Synergistic Density Functional Theory and Molecular Dynamics Approach to Elucidate PNIPAM–Water Interaction Mechanisms
Noor Alomari, Santiago Aparicio, Paul Meyer, Yi Zeng, Shuang Cui, Alberto Gutiérrez, Mert Atilhan

TL;DR
This study uses advanced simulations to understand how water interacts with a temperature-sensitive polymer, revealing key molecular interactions and structural changes.
Contribution
The work introduces a combined DFT, QTAIM, and MD approach to systematically quantify hydration dynamics and pseudo-saturation thresholds in PNIPAM.
Findings
DFT identifies enhanced water binding in the linker zone of PNIPAM.
Hydrogen bonding and steric hindrance are critical for hydration dynamics.
Temperature changes alter hydration behavior, increasing hydrophobicity above the LCST.
Abstract
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…
Genes, proteins, chemicals, diseases, species, mutations and cell lines named across the full text — each resolved to its canonical identifier and authoritative record.
Click any figure to enlarge with its caption.
Figure 1
Figure 2
Figure 3
Figure 4
Figure 5
Figure 6
Figure 7
Figure 8
Figure 9
Figure 10
Figure 11
Figure 12
Figure 13
Figure 14
Figure 15
Figure 16
Figure 17
Figure 18
Figure 19
Figure 20Peer Reviews
No public reviews on file for this paper yet. If you reviewed it on a platform where reviews are public (OpenReview, ICLR, NeurIPS, ICML), you can paste yours below so the community can read it here.
Videos
No videos yet. Explain this paper in a talk, walkthrough, or lecture? Add one.
Taxonomy
TopicsHydrogels: synthesis, properties, applications · Spectroscopy and Quantum Chemical Studies · Material Dynamics and Properties
