ABSTRACT
I. Introduction 435 II. Solution Stability 436
III. Nucleation 439 A. Homogeneous nucleation 440 B. Heterogeneous nucleation 443 C. Secondary nucleation 444
IV. Crystal Growth 444 A. Transport controlled growth 446 B. Surface reaction controlled growth 449 C. Growth controlled by different mechanisms 457
V. Crystal Dissolution 458 VI. Influence of Impurities 459
VII. Aging 462 A. Flocculation 462 B. Ostwald ripening 463 C. Transformation of metastable phases 463
VIII. Experimental Approach 464 Symbols 469 References 471
I. INTRODUCTION
Considerable interest in the chemistry and physics of solids has led to research on crystal growth. This has also given rise to the development of the scientific basis of crystallization. However, most publications on the theory of crystal growth have elaborated the physical characteristics of the processes involved rather than the chemical phenomena occurring. Besides, most measurements of the rates of crystal growth from solution have been performed with rather soluble substances [1 ,2 ], so that the present state of knowledge of the crystallization of readily soluble substances is better than that of sparingly soluble ones. A relatively high supersaturated solution is requested for particles of sparingly soluble substances to be formed, so most processes involved often occur simultaneously
II. SOLUTION STABILITY
To understand the kinetics and mechanisms of crystal formation, some knowledge of the thermodynamics of solution and of its properties is needed.
