280324 Multiblock Magnetic Nanowires

Thursday, November 1, 2012: 4:20 PM
413 (Convention Center )
Sangyeul Hwang, Chemical Engineering Department, University of Michigan, Ann Arbor, MI, Tae-Hong Park, Chemical Engineering, U of Michigan, Ann Arbor, MI and Joerg Lahann, Department of Chemical Engineering, Macromolecular Science and Engineering, Biomedical Engineering, and Materials Science and Engineering, University of Michigan, Ann Arbor, MI

Magnetic particles (MPs) are known to align to form a chain structure under a parallel magnetic field. It is expected that different MPs are randomly arranged in these one-dimensional (1-D) chains. We introduce a novel method to direct a highly ordered dipole chains of different MPs. A magnetic field gradient is utilized to create a potential well, where a magnetic force decreases far away from a boundary line that has the highest magnetic force and thus the lowest potential energy. Two distinct types of MPs can be assembled at the boundary line to form diblock-like 1-D structures. In principle, many other sets of different MPs can be added into the assembled diblock MP chains, producing mutilblock particle organizations. To conserve the high ordered 1-D patterns in the absence of a magnetic field, we also report a new strategy that interconnects the aligned particles in-situ. By adding a dispersant (solvent such as tetrahydrofuran) into the aligned particles in anti-solvent (water), the adjacent particles that are contact in each other start to deform and are fused together. Quenching the deformation before complete polymer dissolution of the particles readily produces mutiblock magnetic nano/microwires.

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See more of this Session: Colloidal Assembly and Device Fabrication
See more of this Group/Topical: Engineering Sciences and Fundamentals