Heterogeneous ice nucleation on model substrates

Area of Science:

• Physical Chemistry
• Materials Science
• Climate Science

Background:

• Ice nucleation is critical across diverse fields, including climate change, cryobiology, geology, and the food industry.
• Predicting a substrate's ice nucleating ability is challenging due to complex interactions between water and material surfaces.

Purpose of the Study:

• To investigate how substrate lattice structure and orientation influence ice nucleation ability using molecular simulations.
• To assess the ice nucleating performance of simple cubic, body-centered cubic, and face-centered cubic lattices.

Main Methods:

• Molecular simulations were employed to calculate ice nucleation rates for various model lattices and orientations.
• Classical nucleation theory was adapted to estimate key nucleation parameters like contact angle and free energy barrier height.

Main Results:

• Ice nucleating ability is significantly influenced by the underlying crystal plane, not solely by lattice symmetry (e.g., hexagonal symmetry does not guarantee better performance).
• More efficient nucleants promote a more structured liquid layer adjacent to the substrate.
• The ice nucleating ability of efficient substrates shows high sensitivity to lattice parameters.

Conclusions:

• Substrate crystal plane and induced liquid structuring are crucial factors in ice nucleation.
• The developed methodology validates classical nucleation theory for predicting nucleation parameters even for small critical clusters.