Self‐Healing of Polarizing Films via the Synergy between Gold Nanorods and Vitrimer

Abstract

Conventional self‐healing is about the recovery of shape and mechanical properties. In contrast, recovery of functional properties is still a great challenge, especially for optical functional materials, as the known self‐healing methods are incompatible with optical properties. By utilizing the synergistic effect between Au nanorods and vitrimer, the alignment of Au nanorods can be achieved in the crosslinked polymer. The optical properties of the resulting polarizing film, such as light transmittance and polarization degree, can be fully recovered without an external repair agent. With simple laser irradiation to induce the photothermal effect of Au nanorods, the shape‐memory effect of vitrimer returns the Au nanorods to their initial orientation, and the plasticity achieves in situ self‐healing of the cutting area. The self‐healing of polarizing film provides a new research direction and reference for the application of self‐healing systems in functional materials.

Photonic Vitrimer Elastomer with Self‐Healing, High Toughness, Mechanochromism, and Excellent Durability based on Dynamic Covalent Bond

“…Figure 2e illustrates a proposed selfhealing mechanism based on the dynamic carbamate bond in a vitrimer elastomer. [11] The topological structure of the vitrimer network is reconfigured with the exchange reaction of dynamic carbamate bond, granting the material with self-healing ability. With the prolongation of contact time, the probability to reform carbamate bond is increased, resulting in higher recovery efficiency.…”

Biosourced Acetal and Diels–Alder Adduct Concurrent Polyurethane Covalent Adaptable Network

“…Associative transcarbamoylation processes are sluggish for carbamates, and the dissociative reversion of carbamates to isocyanates and alcohols that typically occurs at high temperatures (>200 °C) can be associated with deleterious side reactions . Therefore, repairable PU thermosets based on carbamate bonds invariably demand the implantation of additional catalysts or redundant nucleophilic hydroxyl groups or structure alternation of carbamate bonds. − More recently, Xie and co-workers , reported that PU thermosets containing catalytic dibutyltin dilaurate (DBTDL) or polyol based on tertiary amine exhibited a rapid stress relaxation behavior; then, Dichtel and his co-workers reported that Lewis acid can also activate the dynamic exchange of carbamate bonds. Further work has demonstrated that tin-mediated urethane exchange is a common way to achieve stress relaxation and reprocessability for cross-linked PUs. ,− Although the addition of a catalyst can endow PU with a high degree of plasticity, metal catalysts are commonly toxic and unstable at high temperatures.…”

Reprocessable, Reworkable, and Mechanochromic Polyhexahydrotriazine Thermoset with Multiple Stimulus Responsiveness

“…through the reversible depolymerization or exchange reactions of their dynamic cross-links [ 3 , 9 , 10 , 11 ]. So far, a number of CANs based on Michael addition [ 12 , 13 , 14 ], Diels-Alder reaction [ 15 , 16 ], disulfide exchange [ 17 , 18 , 19 ], imine metathesis [ 20 , 21 , 22 ], transesterification [ 23 , 24 , 25 ], olefin metathesis [ 26 , 27 ], silyl ether transalkoxylation [ 28 , 29 ], diketoenamine exchange [ 30 , 31 ], and dioxaborolane metathesis [ 32 , 33 ] have been proposed in the literature. Besides recyclability, many other adaptive properties of CANs were also investigated, such as reconfigurability [ 34 , 35 ], shape memory [ 36 , 37 ], and network topological transformation [ 18 , 25 , 38 ].…”