Tuning Ice Nucleation by Mussel-Adhesive Inspired Polyelectrolytes: The Role of Hydrogen Bonding

Abstract

Heterogeneous ice nucleation (HIN) on foreign surfaces plays a crucial role across a wide range of environmental and biological processes, and control of HIN is highly desirable. Functionalizing surfaces to control HIN poses interesting scientific challenges and holds great potential for technological impact. Here, we combine the ice nucleation tuning capability of polyelectrolytes withmussel-inspired adhesives to obtain robust surface functionalization with HIN control. We tune ice nucleation by integrating strongly surface-binding catechol derivatives into three different polyelectrolytes via a facile and scalable strategy. Sum-frequency generation (SFG) spectroscopy reveals that the functionalized surface with the lowest ice nucleation temperature (-22.1 °C) exhibits the strongest hydrogen bonding interaction with water molecules. The coating exhibits long-term stability up to 30 days even under harsh conditions such as 5 M salt solution and can be deposited onto various substrates because of its strong adhesion on solid surfaces. Moreover, the precise ice nucleation temperature window can be tuned by controlling the grafting degree of the catechol derivatives. Our study provides a new strategy for tuning ice nucleation and provides a new perspective on understanding the mechanism of ice nucleation at the molecular level by interfacial molecular spectroscopy, which will help in the design and development of antiice-nucleation materials.