Metal copper mesh with superhydrophobic and superoleophilic surface had been successfully fabricated via a facile solution-immersion process. The hierarchical structure was prepared on the commercial copper mesh surface by etching with the nitric acid. After being modified by 1-hexadecanethiol (HDT), the as-prepared mesh indicated both superhydrophobic and superoleophilic property simultaneously. This as-prepared metal mesh could then be applied for oil and water mixture separation. The unusual wettability of the as-prepared mesh was stable in corrosive conditions, such as acidic, basic, and salt solutions. The solution-immersion method was simple, time-saving, and inexpensive and therefore exhibited great potential application.

No abstract

Conductive copper nanoinks can be used as a low-cost replacement for silver and gold nanoinks that are used in inkjet printing of conductive patterns. We describe a high-throughput, simple, and convenient method for the preparation of copper nanoparticles in aqueous solution at room temperature. Copper acetate is used as the precursor, hydrazine as the reducing agent, and short chain carboxylic acids as capping agents. The concentration of the carboxylic acid plays a key role in the preparation of such copper nanoparticles. Stable copper nanoparticles with a diameter of less than 10 nm and a narrow size distribution were prepared when high concentrations of lactic acid, citric acid, or alanine were used. Thermogravimetric analysis results showed that any lactic acid or glycolic acid adsorbed on the surface of the copper nanoparticles can be removed at a relatively low temperature, especially, glycolic acid, which can be removed from the surface at about 125 °C. Highly conductive copper films prepared using lactic acid and glycolic acid as capping agents were obtained by drop coating a copper nanoparticle paste onto a glass slide followed by low temperature sintering. The electrical resistivity of the copper film using glycolic acid as the capping agent was 25.5 ± 8.0 and 34.8 ± 9.0 μΩ·cm after annealing at 150 and 200 °C for 60 min under nitrogen, respectively. When lactic acid was used as the capping agent, the electrical resistivity of the copper films was 21.0 ± 7.0 and 9.1 ± 2.0 μΩ·cm after annealing at 150 and 200 °C for 60 min under nitrogen, respectively, with the latter being about five times greater than the resistivity of bulk copper (1.7 μΩ·cm).

As a promising candidate to replace the brittle and expensive transparent indium tin oxide (ITO) conductor, the use of silver nanowire (AgNW) networks still involves issues such as high-temperature post-treatments and poor substrate adhesion for industrial application. Here a room-temperature soldering and one-step solution method is developed to achieve high-performance Ag nanowire transparent conductive films (TCFs). A nonconductive binder is prepared from poly(dopamine) and alginic acid which contains abundant catechol and carboxylic acid functional groups. The drying of the binder on the Ag nanowire percolation networks induces tighter contact among the nanowires and strong adhesion to the substrate, simultaneously enhancing the electrical and mechanical properties without a high-temperature annealing process. As a result, a highly conductive and bendable AgNW film is demonstrated on a low-cost polyethylene glycol terephthalate (PET) substrate, showing an 89% optical transmittance at λ = 550 nm and a sheet resistance of 16.3 Ohm sq(-1). Its optical and electrical performances are superior to those obtained from the reported indium tin oxide (ITO) films. Moreover, the AgNW film exhibits strong adhesion to the substrate, maintaining its conductivity after 100 tape tests, and it still resists the tape test even after exposure to solvent for several hours. Most importantly, the film shows good reliability during long-term 85 °C/85% RH (relative humidity) aging, which has been rarely investigated although it is a critical requirement for industrial application. The advanced and wide-ranging features of the prepared AgNW film greatly contribute to its use as a transparent electrode in multifunctional flexible electronic devices.

No abstract