Formation of single-crystalline aragonite tablets/films via an amorphous precursor.
Thin tablets and films of calcium carbonate have been grown at the air-water interface via an amorphous precursor route using soluble process-directing agents and a Langmuir monolayer based on resorcarene. By using appropriate concentrations of poly(acrylic acid-sodium salt) in combination with Mg2+ ion, an initially amorphous film is deposited on the monolayer template, which subsequently crystallizes into a mosaic film composed of a mixture of single-crystalline and spherulitic patches of calcite and aragonite. Of particular importance is the synthesis of single-crystalline "tablets" of aragonite (approximately 600 nm thick), because this phase generally forms needle-like polycrystalline aggregates when grown in vitro. To our knowledge, a tabular single-crystalline morphology of aragonite has only been observed in the nacreous layer of mollusk shells. Therefore, this in vitro system may serve as a useful model for examining mechanistic issues pertinent to biomineralization, such as the influence of organic templates on nucleation from an amorphous phase.
Amos
Fairland F
FF
Department of Materials Science and Engineering, University of Florida, P.O. Box 116400, Gainesville, Florida 32611, USA.
Sharbaugh
Denise M
DM
Talham
Daniel R
DR
Gower
Laurie B
LB
Fricke
Marc
M
Volkmer
Dirk
D
D002119:Calcium Carbonate / Q000737:chemistry*; D003460:Crystallization; D015394:Molecular Structure; D014961:X-Ray Diffraction
D002119:Calcium Carbonate