Growth morphology control

In fact, such biomimetic molecules demonstrate the ability to tailor the growth of silica nanoparticles in a way that is very similar to diatom-extracted species. However, they demonstrate the same limitations in terms of morphological control of nanoparticle assembly. This is because the diatom shell architecture results not only from interactions of silica precursors with templating molecules but also benefits from a cell-driven molding of the vesicular compartment where silicification occurs [29]. Thus, it is very likely that diatom-like synthetic silica will only be achieved when such confinement/molding effects are taken into account in the design of biomimetic experiments [30]. 

The use of tailor made additives holds great promise in the area of crystal growth and morphology control. The routine selection and use of these type of additives will require a fundamental understanding of the mechanism which the additives work on a molecular basis. At the same time, the effect of solvent molecules on the crystal growth process is another related and important problem. In both instances, the relationship between internal aystal structure, aystal growth rate, solvent and impurities are needed to predict the habit of a crystal and thus allow seleaion of the proper conditions and components required to obtain a desired habit... 

A higher level of size and morphology control in the incipient semiconductors has been accomplished in reversed micelles prepared from cadmium AOT [614] and from mixtures of cadmium AOT and sodium AOT [615] or, alternatively, by arresting particle growth by surface derivatization [592, 621, 622]. Indeed, surface derivatization of semiconductor clusters was first reported for particles in reversed micelles [621] the reversed micelles act to confine precursor ions and to control the growth of the semiconductor particles. Conditions are typically arranged so that, initially, there is no more than one metal ion (say Cd2+) per water pool. Addition of a heptane solution of bis(trimethylsilyl) selenium resulted in the formation of size-quantized metal selenide particles (say CdSe) in the reversed micelles. This solution could be evaporated to dryness and the resultant particles could be reconstituted in a hydrocarbon solvent Alternatively, addition of metal (say Cd2+) ions to the reversed-micelle-entrapped metal selenide particles, followed by the addition of alkyl(trimethylsilyl)selenium, RMSiMe3, led to the formation of alkyl-capped... 

Folk R.L. (1978) A chemical model for calcite crystal growth and morphology control. J. Sediment. Petrol. 48, 345-347. 

OECD TG 414 Prenatal Developmental Toxicity Study (OECD, 2001a) At least from implantation to 1 or 2 days before expected birth 3 dose levels plus control n = 20 pregnant females Implantation, resorptions Fetal growth Morphological variations and malformations + malformations are assessed in all fetuses - the dosing period includes only the prenatal period - the effects assessment includes only effects in fetuses... 

So far, hydrothermal and solvothermal synthesis have been widely used in the 1) modification, 2) crystal growth and morphology control, 3) phase-transition study, and 4) discovery of new species of zeolites and porous materials. 

If an oil-in-water interface is used as an inorganic growth medium with the growth direction into the aqueous phase, morphological control of the resulting inorganic-organic... 

The morphology of the poly(2,2 bithiophene) films is quite complex and appears to be a function of several factors such as the nature of the growth substrate, the growth stage, and the rate of growth as controlled by the current rate. When a platinum electrode is used as the growth substrate, a smooth thin layer several hundred angstroms thick initially covers the entire electrode surface. 

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