Formation process of sheets and helical forms consisting of strontium carbonate fibrous crystals with silicate

Strontium carbonate grown in silica gel showed a variety of complex morphologies including sheets and spirals associated with biogenetic products. The non-crystallographic architecture had a hierarchical structure consisting of nanoscale needle-like building blocks enveloped with a silicate sheath. By monitoring the time-dependent growth, a spherical cluster of the fibrous crystals was transformed into the highly ordered morphologies with strange outgrowths in the progressive stages. The unusual morphologies were achieved with a reduction of the subunit size and restriction of the growth direction by selective adsorption of silicate anions on the specific crystal surfaces of the carbonate crystals. (C) 2003 Elsevier Science B.V. All rights reserved.