Tough and fluorescent hydrogels composed of poly(hydroxyurethane) and poly(stearyl acrylate‐co‐acrylic acid) with hydrophobic associations and hydrogen bonds as the physical crosslinks

Abstract

Fluorescent hydrogels have promising applications in biomedical and engineering fields. However, they are usually mechanically weak. Here, we report a fluorescent composite hydrogel with high toughness, which is facilely prepared by solution casting ethanol solution of poly(hydroxyurethane) (PHU) and poly(stearyl acrylate‐co‐acrylic acid) (P[SA‐co‐AAc]) followed by swelling the casted film in water. The composite hydrogels with water content of 62–78 wt% possess remarkable mechanical performances, with tensile breaking stress of 0.3–1.1 MPa, breaking strain of 280%–400%, Young's modulus of 0.2–0.7 MPa, and tearing fracture energy of 1250–2630 J/m2. The high toughness is attributed to the effective energy dissipation of the network with hydrophobic association of SA units and hydrogen bonds between PHU and P(SA‐co‐AAc) as the physical crosslinks. The intense aggregation of carbamates and the formation of carbamate clusters through intra‐ and intermolecular hydrogen bonds endow the composite hydrogel with strong fluorescence. These hydrogels with high toughness and strong fluorescence should find applications in flexible electronics, information display, and biomedical devices.

Multi-level encryption of information in morphing hydrogels with patterned fluorescence

“…14,15 Owing to their close similarity to soft biotissues and promising applications in aqueous and biological environments, 16–19 hydrogels are recognized as ideal materials to carry fluorescent information. 8,20–22 For example, Ji et al prepared a set of fluorescent supramolecular hydrogels containing different chromophores. 23 The obtained hydrogels were assembled into different code arrays to deliver fluorescent information.…”

Metal Cation-Responsive and Excitation-Dependent Nontraditional Multicolor Fluorescent Hydrogels for Multidimensional Information Encryption

“…Up to now, very less attention has been paid to the fabrication of nontraditional fluorescent hydrogels (NTFHs). , Moreover, to our best knowledge, no multicolor FPHs for information encryption have been constructed by NLPs. In this work, we attempted to fabricate NTFHs without any traditional chromophores and explored their applications for information encryption.…”

Tough, Transparent, and Anti-Freezing Nanocomposite Organohydrogels with Photochromic Properties

“…Hydrogels, , consisting of a large amount of water, are soft and wet materials, which have been extensively used in many fields, such as tissue engineering, − sensors, , flexible devices, capacitors, − and smart windows. , The realization of functionalized hydrogels is often achieved by modification of functional groups or functional fillers. Photochromic hydrogels can be fabricated by adding photochromic fillers or ions into a hydrogel matrix.…”

“…28 However, their thin films are rigid and lack flexibility. Hydrogels, 29,30 consisting of a large amount of water, are soft and wet materials, which have been extensively used in many fields, such as tissue engineering, 31−33 sensors, 34,35 flexible devices, 36 capacitors, 37−39 and smart windows. 40,41 The realization of functionalized hydrogels is often achieved by modification of functional groups or functional fillers.…”