- Synthesis and evaluation of properties of: N, N -bis(perfluorooctyl)imine acetate sodium as a gas-wetting alteration agent
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The wettability of a rock's surface is a vital factor for gas flow and fracturing fluid backflow. As a result of this, novel and effective gas wetting alteration agents are required. In this work, a gas-wetting alteration agent, N,N-bis(perfluorooctyl)imine acetate sodium, was synthesized and characterized by different methods. The wettability of a rock's surface was evaluated by contact angle and imbibition measurements, the Owens two-liquid method and glass capillary tube rise testing. The results showed that after treatment with 0.5 wt% N,N-bis(perfluorooctyl)imine acetate sodium the contact angles of water and n-hexadecane on the surface of the rock increased from 36° and 0° to 140° and 119°, respectively. The surface free energy rapidly reduced from primeval 72 mN m-1 to 3.4 mN m-1 after treatment with 0.3 wt% N,N-bis(perfluorooctyl)imine acetate sodium. These values agreed with the imbibition measurements and the results of the glass capillary tube rise testing. Moreover, analysis by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) showed that the roughness of the rock surface significantly increased. The above results fully proved that the wettability of the rock surface is altered from its original water-wetting or oil-wetting to gas-wetting. Furthermore, thermal analysis demonstrated that the gas-wetting alteration agent has good thermal stability, which indicates its great potential to be used as a gas-wetting alteration agent for unconventional gas reservoirs under high temperature conditions.
- Wang, Yanling,Li, Yongfei,Wang, Qian,Li, Qiang,Zhang, Yue,Yuan, Lin
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- Gemini type air humidity reversal agent compound as well as preparation method and application thereof
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The invention relates to a gemini type air humidity reversal agent compound as well as a preparation method and application thereof. The gemini type air humidity reversal agent compound is N,N-di(perfluoro-capryloyl) imine carboxylate. The invention also provides a preparation method of the gemini type air humidity reversal agent compound. The gemini type air humidity reversal agent compound is easy to prepare, relatively high in yield, can be prepared into an aqueous solution with water in any proportion and can change liquid humidity of the surface of a shale reservoir into air humidity, oil-gas recovery ratio is increased, and field application is facilitated.
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- Micelle Formation in Liquid Ammonia
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Perfluorinated long chain alkyl amides aggregate in liquid ammonia with increasing concentration which reflects micelle-type formation based on changes in 19F NMR chemical shifts. The critical micelle concentrations (cmc) decrease with increasing chain length and give Kleven parameters A = 0.18 and B = 0.19. The micelles catalyze the ammonolysis of esters in liquid ammonia. The corresponding perfluorinated long chain alkyl carboxylates form ion pairs in liquid ammonia, but the equilibrium dissociation constants indicate favorable interactions between the chains in addition to the electrostatic forces. These perfluorinated carboxylates form micelles in aqueous solution, and their cmc's generate a Kleven B-value = 0.52 compared with 0.30 for the analogous alkyl carboxylates. The differences in hydrophobicity of CH2 and CF2 units in water and liquid ammonia are discussed, as is the possible relevance to life forms in liquid ammonia.
- Griffin, Joseph M.,Atherton, John H.,Page, Michael I.
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p. 7033 - 7039
(2015/07/28)
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- FLUORINATED IMIDOYLAMIDINES VULCANIZING AGENTS
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The invention provides a compound and, tautomeric forms thereof having the formula (I): wherein Rf1 is selected from the group consisting of hydrogen, a straight chain, branched secondary or branched tertiary C1-C20 perfluoroalkyl group optionally containing ether or thioether linkages and C1-C10 perfluoroalicyclic group optionally containing ether or thioether groups; Rf2 is a straight or branched C1-C20 perfluoroalkylene group optionally substituted with ether and thiother linkages; and X is selected from the group consisting of fluorine and formula (II). . The invention also provides perfluoroelastomeric compositions cured with the perfluoroimidoylamidines of the invention as well as combinations of perfluoroimidoylamidines and other curing agents.
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Page/Page column 30
(2008/06/13)
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