Post-Self-Assembly Cross-Linking of Molecular Nanofibers for Oscillatory Hydrogels

Abstract

After a polymerizable hydrogelator self-assembles in water to form molecular nanofibers, post-self-assembly cross-linking allows the catalyst of the Belousov-Zhabotinsky (BZ) reaction to be attached to the nanofibers, resulting in a hydrogel that exhibits concentration oscillations, spiral waves, and concentric waves. In addition to the first report of the observation of BZ spiral waves in a hydrogel that covalently integrates the catalyst, we suggest a new approach to developing active soft materials as chemical oscillators and for exploring the correlation between molecular structure and far-from-equilibrium dynamics.

Printable hybrid hydrogel by dual enzymatic polymerization with superactivity

“…Recently, our group developed polymer enhanced hybrid self-recovering hydrogels via glucose oxidase mediated polymerization 24. Another post-self-assembly cross-linking approach was reported by Xu et al , who demonstrated that in situ photo-polymerization of acrylic modified oligopeptide hydrogelators with copolymers can achieve a tough hydrogel 25,26. Moreover, these hydrogels have been utilized in multiple applications such as the immobilization of enzymes, controlled release of drugs, controlled cell adhesion and biomimetic materials 21–24,27–29…”

“…Therefore, we report herein a dual enzyme-mediated redox initiation to achieve post-self-assembly cross-linking of acrylic modified hydrogelators (NapFFK-acrylic acid, Scheme S1a†)25,26 with monomers for hybrid hydrogel generation. The injectable supramolecular hydrogel is printed into a 3D structure due to the sol–gel transition and quick recovery during the pressure-driven prototyping.…”

Designed Autonomic Motion in Heterogeneous Belousov–Zhabotinsky (BZ)‐Gelatin Composites by Synchronicity

“…[ 14 , 15 ] When the BZ gel is immersed in a solution containing all the BZ reactants except the metal catalyst, periodic, chemically-driven oxidation and reduction of the catalyst occurs only within the hydrogel, affecting the solubility of the network and producing a swell-deswell motion of the gel, i.e., autonomic conversion of chemical to mechanical energy. [ 16 ] Recently, several interesting works have placed an emphasis on examining the infl uence of internal structure on the behavior of homogeneous oscillating gels, [17][18][19] and on chemical coupling between individual BZ oscillators in close proximity (beads, emulsions, and gel disks). [ 9 , 20-26 ] The nature of the chemical wave in BZ gels is characterized by a critical length ( ≈ 0.8 mm), which is established by the transport of the reactants and products.…”

Organometallic Hydrogels

“…Reprinted and modified from Ref. , , with permission. Copyright 2013 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim, 2013 American Chemical Society.…”

“…To integrate metal‐complexes into BZ hydrogels, a novel synthetic approach, termed as post‐self‐assembly cross‐linking, was proposed by Xu et al . According to this method, they combined molecular nanofibers of hydrogelators with copolymers, generating oscillatory materials via BZ reaction.…”