A Novel Demulsifier with Strong Hydrogen Bonding for Effective Breaking of Water-in-Heavy Oil Emulsions.

In the heavy petroleum industry, the development of efficient demulsifiers for the effective breaking of interfacially active asphaltenes (IAA)-stabilized water-in-heavy oil (W/HO) emulsions is a highly attractive but challenging goal. Herein, a novel nitrogen and oxygen containing demulsifier (JXGZ) with strong hydrogen bonding has been successfully synthesized through combining esterification, polymerization and amidation. Bottle tests indicated that JXGZ is effectual in quickly demulsifying the IAA-stabilized W/HO emulsions; complete dehydration (100%) to the emulsions could be achieved in 4 min at 55 °C using 400 ppm of JXGZ. In addition, the effects of demulsifier concentration, temperature and time on the demulsification performance of JXGZ are systematically analyzed. Demulsification mechanisms reveal that the excellent demulsification performance of JXGZ is attributed to the strong hydrogen bonding between JXGZ and water molecules (dual swords synergistic effect under hydrogen bond reconstruction). The interaction of the "dual swords synergistic effect" generated by two types of hydrogen bonds can quickly break the non-covalent interaction force (π-π stacking, Van der Waals force, hydrogen bonds) of IAA at the heavy oil-water interface, quickly promote the aggregation and coalescence of water molecules and finally achieve the demulsification of W/HO emulsions. These findings indicate that the JXGZ demulsifier shows engineering application prospects in the demulsification of heavy oil-water emulsions, and this work provides the key information for developing more efficient chemical demulsifiers suitable for large-scale industrial applications.

Differences in the catalytic properties of Fe isotopes.

The significant differences in the catalytic properties caused by different 'isotopic catalysts' were discovered for the first time. The commonly purchased Fe2O3 is a 'mixture' of different Fe isotopic oxides which means the catalytic effect of Fe2O3 is theoretically a synthetical result of all isotopic compounds. In this work, the differences in catalytic properties of α-Fe2O3 with natural abundance ratio and separated isotopic α-Fe2O3 (α-54Fe2O3, α-56Fe2O3, and α-58Fe2O3) catalyzing thermal decomposition of ammonium perchlorate (AP) were investigated, and are mainly attributed to the difference in the charge distribution of the nuclei of different iron isotopes. The result suggests that isotope effects in different isotopes when utilized as catalysts are caused by nuclear morphology and the nuclear charge distribution. This study will serve as a base as well as an initiation for future studies of the isotopic catalyst.

High-efficiency 2D nanosheet exfoliation by a solid suspension-improving method.

Two-dimensional (2D) materials with mono or few layers have wide application prospects, including electronic, optoelectronic, and interface functional coatings in addition to energy conversion and storage applications. However, the exfoliation of such materials is still challenging due to their low yield, high cost, and poor ecological safety in preparation. Herein, a safe and efficient solid suspension-improving method was proposed to exfoliate hexagonal boron nitride nanosheets (hBNNSs) in a large yield. The method entails adding a permeation barrier layer in the solvothermal kettle, thus prolonging the contact time between the solvent and hexagonal boron nitride (hBN) nanosheet and improving the stripping efficiency without the need for mechanical agitation. In addition, the proposed method selectively utilizes a matching solvent that can reduce the stripping energy of the material and employs a high-temperature steam shearing process. Compared with other methods, the exfoliating yield ofhBNNSs is up to 42.3% at 150 °C for 12 h, and the strategy is applicable to other 2D materials. In application, the ionic conductivity of a PEO/hBNNSs composite electrolytes reached 2.18 × 10-4S cm-1at 60 °C. Overall, a versatile and effective method for stripping 2D materials in addition to a new safe energy management strategy were provided.

Preparation of Highly Porous Thiophene-Containing DUT-68 Beads for Adsorption of CO2 and Iodine Vapor.

Zirconium-based metal-organic frameworks (Zr-MOFs) have great structural stability and offer great promise in the application of gas capture. However, the powder nature of MOF microcrystallines hinders their further industrial-scale applications in fluid-phase separations. Here, Zr-based DUT-68 was structured into nontoxic and eco-friendly alginate beads, and the gas capture properties were evaluated by CO2 and volatile iodine. DUT-68 beads were synthesized via a facile and versatile cross-linked polymerization of sodium alginate with calcium ions. The composite beads keep the structural integrity and most of the pore accessibility of DUT-68. The resulting DUT-68@Alginate (2:1) porous bead processes a surface area of 541 m2/g and compressive strength as high as 1.2 MPa, and the DUT-68 crystals were well-dispersed in the alginate networks without agglomeration. The DUT-68@Alginate bead with a 60% weight ratio of MOFs exhibits a high carbon dioxide capacity (1.25 mmol/g at 273 K), as well as an excellent high adsorption capacity for iodine, reaching up to 0.65 g/g at 353 K. This work provides a method to construct thiophene-contained composite beads with millimeter sizes for the capture of gases in potential industrial applications.