Temperature‐Sensitive Properties and Mechanism of Smart Magnetic Fluids Modified with Cellulose Derivatives

Abstract

Combining magnetic materials with environmentally sensitive polymers to develop intelligent magnetic fluids that respond to external stimuli has become a new research hotspot. At present, the bottlenecks in the development of temperature‐sensitive materials are the complex composition, and its properties in different laboratories vary greatly. Moreover, despite extensive research on magnetic fluids, there remains a dearth of systematic investigation into temperature‐sensitive intelligent magnetic fluids. In this study, we utilized a UV‐visible spectrophotometer to measure the change in transmittance of different magnetic fluid solutions with temperature variation. We systematically investigated the effects of the magnetic fluid dispersion medium, size and concentration of magnetic nanoparticles, type and viscosity of cellulose on the temperature sensitivity of the magnetic fluid. We found that compared with Hydroxypropyl Methyl Cellulose (HPMC) (type I), HPMC (type II) modified magnetic fluid has better stability and a higher phase transition temperature. Moreover, with the increase of the concentration of magnetic fluid, the phase transition temperature is higher. In addition, the lower the viscosity of HPMC‐modified magnetic fluid, the better the stability and the higher the phase transition temperature. We also studied the mechanism of temperature sensitivity, and the results showed that hydrogen bond interactions play an important role. This research will facilitate the use of temperature‐sensitive smart magnetic fluids for biomedical application.