Microwave-responsive nanoencapsulated fluorescence thermometers for quantitative assessment of microscale localized heat regulation in chemical production

Precise utilization of microscale localized heat to enhance catalytic reactions and nanomaterial preparation requires insights into the effects of external microscale heat transfer and key process factors on its formation and quantitative regulation. Here, we innovatively developed microwave-responsive nanoencapsulated fluorescence thermometers (MNFT S ) as a research platform with regular shapes, excellent thermosensitive fluorescent properties, and adjustable MW-absorbing properties that enable the precise fluorescence thermometry and flexible creation of micro-localized hotspots, allowing the systematical investigation of microscale localized heat regulation in chemical production. In-situ observations of MNFTs revealed that localized thermal convection induced by solid–liquid temperature differences and solvent warming reduced the overheating of the microscale hotspot by 38%. In comparison, the hotspot intensity maintained only 10% of its initial value under forced convection, emphasizing the importance of external microscale heat transfer in quantitatively regulating microscale localized heat. Subsequently, an innovatively developed and rigorously validated theoretical model accurately elucidated the key influencing factors and quantitative regulation mechanisms of MW-induced microscale hotspots, facilitating the precise regulation of microscale hotspots in MW-assisted catalytic reactions, material synthesis, and chemical separation processes. This fundamental research advanced our understanding of quantitatively regulating microscale localized heat, promoting its better application in chemical production.