Dynamic Covalent Hydrogels: Strong yet Dynamic

Hydrogels are crosslinked polymer networks with time-dependent mechanical response. The overall mechanical properties are correlated with the dynamics of the crosslinks. Generally, hydrogels crosslinked by permanent chemical crosslinks are strong but static, while hydrogels crosslinked by physical i...

Full description

Bibliographic Details
Main Authors: Yueying Han, Yi Cao, Hai Lei
Format: Article
Language:English
Published: MDPI AG 2022-09-01
Series:Gels
Subjects:
Online Access:https://www.mdpi.com/2310-2861/8/9/577
_version_ 1797488147052888064
author Yueying Han
Yi Cao
Hai Lei
author_facet Yueying Han
Yi Cao
Hai Lei
author_sort Yueying Han
collection DOAJ
description Hydrogels are crosslinked polymer networks with time-dependent mechanical response. The overall mechanical properties are correlated with the dynamics of the crosslinks. Generally, hydrogels crosslinked by permanent chemical crosslinks are strong but static, while hydrogels crosslinked by physical interactions are weak but dynamic. It is highly desirable to create synthetic hydrogels that possess strong mechanical stability yet remain dynamic for various applications, such as drug delivery cargos, tissue engineering scaffolds, and shape-memory materials. Recently, with the introduction of dynamic covalent chemistry, the seemingly conflicting mechanical properties, i.e., stability and dynamics, have been successfully combined in the same hydrogels. Dynamic covalent bonds are mechanically stable yet still capable of exchanging, dissociating, or switching in response to external stimuli, empowering the hydrogels with self-healing properties, injectability and suitability for postprocessing and additive manufacturing. Here in this review, we first summarize the common dynamic covalent bonds used in hydrogel networks based on various chemical reaction mechanisms and the mechanical strength of these bonds at the single molecule level. Next, we discuss how dynamic covalent chemistry makes hydrogel materials more dynamic from the materials perspective. Furthermore, we highlight the challenges and future perspectives of dynamic covalent hydrogels.
first_indexed 2024-03-09T23:57:54Z
format Article
id doaj.art-e7deba4df09543b587733e040fda98ae
institution Directory Open Access Journal
issn 2310-2861
language English
last_indexed 2024-03-09T23:57:54Z
publishDate 2022-09-01
publisher MDPI AG
record_format Article
series Gels
spelling doaj.art-e7deba4df09543b587733e040fda98ae2023-11-23T16:22:24ZengMDPI AGGels2310-28612022-09-018957710.3390/gels8090577Dynamic Covalent Hydrogels: Strong yet DynamicYueying Han0Yi Cao1Hai Lei2Collaborative Innovation Center of Advanced Microstructures, National Laboratory of Solid State Microstructure, Department of Physics, Nanjing University, Nanjing 210093, ChinaCollaborative Innovation Center of Advanced Microstructures, National Laboratory of Solid State Microstructure, Department of Physics, Nanjing University, Nanjing 210093, ChinaCollaborative Innovation Center of Advanced Microstructures, National Laboratory of Solid State Microstructure, Department of Physics, Nanjing University, Nanjing 210093, ChinaHydrogels are crosslinked polymer networks with time-dependent mechanical response. The overall mechanical properties are correlated with the dynamics of the crosslinks. Generally, hydrogels crosslinked by permanent chemical crosslinks are strong but static, while hydrogels crosslinked by physical interactions are weak but dynamic. It is highly desirable to create synthetic hydrogels that possess strong mechanical stability yet remain dynamic for various applications, such as drug delivery cargos, tissue engineering scaffolds, and shape-memory materials. Recently, with the introduction of dynamic covalent chemistry, the seemingly conflicting mechanical properties, i.e., stability and dynamics, have been successfully combined in the same hydrogels. Dynamic covalent bonds are mechanically stable yet still capable of exchanging, dissociating, or switching in response to external stimuli, empowering the hydrogels with self-healing properties, injectability and suitability for postprocessing and additive manufacturing. Here in this review, we first summarize the common dynamic covalent bonds used in hydrogel networks based on various chemical reaction mechanisms and the mechanical strength of these bonds at the single molecule level. Next, we discuss how dynamic covalent chemistry makes hydrogel materials more dynamic from the materials perspective. Furthermore, we highlight the challenges and future perspectives of dynamic covalent hydrogels.https://www.mdpi.com/2310-2861/8/9/577dynamic covalent chemistryhydrogelsingle molecule force spectroscopyliquid-like properties
spellingShingle Yueying Han
Yi Cao
Hai Lei
Dynamic Covalent Hydrogels: Strong yet Dynamic
Gels
dynamic covalent chemistry
hydrogel
single molecule force spectroscopy
liquid-like properties
title Dynamic Covalent Hydrogels: Strong yet Dynamic
title_full Dynamic Covalent Hydrogels: Strong yet Dynamic
title_fullStr Dynamic Covalent Hydrogels: Strong yet Dynamic
title_full_unstemmed Dynamic Covalent Hydrogels: Strong yet Dynamic
title_short Dynamic Covalent Hydrogels: Strong yet Dynamic
title_sort dynamic covalent hydrogels strong yet dynamic
topic dynamic covalent chemistry
hydrogel
single molecule force spectroscopy
liquid-like properties
url https://www.mdpi.com/2310-2861/8/9/577
work_keys_str_mv AT yueyinghan dynamiccovalenthydrogelsstrongyetdynamic
AT yicao dynamiccovalenthydrogelsstrongyetdynamic
AT hailei dynamiccovalenthydrogelsstrongyetdynamic