As the Internet of Things (IoT) significantly improves people's lifestyles, flexible and low-power displays will become essential to real-time human-computer interaction. Electrophoretic display (EPD) has many advantages, such as low power consumption , flexibility, and high sunlight visibility, which is necessary for IoT terminal display. However, preparing electrophoretic particles with high charge and spatial resistance is difficult. Herein, dual-silane coupling agents, (3-Aminopropyl) trimethoxysilane (APS) and vinyltrimethoxysilane (VTS), were co-grafted on the black particles to optimize the electrophoretic particles' dispersity and charge. To evaluate the charge content and dispersity of particles, we measured the particles with zeta potential , dynamic light scattering, and long-term standing treatment. Fe 3 O 4 -APS 0.5 VTS 0.5 -PLMA, selected as the black particles for EPD, had an average particle size and zeta potential of 300 nm and 25 mV, respectively. Besides, the concentration of the black and white particle would significantly affect the EPD's performance. When optimizing the white and black particle concentration to 4:1, the contrast ratio of EPD was up to 13.2. In addition, the EPD has a response time of 200 ms and exhibits an invertible black and white state under ±15 V. Finally, to improve the stability of electrophoretic particles, the particles were encapsulated in microcups and driven to the black and white state under 30 V. This work demonstrated that dual-silane coupling agent particles have the potential to achieve the fast response and high contrast ratio EPD.
Bin Xu,Qinqin Xu,Maohua Hou,Jieying Su,Haitao Zhang,Xiaohui Lu,Zhongjin Ni
Structural color films with high brightness, saturation and robust mechanical properties have been prepared by a two-step photopolymerization method using colloidal inks. The color saturation of the films could be controlled by the mass of the carbon black (CB) particles and polymerization time while the colors are closely related to the diameter of the CB@SiO 2 microspheres . The inks were prepared by dispersing CB@SiO 2 microspheres with black CB particles as the core and inorganic SiO 2 as the shell in poly(ethylene glycol diacrylate) (PEGDA) resins. The results of bending and rubbing tests showed that the addition of PEGDA prevented the formation of film cracks and enhanced mechanical properties without altering the original color. Structurally colored films were directly attached to a variety of substrates, including glass, metal, paper, and fabric. These colloidal inks have potential application in the fields of displays, paints, and other color-related fields.