Physically cross-linked starch/hydrophobically-associated poly(acrylamide) self-healing mechanically strong hydrogel

Flexible Polymer Hydrogels for Wearable Energy Storage Applications

“…Physical interactions that form the structure of polymer hydrogels in this category are mostly reversible and therefore, physically cross-linked polymer hydrogels can present selfhealing properties. [95] Although chemically cross-linked polymer hydrogels can normally present good mechanical properties, selfrecovery properties can be more easily achieved in physically cross-linked polymer hydrogels, as a fracture in chemically crosslinked polymer hydrogels mostly results in permanent internal damage and irreversible covalent interaction breakup. [96] Physically cross-linked polymer hydrogels with noncovalent bonding can be fabricated via the formation of hydrophobic interactions [95] or catechol-mediated dynamic interactions such as 𝜋-𝜋 or hydrogen/ionic bonding between polymer macromolecules.…”

“…[95] Although chemically cross-linked polymer hydrogels can normally present good mechanical properties, selfrecovery properties can be more easily achieved in physically cross-linked polymer hydrogels, as a fracture in chemically crosslinked polymer hydrogels mostly results in permanent internal damage and irreversible covalent interaction breakup. [96] Physically cross-linked polymer hydrogels with noncovalent bonding can be fabricated via the formation of hydrophobic interactions [95] or catechol-mediated dynamic interactions such as 𝜋-𝜋 or hydrogen/ionic bonding between polymer macromolecules. [97] Fabrication methods such as copolymerization, [95] crystallization, [75a,98] and freeze-thaw [99] can be used for the fabrication of physically cross-linked polymer hydrogels.…”

“…[96] Physically cross-linked polymer hydrogels with noncovalent bonding can be fabricated via the formation of hydrophobic interactions [95] or catechol-mediated dynamic interactions such as 𝜋-𝜋 or hydrogen/ionic bonding between polymer macromolecules. [97] Fabrication methods such as copolymerization, [95] crystallization, [75a,98] and freeze-thaw [99] can be used for the fabrication of physically cross-linked polymer hydrogels. Moreover, many different polymeric precursors or monomers, such as PVA, [100] acrylamide, [101] carboxymethyl cellulose, [102] etc., can be used to fabricate physically cross-linked polymer hydrogels.…”

“…Physically cross‐linked polymer hydrogels with noncovalent bonding can be fabricated via the formation of hydrophobic interactions [ 95 ] or catechol‐mediated dynamic interactions such as π – π or hydrogen/ionic bonding between polymer macromolecules. [ 97 ] Fabrication methods such as copolymerization, [ 95 ] crystallization, [ 75a,98 ] and freeze–thaw [ 99 ] can be used for the fabrication of physically cross‐linked polymer hydrogels.…”

A multifunctional sustainable ionohydrogel with excellent low-hysteresis-driven mechanical performance, environmental tolerance, multimodal stimuli-responsiveness, and power generation ability for wearable electronics

“…To address this challenge, one effective approach when designing hydrogels is to embed interactive rigid macromolecules into the hydrogel matrix to improve the storage modulus, such as cellulose, starch, gelatin, or xanthan gum. [34][35][36][37] Among these, starch is considered as the favorite candidate for reducing internal friction in hydrogels using a glycerol/water binary solvent system due to its outstanding gelatinization abilities both in water and glycerol. [38][39][40][41][42] Establishing stiff starch networks in the entire solvent system can not only address the above-mentioned problems to some degree, but it can also allow a homogeneous gel matrix, avoiding further separation in the gel matrix.…”