Plasmonic Observation of High‐Density Nanoclustering in Low‐Temperature H2O

Abstract

There has been considerable scientific interest in comprehending the behavior and phase transitions of H2O at the nanoscale in low temperatures. Herein, a highly sensitive and nondestructive surface plasmonic detection system operated at low temperatures to investigate the real‐time nanoscale variation in H2O density from a rapidly cooled thin ice layer formed at 77 K is employed. The nanoslit device exhibits a distinct plasmonic response at 180–250 K, correlated to an increase in the local density of H2O at the nanometer scale. Along with theoretical analyses, it is revealed that high‐density H2O clusters form by vigorous aggregation of H2O molecules within the interphase liquid region between polymorphic ice crystals. The utilization of ice‐active materials, known to inhibit ice growth, suppresses the initiation of such high‐density nanoclustering at 180 K. These results contribute to the comprehension of the interplay between polymorphic crystals and density‐variant interphases in low‐temperature H2O systems.

Keywords

• finite‐difference time‐domain simulations
• low‐temperature ice
• molecular dynamic simulation
• plasmonic nanoantenna
• Raman spectrum