Block-Copolymer-Controlled Growth of CaCO_3 Microrings

摘要

A novel way for directed solution growth of hollow superstructures of CaCO_3 has been successfully developed on the basis of controlled self-assembly and polymer concentration gradients using a double-hydrophilic block copolymer with a hydrophobic modification as a directing agent.A formation mechanism of such rings is proposed on the basis of the formation of CaCO_3 nanoparticles in unstructured block copolymer assemblies with subsequent aggregation of these primary nanoparticles.This leads to the formation of a polymer concentration gradient from the inside to the outside of the particle.As the polymer contains multiple chelating units,this leads to a selective dissolution of the center of the particle.