Robust nanostructured POSS-PEG hydrogels. Self-deployment powered by water
Por:
Romo-Uribe A.
Publicada:
1 ene 2022
Resumen:
Molecular networks of polyethylene glycol (PEG) and polyhedral oligomeric silsesquioxane (POSS) were prepared by UV curing at 90:10 wt% ratio. POSS mechanically reinforced and produced robust molecular hydrogels with shape memory (SM) behavior triggered by water. In solid state POSS induced over an order of magnitude increase of shear modulus and temperature-activated SM behavior [Romo-Uribe, Polymer 250, 124,899, 2022]. Here a hydration-activated SM behavior is reported, at temperature below PEG crystallization temperature; first a temporary shape is imposed by melting and then fixing by the recrystallization of PEG when cooling down the specimen. That is, a temporary shape was locked in by PEG crystallization, and the network “remembered” its permanent shape upon water submersion due to the dissolution of the crystallites. The hydration released the stresses through the crystalline phase and resulted in soft actuation. The viscosity of the hydrogels obeyed the power-law scaling |?*| ~ ? -1, thus behaving as perfect networks, and POSS induced nearly two orders of magnitude increase of the shear elastic moduli relative to the unreinforced hydrogel. These versatile and mechanically robust hydrogels also exhibited antibacterial behavior towards Candida albicans and Staphylococcus aureus strains therefore enabling applications in actuators, scaffolds, wound healing, and responsive materials. © 2022 Elsevier Ltd
Filiaciones:
Romo-Uribe A.:
Research & Development, Advanced Science & Technology Division, Johnson & Johnson Vision Care Inc.FL 32256, United States
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