Co 3 O 4 Nanowires “Homo-mesopolymers”

1. Co3O4 Nanowires “Homo-mesopolymers” AuNP-Co3O4 nanowires “Interior functional” Colloidal Polymerization of Ferromagnetic Nanoparticles into Cobalt Oxide NanowiresJeffrey Pyun, University of Arizona, DMR 0645618 “Colloidal Monomers” Polymer Coated Core-Shell AuCo-Nanoparticles Polymer Coated Ferromagnetic Co-Nanoparticles Colloidal Polymerization PtNP-Co3O4 Nanowires “Exterior functional” We have developed a new synthetic method, “Colloidal Polymerization,” where dipolar cobalt nanoparticles are directly polymerized to form cobalt oxide (Co3O4) nanowires. The scope of this technique has recently been expanded to prepare functional Co3O4 nanowires with controllable placement of Au, or Pt nanoparticles. Electrochemical characterization of these materials revealed that noble metal inclusions enhanced the capacitance (charge storage capabilities) by a factor of 2-8 times. These nanowire oxides have also been used to fabricate electrode materials for Li-batteries, exhibiting very high specific capacitance values (1000 mAh/g). ACS Nano 2009, 10, 3143-3157; J. Am. Chem. Soc. 2010, 132, 3234-3235; Chem. Mater. 2010, submitted

2. Polymer Coated Ferromagnetic Nanoparticles as Artificial Flagella & CiliaJeffrey Pyun, University of Arizona, DMR 0645618 Artificial Flagella from CoNP Self-Assembly Multi-gram Synthesis of Ferromagnetic NPs The self-assembly and magnetic acutation of dipolar PS-CoNPs into “artificial flagella and cilia” has been demonstrated. SEM of optical images of dispersed, “swimming” assmblies in DMF are shown. An optimized synthesis of polystyrene coated cobalt nanoparticles (PS-CoNPs) that for the first time enable facile variation of particle size and multi-gram synthesis (20 g) of nanoparticles J. Mater. Chem. 2010, 20, 6023-6025 Soft Mater. 2010, 6, 602-609; ACS Nano 2010, under revision

3. Polymer Coated Ferromagnetic Nanoparticles as Artificial Flagella & CiliaJeffrey Pyun, University of Arizona, DMR 0645618 International Impact: Education: Funding from this NSF-CAREER award has enabled support of three graduate students, Pei Keng (graduated Nov. 2009) Bo Yun Kim (5th-yr), Sarah Rasmussen (MS-2009). and Jared Gabriel (Case Western-intern). Mentoring of undergraduates (Sean Derosa, Laura Seekatz and Friederike Goerstling) was also enabled thru this award. Sean Derosa at Biological, Engineering, & Chemical Undergraduate Research Conference (BECUR) at U of Arizona Pyun recently granted joint appointment in Chemical Engineering at Seoul National University as Associate Professor for work in Energy storage and conversion enabled by NSF-CAREER funded work on polymers. Outreach: Continued outreach efforts with Vale HS in Tucson, has focused on a joint research class with Caitlyn Hall (junior, Vale HS) has been conducting research with Pyun on polymer and magnetic nanoparticles. Caitlyn won first prize in the poster competition for Southern Arizona Regional Science & Engineering Fair (SARSEF) and also presented her work at the Intel International Science & Engineering Fair. K-12 outreach program has also been continued with Jenny Miller at Thornydale Elementary School, Tucson, AZ for lectures to 4rd & 6th students Pyun at Thornydale ES