Nanotube‐Based Ultrafast Electrochromic Display

Abstract

and those measured on PDMS were 100.1 and 77.7. Surface energies of indium tin oxide (ITO) and Alq 3 and interfacial energy from the literature [14] which will bring revolutionary advances in the display technology, owing to attributes such as thin and flexible materials, fast switching times, and low-power consumption. However, current electrochromic technologies need to be improved in order to play moving images due to their slow color-switching rates.[1,2,5±11] Poly(3,4-ethylenedioxythiophene) (PEDOT) and its derivatives are an ideal electrochromic material of conducting polymers for electronic paper due to their good color, mechanical stabilities, and facile fabrication.[5±11] Much work has been performed in order to improve contrast ratios and color switching rates by synthetic approaches.[5±11] It appears, however, that there are no examples of their use in electrochromic displays with moving-image speeds (24 frames/s; switching times of < 40 ms). This is due to the fact that the color-switching rate of PEODT is limited by the diffusion rate of counter-ions into the film during the redox process. The diffusion time, t, of ions required to reach a saturation concentration in a polymer film, that implies switching time, is proportional to the square of film thickness, x: t µ x 2 /D, where D is the diffusion coefficient of an ion in a polymer film. [12,13] Therefore, the simplest way to overcome the slow switching rates is to decrease the diffusion distance of ions, that is, to reduce film thickness. Based on the reported switching time of 2.2 s for a 300 nm thick PEDOT film, [5] we expect the switching time to be approximately 10 ms for a 20 nm thick film. However, the coloration of such a thin film is never sufficient for display applications. An array structure of PEDOT nanotubes provides an attractive solution to both of these limitations, slow switching rates and extent of coloration. Figure 1 explains that the wall thickness of PEDOT nanotubes can provide ions with short COMMUNICATIONS

Template-based syntheses for shape controlled nanostructures

“…Parthasarathy et al [319] showed that the wall thickness of polyaniline (PANI) tubes could be easily altered by controlling polymerization time with longer polymerization times resulting in thicker walls. Nanostructures of other polymers, such as polypyrrole [322][323][324][325][326], poly(3-methylthiophene) (PMT) [323,327], polyacrylonitrile (PAN) [328,329], and poly(3,4-ethylenedioxythiopene) (PEDOT) [330] have also been reported using this in situ polymerizations template filling method.…”

Electrochromism: Basis and Application of Nanomaterials in Development of High Performance Electrodes

“…Graças ao formato longo e tubular, os nanotubos promovem rápida difusão dos contraíons para dentro e para fora das estruturas, sendo que dispositivos flexíveis baseados em transmissão e reflexão foram construídos com base nessa tecnologia. 82,83 Um dispositivo interessante baseado no eletrocromismo de polímeros condutores foi desenvolvido por Takamatsu e colaboradores, 84 constituído por uma tela flexível com pixels que mudam de cor quando ativados por uma caneta luminosa. O conceito geral do dispositivo é mostrado na Figura 9, onde um display eletrocrômico com PEDOT:PSS foi combinado com um arranjo de fotossensores baseados em uma mistura de PEDOT:PSS e rodopsina bacteriana (bR), que é uma proteína fotorreceptora.…”

Simple Preparation of One-dimensional Metal Selenide Nanomaterials Using Anodic Aluminum Oxide Template

“…[12][13][14][15][16][17][18][19][20][21][22][23] Since the production of highly ordered AAO nanohole arrays was reported by Masuda and Fukuda in 1995, 12) extensive research has been devoted to the preparation of nanostructured materials using ordered AAO template. [24][25][26][27][28][29][30][31][32][33][34][35][36][37][38][39][40][41] The AAO membranes show remarkable hardness, high pore density, potentially low cost, uniform pore size, and relative ease of preparation.…”