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oai:riubu.ubu.es:10259/120282026-09-08T00:05:35Zcom_10259_4323com_10259_5086com_10259_2604col_10259_4330

Alomari, Noor 51ffd517-fe82-4928-a989-9b14f9d7a6c1 600 Aparicio Martínez, Santiago 30 600 0000-0001-9996-2426 Meyer, Paul b0c5334b-d85a-4f9d-ab6f-cd80026c0a79 Zeng, Yi 815ce9dd-7524-4501-9fda-72cceee8ce1d Cui, Shuang cd77b7a5-b716-46e0-98cf-03f084740784 Gutiérrez Vega, Alberto 271 600 0000-0003-2000-7413 Atilhan, Mert 51023856-6e72-4667-b27a-fe52e5115d61 600 2026-09-07T11:34:00Z 2026-09-07T11:34:00Z 2025-05 https://hdl.handle.net/10259/12028 10.3390/MA18112498 1996-1944 This study employs Density Functional Theory (DFT) and Molecular Dynamics (MD) simulations to investigate interactions between water molecules and Poly(N-isopropylacrylamide) (PNIPAM). DFT reveals preferential water binding sites, with enhanced binding energy observed in the linker zone. Quantum Theory of Atoms in Molecules (QTAIM) and electron localization function (ELF) analyses highlight the roles of hydrogen bonding and steric hindrance. MD simulations unveil temperature-dependent hydration dynamics, with structural transitions marked by changes in the radius of gyration (Rg) and the radial distribution function (RDF), aligning with DFT findings. Our work goes beyond prior studies by combining a DFT, QTAIM and MD simulations approach across different PNIPAM monomer-to-30mer structures. It introduces a systematic quantification of pseudo-saturation thresholds and explores water clustering dynamics with structural specificity, which have not been previously reported in the literature. These novel insights establish a more complete molecular-level picture of PNIPAM hydration behavior and temperature responsiveness, emphasizing the importance of amide hydrogen and carbonyl oxygen sites in hydrogen bonding, which weakens above the lower critical solution temperature (LCST), resulting in increased hydrophobicity and paving the way for understanding water sorption mechanisms, offering guidance for future applications such as dehumidification and atmospheric water harvesting. This research is based upon work supported by the U.S. Department of Energy’s Office on Energy Efficiency and Renewable Energy (EERE) under the Advanced Manufacturing Office, award number DE-EE0010200. This work was also supported through computational resources and services provided by the Institute for Cyber-Enabled Research at Michigan State University. Author Alberto Gutiérrez received grant BG22/00089, funded by Spanish Ministerio de Universidades. And Shuang Cui also acknowledges the support from the University of Texas at Dallas startup fund and the National Science Foundation (grant No. 2318720). The statements made herein are solely the responsibility of the authors. This work was authored in part by the National Renewable Energy Laboratory, operated by Alliance for Sustainable Energy, LLC, for the U.S. Department of Energy (DOE) under Contract No. DE-AC36-08GO28308. Support for the work was also provided by the Industrial Efficiency and Decarbonization Office under Award Number DE-EE0010200. The views expressed in the article do not necessarily represent the views of the DOE or the U.S. Government. The U.S. Government retains and the publisher, by accepting the article for publication, acknowledges that the U.S. Government retains a nonexclusive, paid-up, irrevocable, worldwide license to publish or reproduce the published form of this work, or to allow others to do so, for U.S. Government purposes. application/pdf eng MDPI Materials. 2025, V. 18, n. 11. art. 2498 https://doi.org/10.3390/ma18112498 Atribución 4.0 Internacional http://creativecommons.org/licenses/by/4.0/ info:eu-repo/semantics/openAccess Poly(N-isopropylacrylamide) (PNIPAM) Water sorption Hydrogen bonding interactions DFT calculations MD(LAMMPS) simulations lower critical solution temperature Dinámica molecular Molecular dynamics Synergistic Density Functional Theory and Molecular Dynamics Approach to Elucidate PNIPAM–Water Interaction Mechanisms info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion Materials 18 11 2498 THUMBNAIL Alomari-materials_2025.pdf.jpg Alomari-materials_2025.pdf.jpg IM Thumbnail image/jpeg 4631 https://riubu.ubu.es/bitstream/10259/12028/4/Alomari-materials_2025.pdf.jpg 6a5fa6b70454e390a4233b1fef5d6b70 MD5 4 LICENSE license.txt license.txt text/plain; charset=utf-8 998 https://riubu.ubu.es/bitstream/10259/12028/3/license.txt aa90105e1c90a1b4fe810649aa967b7d MD5 3 CC-LICENSE license_rdf license_rdf application/rdf+xml; charset=utf-8 908 https://riubu.ubu.es/bitstream/10259/12028/2/license_rdf 0175ea4a2d4caec4bbcc37e300941108 MD5 2 ORIGINAL Alomari-materials_2025.pdf Alomari-materials_2025.pdf application/pdf 9264432 https://riubu.ubu.es/bitstream/10259/12028/1/Alomari-materials_2025.pdf 34e753447aa00729b46e925c15ba953f MD5 1 10259/12028 oai:riubu.ubu.es:10259/12028 2026-09-08 02:05:35.725 Repositorio Institucional de la Universidad de Burgos bubrep@ubu.es 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