Silver-deposited antibacterial phase change microspheres

Phase change materials (PCMs) are promising for personal thermal management, but leakage or loss of the phase-change component during high-temperature treatment remains a major challenge. In addition, multifunctional PCM microspheres that combine thermal regulation, leakage resistance, and antibacterial activity are still limited. In this study, silver-deposited phase-change silica microspheres (m pcm/Ag ) were prepared through vacuum adsorption and the intrinsic reducing ability of polyethylene glycol monostearate (PEG 2 -MS). In this system, PEG 2 -MSserved not only as the phase-change component but also as a weak reducing agent to induce in situ Ag deposition on PCM-loaded silica microspheres. After compression at 2 MPa followed by heat treatment, m pcm/Ag exhibited improved high-temperature phase-change component retention compared with vacuum-adsorbed microspheres without Ag deposition (m pcm ). After treatment at 120 °C for 1 h, the crystallization enthalpy and melting enthalpy increased by 25.70% and 26.61%, respectively. After treatment at 220 °C for 1 h, the corresponding increases reached 67.05% and 70.11%, respectively. Direct leakage observations and gravimetric mass-loss measurements further confirmed that Ag deposition enhanced the thermal leakage resistance of the microspheres. In addition, m pcm/Ag showed strong antibacterial activity against both E. coli and S. aureus. This study provides a PCM-assisted in situ Ag deposition strategy for constructing multifunctional phase-change microspheres with improved high-temperature leakage resistance and antibacterial functionality.