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Alteration in the environmental conditions will cause a reversed reaction between o/w emulsion and w/o emulsion that has similar advantages of different liquids form on the reversible invert emulsion. The reversible phase inversion of the emulsion has a benefit of dealing with drilling cutting, so the reversible invert emulsion also can be thought used as a drilling fluid. The phase inversion from w/o emulsion to o/w emulsion can be divided into three stages. They are w/o emulsion, w/o/w emulsion, and o/w emulsion. In the w/o emulsion stage, the structure appeared among water droplets when the percentage of the HCl solution (5%) was less than 0.375%. In the w/o/w emulsion stage, the structure among water droplets existed at the beginning of this stage; however, the internal phase and the external phase can interchange their positions during the process. In the third stage, the structures among droplets of the emulsion would be broken and the degree of the dispersion of the oil droplet in the emulsion would increase. The changes in the microstructure, conductivity, electrical stability, standing stability, and the viscosity of the emulsion, which have edified among droplets in the process from w/o emulsion to o/w emulsion, were studied. The result of the microstructure microscopic observation agrees with the result of the electrical stability and viscosity experiments. Moreover, the internal phase and the external phase can interchange positions during the process.

Recently, the widespread use of nanocatalytic materials has contributed to an enormous improvement in the performance of energetic materials, especially, highly dispersed nanomaterials. However, the lack of quantitative methods for analyzing the dispersion of nanomaterials limits their further widespread use. Although various techniques such as scanning electron microscopy (SEM), transmission electron microscopy (TEM), etc. are used to analyze the relative dispersion of nanomaterials, it is not possible to quantitatively analyze their dispersion. Therefore, there has been an effort to develop new methods for the quantitative analysis of nanocatalytic materials. Fortunately, we were able to analyze the dispersion of nanocatalytic materials using the difference in their UV absorbance. More importantly, we established the corresponding difference equation to quantify the dispersion of nanocatalytic materials, which is capable of quantifying the dispersion of nano-Fe2O3 in nano-Fe2O3–ultrafine AP composites. The accuracy of the difference equation was verified using a variety of techniques and the desired results were obtained. Based on the above conclusions, the quantitative analysis method for the dispersion of nanomaterials that we established is expected to be widely used and promote the development of energetic materials. [ABSTRACT FROM AUTHOR]

The rapid growth of global energy demand necessitates high-performance water-based drilling fluids (WDFs) with excellent-plugging performance in the deep excavation of shale gas formation. Herein, we report an organic-inorganic nanocomposite (NS-D) as a plugging agent in WDFs to plug the nanoporous of shale and abate the hydration expansion of shale by integrating the advantages of inorganic and polymer nano plugging agents. The results of Fourier Transform infrared spectroscopy (FTIR) and proton nuclear magnetic resonance (H-NMR) revealed that NS-D had been successfully obtained. Additionally, thermogravimetric analysis (TGA) showed that the thermal degradation temperature of NS-D occurred after 354 °C. The results of plugging theory analysis showed that the presence of rich amide groups and rigid material silica not only made NS-D adhere to shale efficiently by hydrogen bonding, but also firmly blocked the nanoporous of shale. The plugging ability was evaluated by pressure transfer test and nitrogen adsorption test. The results showed that WDFs with NS-D can significantly improve plugging efficiency and reduce fluid invasion. On the other hand, NS-D sharply abated the fluid loss of WDFs due to its positive plugging performance. The filtrate volume of WDFs decreased by 90.5% and 88.3%, respectively, before and after hot rolling at 150°C for 16 h. Moreover, the plugging performance of NS-D for WDFs was significantly better than polymer plugging agent crosslinked polyacrylamide microspheres and inorganic plugging agent silica nanoparticles. This work provides a novel strategy to plug the nanoporous of shale in the process of shale gas exploration. [ABSTRACT FROM AUTHOR]

Inour previous work, the extractive dividing-wall column (EDWC)was proved to be a promising energy-saving method for methylal/methanolazeotrope separation because it offered about an 8.3% energy savingover the corresponding conventional extractive distillation columns.We also have explored two effective composition control structuresfor the stabilization of the EDWC previously. However, the compositioncontrol needs online composition analyzers which are usually expensive,require high maintenance, and introduce large lags. Therefore, itis highly desirable to avoid the use of composition analyzers to economicallygain this energy-saving potential. In this work, the use of temperaturecontrol instead of composition control for the EDWC process is investigatedto overcome the above drawbacks. Several control structures are developedon the basis of singular value decomposition (SVD) analysis. Two temperaturecontrol structures with an adjustable vapor split are proposed first.Dynamic simulations show that the structure can handle feed disturbanceseffectively, except for 20% changes in methanol or water concentrations.Then, a differential temperature control is further developed. Dynamicsimulations demonstrate that this structure reduces the offsets inmethanol product purities. Moreover, several group comparisons ofdynamic responses are demonstrated to confirm the feasibility andsuperiority of temperature control for stabilizing the EDWC process. [ABSTRACT FROM AUTHOR]

Recently, the widespread use of nanocatalytic materials has contributed to an enormous improvement in the performance of energetic materials, especially, highly dispersed nanomaterials. However, the lack of quantitative methods for analyzing the dispersion of nanomaterials limits their further widespread use. Although various techniques such as scanning electron microscopy (SEM), transmission electron microscopy (TEM), etc . are used to analyze the relative dispersion of nanomaterials, it is not possible to quantitatively analyze their dispersion. Therefore, there has been an effort to develop new methods for the quantitative analysis of nanocatalytic materials. Fortunately, we were able to analyze the dispersion of nanocatalytic materials using the difference in their UV absorbance. More importantly, we established the corresponding difference equation to quantify the dispersion of nanocatalytic materials, which is capable of quantifying the dispersion of nano-Fe 2 O 3 in nano-Fe 2 O 3 -ultrafine AP composites. The accuracy of the difference equation was verified using a variety of techniques and the desired results were obtained. Based on the above conclusions, the quantitative analysis method for the dispersion of nanomaterials that we established is expected to be widely used and promote the development of energetic materials.

Herein, we fabricated a ternary photocatalyst composed of CaFe 2 O 4 , multiwalled carbon nanotubes (CNTs) and graphitic carbon nitride (g-C 3 N 4 ) via a simple hydrothermal route. CaFe 2 O 4 acted as a photosensitizer medium and the CNT acted as a co-catalyst, which remarkably enhanced the photocatalytic performances of g-C 3 N 4 towards the degradation of hexavalent chromium (Cr(vi)) and the antibiotic tetracycline (TC) under visible light irradiation. To investigate the morphological and topological features of the photocatalyst, field-emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM) analyses were performed. The surface properties and oxidation state of the CaFe 2 O 4 /g-C 3 N 4 /CNT composite were determined by X-ray photoelectron spectroscopy (XPS). The recombination rate of the charge carriers and the band gap values of the as-synthesized catalysts were analyzed by photoluminescence spectroscopy (PL) and diffused reflectance spectroscopy (UV/Vis DRS) studies, respectively. Besides the degradation reactions, the high hydrogen production rate of 1050 μmol h -1 under visible light using the CaFe 2 O 4 /g-C 3 N 4 /CNT composite loaded with 5 wt% CNT was observed. The superior photocatalytic performances of the CaFe 2 O 4 /g-C 3 N 4 /CNT composite can be ascribed to the effective heterojunction formed between g-C 3 N 4 and the CaFe 2 O 4 matrix, in which the CNT act as a conducting bridge in the system, promoting the production of photoinduced charge carriers in the semiconductor system. Finally, the plausible photocatalytic mechanism towards the degradation of pollutants and hydrogen production was discussed carefully., Competing Interests: There are no conflicts of interest in this paper., (This journal is © The Royal Society of Chemistry.)

The coupling of solid-phase extraction (SPE) using bamboo charcoal (BC) as an adsorbent with a monolithic column-high performance liquid chromatography (MC-HPLC) method was developed for the high-efficiency enrichment and rapid determination of 16 polycyclic aromatic hydrocarbons (PAHs) in water. Key influence factors, such as the type and the volume of the elution solvent, and the flow rate and the volume of the sample loading, were optimized to obtain a high SPE recovery and extraction efficiency. BC as an SPE adsorbent presented a high extraction efficiency due to its large specific surface area and high adsorption capacity; MC as an HPLC column accelerated the separation within 8 min because of its high porosity, fast mass transfer, and low-pressure resistance. The calibration curves for the PAHs extracted were linear in the range of 0.2-15 µg/L, with the correlation coefficients (r(2)) between 0.9970-0.9999. This method attained good precisions (relative standard deviation, RSD) from 3.5 to 10.9% for the standard PAHs I aqueous solutions at 5 µg/L; the method recoveries ranged in 52.6-121.6% for real spiked river water samples with 0.4 and 4 µg/L. The limits of detection (LODs, S/N = 3) of the method were determined from 11 and 87 ng/L. The developed method was demonstrated to be applicable for the rapid and sensitive determination of 16 PAHs in real environmental water samples.