Biodegradable polyethylene glycol-based ionic liquids for effective inhibition of shale hydration

A series of ionic liquids based on polyethylene glycol (PEG) with different molecular weights were prepared for inhibiting shale hydration and swelling. The antiswelling ratio was measured to investigate the effect of different PEG-based ionic liquids on bentonite volume expansion, and it has shown that the ionic liquid based PEG200, i.e. PEG with molecular weight of 200, exhibited superior inhibition. The structures of the PEG200-based ionic liquids were characterized by 1H NMR studies. The XRD results indicated that the PEG200-based ionic liquids intercalated into sodium montmorillonite (Na-MMT) reducing the water uptake by the clay. The formation of complexes of Na-MMT and PEG200-based ionic liquids was also verified by FTIR spectroscopy. Thermal degradation analysis suggested that the PEG200-based ionic liquids accessed the interlamellar spaces of Na-MMT and reduced the water content of the complexes obtained. Moreover, no breaks and collapse were observed on the shale samples after immersion in PEG200-based ionic liquid solutions. All the PEG200-based ionic liquids showed biodegradability and potential application in effective inhibition for clay hydration

Water-soluble complexes of an acrylamide copolymer and ionic liquids for inhibiting shale hydration

Here, we report water-soluble complexes of an acrylamide copolymer and ionic liquids for inhibiting shale hydration. The copolymer, denoted as PAAT, was synthesised via copolymerisation of acrylamide (AM), acrylic acid (AA) and N,N-diallyl-4-methylbenzenesulfonamide (TCDAP), and the ionic liquids used were 3-methyl imidazoliumcation-based tetrafluoroborates. X-ray diffraction showed that compared with commonly used KCl, the water-soluble complex of PAAT with 2 wt% ionic liquid 1-methyl-3-H-imidazolium tetrafluoroborate (HmimBF4) could remarkably reduce the d-spacing of sodium montmorillonite in water from 19.24 to 13.16 Å and effectively inhibit clay swelling. It was also found that the PAAT-HmimBF4 complex with 2 wt% HmimBF4 could retain 75% of the shale indentation hardness and increase the anti-swelling ratio to 85%. 13C NMR revealed that there existed interactions between PAAT and HmimBF4. Moreover, the thermal stability of the PAAT-HmimBF4 complex is superior to PAAT, suggesting that this water-soluble complex can be used to inhibit clay and shale hydration in high-temperature oil and gas wells

Water-soluble complexes of hydrophobically modified polymer and surface active imidazolium-based ionic liquids for enhancing oil recovery

The current study introduces the water-soluble complexes containing hydrophobically associating copolymer and a series of surface activity imidazolium-based ionic liquids (CnmimBr, n=6, 8, 10, 12, 14 and 16). The polymer, denoted as PAAD, was prepared with acrylamide (AM), acrylic acid (AA) and N,N-diallyl-2-dodecylbenzenesulfonamide (DBDAP). And the hydrophobic associative behavior of PAAD was studied by a combination of the pyrene fluorescence probe and viscosimetry. Incorporation of CnmimBr (n=10, 12, 14 and 16) in PAAD leaded to the white thick gel, while the pellucid solutions were obtained in complexes of PAAD and CnmimBr (n=6 and 8); addition of C6mimBr around critical micelle concentration resulted in a large decrease in viscosity of solution. Therefore, we particularly investigated the performance of PAAD/C8mimBr complex. The interfacial tension of PAAD/C8mimBr complex solution and crude oil under different conditions was examined. Moreover, PAAD/C8mimBr complex exhibited superior temperature resistance and shear reversible performance for enhancing oil recovery (EOR) by rheological test. The promising EOR of 21.65% can be obtained by PAAD/C8mimBr complex showing high potential to utilize this kind of new complex in EOR processes

<span style="font-size:10.0pt;font-family: "Times New Roman";mso-fareast-font-family:SimSun;mso-bidi-font-family:Mangal; mso-ansi-language:EN-US;mso-fareast-language:ZH-CN;mso-bidi-language:HI" lang="EN-US">Preparation of carbazole and dibenzofuran derivatives by selective b<span style="font-size:10.0pt;font-family:"Times New Roman";mso-fareast-font-family: SimSun;mso-bidi-font-family:Mangal;mso-ansi-language:EN-US;mso-fareast-language: EN-US;mso-bidi-language:HI" lang="EN-US">romination<span style="font-size: 10.0pt;font-family:"Times New Roman";mso-fareast-font-family:SimSun;mso-bidi-font-family: Mangal;mso-ansi-language:EN-US;mso-fareast-language:ZH-CN;mso-bidi-language: HI" lang="EN-US"> on a<span style="font-size:10.0pt;font-family:"Times New Roman"; mso-fareast-font-family:SimSun;mso-bidi-font-family:Mangal;mso-ansi-language: EN-US;mso-fareast-language:EN-US;mso-bidi-language:HI" lang="EN-US">romatic<span style="font-size:10.0pt;font-family:"Times New Roman";mso-fareast-font-family: SimSun;mso-bidi-font-family:Mangal;mso-ansi-language:EN-US;mso-fareast-language: ZH-CN;mso-bidi-language:HI" lang="EN-US"> rings<span style="font-size: 10.0pt;font-family:"Times New Roman";mso-fareast-font-family:SimSun;mso-bidi-font-family: Mangal;mso-ansi-language:EN-US;mso-fareast-language:EN-US;mso-bidi-language: HI" lang="EN-US"> <span style="font-size:10.0pt;font-family:"Times New Roman"; mso-fareast-font-family:SimSun;mso-bidi-font-family:Mangal;mso-ansi-language: EN-US;mso-fareast-language:ZH-CN;mso-bidi-language:HI" lang="EN-US">or <span style="font-size:10.0pt;font-family:"Times New Roman";mso-fareast-font-family: SimSun;mso-bidi-font-family:Mangal;mso-ansi-language:EN-US;mso-fareast-language: EN-US;mso-bidi-language:HI" lang="EN-US">benzylic g<span style="font-size: 10.0pt;font-family:"Times New Roman";mso-fareast-font-family:SimSun;mso-bidi-font-family: Mangal;mso-ansi-language:EN-US;mso-fareast-language:ZH-CN;mso-bidi-language: HI" lang="EN-US">roups with <i style="mso-bidi-font-style:normal"><span style="font-size: 10.0pt;font-family:"Times New Roman";mso-fareast-font-family:SimSun;mso-bidi-font-family: Mangal;mso-ansi-language:EN-US;mso-fareast-language:EN-US;mso-bidi-language: HI" lang="EN-US">N</span></i><span style="font-size:10.0pt;font-family:"Times New Roman"; mso-fareast-font-family:SimSun;mso-bidi-font-family:Mangal;mso-ansi-language: EN-US;mso-fareast-language:EN-US;mso-bidi-language:HI" lang="EN-US">-bromosuccinimide<span style="font-size:10.0pt;font-family:"Times New Roman";mso-fareast-font-family: SimSun;mso-bidi-font-family:Mangal;mso-ansi-language:EN-US;mso-fareast-language: ZH-CN;mso-bidi-language:HI" lang="EN-US"> </span></span></span></span></span></span></span></span></span></span></span>

635-641<i style="mso-bidi-font-style: normal">N-Bromosuccinimide (NBS), a bromine source, has been used to study the bromination of toluidine and cresols systematically to clarify the underlying mechanism and the orientation effect. It has been found that bromination of toluidine and cresols which possess electron-donating NH2/OH with NBS gives electrophilic aromatic substitution products quickly instead of the desired benzylic bromination products. In contrast, when the electronic effect of the substituted groups is reversed, only the benzylic bromination products are gained. Based on this methodology, several potential AChE inhibitors, such as 2-methoxy-5-(benzylamino)methyl-dibenzofuran, 3-bromo-2-methoxy-5-met-hyl-9H-carbazole, 3,6-dibromo-2-methoxy-5-methyl-9H-carb-azole, and 5-(bromomethyl)-2-methoxy-9H-(phenylsulfonyl)-carbazole have been synthesized

Hypoxia-Activated Prodrugs with Dual COX-2/CA Inhibitory Effects on Attenuating Cardiac Inflammation under Hypoxia

Cardiac inflammation is generally accompanied by hypoxia, while myocardial injury and an abnormal microenvironment caused by hypoxia tend to suppress the efficacy of common anti-inflammatory drugs. To improve the anti-inflammatory effect under hypoxia, a hypoxia-activated prodrug HAP1 consisting of a cyclooxygenase-2 (COX-2) inhibitor Ind and a carbonic anhydrase (CA) inhibitor Ace was synthesized. HAP1 was found to be activated by nitroreductase (NTR) under hypoxia to release two pharmacophores and achieve the combinatory medication intensively at the hypoxic site, better than Ind or Ace alone. When NTR activity was inhibited by Na2WO4 under hypoxia, no pharmacophores were found to release from HAP1 without exhibiting its activity. However, the efficacy of the Ind and Ace combination group (I&A) was not affected. Furthermore, HAP1 showed advantages over I&A in vivo not only in improving bioavailability but also in reducing side effects. The HAP approach turns out to inhibit cardiac inflammation efficiently and safely under hypoxia

Hypoxia-Activated Prodrugs with Dual COX-2/CA Inhibitory Effects on Attenuating Cardiac Inflammation under Hypoxia

Cardiac inflammation is generally accompanied by hypoxia, while myocardial injury and an abnormal microenvironment caused by hypoxia tend to suppress the efficacy of common anti-inflammatory drugs. To improve the anti-inflammatory effect under hypoxia, a hypoxia-activated prodrug HAP1 consisting of a cyclooxygenase-2 (COX-2) inhibitor Ind and a carbonic anhydrase (CA) inhibitor Ace was synthesized. HAP1 was found to be activated by nitroreductase (NTR) under hypoxia to release two pharmacophores and achieve the combinatory medication intensively at the hypoxic site, better than Ind or Ace alone. When NTR activity was inhibited by Na2WO4 under hypoxia, no pharmacophores were found to release from HAP1 without exhibiting its activity. However, the efficacy of the Ind and Ace combination group (I&A) was not affected. Furthermore, HAP1 showed advantages over I&A in vivo not only in improving bioavailability but also in reducing side effects. The HAP approach turns out to inhibit cardiac inflammation efficiently and safely under hypoxia

A water-soluble antimicrobial acrylamide copolymer containing sulfitobetaine for enhanced oil recovery

Herein, we report a novel acrylamide copolymer with antimicrobial property as an enhanced oil recovery chemical. The copolymer was synthesized from acrylamide (AM), acrylic acid (AA) and 2-((2-(acryloyloxy)ethyl)dimethylammonio)ethyl sulfite (ADMES) using oxidation-reduction initiation system. Subsequently, the copolymer AM/AA/ADMES was evaluated and characterized on several aspects such as IR, 1H NMR, intrinsic viscosity, and dissolubility. The AM/AA/ADMES solution exerted remarkable thickening ability, salt tolerance ability and viscoelasticity. In addition, the rheological properties, temperature resistance ability and long-term stability of AM/AA/ADMES were investigated systematically in the presence of sulfate-reducing bacteria and relatively low viscosity loss could be obtained compared to partially hydrolyzed polyacrylamide. On the basis of core flooding experiments, AM/AA/ADMES was found to be a valuable prospect with 10.5 resistance factor, 4.6 residual resistance factor and up to 11.0% enhanced oil recovery