Maoxiang Jing

Highly bendable, transparent, and conductive AgNWs-PET films fabricated via transfer-printing and second pressing technique

Highly bendable, transparent, and conductive films composed of silver nanowires (AgNWs) network and polyethylene terephthalate (PET) substrate were prepared by a transfer-printing and second pressing technique using different dimensional AgNWs. The performance of the films as a function of optical and bending performances with low sheet resistance is enhanced, by controlling the diameter and length of AgNWs, area density, and the mechanical press condition. With the optimized mean diameter (D) ~40xa0nm and length (L) ~15xa0μm, the as-prepared AgNWs-PET film possesses a sheet resistance of 11.5xa0Ω/sq, transmittance (T550) of 93.4xa0%, and haze of 1.23xa0%. The AgNWs-PET film with the second press treatment at 10xa0MPa for 20xa0s shows a very excellent bending performance, with less than 8xa0% change of the sheet resistance after 46,000 bending cycles without any additional conductive polymer. This highly bendable, transparent, and conductive film is suitable for emerging technologies such as flexible display, electrical skins, and bendable solar cells.

Efficient Removal of Dyes from Aqueous Solution by Mesoporous Nanocomposite Al2O3/Ni0.5Zn0.5Fe2O4 Microfibers

AbstractA novel mesoporous, nanocomposite, magnetically separable adsorbent, namely activated alumina (γ-Al2O3)/ferrite (Ni0.5Zn0.5Fe2O4) microfibers have been successfully prepared by the sol–gel process. These nanocomposite γ-Al2O3/Ni0.5Zn0.5Fe2O4 microfibers are formed after calcination of the precursor at 450xa0°C for 3xa0h, and characterized with high aspect ratios and uniform diameters of 1–10xa0μm. In the nanocomposite γ-Al2O3/Ni0.5Zn0.5Fe2O4 microfibers, the spherical γ-Al2O3 particles are homogeneously embedded on the microfiber. Their specific surface areas and magnetic properties are significantly influenced by the γ-Al2O3 content and calcination conditions. With the designed γ-Al2O3 mass fraction of 0.2 and the calcination temperature of 550xa0°C, the γ-Al2O3/Ni0.5Zn0.5Fe2O4 microfibers possess a high specific surface area of 118.3xa0m2/g and saturation magnetization (Ms) of 20.4xa0Am2xa0kg−1, respectively. The adsorption behaviors of the nanocomposite γ-Al2O3/Ni0.5Zn0.5Fe2O4 microfibers were examined using the Congo red and methyl blue dyes as the adsorbate. The adsorption kinetics, effects of the adsorbent dosage and solution pH, adsorption isotherms, and regeneration of the microfiber adsorbents were investigated. The pseudo-second-order model can be used to describe the adsorption kinetics. The resultant isotherm data are well fitted by the Temkin model, implying that the dyes adsorption on the γ-Al2O3/Ni0.5Zn0.5Fe2O4 microfibers is a multilayer adsorption combined with some degrees of chemical interactions. Considering the simple synthesis process, high adsorption and unique magnetic property, these mesoporous, magnetic, nanocomposite γ-Al2O3/Ni0.5Zn0.5Fe2O4 microfibers can be used as a highly efficient, fast, and convenient adsorbent for dyes removal.Highlightsn The magnetic mesoporous Al2O3/Ni0.5Zn0.5Fe2O4 microfibers were synthesized.Adsorption kinetics and adsorption isotherms were investigated.The separation, regeneration, and adsorption efficiency were enhanced.FigureThe novel mesoporous, magnetic, nanocomposite-activated alumina (γ-Al2O3)/ferrite (Ni0.5Zn0.5Fe2O4) microfiber adsorbents can be used as an efficient, fast, and convenient tool for dyes removal from wastewater.

Effects of reduced graphene on crystallization behavior, thermal conductivity and tribological properties of poly(vinylidene fluoride)

The reduced graphene/poly(vinylidene fluoride) nanocomposite films were prepared by the solution casting-thermal reduction process using graphene oxide and poly(vinylidene fluoride) resin. The results show that with the presence of reduced graphene nano sheets in the nanocomposite, the structure of poly(vinylidene fluoride) tends to transform from α- to β-phase and the β-phase fraction and its crystallinity are largely affected by the reduced graphene content. The thermal conductivity of poly(vinylidene fluoride) can be effectively improved by the reduced graphene nano sheets introduction and when the reduced graphene content increased to about 10.0u2009wt%, it is about two times higher than the pure poly(vinylidene fluoride), due to the excellent thermal conductivity of reduced graphene and formation of thermal conductive networks. With comparison of the pure poly(vinylidene fluoride), the reduced graphene/poly(vinylidene fluoride) nanocomposite films show a better tribological property at a low reduced graphene content (below 4.0u2009wt%), mainly owing to the lubricant and heat spreading effects of reduced graphene nano sheets. The friction coefficient and wear rate for 0.75u2009wt% reduced graphene/poly(vinylidene fluoride) nanocomposite film compared to the pure poly(vinylidene fluoride) are improved by 41.2% and 49.4%, respectively.

Preparation, magnetic and electrochemical properties of xCuFe2O4/CuO composite microfibers

The nanocrystalline xCuFe2O4/CuO (xxa0≤xa050xa0%) composite microfibers with a fiber diameter about 0.5–2xa0μm, length of tens to hundreds of micrometers were prepared by the sol–gel process. The content of CuFe2O4 on the magnetic and electrochemical properties of CuFe2O4/CuO composite microfibers was investigated. The microfibers were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, vibrating sample magnetometer and X-ray photoelectron spectroscopy analysis. At the calcination temperature of 900xa0°C, with a content of copper ferrite phase about 10xa0%, the optimized porous composite microfibers are obtained. These composite microfibers show a typical soft magnetic property, and the specific saturation magnetization is related to the calcination temperature as well as CuFe2O4 content, with a steady Mr/Ms value of 0.64 at CuFe2O4 content (x) range from 10 to 50xa0%. The electrochemical properties of the as-prepared microfibers were investigated by cyclic voltammetry method, and the results show these composite microfibers are good electrode materials for supercapacitors. The 10xa0% CuFe2O4/CuO composite microfibers have the highest specific capacity of 81.7 F/g, with almost no decay after 200 cycles.Graphical Abstract

Catalytic Performance of La0.8K0.2Fe0.7Mn0.3O3 with Pt-Substitution in B-Site for Removal of NOx and Soot.

Nanocrystalline, porous, perovskite La0.8K0.2Fe0.69Mn0.3Pt0.01O3, La0.8K0.2Fe0.67Mn0.3Pt0.03O3, La0.8K0.2Fe0.65Mn0.3Pt0.05O3 catalysts were prepared by the citrate-gel process. The optimized chemical composition La0.8K0.2Fe0.67Mn0.3Pt0.03O3 has a porous structure and it shows a good activity for soot combustion, with T20, T50 and T90 being 149, 367 and 409 °C, respectively. Furthermore, the La0.8K0.2Fe0.67Mn0.3Pt0.03O3-coated honeycomb ceramic device was prepared by the citrate-gel assisted dip-coating process and it has the effect of simultaneous removal of diesel soot and nitrogen oxides at the operational temperature range of 200 to 400 °C, with a NOx maximum conversion rate of 21.2%. It seems that the perovskite structure benefits the activity of low Pt content due to higher contribution of lattice oxygen and local changes in redox reaction.