Synthesis and Magnetic Properties of Pt3Co/Fe3O4 Nanocomposites

Bimagnetic Pt₃Co/Fe₃O₄ nanocomposite is synthesized in aqueous solution. The nanoparticles are characterized with TEM, FTIR, and magnetic measurements. The as‐synthesized nanocomposite exhibits ferromagnetic properties at room temperature due to the exchange coupling between Pt₃Co and Fe₃O₄. Magnetic properties of Pt₃Co/Fe₃O₄ nanoparticle can be tuned by varying of the molar ratio of iron to platinum. Pt₃Co/Fe₃O₄ nanoparticles exhibit higher saturation magnetization when the molar ratio of iron to platinum is 1.     

Polymers-Copolymer as Flow Improvers for Fuel Oils and Their Electrical Conductivity

In order to find efficient cold flow improvers for fuel oil, polymethylmethacrylate (PMMA), polystyrene (PS), and a copolymer [styrene (S)–methylmethacrylate (MMA) were prepared. The structure of these polymers and the copolymer were characterized by infrared spectral analysis and their molecular weights were measured. These polymers-copolymer were used as additives for fuel oils in order to lower their pour point. Accordingly, they were evaluated as flow improvers for fuel oil. The results indicated that PMMA possesses less performance as pour point depressant. While the addition of PS and the copolymer (S–MMA) yield excellent pour point depressants for fuel oil. Upon studying the prepared additives and their properties, it was found that the electrical properties of the copolymer were changed due to the presence of polar ion in MMA effect on the electrical properties. The highest electrical conductivity was found when styrene:MMA molar ratio was 1:1.     

Rheological Properties of Mixed Aqueous Solutions of Geminis (12‐3‐12,2Br−) and SDS

The rheological properties of surfactant solutions are the main parameter that affects the surfactant application. In this work, the rheology of the mixed system 12‐3‐12,2Br^?/SDS/H₂O was discussed particularly. The relationship between the microstructure of surfactant aggregates and rheology of mixed solutions was explored. It is shown that the rheological properties of solutions have different behaviors at different molar ratio of two surfactants under given total concentration. With the increase of molar ratio (12‐3‐12,2Br^?/SDS), the solution change from Newtonian liquid into positive thixotropy then to negative thixotropy, at last turn to positive thixotropy again, and ATPS becomes the dividing line. The difference of rheological properties is the embodiment of difference for surfactant aggregates' microstructures. The cryo‐TEM results shown that the solutions containing aggregates with big size, such as rodlike micelles, multilamellar micelles, show positive thixotropy. However, the solutions containing lamellar micelles or liquid crystal will show negative thixotropy. The positive thixotropy endows the mixied system a potential application in enhanced oil recovery.     

Electrical Properties of Cylindrical Reverse Micelle

In this article, accurate analytic expressions of the surface charge density/surface potential and adsorption excesses for cylindrical reverse micelle in a solution of symmetric electrolyte are derived from the nonlinear cylindrical Poisson–Boltzmann equation. These expressions are in good agreement with numerical values and Van Aken's results for cylindrical reverse micelle with high surface potentials and large κa.     

Surface-Modified Sb2S3 Nanoparticles and Their Tribological Behaviors in Liquid Paraffin

Sb₂S₃ nanoparticles surface-modified with S-tetradecyl N, N-dihydroxyethyl dithiocarbamate (C₁₄DTC-Sb₂S₃) have been synthesized via extraction of Sb₂S₃ colloidal particles from ethylene glycol into toluene in the presence of C₁₄DTC. The obtained products were characterized by high-resolution transmission electron microscope (HRTEM) and Fourier transformation infrared (FTIR), and their tribological behaviors as an additive in liquid paraffin were investigated using a four-ball tribometer. The results show that C₁₄DTC-Sb₂S₃ nanoparticles can significantly improve the friction reduction, anti-wear, and load-carrying properties of base oils. The preliminary lubrication mechanism was discussed based on the SEM and XPS investigation of the rubbed surfaces.     

Heat-resistant pyridine-based poly(ether-ester)s: Synthesis, characterization and properties

A pyridine-based diacid was synthesized via nucleophilic substitution reaction of 4-hydroxy benzoic acid with 2,6-dichloropyridine in the presence of potassium carbonate. The diacid was characterized using FT-IR and 1H-NMR spectroscopic methods and also with elemental analysis. Polycondensation reaction of the diacid with different diols including 1,4-dihydroxy benzene, 1,5-dihydroxy naphthalene, bis-phenol A and bis-phenol-P resulted in preparation of pyridine-based poly(ether-ester)s. The polymers were characterized and their physical and thermal properties including inherent viscosity, molecular weight, solubility, thermal stability, thermal behavior and crystallinity were studied. They revealed high heat-resistance and improved solubility in polar solvents. Structure-property relations for the prepared polyester were also studied.     

Theoretical Study on the Structural and Optoelectronic Properties of the Linear Perfluorooctane Sulfonate （PFOS）

The perfluoroalkyl substances(PFS) have attracted considerable attention in recent years as a persistent global pollutant to be able to bioaccumulate in higher organisms.In this paper,theoretical analysis on electronic structures,optoelectronic properties and absorption spectra properties of the perflurooctane sulfonate(PFOS) in gas phase have been investigated by using the DFT/TD-DFT method.The geometric structures,electrostatic potentials,energy gaps,ionization potentials,electron affinities,frontier molecular orbital,excitation energies and absorption spectra for the ground state of PFOS were calculated.The result indicates that the ability of accepting electron of neutral PFOS is larger than that of anionic PFOS,while the electron excited by UV irradiation from HOMO to LUMO in the anionic PFOS is easier than that in the neutral PFOS.     

Synthesis,Crystal Structure and Luminescent Properties of a 1D Loop-chain Coordination Polymer [Ag（3,3-pybz）（3,3-Hpybz）]n

A new coordination polymer, [Ag（3,3-pybz）（3,3-Hpybz）]n （1, 3,3-Hpybz = 3-pyri- din-3-yl-benzoic acid）, has been synthesized and characterized by elemental analysis, IR spectra, PXRD, and single-crystal X-ray diffraction. In complex 1, the Ag（1）ions are linked by the paired 3,3-pybz ligands to generate an infinite 1D loop chain, and further through π-π stacking interactions to form a 2D supramolecular architecture. Crystal data for 1： triclinic, space group P1, a = 10.2635（17）, b = 10.3041（12）, c = 10.8060（13） A, V= 1679.1（5）A3, α = 62.028（11）, β = 80.325（15）, γ = 78.738（14）°, Z = 2, C24H17AgN2O4, Mr = 505.27, Dc= 1.698 g/cm3, μ= 1.058 mm--, F（000） = 506, S = 1.012 and T = 293（2） K. The final R = 0.0293 and wR = 0.0667 for 3435 observed reflections with I〉 2a（/）, and R = 0.0350 and wR = 0.0688 for all data.     

One-dimensional Vanadyl Phosphate Containing the Tancoite-like {vIvO（HPO4）2}2- Chain

A vanadyl phosphate containing a new member of tancoite-like single chain, （DAPH2）[VIVO（HPO4）2]·xH20 （x ≈ 0.2, DAP = 1,3-diaminopropane, C3H10N2）, has been synthesized under hydro（solvo）thermal conditions. It crystallizes in orthorhombic space group P21212 （No. 18） with a = 7.1730（14）, b = 19.252（4）, c = 8.6557（17） A, Z= 4, V= 1195.3（4）A3, C3H14.38N2P2VO9.19, Mr = 338.47, Dc = 1.881 g/cm3,μ（MoKa） = 1.138 mm-1 and F（000） = 692. The final full-matrix least-squares refinement converged to R = 0.0408, wR = 0.1046 for 2498 observed reflections with I 〉 2σ（I） and R = 0.0456 and wR = 0.1080 for all data （2750） and S = 1.001. Its one-dimensional 1 structure consists of tancoite-like ∞1 {vIVO（HPO4）2}2- single chains surrounded by DAPH22＋ ions and water molecules. The single chain is built from trans-corner-sharing octahedral {VIV= O…VIV} backbone loop-branched by HPO4 groups like staple forming a new member of tancoite single chain. Due to the special coordination of VIVO6, the ∞1 {VO（HPO4）2-} chain adopts a larger M-O-M angle （V-O-V = 135°） than those of tancoite chains reported before. The corner-sharing linear {VIV = O…VIV} chain structure also leads to a one-dimensional weak antiferromagnetic interaction at low temperature. The magnetic measurements confirm the 4＋ valence state of vanadium. IR and TG results of the title compound are also discussed.     

Crystal Structure and Thermal Stability Properties of a New 1D Chain Cu（ll） Coordination Polymer with 2,3-Pyridinedicarboxylic Acid as the Ligand

A new 1D chain copper coordination polymer [CuE（H2L）2（C10HsN2）（HEO）2]n＇3n（H20） with 2,3-pyridinedi carboxylic acid （H2L） and 2,2＇-bipyridine （2,2＇-bipy） as ligands has been synthesized in the mixed ethanol and water solvents. Crystal data for this complex are as follows： monoclinic, space group P2Jc, a = 7.7713（7）, b = 27.478（3）, c = 13.2621（13）/1,, fl = 100.6940（10）, V= 2782.8（5） A3, Dc = 1.722 g/cm3, Z = 4, p = 1.61 mm-1, F（000） = 1472, the final R = 0.0363 and wR = 0.0933. In the crystal structure, the whole molecule consists of two cooper ions, two H2L, one 2,2＂-bipy molecule and six water molecules. Each central copper ion is coordinated with three oxygen atoms from two H2L and one water molecule, two nitrogen atoms from one 2,2＇-bipy molecule and two H2L, giving a distorted tetragonal pyramidal geometry. Thermal stability properties of the complex were investigated.