What are the best practices for designing nanomaterials with high strength and toughness?

1 Nanoscale mechanics

One of the first steps to design nanomaterials with high strength and toughness is to understand how the size and shape of the nanoscale components affect their mechanical behavior. For example, nanowires and nanotubes have very high strength due to their high aspect ratio and defect-free structure, but they also have very low toughness due to their brittle nature and lack of plastic deformation. On the other hand, nanocrystals and nanocomposites have lower strength but higher toughness due to their ability to accommodate strain and dissipate energy through various mechanisms, such as dislocation motion, grain boundary sliding, and crack deflection. Therefore, depending on the application and the loading conditions, you need to choose the appropriate type and geometry of the nanoscale components to achieve the desired balance between strength and toughness.

2 Microstructure optimization

Another important factor that influences the strength and toughness of nanomaterials is the microstructure, which refers to the arrangement and distribution of the nanoscale components within the material. The microstructure can be controlled by various methods, such as synthesis, processing, and heat treatment, to create different features, such as grain size, porosity, phase composition, and orientation. These features can have significant effects on the mechanical properties of nanomaterials, such as enhancing or reducing the stress concentration, facilitating or hindering the deformation mechanisms, and increasing or decreasing the fracture resistance. Therefore, you need to optimize the microstructure of nanomaterials to maximize their strength and toughness, by creating a hierarchical and heterogeneous structure that can adjust to the applied stress and prevent crack propagation.

3 Interface engineering

The third aspect that you need to consider when designing nanomaterials with high strength and toughness is the interface, which refers to the boundary or contact region between different nanoscale components or between the nanomaterial and the surrounding environment. The interface can have a significant impact on the mechanical properties of nanomaterials, as it can act as a source or a sink of defects, a barrier or a pathway of mass and energy transfer, and a site of chemical or physical interactions. Therefore, you need to engineer the interface of nanomaterials to enhance their strength and toughness, by creating a strong and stable bond between the nanoscale components, by introducing a compliant or sacrificial layer to reduce the stress concentration, and by modifying the surface chemistry or morphology to improve the adhesion or resistance to the external factors.

4 Here’s what else to consider

This is a space to share examples, stories, or insights that don’t fit into any of the previous sections. What else would you like to add?