Hydrogen-Bond Association-Mediated Dynamics and Viscoelastic Properties of Tough Supramolecular Hydrogels

Du, Cong; Zhang, Xin Ning; Sun, Tao Lin; Du, Ming; Zheng, Qiang; Wu, Zi Liang

doi:10.1021/acs.macromol.1c00152

Cited by 111 publications

(92 citation statements)

References 65 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The relatively low modulus of the glassy hydrogel is due to the strong plasticizing effect of water that weakens the strength of associative interactions between the polymer chains . Similar phenomena have been found in other glassy hydrogels with dense hydrogen bonds or polyelectrolyte complexes. ,, …”

Section: Resultssupporting

confidence: 54%

“…As shown in Figure e, the frequency-sweep spectra of the MC-3-1/10 hydrogel at different temperatures converge to a master curve by time–temperature superposition (TTS). The validity of TTS to PESC hydrogel at a relatively low test temperature should be related to the stable network structure with robust physical cross-links, , in which the hydrophobic interaction enhances and stabilizes the electrostatic interaction between the surfactants and PMAAc chains. The apparent activation energy value E a is calculated as 137 kJ/mol from the Arrhenius plot of the shift factor α T (Figure e,f), indicating the high strength of PESCs.…”

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Plastic-Like Supramolecular Hydrogels with Polyelectrolyte/Surfactant Complexes as Physical Cross-links

et al. 2021

Self Cite

View full text Add to dashboard Cite

Developing hydrogels with new structures and extraordinary performances is fundamental and mission-critical for the advancements of gel materials. Here, we report a class of tough supramolecular hydrogels facilely prepared by polymerizing methacrylic acid precursor solution in the presence of hexadecyltrimethylammonium chloride micelles. After swelling the as-prepared hydrogels in water, strong polyelectrolyte/surfactant complexes (PESCs) are formed between the weakly charged polymer chains and oppositely charged surfactants, serving as the physical cross-links of the gel matrix. The equilibrated hydrogels are transparent with a water content of 50–85 wt % and possess excellent mechanical properties, with a tensile breaking stress of 0.1–5 MPa, a breaking strain of 600–1200%, and Young’s modulus of 1–70 MPa. Typical yielding is observed at a small tensile strain of ∼10%, followed by forced elastic deformation of the hydrogels, which are in a glassy state due to the reduced segmental mobility of the matrix highly cross-linked by PESCs. The plastic-like mechanical properties of hydrogels could be well tuned by pH, temperature, and ionic strength that influence the ionization of polymer chains and the strength of PESCs. These dynamic behaviors render the hydrogels with self-recovery and shape-memory properties. Furthermore, the nanosized hydrophobic pockets within the hydrogels afford the capacity of loading functional hydrophobic molecules with promising applications as fluorescent materials and drug delivery systems. The design principle and strategy should be extended to other systems, including biomacromolecules and lipids, toward broad applications in biomedical and engineering fields.

show abstract

Section: Resultssupporting

confidence: 54%

Section: Resultsmentioning

confidence: 99%

Plastic-Like Supramolecular Hydrogels with Polyelectrolyte/Surfactant Complexes as Physical Cross-links

et al. 2021

Self Cite

View full text Add to dashboard Cite

show abstract

“…These results imply that these samples developed cross‐linked structures via photo‐polymerization due to the introduction of the PEEL as a physical cross‐linker 41,42,49 . Generally, the G ′ value increased with increasing the hydrogen bonding strength due to the aspect of the increased hydrophobic surrounding in the physical cross‐linked networks system 50–52 . Along with, in this system, the G ′ value of all the samples increased with a larger proportion of DUCA.…”

Section: Resultsmentioning

confidence: 82%

“…41,42,49 Generally, the G 0 value increased with increasing the hydrogen bonding strength due to the aspect of the increased hydrophobic surrounding in the physical cross-linked networks system. [50][51][52] Along with, in this system, the G 0 value of all the samples increased with a larger proportion of DUCA. For example, CPNs-5 (DUCA networks) has a much higher G 0 value than that of CPNs-1 (DUA networks), which results in the higher G 0 value of cross-linked CPNs with a higher proportion of DUCA.…”

Section: Rheological Properties Of Crosslinked Copolymer Networkmentioning

confidence: 91%

Tunable cross‐linked copolymer networks for improvement of physical performance

Kim

Park

Choi

et al. 2021

Journal of Polymer Science

View full text Add to dashboard Cite

The ability to tune the physical properties of polymeric materials through the different compositions in copolymer networks is suitable for the strategy of materials accompanied by combined high mechanical strength and stretchability simultaneously. Here, we developed a practical and straightforward strategy of a copolymer network structure via controlling the compositions of the acrylic-based urethane copolymers of diurethane acrylate (DUA) and diurethane cyclic acrylate (DUCA) with hydrogen-bonds through photo-polymerization. The copolymer networks led to the development of a physically cross-linked structure between the amide groups of DUA and/or DUCA and the hydroxyl groups of pentaerythritol ethoxylate (PEEL) by hydrogen-bonds. Based on the rheological analysis, the composition of the copolymer networks had a significant effect on the control of physical properties and development of cross-linked structure and thus led to the tunable comprehensive properties including high elastic modulus, high chain mobility and high recovery performance with a higher proportion of DUCA in the copolymer networks. Consequently, the tunable copolymer networks based on the developed physically cross-linked structure can improve the elastic properties, recovery performance, and healing ability simultaneously, providing significant progress in the fields of coating and adhesive. K E Y W O R D Scopolymers, cross-linked networks, hydrogen-bond, photo-polymerization, polyurethane acrylate | INTRODUCTIONDesigning polymer networks to tune their physical properties is essential for self-healing materials. They have recently been tremendous attention, which has been used in a wide range of fields such as high-performance coating, adhesives, paints, biomedical applications and so forth. [1][2][3][4][5][6] To further expand the applications fields, the recent approaches to achieve self-healing functions give rise to simultaneously not only excellent mechanical properties including strength, toughness, and elasticity but also self-healing behaviors. However, the concurrent combination of high modulus and high flexibility of the materials is still a great challenge because there is a trade-off between these properties. [7][8][9] To achieve the requirement for the self-healing materials, they are widely derived from the introduction of cross-linked polymer networks, which are able to link between

show abstract

“…Recent works showed that U ̃≈ 2−7k b T in isolated conditions. 33 Du et al 13 obtained the critical energy U ̃≈ 19k b T for hydrogen bond dissociation from the dynamic moduli spectra determined by rheological measurements.…”

Section: Dissociation Of a Hydrogen Bond Based Cross-linkmentioning

confidence: 99%

Understanding the Dissociation of Hydrogen Bond Based Cross-Links In Hydrogels Due to Hydration and Mechanical Forces

Cohen

2021

Macromolecules

Self Cite

View full text Add to dashboard Cite

The submersion of a polymer network with a high density of hydrogen bond based cross-links in an aqueous bath results in the formation of a rubberlike hydrogel. The cross-links, which connect chains and maintain the structure of the network, can dissociate as a result of two main factors: (1) the interactions between the hydrogen bonds and the surrounding water molecules and (2) the forces that are exerted on the cross-link from the interconnected chains. We recall that these forces depend on the ratio between the end-to-end distance and the overall contour length of the chains. The application of an external loading translates into the stretching of chains in the network and, as a consequence, an increase in the forces that are exerted. Sufficiently large external loadings can break cross-links and alter the microstructure of the network. From a macroscopic viewpoint, the breaking of cross-links leads to significant microstructural changes such as a reduction in the chain density and an entropic gain. In this work, we derive a microscopically motivated and energy-based model that captures the effects of hydration and external loadings on the overall changes in properties and mechanical response of hydrogels. We provide a systematic method to estimate the percentage of crosslinks that dissociate due to hydration and application of a force and provide representative examples to highlight the influence of the orientations of the interconnected chains with respect to a cross-link. To validate the model, we carry out uniaxial tension experiments on poly(methacrylic acid) hydrogels with five different water contents and fit the model parameters. We show that the model is capable of qualitatively and quantitatively capturing the experimental results. The model is also used to approximate the number of cross-links that dissociate due to the water and the externally applied uniaxial force. This work paves the way to the efficient design of multifunctional synthetic hydrogels with programmable properties and behaviors.

show abstract

Hydrogen-Bond Association-Mediated Dynamics and Viscoelastic Properties of Tough Supramolecular Hydrogels

Cited by 111 publications

References 65 publications

Plastic-Like Supramolecular Hydrogels with Polyelectrolyte/Surfactant Complexes as Physical Cross-links

Plastic-Like Supramolecular Hydrogels with Polyelectrolyte/Surfactant Complexes as Physical Cross-links

Tunable cross‐linked copolymer networks for improvement of physical performance

Understanding the Dissociation of Hydrogen Bond Based Cross-Links In Hydrogels Due to Hydration and Mechanical Forces

Contact Info

Product

Resources

About