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N-doped porous carbon with the large interlayer spacing needed for Na + intercalation is synthesized by a method of self-etching and graphitization of bimetallic MOF-based composites and shows good electrochemical performance for Na-ion batteries.

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To investigate the influence of structure variables of polymeric additives on the pour-point depression and rheological behavior of waxy crude oil, maleic anhydride co-polymer and its derivatives with different polar and/or aromatic pendant chains were designed and synthesized. All prepared additives were characterized by Fourier transform infrared (FTIR) spectroscopy and gel permeation chromatography (GPC). The pour-point and rheological properties of Changqing (CQ) crude oil with a low asphaltene content before and after additive beneficiation were studied in detail. Differential scanning calorimetry (DSC) and polarizing light microscopy were employed to gain insight on the interactions between such additives and wax crystals. The results are encouraging and showed that all four polymeric additives exhibited good efficiency as flow improvers in CQ crude oil. The reduction of pour-point and rheological parameters after additive addition largely related to the polymer structure. The polymer containing aromatic units showed the best performance, which could depress the pour point by 19 °C and decrease the yield stress as well as viscosity to a large extent.

A liquid paraffin-water emulsion was investigated using layered double hydroxide (LDH) particles and sodium dodecyl sulfate (SDS) as emulsifiers. Both emulsifiers are well-known to stabilize oil-in-water (o/w) emulsions. Surprisingly, a double phase inversion of the emulsion containing LDH particles is induced by the adsorption of SDS. At a constant LDH concentration, the emulsion is o/w type when SDS concentrations are low. At intermediate SDS concentrations, the first emulsion inversion from o/w to w/o occurs, which is attributed to the enhanced hydrophobicity of LDH particles caused by the desorption of the second layer of surfactant, leaving a densely packed SDS monolayer on the LDH exterior surfaces. The second inversion from water-in-oil (w/o) to o/w occurs at higher SDS concentrations, which may be due to the competitive adsorption at the oil/water interfaces between the LDH particles modified by the SDS bilayers and the free SDS molecules in the bulk solution, but the free SDS molecules dominate and determine the emulsion type. Laser-induced fluorescent confocal micrographs clearly confirm the adsorption of LDH particles on the surfaces of the initial o/w and intermediate w/o emulsion droplets, whereas no LDH particles were adsorbed on the final o/w emulsion droplet surfaces. Also, transmission electron microscopy (TEM) observations indicate that the shape of the final o/w emulsions is similar to that of the monomeric SDS-stabilized emulsion but different from that of the initial o/w emulsions. The adsorption behavior of SDS on LDH particles in water was investigated to offer an explanation for the emulsion double phase inversion. The zeta potential results show that the particles will flocculate first and then redisperse following surfactant addition. Also, X-ray diffraction (XRD) measurements indicate that SDS adsorption on the LDH interior surfaces will be complete at intermediate concentrations.

In this paper, Cu 2+ doped ceria nanospheres were produced from a one-step hydrothermal synthesis. The products were characterized in detail at the structural and electronic level by X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy, high-resolution transmission electron microscopy (HRTEM) and X-ray photoelectron spectroscopy (XPS). XRD results revealed that the doped ceria was free of other crystallographic phases, such as CeOHCO 3 , CuO or Cu 2 O. By introducing various reactant molar ratios of Cu : Ce, the composition can be freely manipulated. The H 2 -TPR measurement shows the improved reduction behaviour of the doped ceria samples prepared by us. A preliminary CO catalytic oxidation experiment indicated that the Cu 2+ doped ceria samples showed strikingly higher catalytic activity, due to the intrinsic surface defects of the samples. In addition ceria doped with other transition metal ions (M 2+ ), such Co 2+ , Ni 2+ and Mn 2+ , has also been successfully prepared. Considering this one-step synthesis as a versatile approach, it can be further extended to other binary metal oxide systems.