High crystal design

It is obvious that this volume cannot be fully comprehensive, but at least it should provide a rough overview, covering some of the important subjects in the field of liquid crystal design and self-assembly. Nevertheless, I hope the present volume will be highly informative and inspiring for chemists and physicists who are interested in developing new materials based on the unique combination of order and mobility provided by the LC state. 

An agitated cooler is more expensive to operate than a simple tank crystallizer, but it has a much higher productivity. Labour costs for product handling may still be rather high. The design of tank crystallizers varies from shallow pans to large cylindrical tanks. 

Appropriate magnesium aluminosilicate compositions were selected which have not only relatively low melt viscosities above their liquidus temperatures but also high crystallization rates when crystallization occurs. Addition of yttria to these compositions reduces the crystallization rate (Table V) and increases the modulus. In this process, the fiber forming cones under the bushing tips consist of two sections. The first, just below the bushing tips, has a much lower viscosity than the second, where aystallization may occur before the fibers solidify. To assure adequate process continuity, a precision process was designed that also relies on forced cooling of the fiber cones. 

In this example, it is assumed that desupersaturation is complete when point 0 is again reached. For this case, it is dear that the level of the supersaturation produced at the level of the solution depends on the redrculation flow rate. High recirculation flow rates reduce the supersaturation produced there (dilution), while low redrculation flow rates increase it. The redrculation flow rate, adjusted to the production output, is therefore the most important design parameter in industrial crystallizers. Where the production outputs are the same, this parameter is equal for all crystallizer designs. The required recirculation flow rate depends on the metastable zone width. If this is not known, it has to be determined beforehand by means of measurements. In practice, half of the metastable zone width is used for determining the required redrculation flow rate. Therefore,... 

The stabilization of usually metastable crystal modifications hints at the potential DHBCs may have for crystal design purposes besides the morphological control, as many crystals of technical importance are made at high temperature to obtain the desired crystal modification. The same may be achieved by a polymer in water, via a kinetic metastable phase, if the fimc-tional block has the appropriate functional pattern, which requires a modular synthesis strategy towards DHBCs. 

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