Single crystals growth from solutions

Fig. 3.15. Growth rates of (110) and (200) sectors of polyethylene single crystals grown from solution in tetradecanol (courtesy of S. Organ)...

Controlled crystallization Natural and synthetic single crystals Crystal growth from solutions, gels and by coarsening of solids... 

Scheme 3 The solid yielded by mechanical mixing of the reactants can be used to seed crystal growth from solution to obtain crystals for single-crystal X-ray diffraction experiments. This procedure allows one to compare the X-ray powder diffraction pattern measured on the mechanochemical sample with that calculated on the basis of the single-crystal experiment for the solids obtained by crystallization via seeding of a solution of the ground powder of the adduct...

A special focus has been then given to structural properties and the open challenge concerning epitaxial growth of CBD films, which appears as another case of Chemical single Crystal Routes from solutions recently highlighted [257]. It appears that this technique offers many possibilities in this area which have been not yet explored. Important efforts have still to be made to increase the quality of the CBD epitaxial films to the level of vapor phase films, in order to get all the benefits from a unique deposition process at low temperatures. A better control of deposition chemistry in combination with surface chemistry of single crystals is an important aspect. 

Figure 2.36 Recirculation apparatus for single crystal growth. [From P. Slaminko and A.S. Myerson (1981), The Effect of Crystal Size on Occlusion Formation During Crystallization from Solution, AIChE J. 27(6), 1029-1031. Used by permission of the American Institute of Chemical Engineers. 1981 AIChE.]...

An interesting special case of crystal growth from solution are the macroscopic polymer single crystals of diacetylenene, the poly-diacetylene crystals. For their preparation, as a first step, macroscopic molecular crystals of substituted diacety-... 

While the growing of single crystals from the melt or the gas pha.se may sometimes be important for industrial purposes (as in the crucible pulling method used for semiconductors such as Si and Ge), in X-ray structure analysis such methods are secondary to crystal growth from solution, and they are employed only when other techniques are not possible. 

The preference for similar polarities could also be attributed to similar solubilities of co-crystal formers. Most co-crystals in the CSD were prepared as single crystals grown from solution, and similar co-former solubilities make finding the right conditions for single crystal growth easier. However, the lack of correlation in descriptors usually associated with aqueous solubility (Log P, polar surface area) suggests that solubility is not the decisive factor behind the preferred similarity of polarity descriptors. 

Multilayer crystals with a central screw dislocation were commonly seen. A micrograph of a beautiful solution-grown multilayer crystal with regularly rotated terraces was presented by Keller [38]. This mechanism to multiply a single crystal layer into many crystal layers is important for the crystal growth from the melt to form spherulites. 

S. Dost, B. Lent, Single Crystal Growth of Semiconductors from Metallic Solutions (Elsevier, Amsterdam, 2006)... 

Brice, J.C. (1986) Crystal Growth Processes, Blackie, Glasgow. A clear description of aU the major (and most of the minor) techniques used to produce single crystals and a useful discussion on method selection. Elwell, D. and Scheel, H.J. (1975) Crystal Growth from High Temperature Solutions, Academic Press, New York. An excellent place to look for fluxes for crystal growth. 

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