Polyvinyl Alcohol‐Based Thermogel with Tunable Gelation and Self‐Healing Property

Abstract

Self-Healing HydrogelsInjectable thermogelated hydrogels with self-healing and multi-responsiveness are emerging as a class of significant "smart" materials because of their many potential applications. However, there are only very limited precedents that combine thermogels with self-healing and tunable functions. In this work, it is demonstrated that N-alkyl substituted carbamate modified polyvinyl alcohol with borax as a crosslinker enables a variety of tunable and dynamic thermogelation properties. As far as it is known, this is the first polyvinyl alcoholbased thermogel system. This system characterizes shear thinning, multiple responsiveness, and dynamic gelation features. Systematic investigation suggests that these features collaborate to contribute to attractive injectability, quick self-healing ability, and tunable thermogelation behavior. A stepwise in situ gelation and carbon dioxide-triggered release are demonstrated. 2 of 7) www.advancedsciencenews.com www.mcp-journal.de (

A simple PVA/Cu(OAc)2 thermogel with an inherent near-infrared light response and its applications in smart windows and photoresistors

“…It is known that the broadening of proton peaks implies that insoluble polymer segments form or polymer chains are kinetically limited in solution, as 1 H NMR signals arise only from protons in a liquid-like fraction. 45 Therefore, it was deduced that the generated Cu(OH)2 clusters can be surrounded by PVA hydrophobic backbones to form a green clathrate complexes [Cu(OH)2-PVA] via hydrophobic forces, similar to the report by Yokoi. 41,42 In this case, PVA chains fixed by Cu(OH)2 clusters had undetectable 1 H NMR signals while Cu(OH)2 clusters surrounded by PVA chains were difficult to aggregate into larger-sized precipitates.…”

“…On account of the absorption of NIR light and the intrinsic temperature sensitivity, this PVA/Cu(OAc)2 thermogel showed a promising application in the fields of smart window and photoresistor (Scheme 1). Notably, different from other reported PVA-based hydrogels which either required the tedious modification of PVA or the extra harsh basic condition, [45][46][47] our PVA/Cu(OAc)2 thermogel was induced by NIR light directly without additional chemical modification of PVA or incorporation of extra reagents. In this system, Cu 2+ acted as a photothermal reagent and a crosslinker simultaneously.…”

Strong, thermo-reversible salogels with boronate ester bonds as thermal energy storage materials

“…S3† showing that in high frequency regime beyond the modulus crossover both storage and loss moduli continued to increase. Note that the frequency-dependent behavior of the crossover point was broadly reported for many physical gels, 9,45,46 including borax-crosslinked systems, 47,48 and often explained by heterogeneity and clustering of weak physical crosslinks, 13,49 which is likely to occur in the borax-free PVA salogels stabilized by intermolecular hydrogen bonding. Fig.…”

Branched PCL-Based Thermogelling Copolymers: Controlling Polymer Architecture to Tune Drug Release Profiles

“…The EPCG thermogels formed were also demonstrated to have good recoverability after being subjected to high strains, as characteristic of many injectable supramolecular hydrogels ( Liu et al, 2018 ; Ren et al, 2020 ). They were able to fully regain their storage moduli despite being subjected to repeated cycles of high strains that cause the temporary disruption of the supramolecular matrixes ( Figure 4D ).…”