Crystal growth by oriented attachment of nanoparticles observed in liquid by electron microscopy
Together with colleagues from Berkeley, Cathrine Frandsen from DTU Physics, have observed how iron oxide nanoparticles move in solution and orient themselves such that their crystal lattices match perfectly prior to a jump-to-contact attachment. This direction specific attachment appears to be driven by the electrostatic charges of surface atoms. The attachment processes have been observed directly by use of a liquid cell inserted into a high-resolution electron microscope at the Lawrence Berkeley National Laboratory. The results are important for understanding crystal growth in solution and for designing new materials using nanoparticles as building blocks.
The results have just been published in the journal Science.
Article: Direction-Specific Interactions Control Crystal Growth by Oriented Attachment, Dongsheng Li, Michael H. Nielsen, Jonathan R. I. Lee, Cathrine Frandsen, Jillian F. Banfield, and James J. De Yoreo, Science 336 (2012) 1014.*
The article can be found at http://www.sciencemag.org/content/336/6084/1014
Videos showing the oriented attachment of nanoparticles can be seen at
http://www.sciencemag.org/content/suppl/2012/05/23/336.6084.1014.DC1/1219643s2.mov
http://www.sciencemag.org/content/suppl/2012/05/23/336.6084.1014.DC1/1219643s3.mov
Popular science description to be found at http://sciencenordic.com/crystals-connect-lego-bricks
Cathrine Frandsen’s work and collaboration with the group in Berkeley is sponsored by The Danish Council for Independent Research. 