Robust hydrogen-bonding interactions from deep eutectic solvent enabling high magneto-responsive performances

In this study, magnetorheological fluids (MRFs) with a choline chloride/glycerol deep eutectic solvent (DES) as the carrier liquid were elaborately developed and studied. Because of the strong hydrogen bonding interactions between the DES and the functional groups on the surfaces of the magnetic particles, the mechanical properties and sedimentation stability of the MRF were improved significantly. The influence of the hydrogen bond donor (HBD) type and water content of DES, the hydrogen bond acceptor (HBA):HBD ratio, and the concentration of magnetic particles on the magnetorheological (MR) properties was investigated. It was found that, except for the HBA:HBD ratio, these factors had a significant influence on the properties. The results showed that DES is an efficient carrier liquid, capable of forming MRFs with Fe3O4-based or carbonyl iron particles, and it showed more excellent MR properties compared with silicone oil-based MRFs. This paper demonstrates the design and fabrication of a new type of eco-friendly, high-performance MRF enabling the future development of efficient MRFs based on the modulation of chemical or molecular interactions.