Dong C, Liu Y, Meng Y, Du S, Zhu S, Tian Y, Ma L. Ion-specific ice provides a facile approach for reducing ice friction.
J Colloid Interface Sci 2024;
675:451-460. [PMID:
38981254 DOI:
10.1016/j.jcis.2024.07.015]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2024] [Revised: 07/01/2024] [Accepted: 07/02/2024] [Indexed: 07/11/2024]
Abstract
HYPOTHESIS
Ice friction plays a crucial role in both basic study and practical use. Various strategies for controlling ice friction have been developed. However, one unsolved puzzle regarding ice friction is the effect of ion-ice interplay on its tribological properties.
EXPERIMENTS AND SIMULATIONS
Here, we conducted ice friction experiments and summarized the specific effects of hydrated ions on ice friction. By selecting cations and anions, the coefficient of ice friction can be reduced by more than 70 percent. Experimental spectra, low-field nuclear magnetic resonance (LF-NMR), density functional theory (DFT) calculations, and Molecular dynamics (MD) simulations demonstrated that the addition of ions could break the H-bonds in water.
FINDINGS
The link between the charge density of ions and the coefficients of ice friction was revealed. A part of the ice structure was changed from an ice-like to a liquid-like interfacial water structure with the addition of ions. Lower charge density ions led to weaker ionic forces with the water molecules in the immobilized water layer, resulting in free water molecules increasing in the lubricating layer. This study provides guidance for preparing ice-making solutions with low friction coefficients and a fuller understanding of the interfacial water structure at low temperatures.
Collapse