2 research outputs found
Tannic Acid-Based Multifunctional Hydrogels with Facile Adjustable Adhesion and Cohesion Contributed by Polyphenol Supramolecular Chemistry
Adhesiveness of hydrogels
depends on the balance and synergy of
their cohesion and adhesion. However, it is a challenge to fabricate
catechol-based hydrogels with high adhesiveness because the required
condition for cohesion and adhesion of these hydrogels is in conflict
with each other: strong cohesion (gelation) requires a weak basic
condition, whereas strong adhesion requires an acidic condition. Here,
we demonstrated that by utilizing polyphenol supramolecular chemistry,
the coexistence of strong cohesion and adhesion can be achieved in
a hydrogel via the one-pot method. PolyÂ(dimethyl diallyl ammonium
chloride)/tannic acid (PDDA/TA) hydrogel has been studied as a proof
of concept. Compared with catechol moieties that covalently grafted
on polymer chains, TA can bring high density of pyrogallol/catechol
functional groups for polymers via a noncovalent pathway, as well
as high acidity in the system. As a result, the cohesion of the hydrogel
is enhanced significantly, the highest storage moduli can reach up
to ca. 0.15 MPa; besides, the high acidity of the hydrogel prevents
pyrogallol/catechol groups from oxidation and guarantees strong adhesion;
thus, the hydrogel can adhere to diverse substrates steadily, including
tissues, glass, metals, and plastic. Moreover, because of the adjustable
adhesiveness via changing the pH, the PDDA/TA hydrogel becomes a unique
system with patternable adhesiveness. In addition, the hydrogel has
rapid self-healing and high ionic conductivity (∼4.3 S m<sup>–1</sup>). This study demonstrates that utilizing polyphenol
chemistry in the construction of hydrogels opens a new path toward
multifunctional hydrogels with improved properties
Tannic Acid-Based Multifunctional Hydrogels with Facile Adjustable Adhesion and Cohesion Contributed by Polyphenol Supramolecular Chemistry
Adhesiveness of hydrogels
depends on the balance and synergy of
their cohesion and adhesion. However, it is a challenge to fabricate
catechol-based hydrogels with high adhesiveness because the required
condition for cohesion and adhesion of these hydrogels is in conflict
with each other: strong cohesion (gelation) requires a weak basic
condition, whereas strong adhesion requires an acidic condition. Here,
we demonstrated that by utilizing polyphenol supramolecular chemistry,
the coexistence of strong cohesion and adhesion can be achieved in
a hydrogel via the one-pot method. PolyÂ(dimethyl diallyl ammonium
chloride)/tannic acid (PDDA/TA) hydrogel has been studied as a proof
of concept. Compared with catechol moieties that covalently grafted
on polymer chains, TA can bring high density of pyrogallol/catechol
functional groups for polymers via a noncovalent pathway, as well
as high acidity in the system. As a result, the cohesion of the hydrogel
is enhanced significantly, the highest storage moduli can reach up
to ca. 0.15 MPa; besides, the high acidity of the hydrogel prevents
pyrogallol/catechol groups from oxidation and guarantees strong adhesion;
thus, the hydrogel can adhere to diverse substrates steadily, including
tissues, glass, metals, and plastic. Moreover, because of the adjustable
adhesiveness via changing the pH, the PDDA/TA hydrogel becomes a unique
system with patternable adhesiveness. In addition, the hydrogel has
rapid self-healing and high ionic conductivity (∼4.3 S m<sup>–1</sup>). This study demonstrates that utilizing polyphenol
chemistry in the construction of hydrogels opens a new path toward
multifunctional hydrogels with improved properties