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991.
CO2驱是一种具有广阔前景的提高油藏采收率的方法。其中,降低CO2与原油的最低混相压力以实现混相驱是增强CO2驱效果的重要手段。由此我们设计了由亲油基团十六烷基和亲CO2基团全乙酰蔗糖酯基结合的新型“亲油-亲CO2助混分子”十六酸全乙酰基蔗糖酯CAA8-X,研究发现,CAA8-X对超临界CO2流体和不同油相的煤油、白油以及长庆原油有优异的助混效果,界面张力消失法和细管实验法测定结果表明,CAA8-X可以将超临界CO2/长庆原油的最低混相压力降低20.5%。用分子动力学模拟计算了CO2分子与全乙酰蔗糖酯基的亲和能力,研究了这类新型“亲油-亲CO2助混分子”通过多酯头基降低与CO2亲和势能而降低油/CO2界面能的助混机理。 相似文献
992.
合成了氨基化氧化石墨烯(NH_(2)-PEG-GO),利用界面张力仪研究了脂肪酸质量浓度、NH_(2)-PEG-GO质量浓度以及脂肪酸链长度对于NH_(2)-PEG-GO与脂肪酸在水-油界面共吸附行为的影响。结果表明,当NH_(2)-PEG-GO与脂肪酸共同存在于液相且质量浓度较低时,此时的水-油界面张力值要明显低于体系中只添加NH_(2)-PEG-GO或脂肪酸时的张力值。脂肪酸的链长越长,NH_(2)-PEG-GO与脂肪酸共吸附降低界面张力能力越强。由于相对于NH_(2)-PEG-GO,脂肪酸尺寸较小,所以初期的界面张力降低由脂肪酸吸附引起,而且,脂肪酸在水-油界面的吸附能够吸引NH_(2)-PEG-GO向界面扩散,表现出吸附的协同效应。而在吸附后期,界面张力降低现象由NH_(2)-PEG-GO主导,NH_(2)-PEG-GO与脂肪酸之间存在竞争吸附。 相似文献
993.
Dr. Lukas Brieger Tobias Schrimpf Rebecca Scheel Dr. Christian Unkelbach Prof. Dr. Carsten Strohmann 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(69):e202202660
The metalation of N,N-dimethylaminomethylferrocene in THF by the superbasic mixture of nBuLi/KOtBu proceeds readily at low temperatures to afford a bimetallic Li2K2 aggregate containing ferrocenyl anions and tert-butoxide. Starting from an enantiomerically enriched ortho-lithiated aminomethylferrocene, an enantiomerically pure superbase can be prepared. The molecular compound exhibits superbasic behavior deprotonating N,N-dimethylbenzylamine in the α-position and is also capable of deprotonating toluene. Quantum chemical calculations provide insight into the role of the bridging THF molecule to the possible substrate–reagent interaction. In addition, a benzylpotassium alkoxide adduct gives a closer look into the corresponding reaction site of the Lochmann–Schlosser base that is reported herein. 相似文献
994.
《Arabian Journal of Chemistry》2022,15(5):103784
Herein thermally treated empty fruit bunch SiO2 nanoparticles (EFBSNP) was produced by ultrasound-assisted wet-milling and their effectiveness in enhancing cavitation effect of ultrasound to improve heavy oil recovery was evaluated. Empty fruit bunch ash (EFBA) was thermally treated to enhance its SiO2 content. Surface properties and size distribution of EFBSNP were studied using transmission electron microscopy and dynamic light scattering. X-ray diffractometer identified the crystal phase, the active group was ascertain using Fourier-transform infrared spectroscopy and thermal stability was established by differential scanning calorimetry. Moreover, the surface chemical composition was determined by X-ray photoelectron spectroscopy. The ability of empty fruit bunch SiO2 nanofluid (EFBSNF) to absorb ultrasound in heavy oil and the impact of ultrasound assisted EFBSNF flooding to enhance oil recovery of heavy oil was assessed. The microstructure analysis revealed EFBSNP of size ranges 17.78–115.38 nm with a purity of 94%. EFBSNF assisted ultrasound decreased interfacial tension to 0.2 mN/m, thus mobilizing the trapped oil droplet in the pores effectively. Ultrasound assisted EFBSNF flooding increased oil recovery by 44.33% compared to 26.33% without ultrasound. 相似文献
995.
Dr. Girish D. Salian Dr. Jonathan Højberg Dr. Christian Fink Elkjær Yonas Tesfamhret Dr. Guiomar Hernández Dr. Matthew J. Lacey Assoc. Prof. Dr. Reza Younesi 《ChemistryOpen》2022,11(6):e202200065
Two water-soluble binders of carboxymethyl cellulose (CMC) and sodium alginate (SA) have been studied in comparison with N-methylpyrrolidone-soluble poly(vinylidene difluoride–co-hexafluoropropylene) (PVdF-HFP) to understand their effect on the electrochemical performance of a high-voltage lithium nickel manganese oxide (LNMO) cathode. The electrochemical performance has been investigated in full cells using a Li4Ti5O12 (LTO) anode. At room temperature, LNMO cathodes prepared with aqueous binders provided a similar electrochemical performance as those prepared with PVdF-HFP. However, at 55 °C, the full cells containing LNMO with the aqueous binders showed higher cycling stability. The results are supported by intermittent current interruption resistance measurements, wherein the electrodes with SA showed lower resistance. The surface layer formed on the electrodes after cycling has been characterized by X-ray photoelectron spectroscopy. The amount of transition metal dissolutions was comparable for all three cells. However, the amount of hydrogen fluoride (HF) content in the electrolyte cycled at 55 °C is lower in the cell with the SA binder. These results suggest that use of water-soluble binders could provide a practical and more sustainable alternative to PVdF-based binders for the fabrication of LNMO electrodes. 相似文献
996.
997.
Full Protection for Graphene‐Incorporated Micro‐/Nanocomposites Containing Ultra‐small Active Nanoparticles: the Best Li‐Storage Properties
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Bao‐Hua Hou Xing‐Long Wu Ying‐Ying Wang Hong‐Yan Lü Dai‐Huo Liu Hai‐Zhu Sun Jing‐Ping Zhang Hong‐Yu Guan 《Particle & Particle Systems Characterization》2015,32(11):1020-1027
In recent years, graphene‐incorporated micro‐/nanocomposites represent one of the hottest developing directions for the composite materials. However, a large number of active nanoparticles (NPs) are still in the unprotected state in most constructed graphene‐containing designs, which will seriously impair the effects of the graphene additives. Here, a fully protected Fe3O4‐based micro‐/nanocomposite (G/Fe3O4@C) is rationally developed by carbon‐boxing the common graphene/Fe3O4 microparticulates (G/Fe3O4). The processes and results of full protection are tracked in detail and characterized by X‐ray diffraction, X‐ray photoelectron spectroscopy, and nitrogen absorption–desorption isotherms, as well as scanning and transition electron microscopy. When used as the anode for lithium‐ion batteries, the fully protected G/Fe3O4@C exhibits the best lithium‐storage properties in terms of the highest rate capabilities and the longest cycle life compared to the common G/Fe3O4 composites and commercial Fe3O4 products. These much improved properties are mainly attributed to its novel structural features including complete protection of active Fe3O4 nanoparticles by the surface carbon box, a robust conductive network composed of nitrogen‐doped graphene nanosheets, ultra‐small Fe3O4 NPs of 4–5 nm, abundant mesopores to accommodate the volume variation during cycling, and micrometer‐sized secondary particles. 相似文献
998.
Encapsulation of SnO2/Sn Nanoparticles into Mesoporous Carbon Nanowires and its Excellent Lithium Storage Properties
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Qinghua Tian Zhengxi Zhang Li Yang Shin‐ichi Hirano 《Particle & Particle Systems Characterization》2015,32(3):381-388
A peculiar nanostructure of encapsulation of SnO2/Sn nanoparticles into mesoporous carbon nanowires (CNWs) has been successfully fabricated by a facile strategy and confirmed by scanning electron microscopy (SEM), transmission electron microscopy (TEM), high‐resolution TEM (HRTEM), X‐ray diffraction (XRD), BET, energy‐dispersive X‐ray (EDX) spectrometer, and X‐ray photoelectron spectroscopy (XPS) characterizations. The 1D mesoporous CNWs effectively accommodate the strain of volume change, prevent the aggregation and pulverization of nanostructured SnO2/Sn, and facilitate electron and ion transport throughout the electrode. Moreover, the void space surrounding SnO2/Sn nanoparticles also provides buffer spaces for the volumetric change of SnO2/Sn during cycling, thus resulting in excellent cycling performance as potential anode materials for lithium‐ion batteries. Even after 499 cycles, a reversible capacity of 949.4 mAh g?1 is retained at 800 mA g?1. Its unique architecture should be responsible for the superior electrochemical performance. 相似文献
999.
Three‐Dimensional Multilayer Assemblies of MoS2/Reduced Graphene Oxide for High‐Performance Lithium Ion Batteries
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Geng Liu Yiyu Feng Yu Li Mengmeng Qin Haoran An Wenping Hu Wei Feng 《Particle & Particle Systems Characterization》2015,32(4):489-497
Three‐dimensional (3D) multilayer molybdenum disulfide (MoS2)/reduced graphene oxide (RGO) nanocomposites are prepared by a solution‐processed self‐assembly based on the interaction using different sizes of MoS2 and GO nanosheets followed by in situ chemical reduction. 3D multilayer assemblies with MoS2 wrapped by large RGO nanosheets and good interface are observed by transmission electron microscopy. The interaction of Na+ ions with oxygen‐containing groups of GO is also investigated. The measurement of lithium ion batteries (LIBs) shows that MoS2/RGO anode nanocomposite with a weight ratio of MoS2 to GO of 3:1 exhibits an excellent rate performance of 750 mAh g?1 at 3 A g?1 outperforming many previous studies and a high reversible capacity up to ≈1180 mAh g?1 after 80 cycles at 100 mA g?1. Good rate performance and high capacity of MoS2/RGO with 3D unique layered‐structures are attributed to the combined effects of continuous conductive networks of RGO, good interface facilitating charge transfer, and strong RGO sheets preventing the volume expansion. Results indicate that 3D multilayer MoS2/RGO prepared by a facile solution‐processed assembly can be developed to be an excellent nanoarchitecture for high‐performance LIBs. 相似文献
1000.
Controllable Synthesis of 3D Hollow‐Carbon‐Spheres/Graphene‐Flake Hybrid Nanostructures from Polymer Nanocomposite by Self‐Assembly and Feasibility for Lithium‐Ion Batteries
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