writer：Jiameng Huang, Jin Feng, Haoran Xu, Huaiyu Zhao, and Tao Zhou*
keywords：LDW; polymer; NIR laser; micro-emulsion method; core-shell microspheres
source：期刊
Issue time：2022年
In this study, new core?shell microspheres for polymer laser direct writing (LDW) were successfully designed and prepared by a facile one-step micro-emulsion method. The color-changing core-shell microsphere consists of SnO2 "core" which can absorb near-infrared (NIR) laser energy and PPO "shell" which can be easily carbonized at high temperatures. Owing to the unique core-shell structure, the SnO2@PPO microsphere remarkably enhanced the polymer LDW performance. SEM, TEM and EDS indicated microspheres were regular spheres with an average size of 15.1 μm. Raman spectroscopy and XPS revealed that the SnO2 absorbed NIR laser energy to cause instantaneous high temperatures, leading to the carbonizing of PPO shell. Thus, the color-change mechanism of polymer during NIR LDW was confirmed as the formation of amorphous carbon by high-temperature carbonization. We believe these novel microspheres will have wide applications in the field of polymer LDW. Besides, the concept of preparing core-shell microspheres by the one-step micro-emulsion method provides a new idea for designing color-changing microspheres.