黄酮类冠醚钾离子选择电极的研制及其对陶瓷原料含钾量的测定

黄酮类取代基能加强冠醚对钾离子的敏感性和络合选择性，本工作研制了以两种结构相似的黄酮类冠醚为电活性物质的钾离子选择电极，探讨了它们的响应功能及在测定陶瓷原料的应用。     

比浊测定法在陶瓷原料及成品分析中的应用——氧化钾含量测定的初步试验

氧化钾的含量测定分析法,目前有重量法,火焰光度法,离子选择性电极等。重量法虽经典,但很费时;火焰光度法和离子选择性电极均要有价格昂贵的复杂仪器。氧化钾比浊测定,基于陶瓷原料及成品经熔矿处理后,存在于其中的钾离子与四苯硼钠作用形成不溶的四苯硼钾,在碱性溶液中呈混浊     

新型吡啶冠醚的全合成

吡啶基冠醚是一类具有重要生理活性的冠醚类化合物。本文拟定了一条以基本原料合成冠醚的路线。并成功地合成出新型吡啶基冠醚——3,5’-(2’,6’-二甲基吡啶)-18-冠醚-5(V)。络合迁移试验表明,它对钾离子良好的选择性络合迁移性能。     

用离子选择性电极测定陶瓷原料中的钾、钠

采用离子选择性电极测定陶瓷原料中的钾、钠,实验操作简便、快速,准确度和精密度高、选择性好等优点。适用于陶瓷企业测定陶瓷原料中的钾、钠含量,结果令人满意。     

高选择识别铜和铁的冠醚类化合物

冠醚类化合物选择性识别金属阳离子。在大量调研文献的基础上,设计合成了冠醚类化合物,通过对蒽醌化合物进行修饰,合成了冠醚环和吡唑啉,将产物进行了荧光测定,发现该化合物能够很好的识别铜离子和铁离子。对该化合物进行了进一步的干扰离子测定,发现其基本不受影响,得到了较好的识别效果。     

用G—SZ—2型离子计直读浓度离子选择性电极测定钾肥中有效钾

目前,用钾离子选择性电极测定钾,文献上已有许多报导。但现用的电极电位仪(或离子计)测出是测定组份浓度的负对数值。需经作图换算才得出含量。本报告用G—SZ—2型离子计直读浓度挡和7601PVC膜钾离子选择性电极测定各种化肥中的有效钾,并试验了铵离子干扰的消除。方法简单、快速。经和四苯硼钠容量法对照,结果一致。     

冠醚配位的钠、钾催化外消旋丙交酯聚合研究进展

冠醚配位的钠、钾催化外消旋丙交酯开环聚合具有高可控性、高活性和高选择性等特点。钠、钾离子具有自然界中含量丰富,无毒和生物相容性好等等特点。因此钠、钾离子催化剂成为近期研究催化外消旋丙交酯聚合催化剂的热点。本文主要介绍近五年内报道的冠醚配位的钠、钾催化剂。根据配体的不同分为萘酚盐类、苯酚盐类、苯磺酸胺盐类、8-羟基喹啉盐类、离子类等五类进行介绍。希望能给研究催化丙交酯聚合的研究者一定启发。     

光度法测定陶瓷原料中大范围铁

利用光度法及以邻菲绕啉、抗坏血酸、EDTA、草酸、醋酸铵为基础制备的试剂，适应于陶瓷原料中大范围Fe2O3的快速测定，且其准确度高，选择性好，手续简单。     

光度法测定陶瓷原料中大范围铁

利用光度法及以邻菲绕啉，抗坏血酸，ＥＤＴＡ，草酸，醋酸铵为基础制备的试剂，适应于陶瓷原料中大范围Ｆｅ２Ｏ３的快速测定，且其准确度高，选择性好，手续简单。     

冠醚化合物合成应用研究的新进展

简要介绍了冠醚化合物的结构特征及应用，重点综述了新型冠醚的合成及选择性组装键合作用、新型冠醚衍生物的合成及应用、特殊结构冠醚的合成及应用，并对冠醚化学的发展进行了展望。     

ISE电势滴定法对陶瓷分析的应用

目前使用作为离子敏化学传感器的离子选择电极（ＩＳＥ）已成为电势分析法的最佳应用之一［１］。采用离子选择电极的电势滴定法用于陶瓷原料的成份检测,文中分别简述了两种测量方法———典型电势滴定法和格氏滴定法,提出了在陶瓷分析中,可应用氟化镧电极测定Ｌｉ２Ｏ、用钾离子电极测定Ｋ２Ｏ、用硫化银电极测定ＣａＯ和ＭｇＯ以及用硫化铜电极测定Ｆｅ２Ｏ３［２,３］。     

Photokatalytische Systeme. XXI. Zum Mechanismus der Photoreduktion von Kaliumchromat in Alkoholen

Photocatalytic Systems. XXI. On the Mechanism of the Photoreduction of Potassium Chromate in Alcohols The photolysis of crown ether complexes of potassium chromate in several alcohols has been investigated by e.s.r.-spectroscopy. Two different relatively long-lived Cr(V) intermediates formed by different reaction pathways have been observed. Radicalic oxidation products of the alcohols (alkoxy and hydroxyalkyl radicals as well as fragmentation products) and of the crown ether have been detected by spin trapping.     

特种表面活性剂和功能性表面活性剂()——冠醚型表面活性剂的合成及应用进展

概述了冠醚的结构特征及其分类;重点介绍了近几年合成冠醚常用的两种方法:末端活性基团逐步反应成环法和直接侧链化方法;综述了冠醚类表面活性剂的独特性质;最后,对冠醚型表面活性剂在有机合成、生物膜体系、感光材料、离子选择电极中的应用做了阐述,并对其今后的研究方向及发展趋势进行了展望。     

Effect of some potassium selective crown ethers on the permeability and structure of a phospholipid membrane

The effect of some new crown ethers on the cation efflux and phase transition parameters of dipalmitoyl phosphatidylcholine liposomes was studied. The effects were correlated with the lipophilicity of the crown ethers. The results indicate that the presence of two crown ring structures in one crown ether molecule is a prerequisite for the increase of ion permeability of liposomes. The effective crown ethers decrease the temperature, enthalpy and cooperativity of the gel-to-liquid crystalline phase transition. The crown ethers increase membrane permeability for potassium and, to a lesser extent, for rubidium and sodium. The ratio of permeability increase for potassium/rubidium significantly correlates with the lipophilicity of the crown ethers.     

Studies of the Size-Selective Extraction of Alkali Metal Ions by the Synergistic Extraction System,Crown Ether-DI(2-Ethylhexyl) Phosphoric Acid-Benzene

Abstract

In order to take practical advantage of the size-selective cation-coordinating ability of the cyclic polyethers (crown ethers), experiments seeking a means of avoiding the problem of solubilizing a mineral-acid anion in a nonpolar organic diluent were performed. Mixtures of several known extractants and crown ethers were tried. Results presented indicate that organic soluble cation exchangers mixed in solution with crown ethers produce a synergistic extractant mixture that largely exhibits the size-selective properties expected of the crown ether. Data are presented for the extraction of macro concentrations of alkali metals by di(2-ethylhexyl) phosphoric acid—dicyclohexyl-18-crown-6 mixtures at a single pH, and at nonloading condition(σ metal cone < 0.04 M) as a function of pH, 2 to 6. In both cases potassium is synergized most strongly presumably because of its best fit to the crown ether cavity. Other data indicate, however, that the size-fit principle is not as consistent for all alkali metal ions and crown ethers as for potassium and dicyclohexyl-18-crown-6. Other effects such as competition for ion hydration and aqueous-phase distribution of the complex may have important effects that have not been elucidated.     

Sol-Gel Glass-Encapsulated Crown Ethers for the Separation and Preconcentration of Strontium from Acidic Media

Extraction chromatography employing an inert polymeric support impregnated with a crown ether (typically, 4,4’,(5’)-di-(tert-butylcyclohexano)-18-crown-6 (DtBuCH18C6)), either neat (i.e., undiluted) or as a solution in 1-octanol, has previously been shown to provide an effective means for the isolation of radiostrontium from a variety of sample types for subsequent determination. In this study, sol-gel chemistry has been employed to prepare sorbents in which DtBuCH18C6 is encapsulated in a silica matrix. The resultant materials have been evaluated for their ability to retain strontium ion and compared to a commercially available extraction chromatographic (EXC) resin. Certain of the new materials are shown to provide uptake efficiencies comparable to those obtained with the commercial resins, although unless a porogen is employed, the kinetics of strontium uptake are significantly slower. In contrast to conventional EXC materials, however, strontium uptake by DtBuCH18C6-loaded glasses does not increase in proportion to the amount of extractant present, indicating that not all of the crown ether present is available for interaction with the metal ion.     

陶瓷材料可靠性分析中的统计断裂强度理论Ⅰ—经典统计断裂强度理论

综述了当前陶瓷材料统计断裂强度理论的发展概况 ,分析了几种建立强度分布方程的经典统计方法 ,探讨了它们用于陶瓷材料可靠性分析和陶瓷部件设计的可行性与合理性 ,指出该方面的研究尚有待于进一步加强。     

组成对陶瓷电容器酚醛树脂包封料性能的影响

采用正交设计方法研究了组成对陶瓷电容器酚醛树脂包封料(简称包封料)性能的影响,得到了影响包封料性能的主次因素,各因素水平影响其性能的趋势。同时得到了干燥时间最短的配方和耐溶剂性时间最长的配方。得到了综合性能最佳的包封料,它具有干燥时间为6小时(室温),耐溶剂性时间为56小时(36—38℃丙酮中)。探讨了各组分对包封料性能影响机理,为研制陶瓷电容器酚醛树脂包封料提供理论依据。     

Evaluation of Transport Capacity through Liquid Membranes of Some Crown Ether‐Siloxane Copolymers

The complexation ability of some linear crown ether‐siloxane copolymers of ester or amide type with cations as K⁺ and NH₄⁺ was investigated spectrophotometrically in order to select the polysiloxane receptors that achieve good ion transport ability by bulk liquid membrane systems. The transport properties of the potassium picrate through a liquid membrane using siloxane‐crown ether polyamide as carrier were discussed.