A Facile Approach to Prepare Self-Assembled, Nacre-Inspired Clay/Polymer Nano-Composites

TL;DR

This paper introduces a simple water-evaporation self-assembly method to create large-scale, nacre-inspired clay/polymer nanocomposites with hierarchical structures, exhibiting high strength, flexibility, transparency, and flame resistance.

Contribution

It presents a novel, facile approach to fabricate biomimetic nacre-like composites with enhanced mechanical and functional properties using natural clay, cellulose, and metal ion coordination.

Findings

Achieved high Young's modulus (9.09 GPa) and strength (298.02 MPa) in dried films.

Demonstrated excellent transparency and flame shielding capabilities.

Enhanced properties through metal ion coordination, improving stability and resistance.

Abstract

Nature provides many paradigms for the design and fabrication of artificial composite materials. Inspired by the relationship between the well-ordered architecture and biopolymers found in natural nacre, we present a facile strategy to construct large-scale organic/inorganic nacre-mimetics with hierarchical structure via a water-evaporation self-assembly process. Through hydrogen bonding, we connect Laponite-nanoclay platelets with each other using naturally abundant cellulose creating thin, flexible films with a local brick-and-mortar architecture. While the aqueous solution displays liquid crystalline textures, the dried films show a pronounced Young's modulus (9.09 GPa) with a maximum strength of 298.02 MPa and toughness of 16.63 MJm-3. In terms of functionalities, we report excellent glass-like transparency along with exceptional shape-persistent flame shielding. We also demonstrate that through metal ion-coordination we can further strengthen the interactions between the polymers and the nanoclays. These ion-treated hybrid films exhibit further enhanced mechanical, and thermal properties as well as resistance against swelling and dissolution in aqueous environments. We believe that our simple pathway to fabricate such versatile polymer/clay nanocomposites can open avenues for inexpensive production of environmentally friendly, biomimetic materials in aerospace, wearable electrical devices, artificial muscle, and food packaging industry.