The Directed Alignment of Functionalized Nanowires Relative to Chemical Patterns

This research investigates the directed alignment of functionalized nanowires relative to chemical patterns, with applications for nanoelectronics.  Nanowires are fabricated by membrane templated electrodeposition, in which a constant current is applied to an Ag backed membrane filled with a solution of metal ions.  The ions are reduced to form nanowires of uniform diameter and length, with the diameter controlled by the membrane pore diameter and the length dictated by the conditions of the deposition.  The surfaces of the nanowires are then functionalized with self-assembled monolayers (SAMs), whose exposed termini are tailored with chemical functional groups.  Research began by dropcasting functionalized single component nanowires onto substrates with complimentary SAMs.  Initial analysis using scanning electron microscopy did not give any indication that order was present among the nanowires.  Currently, Pt-Au bicomponent nanowires are being functionalized using orthogonal chemistry with a methyl terminated isocyanide binding to the Pt and a carboxylic acid terminated thiol binding to the Au.  Substrates for directed deposition are then patterned with decanethiol and amino-undecanethiol using micro-contact printing or photo-oxidative patterning.  This research aims to utilize functional groups to direct the assembly and incorporation of the nanowires into hierarchical architecture.