Water-dissolvable sodium sulfate nanowires as a versatile template for the fabrication of polyelectrolyte- and metal-based nanotubes

Abstract

This study presents the synthesis of water-dissolvable sodium sulfate nanowires, where Na2-SO4 nanowires were produced by an easy reflux process in an organic solvent, N,N-dimethylformamide (DMF) and formed from the coexistence of AgNO3, SnCl2, dodecylsodium sulfate (SDS), and cetyltrimethylammonium bromide (CTAB). Na2SO 2 nanowires were derived from SDS, and the morphology control of the Na2SO4 nanowires was established by the cooperative effects of Sn and NO3-, while CTAB served as the template and led to homogeneous nanowires with a smooth surface. Since the as-synthesized sodium sulfate nanowires are readily dissolved in water, these nanowires can be treated as soft templates for the fabrication of nanotubes by removing the Na2SO4 core. This process is therefore significantly better than other reported methodologies to remove the templates under harsh condition. We have demonstrated the preparation of biocompatible polyelectrolyte (PE) nanotubes using a layer-by-layer (LbL) method on the Na2SO 4 nanowires and the formation of Au nanotubes by the self-assembly of Au nanoparticles. In both nanotube synthesis processes, PEI (polyethylenimine), PAA (poly(acrylic acid)), and Au nanoparticles served as the building blocks on the Na2SO4 templates, which were then rinsed with water to remove the core templates. This unique water-dissolvable template is anticipated to bring about versatile and flexible downstream applications. © 2006 American Chemical Society.