Preparation and Thermal Properties of Magnetic PW@CaCO3@Fe3O4 Phase-Change Microcapsules and Their Application to Textile Fabrics

Multifunctional thermal regulation materials with good thermal properties, efficient magnetic performance, and satisfactory interface bonding on fabrics are highly desirable for protective fabrics, building winter protection materials, medical thermal regulation materials, and special-environment work clothing. Herein, a new class of magnetic phase-change PW@CaCO₃@Fe₃O₄ microcapsules was successfully produced by controlling the content of magnetic Fe₃O₄ through a self-assembly method. The microstructure, chemical composition, phase-change behavior, and magnetic properties of the products were sequentially characterized and analyzed. The findings revealed that the obtained microcapsules possessed regular spherical structure with uniform size and excellent thermal properties. Furthermore, PW@CaCO₃ with Fe₃O₄ (i.e., 8% mass fraction) showed the highest thermal regulation and magnetic properties and reached an enthalpy value of 94.25 J·g^-1, which is clearly superior to the value of 77.51 J·g^-1 for PW@CaCO₃ microcapsules. At the same time, the encapsulation efficiency of 38.7% and saturation magnetization of 2.50 emu·g^-1 were the best among the four given samples. Therefore, the good paramagnetic feature had a significant synergistic effect on the thermal properties of the PW@CaCO₃ microcapsules under study. More importantly, multifunctional fabrics loaded with PW@CaCO₃@Fe₃O₄ microcapsules still showed an enthalpy value of 25.81 J·g^-1 after several washes and have the potential to be used widely in the field of temperature control. The thermal regulation fabrics in this study exhibited excellent thermal properties and fastness, which contribute to their practical applications in advancing multifunctional textiles and high-technology modern fabrics.