Volume 249, 2024

Understanding the impact of ammonium ion substitutions on heterogeneous ice nucleation

Abstract

Understanding the mechanisms underpinning heterogeneous ice nucleation in the presence of ionic inclusions is important for fields such as cryopreservation and for improved models of climate and weather prediction. Feldspar and ammonium are both present in significant quantities in the atmosphere, and experimental evidence has shown that feldspar can nucleate ice from ammonium-containing solutions at temperatures warmer than water alone. In recent work, Whale hypothesised that this increase in nucleation temperature is due to an increase in configurational entropy when an ammonium ion is included in the ice hydrogen bond network (T. F. Whale, J. Chem. Phys., 2022, 156, 144503). In this work, we investigate the impact of the inclusion of an ammonium ion on the hydrogen bond network by direct enumeration of the number of structures found using Rick's algorithm. We also determine the energy of these systems and thus compare the effects of enthalpy and entropy to test Whale's hypothesis. We find that the inclusion of an ammonium ion increases the total number of configurations under conditions consistent with a realistic surface charge. We also find that the enthalpic contribution is dominant in determining the location of the ammonium ion within the structure, although we note that this neglects other practicalities of ice nucleation.

Graphical abstract: Understanding the impact of ammonium ion substitutions on heterogeneous ice nucleation

Associated articles

Supplementary files

Article information

Article type
Paper
Submitted
15 মে 2023
Accepted
21 জুলাই 2023
First published
24 জুলাই 2023
This article is Open Access
Creative Commons BY license

Faraday Discuss., 2024,249, 114-132

Understanding the impact of ammonium ion substitutions on heterogeneous ice nucleation

K. E. Blow, T. F. Whale, D. Quigley and G. C. Sosso, Faraday Discuss., 2024, 249, 114 DOI: 10.1039/D3FD00097D

This article is licensed under a Creative Commons Attribution 3.0 Unported Licence. You can use material from this article in other publications without requesting further permissions from the RSC, provided that the correct acknowledgement is given.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements