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[Display omitted] • Proposed a strategy for developing a low-temperature oil-in-water demulsifier. • Increasing the aromaticity and polarity could enhance the effectiveness and rate of demulsifiers. • The role of structure and interfacial activity in demulsifiers has been discussed. • Poly (amino acids) demulsifier performs well in terms of efficiency and rate at room temperatures. To improve the universality and efficiency of polymer demulsifiers at low temperatures, a unique type of biodegradable poly (ε-carbobenzyloxy-L-lysine) - block -poly (L-phenylalanine) (PZLL- b -PPA) demulsifier with stronger polarity and higher aromaticity was developed. The molecular structure and weight of PZLL- b -PPA were determined using Fourier transform infrared (FT-IR) spectroscopy, 1H nuclear magnetic resonance hydrogen spectra (NMR) and gel permeation chromatography (GPC). A bottle test was used to evaluate the demulsification performance of PZLL- b -PPA with different block ratios, structure and interfacial activity. Numerous critical variables, such as demulsifier structure and dosage, pH levels, emulsion salinity, oil content and oil type, were carefully examined. The demulsification results showed that PZLL 5 - b -PPA 25 has excellent low-temperature demulsification capability and can effectively separate oil from water emulsions with different pH values (4.0 ∼ 11.0) and oil contents ranging from 1.0 ∼ 20.0 wt% within 2 min at room temperature. The best demulsification efficiency reached 99.98 %, with only 6.0 mg/L of residual oil in the separated water. The analysis of interfacial self-assembly behavior revealed that PZLL- b -PPA has a strong affinity for aromatic molecules and exhibits high interfacial activity. The quantum chemical calculation indicated that the main chain polyamide skeleton of PZLL- b -PPA has a stronger interaction for asphaltene, resin and naphthenic acid molecules than conventional oxygen-containing skeleton polymers. Furthermore, the microscopy analysis indicated that PZLL- b -PPA has excellent capacity for flocculation and coalescence of oil droplets in an O/W emulsion. As a result, when PZLL- b -PPA is added to the emulsion, it can quickly migrate to the oil-water interface and interact with and displace the emulsion's stabilizers (asphaltenes and resins), promoting oil droplet coalescence and separation from water at low temperature. [ABSTRACT FROM AUTHOR]

Functionalized carbon black (F-CB) nanoparticles were synthesized by covalently grafting the polyvinyl alcohol on carbon black (CB) surfaces and used as demulsifier to separate the oil from the emulsified oily wastewater. The bottle test showed that the residual oil content in the separated water was as low as ∼50 mg/L corresponding to a demulsification efficiency of about 99.90% at an optimal condition within a few minutes. It was believed that the surface wettability of the carbon black could be tuned by modifying with the PVA molecules, which enables the F-CB nanoparticles to be readily migrated to the oil/water interface and have the opportunity to interact with and/or displace the stabilizers of the emulsion. As a result, the demulsification process was accomplished with the coalescence of the oil droplets promoted by the F-CB nanoparticles. The interaction behavior between F-CB nanoparticles and asphaltenes was investigated by quantum chemical calculations. The results showed that the F-CB nanoparticles have strong interaction with the asphaltene molecules in form of π−π and θ−π forces. The findings in present study are significant for understanding the demulsification mechanism and also provide a novel demulsifier for the demulsification of emulsified oily wastewater. [ABSTRACT FROM AUTHOR]

• Co-, Ni-, and Ru-based catalysts show good primary amine selectivity. • The competitive adsorption of FAM and H 2 suppresses its excessive hydrogenation. • The adsorption energies of FAM on Co, Ni, and Ru surfaces are calculated. • The activation energy is not the key factor in determining the FAM hydrogenation. In addition to the main reaction, understanding the structure-activity relationship in the side reactions is another important goal for catalysis science. In this work, the catalytic activities and selectivities of various active metals were studied in the reductive amination of furfural (FAL). Compared with Co- and Ni-based catalysts, the excessive hydrogen of furfurylamine (FAM) was found over Ru-based catalysts at much higher reaction temperature (130 vs. 50 °C). Moreover, the evaluation of FAM hydrogenation undoubtedly substantiated the intimate relationship between H 2 reaction pressure and catalytic activity. Combining the theoretical and experimental results, it is clearly verified that the active metal determines the excessive hydrogen of FAM by affecting the competitive adsorption of FAM and H on the active sites. [Display omitted] [ABSTRACT FROM AUTHOR]

Graphene oxide (GO) nanosheets have been experimentally proved to be a highly efficiency, rapid and universal demulsifier to break up the crude oil-in-water emulsion and/or the emulsified oily waste water in our previous study. To recycle the GO nanosheets and avoid the possible contamination of GO for crude oil, in this work, the magnetic graphene oxide (M-GO) was successfully synthesized and used for separating oil/water emulsions. Demulsification tests indicated that M-GO could separate the oil/water emulsions within a few minutes and recycle 6–7 times without losing its demulsification capability. The residual oil content in the separated water was as low as ∼10 mg/L, corresponding to a demulsification efficiency of 99.98% at an optimal dosage. Quantum chemical calculation results indicated that the π-π/σ-π interactions between GO materials and asphaltene molecules are the major driven forces for the high demulsification performance of M-GO nanosheets. This work not only provides a promising demulsifies to demulsify the crude oil-in-water emulsion or the oily wastewater but also give a deep understanding on the intrinsic interaction between demulsifiers and asphaltenes. [ABSTRACT FROM AUTHOR]

[Objective] To study the influence of different processing methods to the quality of Cynanchum paniculatum, (Bge.) Kitaga. [Methods] To carry out comparing test of different drying and cleaning methods for Cynanchum paniculatum (Bge.) Kitaga. For comparing test of different drying methods, the content of paeonol, the active ingredient, was used as index to evaluate the effects of different processing technics on medicinal material quality. [Results] The drug quality can't be declined after the drug is washed quickly. Oven drying at low temperature is superior to traditional drying method. [Conclusions] The optimum processing method in producing area is that the drug is washed quickly, then drying by oven at the temperature gradient of 40↠50↠60 °C. [ABSTRACT FROM AUTHOR]

In this paper, the adsorption of CO on FexCuy (x + y = 3) clusters was studied by BPW91 method, and all conceivable geometries and electronic states of carbonyl complexes were explored. The results show that bimetallic clusters tend to have higher stepwise CO adsorption energy than corresponding pure clusters, and the adsorption capacity of FeCu2 with CO is substantially larger than that of other carbonyl complexes. The CO bond length and CO stretching indicated that the CO bond is significantly weakened in Fe3(CO)6. In addition, the frontier molecular orbital theory was used to analyze the effect of the second element in the ligand reactions, which also confirmed that the reactions of CO with bimetallic clusters are easier than that of pure cluster systems. Finally, the energy gaps of HOMO and LUMO were used to explore the reactive activity of carbonyl complexes, and it was found that the Fe2Cu(CO)1 has lower energy gap than that of other carbonyl complexes. This suggests that it may be possible to tune bimetallic cluster to get higher activity carbonyl complexes in the reactions. [ABSTRACT FROM AUTHOR]

Motivated by the prominent catalytic performance and durability of nanoalloy catalysts, the Pd-based bimetallic nanoalloy catalysts were prepared using an aqueous reduction method. The Fe-Pd bimetallic nanoalloy catalyst (nano-Fe/Pd) demonstrated 98.4% yield and 99.7% selectivity for the unsaturated 1,4-dicarboxylic acid diesters. Moreover, the inductively coupled plasma (ICP) analysis shows that the Pd leaching of the catalyst can be effectively suppressed by alloying Fe atoms into the Pd crystal lattice for acetylene dicarbonylation. The detailed catalyst structure and morphology characterization demonstrate that introducing Fe into the Pd nanoparticles tunes the electronic–geometrical properties of the catalyst. Theoretical calculations indicate that the electrons of Fe transfer to Pd in the nano-Fe/Pd catalyst, enhancing activation of the C≡C bond in acetylene and weakening CO absorption capacity on catalyst surfaces. Alloying Fe into the Pd nanocatalyst effectively inhibits active metal leaching and improves catalyst activity and stability under high-pressure CO reactions. [ABSTRACT FROM AUTHOR]

Amphiphilic aromatic poly (amino acids) polymers were designed as biodegradability demulsifiers with higher aromaticity, stronger polarity, and side chain-like combs. The effects of demulsifier dosage, structural characteristics and emulsion properties such as pH, salinity, and oil content on the demulsification efficiency were investigated. The results show that the poly (L-glutamic-benzyl ester)-block-poly (L-phenylalanine) (PBLG 15 - b -PPA 15) as the demulsifier can remove more than 99.97% of the oil in a 5.0 wt% oil-in-water (O/W) emulsion at room temperature within 2 min. The poly (L-tyrosine)-block-poly (L-phenylalanine) (PTyr 15 - b -PPA 15) with environmental durability demonstrates high effectiveness, universality, and demulsification speed. It achieves a remarkable demulsification efficiency of up to 99.99% for a 20.0 wt% O/W emulsion at room temperature. The demulsification mechanism indicates that demulsifiers have sufficient interfacial activity can quickly migrate to the oil-water interface after being added to the emulsions. Additionally, when demulsifiers are present in a continuous phase in the molecular form, their "teeth" side chains are beneficial for increasing coalescence and flocculation capacities. Furthermore, according to the Density Functional Theory (DFT) calculations, enhancing the intermolecular interactions between demulsifiers and the primary native surfactants that form an oil-water interfacial film is a more efficient approach to reducing demulsification temperature and improving demulsification efficiency and rate. [Display omitted] • Proposed a strategy for developing a low-temperature oil-in-water demulsifier. • Improving the polarity and aromaticity of demulsifiers enhances their performance. • Aromatic poly (amino acids) demulsifiers perform well at low temperatures. • The intermolecular interactions determine the deoiling temperature and efficiency. [ABSTRACT FROM AUTHOR]

The integrated synergistic effect of the ligand and the strong metal-support interaction (SMSI) effectively improves the selectivity and stability of heterogeneous Pd-based catalysts for acetylene dicarbonylation under high-pressure CO conditions. [Display omitted] • Stabilizing the catalytic active site Pdδ+ for acetylene dialkoxycarbonylation. • Oxygen-containing functional groups of AC provide anchoring sites for stabilize active Pd2+ ions. • The coordination of I- not only accelerates the reaction but also stabilizes the catalyst. The support and ligand play a crucial role in regulating the catalytic performance, selectivity, and stability of heterogeneous catalysis. Herein, activated carbon (AC) supported palladium (Pd) catalysts (2.0 wt%) were prepared by impregnation for acetylene dicarbonylation. The oxygen-containing groups on the surface of the AC support were modulated by nitric acid (HNO 3) to investigate metal–support interactions on the catalytic performance and stability of the Pd/AC. The characterization of the chemical composition and structure of the supports and catalysts demonstrates that high concentrations of oxygen-containing groups on the surface of the carbon support lead to the fine dispersion of Pd nanoparticles. Notably, the finely dispersed Pd/AC 70 catalyst exhibited good activity and stability for acetylene dicarbonylation under high-pressure CO conditions after several rounds of regeneration. Furthermore, operational parameters including the type of support, co-catalyst (KI), and reaction time and temperature were identified for their impact on the reaction. It was found that I- anions serve as a co-catalyst and can ligate with Pd species, thereby preventing the leaching of Pd and improving reaction selectivity. This study presents a straightforward and sustainable modulation strategy to improve the dispersion of active metals, as well as to prevent the leaching and sintering of these metals during high-pressure CO reactions. [ABSTRACT FROM AUTHOR]

Fe(III) has been proved to be a more effective oxidant than dissolved oxygen at ambient temperature, however, the role of Fe(III) in pyrite acidic pressure oxidation was rarely discussed so far. In this paper, in-situ electrochemical investigation was performed using a flow-through autoclave system in acidic pressure oxidation environment. The results illustrated that increasing Fe(III) concentrations led to raising in redox potential of the solution, and decreased passivation of pyrite caused by deposition of elemental sulfur. Reduction of Fe(III) at pyrite surface was a fast reaction with low activation energy, it was only slightly promoted by rising temperatures. While, the oxidation rate of pyrite at all investigated Fe(III) concentrations increased obviously with rising temperatures, the anodic reaction was the rate-limiting step in the overall reaction. Activation energy of pyrite oxidation decreased from 47.74 to 28.79 kJ/mol when Fe(III) concentration was increased from 0.05 to 0.50 g/L, showing that the reaction kinetics were limited by the rate of electrochemical reaction at low Fe(III) concentrations, while, it gradually turned to be diffusion control with increasing Fe(III) concentrations. [ABSTRACT FROM AUTHOR]

The synthesis and X-ray structure of a novel glycoluril derivative are described. The crystal of the glycoluril derivative is obtained by slow evaporation in a refrigerator at about 5 °C. X-ray crystallographic analysis revealed that the compound crystallized in an unusual as conformation instead of the usual clip-shaped aa conformation. Structural analysis shows that the solvation effect, hydrogen bonding, and space-occupying effect influenced the crystallization conformation of the derivative. The X-ray crystallographic analysis in this work provides additional crystallographic evidence of the as conformation of the 3U glycoluril derivative and shows the effect of solvent water on the conformational behavior. [ABSTRACT FROM AUTHOR]

Carbon nano-materials have been widely used in many fields due to their electron transport, mechanics, and gas adsorption properties. This paper introduces the structure and properties of carbon nano-materials the preparation of carbon nano-materials by chemical vapor deposition method (CVD)—which is one of the most common preparation methods—and reaction simulation. A major factor affecting the material structure is its preparation link. Different preparation methods or different conditions will have a great impact on the structure and properties of the material (mechanical properties, electrical properties, magnetism, etc.). The main influencing factors (precursor, substrate, and catalyst) of carbon nano-materials prepared by CVD are summarized. Through simulation, the reaction can be optimized and the growth mode of substances can be controlled. Currently, numerical simulations of the CVD process can be utilized in two ways: changing the CVD reactor structure and observing CVD chemical reactions. Therefore, the development and research status of computational fluid dynamics (CFD) for CVD are summarized, as is the potential of combining experimental studies and numerical simulations to achieve and optimize controllable carbon nano-materials growth. [ABSTRACT FROM AUTHOR]