Superior Hard but Quickly Reversible Si–O–Si Network Enables Scalable Fabrication of Transparent, Self-Healing, Robust, and Programmable Multifunctional Nanocomposite Coatings

Abstract

A coating with programmable multifunctionality based on application requirements is desirable. However, it is still a challenge to prepare a hard and flexible coating with a quick self-healing ability. Here, a hard but reversible Si–O–Si network enabled by aminopropyl-functionalized poly­(silsesquioxane) and triethylamine (TEA) was developed. On the basis of this Si–O–Si network, basic coatings with excellent transparency, hardness, flexibility, and quick self-healing properties can be prepared by filling soft polymeric micelles into hard poly­(silsesquioxane) networks. The highly cross-linked continuous network endows the coating with a hardness (H = 0.83 GPa) higher than those of most polymers (H < 0.3 GPa), while the uniformly dispersed micelles decrease the Young’s modulus (E = 5.89 GPa) to a value as low as that of common plastics, resulting in excellent hardness and flexibility, with an H/E of 14.1% and an elastic recovery rate (W e) of 86.3%. Scratches (∼50 μm) on the coating can be healed within 4 min. The hybrid composition of poly­(silsesquioxane) networks also shows great advantages in integration with other functional components to realize programmable multifunctionality without diminishing the basic properties. This nanocomposite design provides a route toward the preparation of materials with excellent comprehensive functions without trade-offs between these properties.

Multifunctional Hard Yet Flexible Coatings Fabricated Using a Universal Step‐by‐Step Strategy

“…[ 11 ] Some omniphobic flexible hard coatings with excellent anti‐smudge ability have been developed but the anti‐biofouling problem still exists. [ 12 ] To solve this problem, a zwitterion‐modified flexible hard coating has been reported, [ 13 ] which has not only excellent oil repellency but also anti‐biofouling ability. Compared with zwitterion‐modified coating, the results show that the coating in this study demonstrates similarly anti‐biofouling ability but better wear resistance and anti‐smudge ability.…”

“…Alternatively, multifunctional nanocomposite coatings have been developed by filling soft polymeric micelles into hard poly(silsesquioxane) networks, which exhibit excellent hardness, flexibility, anti‐smudge, and quick self‐healing properties. [ 13 ] Note that the above coatings still lack anti‐biofouling ability and the photocatalytic cross‐linking reaction needs complex UV irradiation and limits the thickness, which in turn limits the application fields of the coatings. [ 14 ] Recently, our group reported a hybrid antifouling coating consisting of an epoxy‐zirconium particle and an amine‐terminated hyperbranched polysiloxane.…”

Self‐Healing Perovskite Films Enabled by Fluorinated Cross‐Linked Network Targeting Flexible Light‐Emitting Diode

“…However, the highly condensed Si–O–Si network of silanol groups in TEOS‐based perovskite films contributes to a stable and irreversible framework. [ 42 ] In contrast, these organic side‐chains in TFPTMS‐based perovskite films endow the 3D network with remarkable adaptability to various circumstances. Specifically, due to the strong electron‐withdrawing inductive effect of fluorine elements, fluorinated alkyl chains are capable of coupling with silanol groups in a silica network to form intermolecular hydrogen bonds.…”

High strength, stable and self-healing copolyimide for defects induced by mechanical and electrical damages

“…22,23 Since the self-healing process requires the material to have high molecular chain mobility and large free volume, which reduces the mechanical properties and insulation strength in turn. 24,25 This study started from the search of monomers containing special functional groups, including disulfide bonds, flexible molecular segments and polyphenyl ring structures, which can provide CPI good healing and high comprehensive properties. As shown in Fig.…”