Previous Research

Automated, easy to use, self-shielded microfluidic radiosynthesizer for on-demand production of PET probes

Synthesis of well-defined polymer ligand and uniform size cobalt nanoparticles as "colloidal monomers".  The ferromagnetic "colloidal monomers" self-assembled into 1-dimensional chain via dipole-dipole interaction.  The 1-D chain can be "locked" via oxidation to form a permanently interconnected cobalt oxides nanowires with interesting electrochemical properties. The 1-D chain can also be use to form artificial cilia through chemical cross-linking.

Keng, PY. et al. ACS Nano 2009, 3, 3143.  (a) Self assembly of ferromagnetic cobalt nanoparticle in lamellar-like morphology due to the strong head-to-tail dipolar associations and the weaker lateral associations between nanoparticle chains via anti-paralle alignment of unpaired spins. (b) The effect of the size of polymer ligands.  As the size of the polymer increases, the dipolar associations between nanoparticles weakens, thus favors the formation of nanorings. 

Colloidal polymerization of ferromagnetic cobalt nanoparticles (a) into hollow cobalt oxides nanowires (b)