Porous and hierarchical materials have potential in catalysis, separations, drug delivery and sensor technology. Creating calcium carbonate with such a structure might also have benefits in bone reconstruction and materials science. By using a poly(ethylene glycol)-b-poly(aspartic acid) (PEG-b-pAsp) block copolymer in a mixed solvent of N,N-dimethylformamide (DMF) and cyclohexanol, researchers in China have been able to control the crystal growth of such particles.

Surface area, porosity and particle size (tens to hundreds of nanometers) can be fine-tuned by altering the solvent ratio.

• Controlled crystallization of hierarchical and porous calcium carbonate crystals using polypeptide type block copolymer as crystal growth modifier in a mixed solution
  Xiaohui Guo, Lei Liu, Wanv Wang, Ji Zhang, Yaoyu Wang, Shu-Hong Yu,
  CrystEngComm 2011.
  DOI: 10.1039/C0CE00202J