Showing papers by "Jiajie Liang published in 2014"

Silver Nanowire Percolation Network Soldered with Graphene Oxide at Room Temperature and Its Application for Fully Stretchable Polymer Light-Emitting Diodes

Abstract: Transparent conductive electrodes with high surface conductivity, high transmittance in the visible wavelength range, and mechanical compliance are one of the major challenges in the fabrication of stretchable optoelectronic devices. We report the preparation of a transparent conductive electrode (TCE) based on a silver nanowire (AgNW) percolation network modified with graphene oxide (GO). The monatomic thickness, mechanical flexibility, and strong bonding with AgNWs enable the GO sheets to wrap around and solder the AgNW junctions and thus dramatically reduce the inter-nanowire contact resistance without heat treatment or high force pressing. The GO-soldered AgNW network has a figure-of-merit sheet resistance of 14 ohm/sq with 88% transmittance at 550 nm. Its storage stability is improved compared to a conventional high-temperature annealed AgNW network. The GO-soldered AgNW network on polyethylene terephthalate films was processed from solutions using a drawdown machine at room temperature. When bent to...

Healable capacitive touch screen sensors based on transparent composite electrodes comprising silver nanowires and a furan/maleimide diels-alder cycloaddition polymer.

Abstract: A healable transparent capacitive touch screen sensor has been fabricated based on a healable silver nanowire–polymer composite electrode. The composite electrode features a layer of silver nanowire percolation network embedded into the surface layer of a polymer substrate comprising an ultrathin soldering polymer layer to confine the nanowires to the surface of a healable Diels–Alder cycloaddition copolymer and to attain low contact resistance between the nanowires. The composite electrode has a figure-of-merit sheet resistance of 18 Ω/sq with 80% transmittance at 550 nm. A surface crack cut on the conductive surface with 18 Ω is healed by heating at 100 °C, and the sheet resistance recovers to 21 Ω in 6 min. A healable touch screen sensor with an array of 8 × 8 capacitive sensing points is prepared by stacking two composite films patterned with 8 rows and 8 columns of coupling electrodes at 90° angle. After deliberate damage, the coupling electrodes recover touch sensing function upon heating at 80 °C f...

A Flexible and Transparent Thin Film Heater Based on a Silver Nanowire/Heat‐resistant Polymer Composite

Abstract: It has been a challenge to develop a new transparent conductor to replace the brittle and expensive indium tin oxide (ITO) film to make film heater with high transmittance in the visible wavelength range, high surface conductivity and mechanical flexibility. Here, we report the synthesis of a transparent composite film comprising a silver nanowire (AgNW) percolation network inlaid in the surface of a heat-resistant polymer film. This composite conductor has a figure-of-merit sheet resistance of 25 Ω · sq−1 with 86.4% transmittance at 550 nm. The composite film possesses outstanding heat-resistant property and can generate high temperature up to 230 °C at low operation voltages as an efficient thin film heater. Compared with the film heaters previously reported, the composite film heater shows faster heating response and higher saturation temperature under the same input voltage. The film heater could be bent to 10 mm diameter and the generated temperature decreased by less than 3 °C after 3 000 bending cycles.

The use of graphene oxide membranes for the softening of hard water

Abstract: Strong chemical interactions between the oxygen-containing functional groups on graphene oxide (GO) sheets and the ions of divalent metals were exploited for the softening of hard water. GO membranes were prepared and evaluated for their ability to absorb Ca2+ and Mg2+ ions. These GO membranes can effectively absorb Ca2+ ions from hard water; a 1 mg GO membrane can remove as much as 0.05 mg Ca2+ ions. These GO membranes can be regenerated and used repeatedly.

High microwave absorption performances for single-walled carbon nanotube?epoxy composites with ultra-low loadings

Abstract: Microwave-absorbing polymeric composites based on single-walled carbon nanotubes (SWNTs) are fabricated via a simple yet versatile method, and these SWNT?epoxy composites exhibit very impressive microwave absorption performances in a range of 2 GHz?18 GHz. For instance, a maximum absorbing value as high as 28 dB can be achieved for each of these SWNT?epoxy composites (1.3-mm thickness) with only 1 wt% loading of SWNTs, and about 4.8 GHz bandwidth, corresponding to a microwave absorption performance higher than 10 dB, is obtained. Furthermore, such low and appropriate loadings of SWNTs also enhance the mechanical strength of the composite. It is suggested that these remarkable results are mainly attributable to the excellent intrinsic properties of SWNTs and their homogeneous dispersion state in the polymer matrix.