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Development of a multifunctional nanocomposite film with record-high ultralow temperature toughness and unprecedented fatigue-resistance


 In the quest of materials that can tolerate extreme environments (i.e., aerospace, polar regions of earth), facile design of self-healing, high fatigue-resistant and multifunctional nanocomposite materials with excellent ultralow temperature toughness, especially by utilizing inexpensive and sustainable bioresources is still currently challengeable. In current study, we present a material that displays remarkable ultralow temperature toughness, shows excellent toughness (107.3 MJ·m-3) at − 196°C and maintains high mechanical strength in highly humid environments. This material is a spider silk-inspired, poly(vinyl alcohol) (PVA)-based, autonomous room temperature self-healable nanocomposite by complexation of boron nitride (BN), quantum dots (QDs) and soybean protein isolate grafted lignin (SPI-lignin). The fabricated material, namely PVA-BN-QDs-SPI-lignin, simultaneously exhibits outstanding tensile strength (53.3 MPa), toughness (182.8 MJ·m-3), fatigue-resistance as well as antiultraviolet and fluorescent properties and sets an impressive new record of folding-failure (900 000 times) and toughness, which are 10.6 to 45.7 times higher than other graphene-based nanocomposites. It can be impressively self-healed within only 2 minutes. Of particular interest is its facile, green, mild and inexpensive preparation method that can be easily scale up. It is believed that this work, beginning with abundant biodegradable resources, opens the door to develop biobased multifunctional materials in practical applications, such as flexible wearable materials.