Construction and Properties of Hydrophobic Association Hydrogels with High Mechanical Strength and Reforming Capability

Abstract

Hydrophobic association hydrogels (HA‐gels) with almost ideal properties were successfully prepared by micellar copolymerization, and the associated micelles acted as physical cross‐linking points in the network of HA‐gels. HA‐gels exhibit exceptional mechanical properties and transparency. However, the most striking properties are that HA‐gels possess the capability of self‐healing and remolding, which is mainly due to the dissociation and re‐association process of the associated micelles. Dried‐gels, which were prepared by stretching HA‐gels to a certain elongation for a period of time in the air, can be used as shrinkable or thermal sensitivity materials. HA‐gels have a broad selectivity for components, so we have synthesized HA‐gels with variously available properties by changing a corresponding component: thermoresponsive HA‐gels, nanosphere‐composite HA‐gels, and fluorescent HA‐gels. Therefore, we are sure that HA‐gels will be widely used in various fields, such as biology, medication, sensors, optics, and oil exploitation.magnified image

Facile fabrication method of hydrophobic-associating cross-linking hydrogel with outstanding mechanical performance and self-healing property in the absence of surfactants

“…The first category produces chemical cross-linking hydrogels, including topological hydrogels (TP gels) [6,7], double network hydrogels (DN gels) [8], nanocomposite hydrogels (NC gels) [9,10], and macromolecular microsphere composite hydrogels (MMC gels) [11,12]. The second category produces physical cross-linking hydrogels, including those formed through electrostatic force [13,14], hydrogen bonding [15], pep stacking interaction [16] and hydrophobic interaction [17].…”

Hydrogen‐bonded supramolecular polymers as self‐healing hydrogels: Effect of a bulky adamantyl substituent in the ureido‐pyrimidinone monomer

“…Recently, self‐healing hydrogel films have been created by the alternating layer‐by‐layer deposition of a covalently crosslinked anionic polymer (as a “microgel”) and a cationic polymer containing quaternary amine moieties . Hydrogels have been also reported where the self‐healing characteristics appeared to be imparted by hydrophobic interactions . Other re‐mendable hydrogels can result from a process of molecular recognition in cyclodextrin systems …”

Fast and excellent healing of hydroxypropyl guar gum/poly(N,N‐dimethyl acrylamide) hydrogels

“…The healing of hydrogels is mostly realized by reversible interactions between polymer backbones or functional groups on the polymer chains in the hydrogels . The interactions used for healing mainly include hydrogen bonding, ionic bonding, hydrophobic bonding, and dynamic covalent bonding . For example, thanks to the complex structures of nanoparticles, which cannot just dispersed into the polymer network, but act as multifunctional crosslinks and form reversible interactions, more healing hydrogels have been developed .…”