Coupling‐Grafting‐Ultrasonication Modification of Electrophoretic Particles for Fast Response and High Contrast Ratio Electrophoretic Display

Abstract Electrophoretic displays (EPDs) show great promise in the field of information display because of their eye‐friendly feature and high ambient visibility. Enhancing electrophoretic particle preparation and optimizing charge properties are crucial for display quality, response speed, and the capability to show full color. Despite the various methods explored, achieving a balance among simplicity, cost‐effectiveness, high surface charge, rapid response, and contrast improvement remains challenging. This study introduces a coupling‐grafting‐ultrasonication (CGU) approach. The surface charge and stability of the particles are turned by precisely adjusting the thickness of the poly (lauryl methacrylate) (PLMA) layer. Through optimization, TiO₂‐PLMA electrophoretic particles with a grafting mass of 10 exhibit a fast response (170 ms for white, 120 ms for black), high contrast (30), and demonstrated long‐term stability in EPD devices. Furthermore, the CGU method proves to be versatile for colored EPD particle preparation, providing a new direction for the future development of EPD.