{
  "abstract": "Chitosan grafted with N-alkyl-substituted polyacrylamide yields dual-responsive materials sensitive to both pH and temperature. For instance, the phase transition of poly(N,N-diethylacrylamide) can be tuned by copolymerizing it with more hydrophilic units, such as N,N-dimethylacrylamide or N-ethylacrylamide. While hydrophilic and hydrophobic interactions between macromolecular segments drive this phase transition, the specific role of hydrogen bonding between chitosan and the polyacrylamide grafts is not fully understood yet. Clarifying how these interactions influence the volume phase transition is essential for predicting hydrogel behavior. Chitosan-g-poly(DEAm-co-DMAm) and chitosan-g-poly(DEAm-co-NEAm) hydrogels showed continuous volume phase transitions that broadened with increased content of hydrophilic units (DMAm or NEAm). The critical temperature (Tc) of chitosan-g-poly(DEAm-co-DMAm) hydrogels increased linearly with the content of DMAm, while chitosan-g-poly(DEAm-co-NEAm) hydrogels exhibited a downward deviation from the linear variation in Tc from 0 to 100 mol-% DEAm. Both hydrogels showed higher swelling in acidic conditions at temperatures below the Tc, with a marked reduction as pH turned basic. Above the Tc, the pH response was almost negligible. Evidence suggests that the formation of hydrophobic domains of N,N-diethylacrylamide units during heating could bring the N-alkyl polyacrylamide and the chitosan chains closer together. This promotes inter-chain hydrogen bonding, which favors the cooperative character of the transition.",
  "abstract_shown": true,
  "affiliations": [
    "Centro de Investigación en Alimentación y Desarrollo, Hermosillo 83304, Sonora, Mexico",
    "Faculty of Chemistry, Universidad de La Habana, La Habana 10400, Cuba"
  ],
  "article_type": null,
  "arxiv": null,
  "author_total": 4,
  "authors": [
    {
      "affs": [
        0
      ],
      "name": "José Javier Coca-Hidalgo",
      "orcid": "0009-0009-0491-7936"
    },
    {
      "affs": [
        1
      ],
      "name": "Carlos Peniche-Covas",
      "orcid": "0000-0003-2563-0132"
    },
    {
      "affs": [
        0
      ],
      "name": "Jaime Lizardi-Mendoza",
      "orcid": "0000-0003-4636-4371"
    },
    {
      "affs": [
        0
      ],
      "name": "Waldo Manuel Argüelles-Monal",
      "orcid": "0000-0002-8356-1123"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/6w8dk58zj29s8.bib",
  "cited_by": 0,
  "doi": "10.3390/polym18212787",
  "fulltext_url": null,
  "id": "6w8dk58zj29s8",
  "issns": [
    "2073-4360"
  ],
  "landing_url": "https://www.mdpi.com/2073-4360/18/21/2787",
  "language": null,
  "licence": "CC-BY-4.0",
  "licence_label": "CC BY 4.0",
  "licence_source": "article",
  "licence_url": "https://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": null,
  "native_subjects": [],
  "openalex": null,
  "pdf_url": null,
  "pmcid": null,
  "pmid": null,
  "published": "2026-11-07",
  "publisher": "MDPI AG",
  "ris": "https://research.draconitic.com/paper/6w8dk58zj29s8.ris",
  "sources": [
    {
      "first_seen": "2026-11-10T00:21:22Z",
      "native_id": "10.3390/polym18212787",
      "source": "crossref",
      "url": "https://www.mdpi.com/2073-4360/18/21/2787"
    }
  ],
  "subjects": [
    {
      "field": "chemistry",
      "origin": "issn:2073-4360",
      "subfield": "materials-polymers"
    }
  ],
  "title": "Thermal and pH Responses of Hydrogels Based on Chitosan-g-N-Alkyl-Substituted Polyacrylamide Copolymers",
  "title_text": "Thermal and pH Responses of Hydrogels Based on Chitosan-g-N-Alkyl-Substituted Polyacrylamide Copolymers",
  "type": "peer-reviewed",
  "updated_at": "2026-11-10T00:21:22Z",
  "url": "https://research.draconitic.com/paper/6w8dk58zj29s8",
  "venue": "Polymers",
  "versions": []
}