The dynamic interfacial tensions (IFTs) of enhanced oil recovery (EOR) surfactant/polymer/organic alkali systems against a homologous series of alkanes have been investigated by a spinning drop interfacial tensiometer. Two organic alkalis with different molecular sizes, ethanolamine (EA) and diethanolamine (DEA), two surfactants with high interfacial activity, heavy alkyl benzenesulfonate (HABS) and petroleum sulfonate (SLPS), and two kinds of polymers, partly hydrolyzed polyacrylamide (HPAM) and hydrophobically modified polyacrylamide (HMPAM), were employed to study the real mechanisms controlling the IFT behavior. The experimental results show that the addition of organic alkali may affect the dynamic IFTs of surfactant solutions through different mechanisms. First, the possible reaction of organic alkali with the oil-soluble components in industrial surfactants will influence the surface active spices at the interface and enhance the dynamic behavior. Second, the hydrophilic–lipophilic balance (HLB) of the surfactant may vary, and the surfactant may become more water-soluble because of the ionization of oil-soluble components, especially for HABS. Finally, the organic counterion with larger molecular sizes may affect the arrangement of interfacial surfactant molecules. For both HABS and SLPS surfactants, interfacial interactions between the hydrophobic part of surfactants and the hydrophobic blocks of HMPAM will reduce the interfacial concentration of surfactant monomers by forming aggregates and result in an obvious increment of the IFT value. On the other hand, HPAM will obviously enhance the water solubility of the surfactant/organic alkali solutions and reduce the IFT values for the hydrocarbons with lower alkyl carbon number (ACN).

A new coordination polymer was synthesized under hydrothermal conditions, namely [Zn(Bpy)(DHTA)0.5]n (DHTA = 2,5-dihydroxy-1,4-terephthalic acid tetra-anion, Bpy = 2,2’-bipyridine). There is one Zn(II) ion in [Zn(Bpy)(DHTA)0.5]n, the metal center Zn(II) is five-coordinated and forms a slightly twisted square pyramidal geometry. It remains stable at temperatures as high as 380 °C, and a sharp drop in weight is found in the temperature range of 380–570 °C. The calculation results show that the residual is zinc(II) oxide (ZnO). The emission peak of the complex appears at 365 nm (λex = 366 nm). The photoluminescence results suggest that the complex has potential as a new luminescence material. At the same time, in luminescence explorations experiments, the complex showed a high degree of selectivity and sensitivity to organic solvents, acetone (DMK) and metal ions (Fe3+).

The title compound, [Cd(C8H4O4)(C18H10N4)]n, was synthesized under mild hydro­thermal conditions. The Cd center is coordinated by four O atoms from three different benzene‐1,3‐dicarboxyl­ate ligands and two N atoms from the dipyrido[3,2‐a:2′,3′‐c]phenazine ligand in a distorted octa­hedral geometry. The polymeric chain extends along the c axis, forming a one‐dimensional helical structure.

A rapid and simple analytical method was developed for the simultaneous and quantitative determination and separation of hydrophilic imidazolium ionic liquids (ILs) (1-butyl-3-methylimidazolium chloride, [C(4)mim]Cl; 1-hexyl-3-methylimidazolium chloride, [C(6)mim]Cl; 1-octyl-3-methylimidazolium chloride, [C(8)mim]Cl; 1-allyl-3-methylimidazolium chloride, [Amim]Cl; or 1-allyl-3-methylimidazolium bromide, [Amim]Br) with miscible ethyl acetate and EtOH and their mixtures using reverse phase liquid chromatography coupled with refractive index detection (RPLC-RI). The influence of 60 to 100% (volume percentage) methanol in the mobile phase on the IL systems ([C(4)mim]Cl, [C(6)mim]Cl, [C(8)mim]Cl, [Amim]Br, or [Amim]Cl)-ethyl acetate-EtOH was investigated. The optimum mobile phase for the system [C(8)mim]Cl-ethyl acetate-EtOH, [C(4)mim]Cl-ethyl acetate-EtOH, [Amim]Br-ethyl acetate-EtOH and [Amim]Cl-ethyl acetate-EtOH was methanol/water (60:40, v/v), and methanol/water (70:30, v/v) for [C(6)mim]Cl-ethyl acetate-EtOH. Under optimum mobile phase conditions for each system, the RSD of the retention time ranged from 0.02 to 0.04%, and the RSDs of the peak area percent ranged from 0.23 to 1.85%, which showed good reproducibility of the RPLC-RI method. The RPLC-RI method can determine IL, ethyl acetate, and EtOH simultaneously in 5 min, and the analytes, especially IL, can be eluted completely. The results show that the RPLC-RI method can be used to separate and determine ILs in mixtures with organic compounds simultaneously and quantitatively.

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