Single crystal growth rate

In addition to induction time measurements, several other methods have been proposed for determination of bulk crystallization kinetics since they are often considered appropriate for design purposes, either growth and nucleation separately or simultaneously, from both batch and continuous crystallization. Additionally, Mullin (2001) also describes methods for single crystal growth rate determination. 

Mulliii, J.W. and Garside, J., 1967. Crystallization of aluminium potassium sulphate a study in the assessment of crystallizer design data I Single crystal growth rates, II Growth in a fluidised bed. Transactions of the Institution of Chemical Engineers, 45, 285-295. 

V ni - single crystall growth rate V p - polyciy stalline growth rate. 

Spherulitic and Single Crystal Growth Rates.—Rate measurements have been made on poly(ethylene oxide), plasticized polycarbonate, and polydioxolan. ... 

Fig. 20. Influence of supeisaturation on the average distance between steps and on the single-crystal growth rate (summarized for dilfeient rotation speeds) in the case of Y123 grown by the SRL-CP melhod (Kanamori...

Over 50 acidic, basic, and neutral aluminum sulfate hydrates have been reported. Only a few of these are well characterized because the exact compositions depend on conditions of precipitation from solution. Variables such as supersaturation, nucleation and crystal growth rates, occlusion, nonequilihrium conditions, and hydrolysis can each play a role ia the final composition. Commercial dry alum is likely not a single crystalline hydrate, but rather it contains significant amounts of amorphous material. 

The induction period for nucleation that takes the reciprocal of nucleation rate is often used. For single-crystal growth, a longer induction period indicates a more stable solution which makes the growth easier. 

Myerson (2002), Mullin (2001), and Mersmann (2001) provide excellent descriptions of methods for crystal growth rate measurements. These methods involve measurements of either single crystals or suspensions. Much information can be gained from the traditional technique of measuring ( grab samples or in-line) solute concentration versus time in batch crystallization on a seed bed. Initial and later slopes on such a plot can provide multiple data points of growth rate versus supersaturation. 

Measurement of Crystal Growth Rates. Techniques used to measure crystal growth rates can be divided into two main groups. The first group is comprised of methods that rely on the growth of a single crystal to obtain the needed data. The second set of methods involves the growth of a suspension of crystals. Discussion of experimental methods can be found in a number of references (Laudise 1970 Nyvlt et al. 1985 Mullin 1993 Randolph and Larson 1986). 

Figure 17.9 Comparison of single crystal growth cell, fluidized bed agitated vessel growth rates for ammonium alum at J2"C ...

Knowledge of the variation and complexity of crystalhne shapes opens a universe of new polymers and properties. H. D. Keith and F. J. Padden, Jr., observed that crystalhne characteristics are a function of crystal growth rate, and crystalline transformation occurs when a single crystal grows to predictable size. To calculate a predictable crystal size from melt for homopolymers [10],... 

---