{"title":"长尾吡啶基离子液体介导阴离子型聚丙烯酰胺的疏水缔合行为","authors":"Xiangfeng Zhang","doi":"10.1016/j.molliq.2025.128629","DOIUrl":null,"url":null,"abstract":"<div><div>Hydrophobic associative polymers (HAPs) often suffer from slow dissolution and exhibit limited performance under the high-flow, high-shear conditions typical in hydraulic fracturing. To address this challenge, thepyridinium ionic liquids with varied alkyl chain lengths (C8, C10, C12, C14) were synthesized and assembled with anionic partially hydrolyzed polyacrylamide (HPAM) to form hydrophobically associated composite fluids. Systematic rheological testing identified the optimal formulation: 40 mg/L [C<sub>12</sub>Py]Br and 2000 mg/L HPAM, which possessed maximal viscosity and superior thixotropy. This composite fluid demonstrated excellent shear-thinning and shear-recovery properties, retained ≥71 % of its viscosity after heating to 120 °C, and showed robust resistance to Na<sup>+</sup>, Ca<sup>2+</sup>, and Mg<sup>2+</sup> salts, outperforming both HPAM and conventional hydrophobic polymers. Furthermore, the composite fluid exhibited enhanced viscoelasticity and significantly reduced surface/interfacial tensions, and these advantages were further improved in the presence of NaCl. These improvements are attributed to the synergistic effect of electrostatic shielding and hydrophobic association, which yields a three-dimensional network structure. The findings present a promising strategy for designing high-performance thickening and drag-reduction agents for high-rate hydraulic fracturing in harsh downhole environments.</div></div>","PeriodicalId":371,"journal":{"name":"Journal of Molecular Liquids","volume":"437 ","pages":"Article 128629"},"PeriodicalIF":5.2000,"publicationDate":"2025-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Hydrophobic association behavior of anionic polyacrylamide mediated by long-tailed pyridinium-based ionic liquid\",\"authors\":\"Xiangfeng Zhang\",\"doi\":\"10.1016/j.molliq.2025.128629\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><div>Hydrophobic associative polymers (HAPs) often suffer from slow dissolution and exhibit limited performance under the high-flow, high-shear conditions typical in hydraulic fracturing. To address this challenge, thepyridinium ionic liquids with varied alkyl chain lengths (C8, C10, C12, C14) were synthesized and assembled with anionic partially hydrolyzed polyacrylamide (HPAM) to form hydrophobically associated composite fluids. Systematic rheological testing identified the optimal formulation: 40 mg/L [C<sub>12</sub>Py]Br and 2000 mg/L HPAM, which possessed maximal viscosity and superior thixotropy. This composite fluid demonstrated excellent shear-thinning and shear-recovery properties, retained ≥71 % of its viscosity after heating to 120 °C, and showed robust resistance to Na<sup>+</sup>, Ca<sup>2+</sup>, and Mg<sup>2+</sup> salts, outperforming both HPAM and conventional hydrophobic polymers. Furthermore, the composite fluid exhibited enhanced viscoelasticity and significantly reduced surface/interfacial tensions, and these advantages were further improved in the presence of NaCl. These improvements are attributed to the synergistic effect of electrostatic shielding and hydrophobic association, which yields a three-dimensional network structure. The findings present a promising strategy for designing high-performance thickening and drag-reduction agents for high-rate hydraulic fracturing in harsh downhole environments.</div></div>\",\"PeriodicalId\":371,\"journal\":{\"name\":\"Journal of Molecular Liquids\",\"volume\":\"437 \",\"pages\":\"Article 128629\"},\"PeriodicalIF\":5.2000,\"publicationDate\":\"2025-09-30\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Journal of Molecular Liquids\",\"FirstCategoryId\":\"92\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S0167732225018069\",\"RegionNum\":2,\"RegionCategory\":\"化学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q2\",\"JCRName\":\"CHEMISTRY, PHYSICAL\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Molecular Liquids","FirstCategoryId":"92","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0167732225018069","RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"CHEMISTRY, PHYSICAL","Score":null,"Total":0}
Hydrophobic association behavior of anionic polyacrylamide mediated by long-tailed pyridinium-based ionic liquid
Hydrophobic associative polymers (HAPs) often suffer from slow dissolution and exhibit limited performance under the high-flow, high-shear conditions typical in hydraulic fracturing. To address this challenge, thepyridinium ionic liquids with varied alkyl chain lengths (C8, C10, C12, C14) were synthesized and assembled with anionic partially hydrolyzed polyacrylamide (HPAM) to form hydrophobically associated composite fluids. Systematic rheological testing identified the optimal formulation: 40 mg/L [C12Py]Br and 2000 mg/L HPAM, which possessed maximal viscosity and superior thixotropy. This composite fluid demonstrated excellent shear-thinning and shear-recovery properties, retained ≥71 % of its viscosity after heating to 120 °C, and showed robust resistance to Na+, Ca2+, and Mg2+ salts, outperforming both HPAM and conventional hydrophobic polymers. Furthermore, the composite fluid exhibited enhanced viscoelasticity and significantly reduced surface/interfacial tensions, and these advantages were further improved in the presence of NaCl. These improvements are attributed to the synergistic effect of electrostatic shielding and hydrophobic association, which yields a three-dimensional network structure. The findings present a promising strategy for designing high-performance thickening and drag-reduction agents for high-rate hydraulic fracturing in harsh downhole environments.
期刊介绍:
The journal includes papers in the following areas:
– Simple organic liquids and mixtures
– Ionic liquids
– Surfactant solutions (including micelles and vesicles) and liquid interfaces
– Colloidal solutions and nanoparticles
– Thermotropic and lyotropic liquid crystals
– Ferrofluids
– Water, aqueous solutions and other hydrogen-bonded liquids
– Lubricants, polymer solutions and melts
– Molten metals and salts
– Phase transitions and critical phenomena in liquids and confined fluids
– Self assembly in complex liquids.– Biomolecules in solution
The emphasis is on the molecular (or microscopic) understanding of particular liquids or liquid systems, especially concerning structure, dynamics and intermolecular forces. The experimental techniques used may include:
– Conventional spectroscopy (mid-IR and far-IR, Raman, NMR, etc.)
– Non-linear optics and time resolved spectroscopy (psec, fsec, asec, ISRS, etc.)
– Light scattering (Rayleigh, Brillouin, PCS, etc.)
– Dielectric relaxation
– X-ray and neutron scattering and diffraction.
Experimental studies, computer simulations (MD or MC) and analytical theory will be considered for publication; papers just reporting experimental results that do not contribute to the understanding of the fundamentals of molecular and ionic liquids will not be accepted. Only papers of a non-routine nature and advancing the field will be considered for publication.