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Colloidal Polymerization of Ferromagnetic Nanoparticles into Cobalt Oxide Nanowires Jeffrey Pyun, University of Arizona, DMR 0645618 We have developed.

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Presentation on theme: "Colloidal Polymerization of Ferromagnetic Nanoparticles into Cobalt Oxide Nanowires Jeffrey Pyun, University of Arizona, DMR 0645618 We have developed."— Presentation transcript:

1 Colloidal Polymerization of Ferromagnetic Nanoparticles into Cobalt Oxide Nanowires Jeffrey Pyun, University of Arizona, DMR 0645618 We have developed a new synthetic method, “Colloidal Polymerization,” where dipolar cobalt nanoparticles are directly polymerized to form cobalt oxide (Co 3 O 4 ) nanowires. The scope of this technique has recently been expanded to prepare functional Co 3 O 4 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). Co 3 O 4 Nanowires “Homo-mesopolymers” PtNP-Co 3 O 4 Nanowires “Exterior functional” AuNP-Co 3 O 4 nanowires “Interior functional” Polymer Coated Ferromagnetic Co-Nanoparticles Polymer Coated Core-Shell AuCo-Nanoparticles “Colloidal Monomers” Colloidal Polymerization 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 & Cilia Jeffrey Pyun, University of Arizona, DMR 0645618 Multi-gram Synthesis of Ferromagnetic NPs Artificial Flagella from CoNP Self-Assembly 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 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. Soft Mater. 2010, 6, 602-609; ACS Nano 2010, under revision

3 Education: Funding from this NSF-CAREER award has enabled support of three graduate students, Pei Keng (graduated Nov. 2009) Bo Yun Kim (5 th -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. International Impact: 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 4 rd & 6 th students 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. Pyun at Thornydale ES Sean Derosa at Biological, Engineering, & Chemical Undergraduate Research Conference (BECUR) at U of Arizona Polymer Coated Ferromagnetic Nanoparticles as Artificial Flagella & Cilia Jeffrey Pyun, University of Arizona, DMR 0645618


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