Novel rapid switching and bleaching electrochromic polyimides containing triarylamine with 2-phenyl-2-isopropyl groups

Applications of polyimide coatings: a review

Polyimides, high-performance polymers with superior properties such as high temperature stability, resistance to solvents and high strength, can be used in high-tech applications of the aerospace and aviation, medical or electronics industry in different forms (film, fiber, nanofiber, membrane, foam, adhesive or coating). Among these applications, coating has a special place and is used to develop advanced structures having high temperature resistance, flame retardancy and etc. for high tech industries via an economical and feasible way. Therefore, in this review, we aimed to report the broad application status of polyimide coatings by reviewing publications, patents and commercial products. Thus, this study can assist in selecting suitable polyimide types and production methods for polyimide coating applications and in understanding their applicability for future products.

Organoselenium chemistry-based polymer synthesis

Novel synthesis of selenium containing polymers with pre-determined structures and applications thereof.

Colorless-to-colorful switching electrochromic polyimides with very high contrast ratio

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 polymers (ECPs) receive great attention due to their facile colour tunablility, however colourless-to-black ECPs with high contrast ratio are still unattainable. Here the authors develop high contrast colourless-to-black switching polyimides by following specific molecular design criteria.

Sorption of nucleic acids and proteins on polyaniline and polyaramide nano-coatings as studied by spectral-correlation interferometry in a real time mode

Polyaniline (PANI) and polyaramides deposited on the surfaces of glass slides and particulate silica were studied as adsorbents of nucleic acids and proteins by flow-through spectral correlation interferometry and solid-state extraction using spin-cartridges. Double stranded DNA from E. coli as well as pepsin, bovine serum albumin and lysozyme were the analytes studied in contact with the polymer nanolayers in phosphate buffer solution, pH 7.2. None of the coated glass slides could bind the DNA, which passed them practically without adsorption. In contact with polyaramides, the proteins of pI > 4 reversibly formed the 0.2-2.5 nm-thick adsorption layers decomposing on further rinsing with the protein-free eluent. In contact with PANI, the proteins formed stable adsorption layers at pH 7.2, which needed the pH 3.0 to be eluted. Thus, in a neutral aqueous medium optimal for separation of biopolymers, polyaramides, although did not retain DNA, had a weaker affinity to proteins as compared to PANI. Since the recovery of DNA passed through the PANI-coated silica was the maximal among the particulate adsorbents, the PANI-modified composites were preferred as the carriers for the single-step isolation of nucleic acids from complex biological mixtures.

Phosphorus-containing polyimide fibers and their thermal properties

Submicron fibers based on phosphorus-containing polyimide were successfully prepared and characterized for their thermal properties.

Fabrication and characterization of novel highly transparent and organo-soluble poly(ether imide)s thin film for gas separation

New poly(ether imide)s with good solubility, film quality and thermal stability were synthesis for high-performance gas separation membrane by solution-casting.

Design and preparation of novel fluorescent polyimides containing ortho-linked units and pyridine moieties

A novel pyridine-containing aromatic diamine monomer, 4-[4-hydroxyphenyl]-2,6-bis[4-(2-aminophenoxy)phenyl]pyridine (p,o-HAPP), was synthesized by a modified Chichibabin reaction of p-Hydroxybenzaldehyde and a substituted acetophenone, 4-(2-nitrophenoxy)acetophenone (p,o-NPAP), followed by a reduction of the resulting dinitro compound 4-[4-hydroxyphenyl]-2,6-bis[4-(2-nitrophenoxy)phenyl]pyridine with Pd/C and hydrazine monohydrate. The aromatic diamine was employed to prepare a series of pyridine-containing polyimides (PIs) by polycondensation with various aromatic dianhydrides in N,N-dimethylformamide (DMF) via the conventional two-step method. The inherent viscosities of the resulting poly(amic acids) and PIs were in range of 0.62-0.76 and 0.52-0.64 dL/g, respectively. The obtained novel PIs exhibited high solubility in common organic solvents, such as m-Cresol, DMF, N,N-dimethylacetamide, dimethylsulfoxide, N-methylpyrrolidone (NMP), tetrahydrofuran, and chloroform. Meanwhile, flexible PI films were obtained, which had excellent thermal stability, with the glass transition temperature (T g) of 259.8-323.4 °C and the temperature at 10% weight loss of 485.5-576.4 °C in nitrogen atmosphere. The protonated polymer showed UV-vis absorption in the region 200-400 nm and displayed strong fluorescence intensity (470 nm) in NMP solution.