Hydration Layers on Nanoparticles Regulate Ice Growth.

Abstract

Nanoparticle hydrophilicity plays an important role in regulating ice growth in supercooled water. Here, we use molecular dynamics simulations to systematically investigate how particle-water interactions affect both the pushing-engulfment transition and ice-growth kinetics. Increasing hydrophilicity progressively enhances the hydration structure around the nanoparticle, increasing its effective excluded size and narrowing the gap available for ice-front propagation. This enhanced geometric confinement requires larger supercooling for particle engulfment, resulting in a nonlinear decrease in the pushing-engulfment transition temperature. The ice-growth rate shows a nonmonotonic dependence on hydrophilicity, arising from a crossover between interfacial deformation and particle embedding at low hydrophilicity and reduced nanoparticle mobility at high hydrophilicity. The growth rate reaches a maximum at intermediate hydrophilicity. These results reveal how nanoscale hydration structures regulate ice growth through coupled geometric and kinetic effects. These findings provide a molecular-level framework for understanding and controlling ice growth in nanoparticle-containing systems and may aid the design of nanostructured materials for anti-icing and ice regulation.

Abstract as supplied by the indexing source. © the authors / publisher.