Colorless-to-colorful switching electrochromic polymers with very high contrast ratio are unattainable and attractive for the applications of smart wearable electronics. Here we report a facile strategy in developing colorless-to-colorful switching electrochromic polyimides by incorporating with alicyclic nonlinear, twisted structures and adjusted conjugated electrochromophores, which minimize the charge transfer complex formation. It is noted that, by controlling the conjugation length of electrochromophore, the colorless-to-black switching electrochromic polymer film (PI-1a) exhibites an ultrahigh integrated contrast ratio up to 91.4% from 380 to 780 nm, especially up to 96.8% at 798 nm. In addition, PI-1a film with asymmetric structure also demonstrates fast electrochemical and electrochromic behaviors (a switching and bleaching time of 1.3 s and 1.1 s, respectively) due to the loose chain stacking, which provides more pathways for the penetration of counterion. Moreover, the colorless-to-black EC device based on PI-1a reveals an overall integrated contrast ratio up to 80%.

Electrochromic polymer (ECPblack) demonstrates an ultrahigh contrast ratio (over 80%) in most of the visible regions, and its electrochemical and electrochromic behaviors remarkably accelerate by doping nanotube/polytriarylamine.

A new approach for polytriarylamine (PTAA)assisted selective dispersion for single-walled carbon nanotubes (SWNTs) in a toluene solution has been developed. The triarylamine-based conjugated polymers are able to selectively wrap the SWNTs with specific chiral indices depending on their backbone structures (e.g., PTAA 12 , PTAA 12 -P, and PTAA 12 -BP) and side-chain functionality (e.g., PTAA 6 , PTAA 6 -alt-PTAA, and PTAA 12 -alt-PTAA). PTAA 12 exhibits highly selective wrapping for the (6,5) chirality from CoMoCAT (catalytic processes) SWNTs but low selectivity in a dispersion of HiPCO (high-pressure carbon monoxide) SWNTs. Therefore, the selection for HiPCO SWNTs has been further improved via PTAA 12 -alt-PTAA wrapping with alternating side chains and mainly exhibits a high affinity to (6,5) SWNTs with high chiral angles (≥24.5°). The wrapping conformation and binding energy of the polymer/(6,5) SWNTs were studied via molecular modeling, and the simulated results are in good agreement with the experimental data for the selective dispersion of (6,5) SWNTs.

Hexa-peri-hexabenzocoronene-containing hydrogenated polynorbornene dispersion showed an intensive emission of the 0–0 transition (465 nm) and excellent dispersibility.

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