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Due to its quite high theoretical specific-energy density, FeF2 nanomaterial is a good candidate for the cathode material of high-energy lithium-ion batteries. The preparation of FeF2 nanomaterial is very important for its application. At present, the preparation process mostly involves high temperature and an inert atmosphere, which need special or expensive devices. It is very important to seek a low-temperature and mild method, without the need for high temperature and inert atmosphere, for the preparation and following application of FeF2 nanomaterial. This article reports a novel sugar-assisted solvothermal method in which the FeF3∙3H2O precursor is reduced into FeF2 nanomaterial by carbon derived from the dehydration and condensation of sugar. The obtained FeF2 nanomaterials are irregular granules of about 30 nm, with inner pores inside each granule. Electrochemical tests show the FeF2 nanomaterial's potential as a lithium-ion battery cathode material. [ABSTRACT FROM AUTHOR]

• Packer rubber thermal aging experiments were carried out and the setting model of packer rubber tube was established. • It was pointed out that the Yeoh model was more suitable for the material constitutive of the packer tube under high temperature conditions. • Analyzed the sealing performance and strength behavior of packer in high temperature condition. • Sensitivity analysis of packer rubber key parameters was carried out. With the exploration and development of high temperature oil and gas wells, high temperature working conditions have gradually become the new normal state of drilling and completion engineering. Due to the high temperature, the failure of the packer rubber seal and the crushing seriously affect the normal development of oil and gas fields. This paper, aiming at the seal failure of rubber tude at high temperature, the parameters of the constitutive model of rubber tude were studied through the rubber thermal aging experiments. And the finite element calculation model of the packer under the sitting condition was established. The effect of temperature load on the sealing performance and strength behavior of packer rubber was studied. The effect of key parameters of the rubber tube-casing gap δ , the dip angle α of the adjacent rubber tube contact surface and the initial setting load on the sealing performance of the packer under high temperature conditions were analyzed. The findings show that the Yeoh model is more suitable to describe the high temperature material constitutive structure of the packer tube; At high temperature, the larger the gap δ is, the worse the packer sealing performance is; While 12–24° for angle α , sealing performance is better; The suggested initial setting limit load for packer rubber tube safety seal is 68–76 kN. The research work in this paper is of great significance to the design of packer rubber tube structure and its adaptability to high temperature conditions. [ABSTRACT FROM AUTHOR]

[Display omitted] • PEI/ZIF-67 membranes were prepared for PM removal under high RH and temperature. • PEI/ZIF-67-2 membrane had removal efficiency of 98.68% for PM 2.5 and 99.09% for PM 10. • The membrane showed superior performance under high temperature (200 °C) and RH (90%). Efficient filtration of particulate matter (PM) is the major goal for various air cleaning technologies. However, most existing air filters are conducted at room temperature with a relative humidity (RH) of around 45%, ignoring the fact that many operate under high temperature and RH above 90%. Herein, we report the successful fabrication of a polyetherimide (PEI)/zeolitic imidazolate framework-67 (PEI/ZIF-67) nanofibrous membranes using electrospinning technology, which showed steady and high efficiency PM filtration performance under a high temperature of 200 °C and RH of 90%. Compared with pure PEI nanofibrous membranes, the resultant nanofibrous membranes containing 2 wt% of ZIF-67 showed an increase of 112% and 109% in removal efficiency of PM 2.5 and PM 10, respectively, which are attributed to synergistic effects of enhanced surface roughness, strengthened electrostatic interaction and small pore size by the introduction of the ZIF-67. More importantly, after operating under a high RH of 90% over 70 h, the removal efficiency of such PEI/ZIF-67 nanofibrous membranes remained almost unchanged. Density functional theory calculations suggested that the ZIF could efficiently reduce water adsorption and thereby avoid the PEI being damaged by water. Such a finding demonstrated that the ZIFs should be promising candidates for designing highly stable nanofibrous membranes under extremely high RH and high temperature conditions. [ABSTRACT FROM AUTHOR]