نمایشگرهای الکتروفورتیک (EPD) Electrophoretic displays (EPD)

The application of nanospheres is in painting, ink, food, electronic displays, textile and medicine. Kuanjun Fang et al (2014) introduced an easy method for preparation of colored poly (styrene-acrylic) nanospheres. This method was performed easily in 21 contrast to previous methods in which the preparation of uniform colored nanospheres with high color purity was very difficult. In this study, the Emulsifier-Free Emulsion Polymerization was performed to synthesize copolymer spherical nanoparticles (AA-St), so that the effect of the active surface was removed. Spherical nanoparticles dispersions were prepared with three solution disperse dyes including blue 56, red 60 and yellow 64, so that each of the dyes are gradually entered to the copolymer spherical nanoparticles (AA-St) due to the heat and then fixed dyes in the spherical nanoparticles are obtained with increasing heat and sedimentation, washing and dying. The process is shown in the Fig. 2-28 [19]. According to the images obtained by transmission electron microscopy, the average size of spherical nanoparticles after dyeing for each three dye is 23nm [19]. Xiao-Meng Liua et al (2014) caused a new innovation in preparation of electrophoretic ink using electro spray method to preparation of E-ink. They prepared electrophoretic ink microcapsules with the narrow size distribution and the white and red particles mean of about 100 and 200 micrometer using Coaxial Jet of figure 2-30 [62]. The results showed that by adjusting the flow velocity of the shell fluids, nuclear and gas which are the important factors in this method, the microcapsules size and shell thickness can be controlled. Fig. 2-31 a shows the alteration of the microcapsule diameter and shell thickness versus different flows speed of 2 to 10 mL/h. It was observed that by increasing the flow rate of the core, the shell thickness is reduced and the microcapsule size is increased. In the Fig. 2-31 b, with increasing continuous flow rate, the shell thickness and size are increased [62]. 22 In this study, orthogonal test was used through three factors and three orthogonal experiments levels. Three factors of core flow rate, shell and gas are separately used in three different levels. In this study the optimum values are reported 4,6, 25 / ml h and coating Ratio was 90%. Fig. 2-32 shows the charged particle movement of red pigment in the electric field [62].