{
  "abstract": "Reducing the oil-to-water ratio (OWR) in oil-based drilling fluids (OBDFs) offers significant economic and environmental benefits, yet severely challenges emulsion stability at high temperatures. To address this issue, we designed a thermoresponsive amphiphilic copolymer that dynamically reinforces the oil–water interface upon heating, thereby stabilizing low-OWR emulsions at elevated temperatures. Here, we report a thermoresponsive amphiphilic copolymer, poly(St-NIPAM-AMPS) (PSNA), synthesized via free-radical polymerization, as a primary emulsifier for low-OWR OBDFs. PSNA incorporates styrene (St) as a hydrophobic anchor, N-isopropylacrylamide (NIPAM) as a thermoresponsive unit, and 2-acrylamido-2-methyl-1-propanesulfonic acid (AMPS) as an electrostatic stabilizer. Systematic optimization identified PSNA-2 (St:NIPAM:AMPS = 1:1:1) as the optimal composition. At an emulsifier loading of 6 wt % and an OWR of 70:30, the PSNA-2-based OBDF achieved an electrical stability of 879 V, a high-temperature, high-pressure filtration loss of 3.2 mL, and a sag factor of 0.513 after dynamic aging at 180 °C for 16 h, meeting all industry criteria. Mechanistic studies reveal a thermally triggered interfacial self-reinforcement mechanism: above its lower critical solution temperature (54 °C), the NIPAM segments collapse, densifying the interfacial film, while the AMPS groups provide sustained electrostatic repulsion. The PSNA-2 formulation also exhibits a nontoxic environmental profile (EC50 > 30,000 mg/L). This work offers a scalable, cost-effective emulsifier design for high-performance, low-OWR OBDFs.",
  "abstract_shown": true,
  "affiliations": [
    "Northeast Petroleum University , , ,",
    "Drilling Fluid Company, Daqing Drilling & Exploration Engineering Corporation , ,"
  ],
  "article_type": "research article",
  "arxiv": null,
  "author_total": 2,
  "authors": [
    {
      "affs": [
        0,
        1
      ],
      "name": "Dapeng Zou",
      "orcid": "0009-0002-8683-5721"
    },
    {
      "affs": [
        0
      ],
      "name": "Jun Wang"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/cc0vkfyst9vqx.bib",
  "cited_by": 0,
  "doi": "10.1021/acsomega.6c08519",
  "fulltext_url": "https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13670298/?tool=EBI",
  "id": "cc0vkfyst9vqx",
  "issns": [
    "2470-1343"
  ],
  "landing_url": "https://europepmc.org/article/PMC/PMC13670298",
  "language": "eng",
  "licence": "CC-BY",
  "licence_label": "CC BY",
  "licence_source": "article",
  "licence_url": "https://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "openalex",
      "2212|Drilling and Well Engineering"
    ]
  ],
  "openalex": "W7214938927",
  "pdf_url": "https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13670298/pdf/?tool=EBI",
  "pmcid": "PMC13670298",
  "pmid": null,
  "published": "2026-09-30",
  "publisher": "American Chemical Society (ACS)",
  "ris": "https://research.draconitic.com/paper/cc0vkfyst9vqx.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:18:18Z",
      "native_id": "PMC:PMC13670298",
      "source": "europepmc",
      "url": "https://europepmc.org/article/PMC/PMC13670298"
    },
    {
      "first_seen": "2026-10-30T12:18:39Z",
      "native_id": "10.1021/acsomega.6c08519",
      "source": "crossref",
      "url": "https://pubs.acs.org/acsodf/article/11/40/62139/5442112/Thermoresponsive-Amphiphilic-Polymer-Emulsifier"
    }
  ],
  "subjects": [
    {
      "field": "chemistry",
      "origin": "issn:2470-1343",
      "subfield": "general"
    }
  ],
  "title": "Thermoresponsive Amphiphilic Polymer Emulsifier for Low-Dosage, High-Stability Oil-Based Drilling Fluids",
  "title_text": "Thermoresponsive Amphiphilic Polymer Emulsifier for Low-Dosage, High-Stability Oil-Based Drilling Fluids",
  "type": "peer-reviewed",
  "updated_at": "2026-10-30T12:18:39Z",
  "url": "https://research.draconitic.com/paper/cc0vkfyst9vqx",
  "venue": "ACS omega",
  "versions": []
}