Water‐Enabled Self‐Healing of Polyelectrolyte Multilayer Coatings

Abstract

Heilt euch selbst! Durch schichtweisen Aufbau erzeugte mehrschichtige Polyelektrolytüberzüge, die unter Umgebungsbedingungen mechanisch robust sind, können selbständig über zehn Mikrometer tiefe und breite Schnitte in ihrer Struktur reparieren, wenn sie in Wasser eingelegt oder mit Wasser besprüht werden. Diese Selbstheilungsfunktion erwächst aus der hohen Fließfähigkeit der Überzüge in Wasser.

Polyelectrolytes

“…In detail, the mobility of the chains in the multilayers favors the healing of the films after a surface damage. Wang et al [237] pointed out the self-healing character of (PEI + PAA) n multilayers. These multilayers present self-healing properties triggered by the water penetration in the internal regions of the multilayers that favors the interdiffussion of the polyelectrolytes in the internal layers to the exterior region of the multilayers.…”

Self-healing hyperbranched poly(aroyltriazole)s

“…With the enthusiastic efforts paid by the polymer chemists, significant progress has been made in aforementioned classes, but the researches on the self-healing approaches were mainly focused on the encapsulated-monomer/catalyst10111213141516, supramolecular self-assembly171819202122232425, and reversible or dynamic covalent bond formation262728293031323334. Among these developed approaches, the first two possess limited mechanical properties with stress generally less than 10 MPa, and the latter could decrease its mechanical property at elevated temperature.…”

Hard Autonomous Self‐Healing Supramolecular Materials—A Contradiction in Terms?

“…Inspired by nature, White et al have proposed the use of vascular channels with healing agent to overcome these limitations. [6] One could conclude that autonomous supramolecular self-healing is possible only for soft rubbery materials that have sufficient chain dynamics above the glass transition temperature of the material. [4] The healing is based on the reversibility of the hydrogen bonds, which are the weakest links and are selectively broken upon rupture.…”