Enhancement of Electrochromic Switching Properties with Tröger's Base-Derived Intrinsic Microporous Polyamide Films.

The formation of Tröger's Base (TB) configuration is a useful approach to synthesize polymers of intrinsic microporosity (PIM). Herein, the V-shaped TB scaffold is incorporated to prepare electrochromic (EC) polyamide with electroactive triphenylamine (TPA) moiety. The presence of intrinsic microporosity derived from inefficient packing of TB scaffolds can facilitate the counterions diffusion between electroactive species and electrolytes. Consequently, the resulting TB-based polyamide exhibits enhanced EC behaviors, such as a lower driving potential, reduced the difference of redox potentials ΔE, and shorter switching response time compared to the corresponding EC counterpart polyamide.

Electrochromic Response Capability Enhancement with Pentiptycene-Incorporated Intrinsic Porous Polyamide Films.

Enhancing switching response capability of electrochromic (EC) polymers has been a topical issue. Herein, the H-shaped nonplanar pentiptycene scaffold is successfully introduced into the polyamide film derived from N,N'-bis(4-aminophenyl)-N,N'-di(methoxyphenyl)-1,4-phenylenediamine (TPPA), and the resulting copolymer shows enhanced EC behaviors, including lower oxidation potential and shorter switching response time, as compared to the corresponding TPPA-derived homopolymer.

Facile Fabrication of Triphenylamine-Based Redox-Active Nanocomposites by a Sol-Gel Method: Enhanced Electrochromic Response Capability and Stability Performance.

In this research, a new design of organic-inorganic hybrid networks involving covalently bonding, novel, electron-donating triphenylamine (TPA)-containing electroactive molecules to inorganic metal oxides is successfully developed by using a facile sol-gel process. These anodically electrochromic TPA-containing materials exhibit multicolor electrochromic behaviors at various oxidation states. By introducing zirconium oxide into electrochromic materials, not only can an excellent optical transparency in the visible light region at a neutral state be achieved given the nature of the large energy bandgap, but the electrochromic switching can also be driven by a lower oxidation potential with an enhanced response capability (shorter coloring times and bleaching times). Moreover, the hybrid films show outstanding electrochemical stability and high reversibility under long-term operations owing to their good adhesion to the electrode. Consequently, the electrochromic devices derived from these novel hybrid electroactive materials reveal a huge potential for electrochromic applications.

Electrochromism and Nonvolatile Memory Device Derived from Triphenylamine-Based Polyimides with Pendant Viologen Units.

Three novel solution-processable polyimides containing triphenylamine and pendant viologen moieties are prepared from the newly synthesized diamine and three commercially available dianhydrides. The thermally stable polyimide with strong donor-acceptor charge-transfer possesses write-once read-many-times memory behavior with excellent operation stability. The obtained multicolored electrochromic polymer films reveal ambipolar electrochemical behavior with high optical transmittance contrast of coloration changed from transmissive neutral state to the cyan/magenta/yellow redox states, implying great potential for application in smart window and displays.

Multilevel nonvolatile flexible organic field-effect transistor memories employing polyimide electrets with different charge-transfer effects.

The electrical memory characteristics of the n-channel organic field-effect transistors (OFETs) employing diverse polyimide (PI) electrets are reported. The synthesized PIs comprise identical electron donor and three different building blocks with gradually increasing electron-accepting ability. The distinct charge-transfer capabilities of these PIs result in varied type of memory behaviors from the write-one-read-many (WORM) to flash type. Finally, a prominent flexible WORM-type transistor memory is demonstrated and shows not only promising write-many-read-many (WMRM) multilevel data storage but also excellent mechanical and retention stability.

A novel molecularly imprinted polymer thin film as biosensor for uric acid.

A novel amine-imide type conducting polymer, denoted as poly(PD-BCD), was molecularly imprinted on an indium-tin oxide (ITO) glass, with uric acid (UA) as the template and without any functional monomer. Intending to improve the imprinting efficiency, the polymer content was varied from 0.3 to 0.9wt% during the preparation of the molecularly imprinted polymer (MIP), thereby varying the thickness of the polymer film; the content of UA as the template was maintained to be the same for all the films. The sensitivities of the thus prepared MIP electrodes were calculated to be more than 3-fold, compared to those of the corresponding non-MIP (NMIP) electrodes, which were obtained through the same method, however, without adding UA during their preparation. A polymer content of 0.6wt% rendered the best performing MIP electrode, as judged by the imprinting efficiency and sensitivity of the electrode for UA. A linear relationship between steady-state currents and UA concentrations from 0 to 1.125mM was obtained for both types of the sensors. The sensitivities of the MIP and the NMIP electrodes made with 0.6wt% of polymer were calculated to be 24.72 and 6.63microAmM(-1)cm(-2), respectively. The limit of detection (LOD) for this MIP was found to be 0.3microM at a signal to noise ratio (S/N) of 3. This MIP electrode was used as a biosensor for the detection of UA in the presence of ascorbic acid (AA) in a sample containing these species in the same concentrations as those in a human serum. The selectivity of MIP electrode is higher than that of NMIP electrode, and the values are 28.76 and 8.85, respectively. The results are substantiated by using cyclic voltammetry (CV), linear sweep voltammetry, amperometry, and scanning electron microscopy.