Strain-Induced Raman Shifts Due to Ice Adhesion*

When ice is formed on a material, it creates a strain proportional to the adhesive strength between the ice and substrate. In order to quantify this adhesion, we use Raman spectroscopy to measure the vibrational modes of various materials with and without ice.  To isolate the ice-material interface, we performed Raman spectroscopy on single-layer graphene from 20 °C to - 30 °C with and without ice. Along with the well-known temperature-dependent Raman shift of graphene, a clear, ~ 3 cm^-1 shift in the G-mode (~1590 cm^-1) developed when the ice formed. We found this Raman shift tracked closely to the temperature-dependent density of ice, suggesting that we are optically measuring ice-created strain on graphene.