Xiaoxia Bai

Synthesis and electromagnetic, microwave absorbing properties of core-shell Fe3O4-poly(3, 4-ethylenedioxythiophene) microspheres.

Highly regulated core-shell Fe(3)O(4)-poly(3, 4-ethylenedioxythiophene) (PEDOT) microspheres were successfully synthesized by a two-step method in the presence of polyvinyl alcohol (PVA) and p-toluenesulfonic acid (p-TSA). And their morphology, microstructure, electromagnetic and microwave absorbing properties were subsequently characterized. By simply adjusting the molar ratio of 3, 4-ethylenedioxythiophene (EDOT) to Fe(3)O(4) (represented by (EDOT)/(Fe(3)O(4))), the thickness of the polymer shell can be tuned from tens to hundreds of nanometers. Moreover, it was found that the composite exhibited excellent microwave absorbing property with a minimum reflection loss (RL) of about -30 dB at 9.5 GHz with a (EDOT)/(Fe(3)O(4)) ratio of 20.

Photoconducting response on bending of individual ZnO nanowires

The bending effect of individual zinc oxide (ZnO) nanowires on photoconducting behavior has been investigated by an in situtransmission electron microscopy (TEM) method. By increasing the nanowire bending, the photocurrent of ZnO nanowire under ultraviolet illumination drops dramatically and the photoresponse time becomes much shorter. A possible mechanism has been proposed and discussed. The improved photo response performance by bending ZnO nanowires could be of significance for their optoelectronics and sensor applications.

Controlled fabrication of highly conductive three-dimensional flowerlike poly (3,4-ethylenedioxythiophene) nanostructures

Poly(3,4-ethylenedioxythiophene) (PEDOT) with three-dimensional (3D) flowerlike nanostructures was fabricated by chemical oxidation polymerization in a ternary phase system, which was composed of the surfactant sodium bis(2-ethylhexyl) sulfosuccinate (AOT), aqueous FeCl3 solution and p-xylene. This kind of 3D flowerlike PEDOT formed by nanofibers was prepared by controlling the molar ratio of water (used to dissolve FeCl3) to the surfactant, AOT. This molar ratio is defined as N which equals nH2O/nAOT. In particular, both the conductivity and specific surface area increased with the molar ratio, N, increasing. The room temperature conductivity of the synthesized PEDOT reached a relative high value of 137 S cm−1. Moreover, the novel 3D flowerlike nanostructures endow a high specific surface area of around 46 m2 g−1. The measurements of UV-visible spectroscopy (UV-vis) and X-ray photoelectron spectroscopy (XPS) indicate that the doping level played a key role in improving conductivity of PEDOT. This study is significant to the potential applications of PEDOT on supercapacitors, sensors, actuators, transistors, and so on.

Two-bit ferroelectric field-effect transistor memories assembled on individual nanotubes

Carbon nanotube (CNT) ferroelectric field-effect transistors (FeFETs) with well-defined memory switch behaviors are promising for nonvolatile, nondestructive read-out (NDRO) memory operation and ultralow power consumption. Here, we report two-bit CNT-FeFET memories by assembling two top gates on individual nanotubes coated with ferroelectric thin films. Each bit of the nanotube transistor memory exhibits a controllable memory switching behavior induced by the reversible remnant polarization of the ferroelectric films, and its NDRO operation is demonstrated. The low driving voltage of 2 V, high carrier mobility over 1000 cm2 V(-1) s(-1), and potential ultrahigh integration density over 200 Gbit inch(-2) of the two-bit FeFET memory are highlighted in this paper.