Effect of solvent–matrix interactions on structures and mechanical properties of micelle‐crosslinked gels

Abstract

Previous studies on hydrogels crosslinked by acrylated PEO99–PPO65–PEO99 triblock copolymer (F127DA) micelles demonstrate outstanding strength and toughness, which is attributed to the efficient energy dissipation through the hydrophobic association in the micelles. The current study further focuses on how the solvent property affects the structures and the mechanical properties of F127DA micelle crosslinked polyacrylamide gels. Binary solvents comprised of dimethyl sulfoxide (DMSO) and water are used to adjust the polymer/solvent interactions, which consequently tune the conformations of the polymer chains in the network. The presence of DMSO significantly decreases the strength but increased the stretchability of the gels, whereas the overall tensile toughness remained unchanged. In situ small‐angle X‐ray scattering measurements reveal the deformation of micelles along with the stretching direction. A structure evolution mechanism upon solvent change is proposed, according to the experimental observations, to explain influence of solvent quality on the mechanical properties of the micelle‐crosslinked gels. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2019, 57, 473–483

Reinforced macromolecular micelle-crosslinked hyaluronate gels induced by water/DMSO binary solvent

“…28,29 For F127 chains, the calculated PPO/H 2 O value is 3.48, much larger than that of the PPO/DMSO pair (0.55). 30 Therefore, the PPO block drives the self-assembly of the copolymer chains into micelles in both solutions, while these micelles collapse much more in water. As a result, the FH 0 hydrogel shows the maximum swelling degree (Fig.…”

Triblock Copolymer Micelle-Crosslinked Hydrogels

“…The influence of solvent quality on the structures and mechanical properties of F127DA micelle-crosslinked hydrogels has been systematically investigated by Xu et al [24]. An organic solvent, dimethyl sulfoxide (DMSO), which is water soluble and less selective than water to the polymer chains, is used to tune the selectivity of solvent in the gels.…”

“…The corresponding meridian scattering profiles of the gels at (c) 0, (d) 100%, and (e) 300% strains. (f) The long period of the gels at different strains as calculated from the scattering vectors q. Reprinted from Ref [24]. with permission.…”

“…SEM images of (b) MFD 1,ex and (c) MFD 0,ex gels after complete solvent exchange. Reprinted from Ref [24]. with permission.…”

Poly(l‐glutamic acid)‐based micellar hydrogel with improved mechanical performance and proteins loading

“…Many efforts have been made to promote the mechanical performance of hydrogels, including chemical–physical double networks and hydrophobic modified hydrogels that would form hydrophobic microdomains in networks to realize the stress consumption . Among these efforts, introduction of micelles, which undergo microscopic phase separation in aqueous environment, could consume the external loading to impart the hydrogels with higher resistance under big strain . Most importantly, the micelles also can work as carriers of biomolecules to realize controlled release, so to improve regeneration effect …”