2D Polymers: The future of fracture-resistant materials

Breakthrough

This accomplishment was made possible by the researchers' use of scientific understanding gained from simulations generated by their Maryland-based colleagues in the creation of two distinct types of COFs. The mechanical characteristics of one COF are unaffected by adding more layers because of its solid interlayer interaction, while the properties of the other COF, like those of most 2D materials, degrade as more layers are added. The simulations also aided the group in understanding what caused the divergent behavior of the two COFs. 

Researchers found that good mechanical characteristics in the multilayer or bulk form of the material persisted because of the strong contacts between the 2D-material layers. They also attribute the chemistry of the hydrogen bond as the primary cause of the robust interlayer interaction. If these interlayer linkages were to break under stress, they would immediately rebuild as the layers slid back over one another. 

The COFs have particular strengths and specific stiffnesses among the highest known, and they are roughly ten times less dense than graphene or hexagonal boron nitride. Because of their strength-to-weight ratio and low cost, COFs find widespread use in filtration membranes and similar devices. 

Scientists are optimistic because 2D polymers like COFs have several chemical "knobs" that can be adjusted by them. Interlayer interaction design allows the logical engineering of new materials into highly robust modular systems. Since Scientists have made significant strides with using 3D polymers in the past, using 2D polymers in large-scale multifunctional applications where mechanical characteristics are crucial is a considerable accomplishment for the team.