Formation of calcite with stepped (104) face under control of poly (ethylene glycol)-b-poly (l-leucine) at the air–solution interface

Abstract

Calcite rhombohedron with stepped indentation on its (104) face attached onto the air–solution interface was easily fabricated by using a non-ionic peptide type block copolymer poly (ethylene glycol)-b-poly (L-leucine) as the structure-directing agent. The balance of gravity and pulling force coming from the surface tension of the solution in combination with the limited Ca²⁺ and CO₃²⁻ ion transport from the mineralization solution together played a significant role in modifying the crystal morphologies. Based on the calcite particle morphologies at different aging times, the mechanism for the formation of stepped calcite in the presence of polymer was proposed. This study provides an example that it is possible to access morphogenesis of calcium carbonate by a non-ionic copolymer which may shed new light on the controlled morphogenesis of other inorganic materials.