Novel electrochromic aromatic poly(amine–amide–imide)s with pendent triphenylamine structures

Research Progress in Special Engineering Plastic-Based Electrochromic Polymers

SPECPs are electrochromic polymers that contain special engineering plastic structural characteristic groups (SPECPs). Due to their high thermal stability, mechanical properties, and weather resistance, they are also known as high-performance electrochromic polymer (HPEP or HPP). Meanwhile, due to the structural characteristics of their long polymer chains, these materials have natural advantages in the application of flexible electrochromic devices. According to the structure of special engineering plastic groups, SPECPs are divided into five categories: polyamide, polyimide, polyamide imide, polyarylsulfone, and polyarylketone. This article mainly introduces the latest research on SPECPs. The structural design, electrochromic properties, and applications of these materials are also introduced in this article, and the challenges and future development trends of SPECPs are prospected.

A core–shell composite of porous ZnO nanosheets and a multichromic conducting polymer: enhanced electrochromic performances

The core–shell composite film exhibits higher optical contrast, faster switching speed and better electrochemical stability.

Effective process to achieve enhanced electrochromic performances based on poly(4,4',4″-tris[4-(2-bithienyl)pheny]amine)/ZnO nanorod composites

Poly(4,4',4″-tris[4-(2-bithienyl)pheny]amine) (PTBTPA) was electrochemically synthesized on a ZnO-coated ITO electrode to form a PTBTPA/ZnO nanocomposite electrode. The composite film exhibited a noticeable electrochromism, with reversible color changes from orange in the reduced state (0 V), olive green in the middle state (0.9 V) to dark gray in the oxidized state (1.2 V). Furthermore, the composite film showed a fast switching time of 0.92 s and a high optical contrast of 65% at 1100 nm, and retained 97% of its original electroactivity after 500 cycles, while PTBTPA film had switching time of 1.63 s and an optical contrast of 52% at 1100 nm, and retained 75% of its original electroactivity. The results demonstrated that the electrochromic performances were significantly enhanced through incorporating PTBTPA with ZnO nanorods. ZnO nanorods were introduced to modify the structure of the electrode: on one hand, to offer a directional attraction for the counterions, and on the other hand, to enhance the adhesion between the polymer and the ITO electrode. Accordingly, a conducting polymer/inorganic nanocomposite system could improve the polymer's electrochromic performance, especially in terms of the switching speed and long-term stability of the electrochromic materials.

High-performance nanostructure chiral poly(amide–imide)s containing benzamide and amino acid linkages: Preparation, characterization and ultrasonic effect on the morphology

In this research work, several novel optically active nanostructure poly(amide–imide)s (PAIs) were synthesized from the direct polycondensation reaction of 3,5-diamino- N-(pyridin-3-yl) benzamide with chiral diacids based on trimellitic anhydride-derived dicarboxylic acids containing different natural amino acids such as l-methionine, S-valine, l-alanine and l-isoleucine in green medium consisting of molten tetrabutylammonium bromide. The diamine was synthesized by a two-step reaction. At first, 3,5-dinitro- N-(pyridin-3-yl)benzamide was prepared from the reaction of one equimolar of 3-amino pyridine and one mole of 3,5-dinitrobenzoyl chloride. In the next step, the obtained dinitro was reduced by Pd/C and hydrazine hydrate. The new thermally stable optically active PAIs with inherent viscosity ranging from 0.31 to 0.46 dL g−1 were obtained with high yield. The synthesized polymers were characterized with Fourier transform infrared, proton-nuclear magnetic resonance spectroscopy, specific rotation measurements, thermogravimetric analysis, x-ray diffraction, field emission scanning electron microscopy (FE-SEM) and elemental analysis techniques. Morphological study by FE-SEM showed that these new PAIs were noncrystalline and nanostructure polymers with particle size between 50 and 70 nm. The effect of ultrasonic radiation on the obtained nanostructured polymers showed that the size of polymeric nanoparticles was reduced to about 30–45 nm.