CHEMISTRY OF CRYSTALLINE ALUMINOSILICATES .I. FACTORS AFFECTING FORMATION OF ZEOLITE A
CHEMISTRY OF CRYSTALLINE ALUMINOSILICATES .I. FACTORS AFFECTING FORMATION OF ZEOLITE A
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DOI：
10.1021/j100876a015
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发表时间：
1966-01-01
影响因子：
--
通讯作者：
KERR, GT
中科院分区：
文献类型：
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作者：
KERR, GT
沸石A的形成速率与反应体系中存在的沸石晶体的数量成正比。在可以观察到晶体形成的时期之前，有一个诱导期，这可能是形成原子核所需的时间。在反应开始时向反应混合物中加入A沸石可以消除诱导期。原子核的形成和沸石晶体的形成都是由溶解在反应混合物的液相（氢氧化钠溶液）中的某些物质的反应产生的，这些物质来源于非晶态底物。沸石A的形成速率随着水相中碱浓度的增加而增加。在碱浓度不变的情况下，随着水相体积的增大，诱导期减小，反应的绝对速率变化不大。提出了一种解释大多数实验观察结果的机制。在过去的20年里，Barrer和他的同事们一直在研究各种沸石基硅铝硅酸盐晶体的合成。弥尔顿、布雷克及其同事在这一领域做出了重大贡献，他们发现了一种新的合成沸石a， 2和一种与faujasite同构的合成沸石x， Barrer尤其研究了许多决定合成沸石组成和晶体结构的变量。Flanigen和Breck对沸石a和X的生长进行了动力学研究；他们的出版物不包含实验细节。4
The rate of formation of zeolite A is proportional to the quantity of crystalline zeolite present in thereaction system. The period during which crystal formation can be ob-served is preceded by an induction period which is probably the time required for forma-tion ofnuclei. The induction period can be eliminated by the addition of zeolite A to the reaction mixture at the beginning of the reaction. The formation of nuclei and the forma-tion of zeolite crystals both result from the reaction of some species dissolved in the liquid phase (sodium hydroxide solution) of the reaction mixture and derived from the amor-phous substrate. Therate of formation of zeolite A is increased as the concentration of alkali in the aqueous phase is increased. Asthe volume of the aqueous phase is increased, at a constant alkali concentration, the induction period is decreased with little change in the absolute rate of reaction. A mechanism is proposed which explains most of the experimental observations.Synthesis of a variety of crystallinealuminosilicates of the zeolite group has been the subject of a series of publications by Barrer and co-workers during the past 20 years. 1 Highly significant contributions to this field were made by Milton, Breck, and co-workers in the discovery of a new synthetic zeolite, zeolite A, 2 and a synthetic zeolite isostructural with faujasite, zeolite X. 3 Barrer, especially, has studied a number of variables which determine the compositions and crystal structures of zeolites prepared synthetically. Flanigen and Breck conducted a kinetic study on the growth of zeolites A and X; their publication does not contain experimental details. 4