Open Access

ARTICLE

Molecular Dynamics Study on Hydrothermal Response of PNIPAM: From Single Chain to Cross-Linked Polymer

Xianzhi Chen¹, Dong Niu^1,*, Hongtao Gao¹, Mu Du^2,3,*
1 Institute of Refrigeration & Cryogenics Engineering, Dalian Maritime University, Dalian, 116026, China
2 Institute for Advanced Technology, Shandong University, Jinan, 250061, China
3 Shenzhen Research Institute of Shandong University, Shandong University, Shenzhen, 518057, China
* Corresponding Author: Dong Niu. Email: ; Mu Du. Email:
(This article belongs to the Special Issue: Microscale Heat and Mass Transfer and Efficient Energy Conversion)

Frontiers in Heat and Mass Transfer https://doi.org/10.32604/fhmt.2024.058274

Received 09 September 2024; Accepted 15 October 2024; Published online 11 November 2024

Abstract

Thermosensitive hydrogel can integrate vapor molecular capture, in-situ liquefaction, and thermal-induced water release for freshwater capture. This study aimed to examine the dynamic behavior of poly (N-isopropylacrylamide) (PNIPAM) single chain and cross-linking thermosensitive hydrogel through molecular dynamics simulation. Specifically, the impact of lower critical solution temperature (LCST) on the conformation of polymer chain and the interaction between water and polymer chain were also investigated. The polymer chain conformation underwent a transition from coil to globule when the temperature exceeded the LCST, indicating the temperature responsiveness of PNIPAM. Additionally, thermosensitive hydrogel samples with different cross-linking degrees (DOC) were studied, and relevant parameters such as the number of free water, the diffusion coefficient of water, and the pore size distribution were counted to evaluate the temperature responsiveness and water release characteristics of thermosensitive hydrogel.

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Graphical Abstract

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Keywords

Thermosensitive hydrogel; water harvesting; coil to globule; cross-linked; molecular dynamics simulation

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