Aggregation-governed oriented growth of inorganic crystals at an organic template.

Sumit Kewalramani, Geoffrey Dommett, Kyungil Kim, Guennadi Evmenenko, Haiding Mo, Benjamin Stripe, Pulak Dutta

Index: J. Chem. Phys. 125(22) , 224713, (2006)

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Abstract

X-ray studies performed during the growth of CdCO(3) and MnCO(3) crystals from supersaturated aqueous solutions, at fatty acid monolayer templates, reveal that the nucleates are nearly three-dimensional powders below a threshold supersaturation. However, at higher supersaturations, the crystals are preferentially oriented with the {0 1 2} direction vertical. Scanning electron microscope images of samples transferred to substrates show discrete crystals at low concentrations, while at higher concentrations the crystals self-aggregate to form linear chains and sheets. The authors speculate that preferential alignment at the organic-inorganic interface is enhanced as a consequence of oriented aggregation of crystals. The role of monolayer-ion interactions in governing the morphologies and the resulting orientation of the inorganic nucleate is discussed.