MODIFICATION OF GROWTH RATE AND HABIT OF ADIPIC ACID CRYSTALS WITH SURFACTANTS
MODIFICATION OF GROWTH RATE AND HABIT OF ADIPIC ACID CRYSTALS WITH SURFACTANTS
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DOI：
10.1021/j100827a014
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发表时间：
1961-01-01
影响因子：
--
通讯作者：
TAUSCH, FW
中科院分区：
文献类型：
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作者：
MICHAELS, AS;TAUSCH, FW
使用专门设计的结晶装置，研究了在精心控制的条件下从水溶液中等温（32.7）生长己二酸晶体作为（a）过饱和水平（1至13％）和（b）各种阴离子和阳离子表面活性剂浓度（0至360毫克/升）的函数。通过显微镜测定晶体的特征面((001)、(010)和(110))的生长速率。独立测定表面活性剂在晶体上的吸附。虽然结果与该系统的早期工作总体上定性一致，但已经检测到许多非常显着和不寻常的效应，如果不控制温度和过饱和度，这些效应是无法观察到的。某些表面的生长迟缓远远大于先前报道的，并且添加剂的效果强烈依赖于过饱和水平；在低过饱和度下，增加添加剂浓度会导致某些表面的生长急剧减少或停止，而在高过饱和度下，无论浓度如何，添加剂对生长的影响相对较小。一个特别有趣的结果是阴离子添加剂实际上显着加速了 (001) 面上的生长。研究还发现，添加剂可以提高发生广泛三维成核的过饱和水平，并且还可以形成更好的晶体。结果根据晶体生长的二维成核和位错理论进行解释，并开发了生长和习惯修改的机制。
The isothermal (32.7) growth of crystals of adipic acid from aqueous solution under carefully controlled conditions has been studied as a function of (a) supersaturation level (1 to 13%) and (b) concentration of various anionic and cationic surfactants (0 to 360 mg./l.), using a specially designed crystallizing apparatus. Growth rates of the characteristic faces ((001),(010) and (110)) of the crystals were determined microscopically. Sorption of surfactants on the crystals was independently determined. While results are in general qualitative agreement with earlier work on this system, a number of very significant and unusual effects have been detected which could not have been observed without control of temperature and supersaturation. The growth-retardation on certain faces is far greater than previously reported, and theeffect of additive is strongly dependent on supersaturation level; at low supersaturation, increasing additive concentration results in drastic reduction or cessation ofgrowth on certain faces, while at high supersaturation levels the additives have relatively little effect on growth, regardless of concentration. A particularly interesting result is that anionic additives actually sig-nificantly accelerate growth on the (001) face. It is also found that additives increase the supersaturation level at which extensive three-dimensional nucleation occurs, and also result in better-formed crystals. The results are interpreted in terms of two-dimensional nucleation and dislocation theories of crystal growth, and mechanisms for growth and habit modification are developed.