One-Dimensional Arrangement of Gold Nanoparticles by Electrospinning

The electrospinning technique was used successfully to fabricate one-dimensional arrays of Au nanoparticles within nanofibers in which the intrinsic nature of the semicrystalline polymer poly(ethylene oxide) (PEO) was employed as a template for the controlled nanoscale organization of nanoparticles. Differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy, UV−visible spectroscopy, scanning electron microscopy, atomic force microscopy, and transmission electron microscopy (TEM) were performed to characterize the resulting electrospun fibers in comparison with pure PEO and PEO/Au nanocomposite before electrospinning. By choosing chloroform as the solvent in this work the observed electrospun fibers were about 400−650 nm in diameter and revealed a well-defined Gaussian distribution. Thermal analysis showed that the dodecanethiol-capped Au nanoparticles preferentially act as heterogeneous nucleating agents for PEO crystallization. Conformational changes occurred by incorporating Au nanoparticles as well as electrospinning. The most common helical structure of PEO was transformed into a trans zigzag planar structure due to the high extensional flow caused by electrospinning. As a striking result, fairly long and one-dimensional chainlike structures consisting of Au nanoparticles within the electrospun fibers were observed by TEM. The present findings demonstrate that the electrospinning process provides not only a fundamental understanding of the conformational changes upon process conditions, but also a straightforward and cost-effective technique to fabricate one-dimensional arrays of nanoparticles for future nanodevices with unique properties in various applications, such as biological sensors, single-electron transistors, photonic materials, etc.