Bioinspired self-assembled films of carboxymethyl cellulose-dopamine/montmorillonite
Among cellulose-based materials, carboxymethyl cellulose (CMC) can be used as alternative eco-friendly packaging materials. However, the conservation of high stiffness and strength against the hydration-induced decay of mechanical properties at high humidity remains a fundamental challenge in such water-borne materials. Inspired by the mussel adhesive proteins (adhesive) and nacre (brick-and-mortar structure), in this work, the bio-inspired multifunctional CMC composite was conjugated to dopamine (DA) and subsequently assembled with montmorillonite (MTM) to generate the bio-inspred and layered nanocomposite films using a simple vacuum filtration-assisted assembly method. The modified CMC and composite films were comprehansively charaterzied, particularly with XPS and NMR. The conjugation of DA on CMC resulted in the nanocomposites with improved stability in wet state, increased tensile strength (162.0 MPa) and elastic modulus (8.7 GPa) at relative humidity up to 90%. Thermogravimetric analysis and horizontal flame test also showed that the nanocomposites possessed high thermal stability and were able to self-extinguish immediately after the removal of the flame. Therefore, the facile strategy developed in this work provides a promising approach to prepare biomimetic materials with excellent moisture resistance and flame retardancy, which have great potential for various applications.