High‐Contrast Electrochromism and Controllable Dissolution of Assembled Prussian Blue/Polymer Nanocomposites

Abstract

To maintain the momentum and impact of the field, assembled materials systems must increasingly incorporate broad functionality to meet real‐world applications. Here we describe nanocomposite films of specially synthesized inorganic Prussian blue (PB) nanoparticles and linear poly(ethylene imine) (LPEI) that possess the unusual functional combination of high‐performance electrochromism for displays and controllable dissolution for drug delivery. Fabrication using layer‐by‐layer (LBL) assembly was followed by spectroelectrochemical characterization, allowing a full composition determination rarely achieved for LBL films. The electrochromic performance of thick LPEI/PB nanocomposites most relevant to applications surpassed that of inorganic PB films with competitive switching speed and superior contrast. Oxidation beyond the primary electrochromic transition removes nanoparticle ionization and can controllably dissolve the films. Because PB is non‐toxic we suggest this mechanism for controlled in‐vivo drug delivery. The performance and multifunctional quality of these nanocomposites promise a strong impact on flexible displays, electrochromic windows, and even biomedical devices.

Electrocatalytic properties of prussian blue nanoparticles supported on poly(m-aminobenzenesulphonic acid)-functionalised single-walled carbon nanotubes towards the detection of dopamine

“…This metal substitution and variation leads to a combination of properties that are not readily found in other inorganic materials [19]. Its unique properties, synthetic versatility and the ability of the cyanide ligands to bridge other ions have been explored in its application in electrochromic devices [20], nanomagnetic devices [21], biomedical sensor [22], molecular sieves [23], catalysis [24] and in solid-state batteries [25].…”

Nanochromics: old materials, new structures and architectures for high performance devices

“…Electrochromic properties of polyaniline and Prussian blue can be combined in a synergic way and were already described for electrodeposited films. The LbL assembly of Prussian Blue can be achieved by using poly(ethyleneimine, LPEI) 39 or PAH 17 and the successful combination of Prussian blue nanoparticles with polyaniline was recently reported. 42 The individual contributions of PANI are related to broad reduction and oxidation peaks, with sloping shoulders, while PB contribution is observed as sharp and well defined peaks.…”

“…For electrochromic electrodes, LbL technique was employed to immobilize Prussian blue nanoparticles 39 by using LPEI as polycation, and the influence of the number of bilayers on the electrochromic behavior was analysed. Figure 8 shows the spectroelectrochemical experiments for 50 bilayers, where UV-Vis spectra were taken at different potentials, fully oxidized PB (deep blue) was achieved at 0.3 V, depicted by a well defined charge transfer band with an absorbance peak at 700 nm ( Figure 8A).…”

A bi-functional device for self-powered electrochromic window and self-rechargeable transparent battery applications

“…As one of known EC materials, iron(II,III) hexacyanoferrate(II,III), commonly known as Prussian blue (PB), is a coordination compound and has long been used as a blue pigment [17][18][19][20] . The application of PB as an EC material was pioneered by Neff and coworkers 21,22 and Itaya et al [23][24][25] PB can be reduced to colourless 'Everitt's Salt' (Prussian white (PW)), oxidized to Berlin green and 'Prussian yellow' by electrochemical reactions 21,26 . Neff 27 also studied a PB battery in which both the anode and cathode are PB films electrochemically deposited on porous graphite, and an improved battery using PB and Nafion composite was also reported by Honda et al 28 However, the Neff cell has a low theoretical output voltage of 0.68 V, and the voltage of the charged battery continually drops in air due to the oxidation of PW to PB.…”