of 250 μg/L was ozonated and residual ozone concentration was about 0.17±0.01 mg/L at the end of the experiment. Patulin showed a weak resistance to ozone, because up to 98% of this toxin was oxidized in only one minute. Degradation rates in the presence of calcium, aluminum, copper and zinc were almost the same in the absence of these metals. However, degradation of patulin was reduced from 98 to 37% when the concentration of manganese increased from 0 to 3 mg/L. Patulin was almost completely degraded in the absence of iron, while the degradation was only 8.5% in the presence of 0.5 mg/L of iron. These results have revealed that manganese and iron significantly reduce the detoxification of patulin by ozone. Agents such as ethylenediaminetetraacetic acid and sodium polyphosphate effectively chelated iron and increased the degradation rate of patulin. None of the tested agents were able to chelate manganese and to enhance patulin degradation by ozone.     

淀粉基重金属捕集剂的研究进展

与传统水处理药剂相比,改性淀粉作为絮凝剂和重金属捕集剂,具有成本低廉、可生物降解、毒性小、可再生等优点.按照反应类型,阐述了近年来酯化、醚化、接枝、氧化等几类改性淀粉作为重金属捕集剂的研究进展、应用现状及优缺点,同时对淀粉基重金属捕集剂的前景及发展趋势进行了展望.     

淀粉基天然高分子重金属离子捕集剂放大试验

以乙二胺改性淀粉接枝甲基丙烯酸缩水甘油酯(AMS)小试工艺为依据,考察了pH、搅拌速度、反应时间和乙二胺用量对放大试验的影响,确定了AMS中间放大试验配方工艺,研究了产品氮含量对重金属捕集性能的影响,并采用傅氏转换红外线光谱分析仪(FTIR)表征产品结构。结果表明:放大试验结果与小试结果基本吻合,反应时间和搅拌速度影响显著,产品氮含量越高捕集重金属离子性能越好,改进后的工艺产品氮含量可达到11.46%;放大试验产品AMS被乙二胺改性。     

铝硅酸盐玻璃中澄清剂的使用研究

主要针对铝硅酸盐玻璃熔化温度高、黏度大、表面张力大、澄清困难等特点,通过试验研究,探讨了适合铝硅酸盐玻璃熔制的最佳澄清剂及澄清剂的比例,对铝硅酸盐玻璃的生产具有指导性的意义。     

高铝硅酸盐玻璃的复合澄清剂研究

通过高温观测系统,研究了澄清剂SnO2、CeO2和Na2SO4在高铝硅酸盐系统中的作用温度,并根据高温观测研究结果选用两组复合澄清剂进行对比,讨论了复合澄清剂对澄清效果的影响,分析了玻璃澄清过程中气泡数量和尺寸的变化规律.结果显示:三种澄清剂在高铝玻璃中的作用温度均略低于普通钠钙硅,采用SnO2和Na2SO4作为复合澄清剂时形成的梯度澄清比SnO2和CeO2组合形成的协同澄清作用更明显,澄清效果良好.     

硼硅酸盐玻璃对耐火材料的侵蚀研究

主要针对熔制硼硅酸盐玻璃时对锆刚玉砖、镁砖、硅砖的侵蚀情况进行实验分析.为合理选择熔窑耐火材料提供参考.     

Comparative Assessment of Complex Stabilities of Radiocopper Chelating Agents by a Combination of Complex Challenge and in vivo Experiments

For ⁶⁴Cu radiolabeling of biomolecules to be used as in vivo positron emission tomography (PET) imaging agents, various chelators are commonly applied. It has not yet been determined which of the most potent chelators—NODA‐GA ((1,4,7‐triazacyclononane‐4,7‐diyl)diacetic acid‐1‐glutaric acid), CB‐TE2A (2,2′‐(1,4,8,11‐tetraazabicyclo[6.6.2]hexadecane‐4,11‐diyl)diacetic acid), or CB‐TE1A‐GA (1,4,8,11‐tetraazabicyclo[6.6.2]hexadecane‐4,11‐diyl‐8‐acetic acid‐1‐glutaric acid)—forms the most stable complexes resulting in PET images of highest quality. We determined the ⁶⁴Cu complex stabilities for these three chelators by a combination of complex challenge and an in vivo approach. For this purpose, bioconjugates of the chelating agents with the gastrin‐releasing peptide receptor (GRPR)‐affine peptide PESIN and an integrin α_vβ₃‐affine c(RGDfC) tetramer were synthesized and radiolabeled with ⁶⁴Cu in excellent yields and specific activities. The ⁶⁴Cu‐labeled biomolecules were evaluated for their complex stabilities in vitro by conducting a challenge experiment with the respective other chelators as challengers. The in vivo stabilities of the complexes were also determined, showing the highest stability for the ⁶⁴Cu–CB‐TE1A‐GA complex in both experimental setups. Therefore, CB‐TE1A‐GA is the most appropriate chelating agent for *Cu‐labeled radiotracers and in vivo imaging applications.     

Promotion of Attack on Glass and Silica by Citrate and Other Anions in Neutral Solution

The observation that essentially neutral solutions of sodium citrate attacked sulfur-treated soda-lime glass bottles of generally high chemical resistance much more than was anticipated led to a general investigation. It has been found that neutral solutions of sodium citrate attack silicate glasses and silica with a severity similar to that of substantially alkaline solutions. This effect was observed for both soda-lime and borosilicate glasses and also for vitreous, crystalline, and amorphous forms of silica. The effect of citrate becomes perceptible at a pH of about 5 and increases rapidly with pH up to 7.6. Solutions of higher pH were not studied. Solutions of certain other complex-forming anions show the effect on sulfur-treated soda-lime glass containers in varying lesser degrees. Although the active anions studied are complexing agents for alkaline earths and aluminum, it was observed that citrate had more action on a fused silica container than on containers made of certain glasses containing calcium and aluminum. Therefore a digestive action on silica and the Si–O–Si structure of glasses is to be recognized. Fluoride, the only anion tested that forms previously known complexes with silicon, had slightly less action on sulfur-treated bottles than citrate. The results suggest that soluble silicon complexes are formed at pH values in the region of 7 by citrate and some of the other organic anions studied.     

4-酰代-双(1,3-二苯基-5-吡唑酮)螯合剂的合成与表征

于 90℃ ,以二氧六环为溶剂 ,Ca(OH) 2 为缩合剂 ,由 1,3 二苯基 5 吡唑酮分别与戊、己和癸二酰氯作用 (量比为 2∶1) ,合成了三种新的 β 二酮螯合剂 4 酰代 双 (1,3 二苯基 5 吡唑酮 )(各以符号P、H和D表示 ) ,收率为 6 5 .5 %、6 7.4%和 6 1.0 %。通过元素分析、红外光谱和核磁共振氢谱证实了产物的结构。测定了以它们为配体的Tb(Ⅲ )配合物的荧光光谱 ,结果表明 :这三种化合物的Tb(Ⅲ )配合物的荧光强度高于 4 酰代 双 (1 苯基 3 甲基 5 吡唑酮 )的Tb(Ⅲ )配合物 ;这三种化合物的Tb(Ⅲ )配合物荧光强度的顺序为P >H >D。     

Upgrade of Proportioning Colorant and Decolorizing Agents for Glass Batch

Different designs of proportioners and screw feeders for colorant and decolorizing agents for glass melt are discussed.__________Translated from Steklo i Keramika, No. 4, pp. 8 – 9, April, 2005.     

硅烷偶联剂在玻纤增强复合材料领域中的应用

介绍了玻纤生产中常用硅烷偶联剂的种类、结构、偶联机理及使用方法。着重介绍了硅烷偶联剂在玻纤增强复合材料中的应用,特别是硅烷结构类型、用量对复合材料性能的影响。同时,对硅烷偶联剂的作用及其在玻纤增强热固性和热塑性树脂中的应用进行了阐述。     

Effect of Silane Coupling Agents on Adhesion of Polybutadiene to Glass

The chosen silane coupling agents consist of a polybutadiene skeleton with  Si(CH₃)₂OCH₃ or  Si(OCH₃)₃ pendent groups hydrolyzable on the glass surface. Their number, and therefore the amount of potential bonds, can be varied. These modified polybutadiene polymers act as primer compatible with the polybutadiene coating to be deposited. The subsequent cross-linking of the double bonds of the silane primed surface with polybutadiene is initiated by benzoyl peroxide, creating chemical bonds between the solid support and its coating. The strength of the adhesion of polybutadiene to glass is measured by the 180° peel test and the values are compared with a non-modified glass surface.     

Effect of Fining Agents on the Solarization of a Borosilicate Glass

The effects of both fining agents and TiO₂ concentration on the solarizability of a borosilicate glass proposed for solar energy applications have been determined. Optical and ESR measurements indicate that chlorine-fined glasses are much less susceptible to solarization than are arsenic-fined glasses. Titanium dioxide acts as a solarization suppressant with either fining agent. The observed increase in optical absorption in the visible region is in marked contrast with the recent report of a solar-induced decrease in optical absorption in the infrared range for soda-lime silicate glasses.     

复合澄清剂在TFT基板玻璃熔制过程中的作用机理

针对当前薄膜晶体管(TFT)基板玻璃熔制过程中澄清剂作用机理认识不足的问题,采用模拟TFT基板玻璃浮法熔制工艺与高温熔融动态观察相结合的方式,研究了SnO₂、CaSO₄、NaCl等单一和复合澄清剂在熔制过程中的适用温度、澄清效果等,对基板玻璃热学性能、玻璃块体中Na⁺含量与NaCl澄清剂使用量的关系进行探讨。结果表明:SnO₂单一澄清剂的适宜用量为0.10%(质量分数);复合澄清剂中0.10%(质量分数)SnO₂+0.35%(质量分数)CaSO₄形成的梯度澄清效果最佳;复合澄清剂SnO₂+NaCl构成协同澄清,澄清效果随NaCl用量的增加而提高,但NaCl澄清剂的使用量应不高于0.076 3%(质量分数),以满足基板玻璃对残留碱金属离子含量的严格要求。以上研究成果对改善TFT基板玻璃熔制质量和产品品质具有重要的参考意义,有利于相关工业化生产降本增效。     

Relation of Surface Structure of Glass to HF Acid Attack and Stress State

The surfaces of commercial glasses (mainly borosilicate glasses) were investigated by HF etching and surface-stress measurement. The HF etch rate was slow at the surface for some phase-separated glasses, which was attributed to excess alumina in the surface layer produced during the glass manufacture. After heat treatment of the glass rods, either with or without the as-Received surfaces, compressive (tangential) stresses were observed in all the glasses studied. These stresses were probably caused by evaporation of water from the surface during heat treatment.     

不同澄清剂对中性医药玻璃澄清效果的影响

中性医药玻璃具有优异的化学稳定性和热稳定性,被广泛应用于药物、食品等包装领域。本文研究了氧化物澄清剂CeO₂,卤化物澄清剂NaCl和复合澄清剂NaCl-CeO₂、NaCl-CeO₂-NaNO₃对中性医药玻璃澄清效果的影响,定量分析了气泡熔占比、气泡个数、气泡平均直径的变化规律,探究出适用于中性医药玻璃的澄清剂。研究结果表明,中性医药玻璃液中加入NaCl-CeO₂-NaNO₃后,气泡熔占比较低,气泡个数较少,气泡平均直径较大,添加NaCl-CeO₂-NaNO₃时澄清效果要优于NaCl和CeO₂。当加入0.4%(质量分数)NaCl-0.20%(质量分数)CeO₂-0.005 0%(质量分数)NaNO₃时,在升温至1 550 ℃后3 h内,中性医药玻璃液的气泡熔占比降至0.6%,气泡个数减少到3个,气泡平均直径为0.60 mm,澄清效果较佳。     

Adsorption of Tagged Phosphute Ions on Glass Surfaces as Related to Alkaline Attack

A preliminary investigation has been made of various factors involved in the sorption of phosphate ions on glass surfaces, particularly with reference to a possible utilization of phosphate sorption as an indicator of alkaline attack of the surface. Sorption has been measured by means of a tracer technique using radioactive phosphorus as trisodium phosphate, and tests have been made with two types of soft glass and with Pyrex-brand glass, with and without alkaline pretreatments. Radioautographs have been prepared to determine the distribution of sorbed phosphate on soft-glass specimens treated in various ways. The sorption of phosphate ions from dilute alkaline solutions at room temperature on fused soft glass and Pyrex-brand glass has been found to be very slight, on the order of one-thousandth of a μ gm. per sq. in. (roughly equivalent to a thousandth of a monomolecular layer on the macrosurface). Treatment of soft glass for a few minutes in sodium hydroxide solution at 80°C. results in a multifold increase in subsequent sorption of phosphate ions at room temperature. A much longer alkaline pretreatment is required in the case of Pyrex-brand glass, but a similar increase in sorption is found. The different results obtained with soda-lime and borosilicate glasses may be explained on the basis of different types of nonadsorbing surface films. Zinc ions in the alkaline pretreatment solution appear to cause an increase in subsequent sorption, and it is proposed that adsorption of polyvalent cations facilitates the adsorption of phosphate ions.