Experimental Validation of the Temperature-Resistant and Salt-Tolerant Xanthan Enhanced Foam for Enhancing Oil Recovery

Xanthan enhanced foam (XGF) is a newly developed chemical agent for enhanced oil recovery in high-temperature and high-salinity reservoirs. In this paper, laboratory experiments were performed to characterize the morphology and foam properties of XGF, to study its performance under different temperature and different salinity conditions, respectively. Based on simulate reservoir formation conditions of Xidaliya field, a series of research on XGF were conducted. The experimental results showed that the scanning electron microscopy of XGF reflected a more viscoelastic and stable nature of the foam system. High temperature had a great adverse impact upon the stability of XGF, and the increase of salinity in the solution helped to improve the stability of foam. The foam stability increased remarkably when XG4 is added, and an increase in ambient pressure made enhancement of foam stability became more noticeable. In the presence of crude oil, Xanthan could enhance the stability of emulsions and was more favorable to stabilize foam. XG4 enhanced foam had dramatic properties for mobility controlling and oil displacement in the porous media.     

Stability of Polymer and Surfactant Mixture Enhanced Foams in the Presence of Oil Under Static and Dynamic Conditions

Three different types of foaming agents including hydrocarbon surfactant TQ01, partial fluorinated surfactant BF01, and per-fluorinated surfactant QF01 exhibited good foaming ability and foam stability under 95°C high temperature and 32,325 ppm salinity conditions. The oil-tolerance ability order with respect to Malaysia Off-shore (MOS) crude oil for surfactant TQ01, BF01, and QF01 is TQ01 < BF01 < QF01. Introduction of polymer into the foam formula could significantly increase foam stability. Different polymers show different abilities of increasing foam stability. Spreading coefficient and entering coefficient are close to zero for surfactant BF01 foaming system and much less than zero for surfactant QF01 foaming system, so the oil-resistance ability of foam generated by surfactant QF01 is the strongest. For surfactant TQ01 foaming system, the calculated spreading coefficient and entering coefficient are greater than zero; therefore, the TQ01 foam system is more sensitive to MOS crude oil and its oil-resistance ability is the poorest. Core flooding test indicated that using the 0.4% BF01 and 0.2% YH1096 combined foaming formula could increase the pressure drop across the porous media significantly, indicating that strong foam was generated in the presence of MOS crude oil.     

A Novel Coordination Polymer Based on Decavanadate Units Linked by Copper(II) Ethylenediamine Complexes

Summary: A novel coordination polymer[{Cu(en)₂}(V₁₀O₂₈)]_n · 2n[Cu(en)₂(H₂O)] · 2n(H₃BO₃) · 2n(H₂O) was obtained by hydrothermal reaction. The compound crystallizes in the monoclinic crystal system, in the C2/c space group, with a = 26.490 (3) Å; b = 11.6558 (11) Å; c = 19.8426 (19) Å; β = 124.011 (1)°; V = 5078.6(8) ų. The solid structure is formed by polymeric chains, [Cu(en)₂(H₂O)]²⁺ cations, and boric acid and water solvate molecules, stabilized through a multiple hydrogen bond network.     

Synthesis,Characterization, and Property Evaluation of a Hydrophobically Modified Polyacrylamide as Enhanced Oil Recovery Chemical

A novel hydrophobically modified polyacrylamide p(AM/NaA/OP-10-AC/BOAM) was successfully synthesized via an aqueous micellar copolymerization method from acrylamide (AM), sodium acrylate (NaA), octylphenol polyoxyethylene acrylate (OP-10-AC), and small amounts of N-benzyl-N-octylacrylamide (BOAM), with the aim of investigating the copolymer's rheological behaviors under various conditions such as polymer concentration, shearing, temperature, and salinity. The copolymer was characterized by infrared spectroscopy, scanning electron microscopy, and atomic force microscope. Scanning electron micrographs show large aggregates in solution formed by the association from the hydrophobic groups of the copolymer. Compared with partially hydrolyzed polyacryamide (HPAM), the copolymer shows a much higher thickening capability and a much greater ability to resist shearing, heat, and salts. This good property of the copolymer is attributed to its three-dimensional dimensional network structure. According to the core flooding test, it can be obtained that oil recovery is enhanced about 4.3% by the copolymer flooding contrasted to the HPAM flooding in mid-low permeability cores under conditions of 1500 mg/L of polymers and 45°C. All the results prove that the copolymer has the capability of increasing oil recovery by improving waterflood sweep efficiency in high-salinity reservoirs.     

Interpenetrating Polymer Networks of Uralkyd Resin Based on Hydrogenated Castor Oil and Poly(Butyl Acrylate)

Abstract

Semi‐ and full‐interpenetrating polymer networks (IPNs) of uralkyd (UA) resin based on hydrogenated castor oil and poly(butyl acrylate) (PBA) were prepared by the sequential mode of synthesis. These IPNs were characterized for their resistance to thermal behavior, swelling (%), and mechanical properties. The morphology of the IPNs was studied by scanning electron microscopy (SEM). The effect of the variations of the blend ratios on the above‐mentioned properties was examined. The mechanical properties significantly enhanced by increasing UA component in the blend. Full‐IPNs exhibited higher apparent densities, mechanical properties, and thermal stability than the corresponding semi‐IPNs.     

重烷基苯磺酸盐的界面性质和驱油机理

重烷基苯磺酸盐是在三次采油中广泛采用的表面活性剂之一，但重烷基苯原料组成复杂导致最终磺化产物的驱油效果差异很大.实验通过柱层析的方法将重烷基苯分离成6个族组分，并对其中的二烷基苯、单烷基苯和二烷基茚萘满、烷基萘、多苯烷进行磺化，中和提纯后对各磺酸盐进行界面张力测定.通过对比不同矿化度下界面张力以及各组分复配后的界面张力，对原油等效烷烃数(EACN)以及各组分碳数最低值(nmin)测定，得出各组分之间协同效应的规律和复配机理，从而阐明了重烷基苯磺酸盐的驱油机理.通过研究十二烷基苯磺酸钠(LAS)与各组分之间的复配作用对上述规律和机理进行了进一步验证.     

Silver Molecularly Imprinting Polymer for the Determination of p-Nitroaniline by Surface Enhanced Raman Scattering

Molecular imprinting and surface enhanced Raman scattering (SERS) were used to prepare a core-shell Ag@molecularly imprinting polymer (MIP) for the determination of p-nitroaniline. The obtained Ag@MIP exhibits a detection limit of 10^?12 M, which demonstrates higher sensitivity toward p-nitroaniline than conventional approaches. In addition, the Ag@MIP shows good recyclability, and simultaneously offers better stability and high SERS activity for recognizing target molecules. To characterize the high SERS activity of the SERS-MIP hybrid material, a possible mechanism for the SERS substrate is proposed involving enhancement by the MIP. This study is expected to provide an alternative approach for the determination of p-nitroaniline in aqueous environments.     

The Mineral Composition of Date Palm Fruits (Phoenix dactylifera L.) under Low to High Salinity Irrigation

Adaptability to salinity varies between different varieties of date palm trees. This research aims to explore the long-term impact of different salinity irrigation levels on the mineral content of 13 date palm varieties grown in the United Arab Emirates (UAE). Date varieties were grown using three irrigation water salinity levels of 5, 10 and 15 dS m⁻¹. The mineral composition (B, Ca, Cu, Fe, K, Mg, Na, P and Zn) of date palm fruits was determined using Inductively Coupled Plasma-Optical Emission Spectrometry (ICP-OES). High salinity levels showed no effect on the mineral content of Ajwat AlMadinah, Naghal, Barhi, Shagri, Abu Maan, Jabri, Sukkari and Rothan varieties. All date varieties remained good sources of dietary potassium, magnesium, manganese and boron even at high salinity levels. Increased salinity had no effect on the percent Daily Value (%DV) categories of most of the analyzed minerals. While no genotypes showed a general adaptation to different saline environments, Barhi, Ajwat Al Madinah, Khinizi, Maktoumi and Shagri varieties were more stable towards salinity variation. In the UAE, the genotype x saline-environment interaction was found to be high which makes it impossible to attribute the variation in mineral content to a single varietal or salinity effect.     

A Simple Relation for the Concentration Dependence of Osmotic Pressure and Depletion Thickness in Polymer Solutions

We propose simple expressions and for the osmotic pressure Π and the depletion thickness δ as a function of the polymer concentration φ. Here, Π₀ and δ₀ correspond to the dilute limit, and φ_ex is an extrapolation concentration which is of the order of the overlap concentration φ_ov. The De Gennes exponent α describes the concentration dependence of the semidilute correlation length ; it is related to the Flory exponent ν through . The quantity φ_ex is experimentally accessible by extrapolating the semidilute limit towards Π = Π₀ or δ = δ₀. These expressions are exact in mean field, where the ratio φ_ex/φ_ov (0.49 for Π, 0.41 for δ) follows from established models. For excluded‐volume chains they describe simulation data excellently: in this case φ_ex/φ_ov is 0.69 for Π and again 0.41 for δ. We find also very good agreement with experimental data.

     

导电高聚物聚2，5－二甲基苯胺的化学合成与特性

报道了聚２，５－二甲基苯胺（ＰＤＭｅＡｎ）的化学合成，并用标准四探针方法测定其电导率，以ＦＴＩＲ、ＵＶ－Ｖｉｓ吸收光谱、元素分析和ＣＶ法对其性质进行了研究，ＰＤＭｅＡｎ的结构与聚苯胺和聚２，５－二甲氧基苯胺的结构类似，是由其单元通过氮原子（Ｎ）在对位上键合而成，本征态的ＰＤＭｅＡｎ能溶于多种有机溶剂，如ＣＨ２Ｃｌ２、ＣＨＣｌ３、ＤＭＳＯ、ＤＭＦ等。     

DBBD及其Cu(Ⅰ)配位聚合物[CuI(DBBD)2]n的合成

In this article we report the synthesis of (R,S)-4,4'-biquinoline-6,6'-dimethyl-3,3'-dicarboxylate (DBBD)(1) and the formation of copper(Ⅰ) coordination polymer [CuI(DBBD)2]n (2) by inducing a bidentate organic ligand (DBBD). The crystal 1 belongs to monoclinic system with space group P21, and a=0.881 30(19) nm, b=1.9660(6)system with space group Fmm2, and a=2.04441 (17) nm, b=1.543 06 (13) nm, c=1.65245 (13) nm, V=5.2129(7)     

导电高聚物聚2,5—二甲基苯胺的化学合成与特性

报道了聚２，５－二甲基苯胺的化学合成，并用标准四探针方法测定其电导率，以ＦＴＩＲ，ＵＶ－Ｖｉｓ吸收光谱，无素分析和ＣＶ法对其性质进行了研究。本征太民的ＰＤＭｅＡｎ能溶于多种有机溶剂，如ＣＨ２Ｃｌ２，ＣＨＣｌ３，ＤＭＳＯ，ＤＭＦ等。     

Analytical Separation of Copper(II), Cobalt(II) and Nickel(II) Using Polymer Bound Anthrantic Acid

Abstract

The preferential complexing tendency of different nietal ions towards chelating agents anchored on a polymer has been used for separation of transition metals. the anthranilic acid group was anchored on the polymeric cellulose back-bone by successive coupling with trifunctional reagent cyanuric chloride, in diozane medium, at pH 7 and 9–10, respectively. This polymer bound chelating agent was used to separate copper(II), nickel(II) and cobalt(II) in the concentration range 1.0–0.1 mmol/L. the separation of a mixture of two components was quantitative using column chromatography.     

Temperature-driven Precipitation of poly(N-isopropylacrylamide-co-methacrylic acid) in Cationic,Anionic and Nonionic Surfactant Solutions

The temperature-driven precipitation of poly(N-isopropylacrylamide-co-methacrylic acid) (P(NIPAM-co-MAA)) in anionic, cationic, and non-ionic surfactants solutions was investigated under an acidic (e.g. pH 3.0) and an alkali condition (pH 9.0). Under the acidic condition, sodium dodecyl sulfate (SDS, anionic) and cetyltrimethylammonium chloride (CTAC, cationic) increased the cloud point of the copolymer and they suppressed the temperature-sensitivity. Under the alkali condition, SDS suppressed the temperature sensitivity as under the acidic condition, but CTAC boosted the temperature sensitivity and it decreased the cloud point of the copolymer. The effect of CTAC on the phase transition under the alkali condition was opposite to the effect observed under the acidic condition. Tween 20 (non-ionic) had little effect on the cloud point and the temperature-sensitivity under both the acidic and the alkali conditions.     

Enhanced Removal of Cu(II) and Pb(II) from Aqueous Solutions by Pretreated Biomass of Fusarium Solani

This study investigated the feasibility of Fusarium solani biomass as a biosorbent for Cu(II) and Pb(II) removal from aqueous solutions. Batch sorption experiments were carried out for Cu(II) and Pb(II) to quantify the sorption kinetics, pH, biosorbent dose and pretreatment of F. solani biomass. Biomass metal uptake clearly competed with protons present in the aqueous medium, making pH an important variable in the process. The maximum biosorption by F. solani biomass was obtained with solutions having pH 5 for both metal ions. An enhanced Cu(II) removal (96.53%) was observed for aluminum hydroxide pretreated biomass. Maximum Pb(II) removal (95.48%) was observed with native biomass. Time dependence experiments for the metal ions uptake showed that adsorption equilibrium reached almost 240 min after metal addition. The kinetic studies showed that the biosorption process followed the pseudo second‐order rate model for Cu(II) and Pb(II). The equilibrium data fitted well to the Langmiur isotherm model.     

A Highly Efficient Chelating Polymer for the Adsorption of Uranyl and Vanadyl Ions at Low Concentrations

A new polymer containing double amidoxime groups per repeating unit was synthesized to enhance the metal ion uptake capacity. The adsorption properties of this new polymeric adsorbent, amidoximated poly(N,N-dipropionitrile acrylamide), for U(VI), V(V), Cu(II), Co(II) and Ni(II) ions were investigated by batch and flow-through processes at very low concentration levels (ppb). The chelating polymer showed high adsorption capacity for uranyl as well as vanadyl ions. In selectivity studies from a mixture of metal ions in aqueous solutions, the adsorbent showed high selectivity for uranyl and vanadyl ions in the following order: U(VI) > V(V) Co(II) = Cu(II) Ni(II) as determined by calculating the distribution coefficients D, of corresponding ions. The adsorption of uranyl and vanadyl ions from natural seawater by the new adsorbent was also examined in flow through mode.     

双(三氟甲基磺酰)亚胺钠基聚合物电解质在固态钠电池中的性能

采用简单的溶液浇铸法制备出由双（三氟甲基磺酰）亚胺钠（NaTFSI）/聚氧乙烯（PEO）构筑的固态聚合物电解质（SPE）,并针对其相转变、结晶性、热稳定性、电导率以及电化学稳定性等基础理化及电化学性质进行了系统表征。结果表明,NaTFSI/PEO（[EO]/[Na⁺]=15）SPE具有相对高的电导率（σ ≈ 10^-3 S·cm^-1,80℃）、高的耐氧化能力（4.86 V vs Na⁺/Na）和热稳定性高达350℃。电池测试结果表明,该NaTFSI基SPE不仅对金属钠电极能够呈现出优异的界面稳定性,而且在Na|SPE|NaCu_1/9Ni_2/9Fe_1/3Mn_1/3O₂电池中展现出良好的循环和倍率性能。     

低介电常数含氟聚芳醚的合成

计算机的高速发展 ,对于微电子器件 (例如印刷电路板的基材、多级金属互联结构的绝缘电介质层以及电子封装涂料等 )的耐高温材料的需求越来越迫切 ,因此对具有低介电常数、良好的热稳定性、低吸水率、溶解性好的芳香族聚合物的研究已引起极大关注 .其中低介电常数是至关重要的性能之一 .将含氟基团和大体积侧基等引入聚合物链中 ,是降低介电常数的有效方法 [1,2 ] .含氟芳香聚合物不仅在低介电常数微电子绝缘材料方面有重要的应用前景 ,而且在光波导器件和气体选择性透过膜等方面极具应用潜力 [3 ,4 ] .本文合成了一种高含氟量的新型聚芳醚 …     

Similarities of Coordination Polymer and Dimeric Complex of Europium(III) with Joint and Separate Terpyridine and Benzoate

A dimeric complex of trivalent europium [Eu₂Cl₄(bc)₂(ptpy)₂] ( 1 ), containing the separate ligands 4'-phenyl-2,2':6',2''-terpyridine (ptpy) and benzoate (bc^–) and a one-dimensional double strand coordination polymer of the composition ¹_∞[EuCl₂(cptpy)] ( 2 ) with 4-[2,2':6',2''-terpyridin]-4'-yl-benzoate (cptpy^–) were obtained. The products exhibit structural similarities despite the character of joint and separate functionality of the ligands. The dimer 1 shows photoluminescence with high quantum yield [61(2) %]. Eu³⁺ emission lifetime is 1.493(1) ms at room temperature and rises to 1.649(1) ms upon cooling to 77 K.