Alternating copolymers of oligoarylenes and naphthalene bisimides as low band gap semiconductors: Synthesis, electrochemical and spectroelectrochemical behavior

Three novel electroactive copolymers, consisting of alternating naphthalene bisimide and oligoarylene segments have been synthesized and studied by cyclic voltammetry and UV–vis-NIR spectroelectrochemistry. These studies show that the conjugation between both copolymer segments is very weak and the reduction of the bisimide part is essentially uninfluenced by the oligoarylene segment. The oxidation of the oligoarylene segment strongly depends on its length but is not affected by the presence of the bisimide part. The HOMO levels, determined electrochemically are systematically below −5.0 eV with respect to the vacuum level, changing from −5.45 eV for poly[1,4-phenylene-(4,3′(4′),3″-trioctyl-2,2′,5′,2″-terthiophene-5,5″-diyl)-1,4-phenylene-1,4,5,8-naphthalenediimide-N,N′-diyl] (6) to −5.50 eV in poly[1,4-phenylene-(4,4′-dioctyl-2,2′-bithiophene-5,5′-diyl)-1,4-phenylene-1,4,5,8-naphthalenediimide-N,N′-diyl] (5) and −5.84 eV for poly[1,4-phenylene-(3,4-dioctylthiophene-2,5-diyl)-1,4-phenylene-1,4,5,8-naphthalenediimide-N,N′-diyl] (4). The LUMO levels in all three cases are close to −4.0 eV. The obtained results clearly indicate that 5 and 6 are good candidates for the fabrication of ambipolar transistors operating in air whereas 4 can be considered as an active component of n-channels FETs.     

High performance Langmuir–Schaeffer film transistors based on air stable n-type diperylene bisimide

Diperylene Bisimide (DIPP–diPBI) mono- and/or multi-layer film using Langmuir–Schaeffer (LS) techniques has been fabricated and the OFET device performance based on the as-prepared LS film is investigated. The thickness of monolayer film is determined to be 2.3 nm by using atomic force microscopy, which is closely matched with the interplanar spacing estimated from the XRD spectra. The length of molecular long axis is measured to be 21.9 Å from the DFT optimized configuration, indicating that the long axis of molecule in LS film approximately stands upright on hydrophobic substrates. The absorption maximum at 417 nm shows a good linear corrleation with the layer number, proving the obtained films are deposited in a layer-by-layer fassion. The film with precision control of the long-range order and lateral packing density by LS deposition exhibits good electron injection properties and high FET device performance. The charge transport behavior is also investigated as a function of the layer number of LS film. The electron mobility gradually increases with the number of layers and saturates at a plateau with a mean value of 0.03 cm² V⁻¹ s⁻¹ in the atmosphere upon completion of the first eight layers. It is a direct evidence of physical size of charge transport layer. Furthermore, the fabricated FET device exhibits long-time stability in the air. The integration of LS method with air stability of the n-type compound affords an opportunity to explore solution-phase self-assembly and electronic devices fabrication with controllable molecular layers.     

Rigid‐rod polybenzoxazoles containing perylene bisimide: Synthesis,structures and photophysical properties

A novel perylene bisimide dye bearing carboxylphenylene substituents on the imide N atoms was synthesized and four conjugated copolymers containing different contents of perylene bisimide dye were synthesized via PPA/P₂O₅ copolymerization method. The structures of the four copolymers were characterized by FTIR, elementary analysis, ¹H‐NMR and XRD. The copolymers showed good thermal stabilities but poor solubilities due to the high rigidity of the backbone. The photophysical characteristics of the copolymers were investigated by UV‐Vis and PL spectra in solutions and films. Because of the conformational change of perylene bisimide chromophore, the absorptions of perylene bisimide core in copolymers showed a large blue‐shift (56 nm) compared to that of the perylene monomer. In PL experiments, when exciting the benzoxazole, an obvious fluorescent quenching was observed in all copolymers, which can be attributed to the energy transfer from benzoxazole units to perylene bisimide fragments and fluorescence quenching. With increasing perylene content, the copolymers turned to layered and friable. The XRD test showed that the interchain distances increased slightly with increasing perylene content. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Probing Bio–Nano Interactions between Blood Proteins and Monolayer‐Stabilized Graphene Sheets

Meeting proteins is regarded as the starting event for nanostructures to enter biological systems. Understanding their interactions is thus essential for a newly emerging field, nanomedicine. Chemically converted graphene (CCG) is a wonderful two‐dimesional (2D) material for nanomedecine, but its stability in biological environments is limited. Systematic probing on the binding of proteins to CCG is currently lacking. Herein, we report a comprehensive study on the interactions between blood proteins and stabilized CCG (sCCG). CCG nanosheets are functionalized by monolayers of perylene leading to significant improvement in their resistance to electrolyte salts and long‐term stability, but retain their core structural characteristics. Five types of model human blood proteins including human fibrinogen, γ‐globulin, bovine serum albumin (BSA), insulin, and histone are tested. The main drving forces for blood protein binding involve the π–π interacations between the π‐plane of sCCG and surface aromatic amonic acid (sAA) residues of proteins. Several key binding parameters including the binding amount, Hill coefficient, and binding constant are determined. Through a detailed analysis of key controlling factors, we conclude that the protein binding to sCCG is determined mainly by the protein size, the number, and the density of the sAA.     

Novel Insoluble Organic Cathodes for Advanced Organic K‐Ion Batteries

Organic redox‐active molecules are inborn electrodes to store large‐radius potassium (K) ion. High‐performance organic cathodes are important for practical usage of organic potassium‐ion batteries (OPIBs). However, small‐molecule organic cathodes face serious dissolution problems against liquid electrolytes. A novel insoluble small‐molecule organic cathode [N,N′‐bis(2‐anthraquinone)]‐perylene‐3,4,9,10‐tetracarboxydiimide (PTCDI‐DAQ, 200 mAh g^?1) is initially designed for OPIBs. In half cells (1–3.8 V vs K⁺/K) using 1 m KPF₆ in dimethoxyethane (DME), PTCDI‐DAQ delivers a highly stable specific capacity of 216 mAh g^?1 and still holds the value of 133 mAh g^?1 at an ultrahigh current density of 20 A g^?1 (100 C). Using reduced potassium terephthalate (K₄TP) as the organic anode, the resulting K₄TP||PTCDI‐DAQ OPIBs with the electrolyte 1 m KPF₆ in DME realize a high energy density of maximum 295 Wh kg^?1_cathode (213 mAh g^?1_cathode × 1.38 V) and power density of 13 800 W Kg^?1_cathode (94 mAh g^?1 × 1.38 V @ 10 A g^?1) during the working voltage of 0.2–3.2 V. Meanwhile, K₄TP||PTCDI‐DAQ OPIBs fulfill the superlong lifespan with a stable discharge capacity of 62 mAh g^?1_cathode after 10 000 cycles and 40 mAh g^?1_cathode after 30 000 cycles (3 A g^?1). The integrated performance of PTCDI‐DAQ can currently defeat any cathode reported in K‐ion half/full cells.     

Fluorescent Polymer—Single‐Walled Carbon Nanotube Complexes with Charged and Noncharged Dendronized Perylene Bisimides for Bioimaging Studies

Fluorescent nanomaterials are expected to revolutionize medical diagnostic, imaging, and therapeutic tools due to their superior optical and structural properties. Their inefficient water solubility, cell permeability, biodistribution, and high toxicity, however, limit the full potential of their application. To overcome these obstacles, a water‐soluble, fluorescent, cytocompatible polymer—single‐walled carbon nanotube (SWNT) complex is introduced for bioimaging applications. The supramolecular complex consists of an alkylated polymer conjugated with neutral hydroxylated or charged sulfated dendronized perylene bisimides (PBIs) and SWNTs as a general immobilization platform. The polymer backbone solubilizes the SWNTs, decorates them with fluorescent PBIs, and strongly improves their cytocompatibility by wrapping around the SWNT scaffold. In photophysical measurements and biological in vitro studies, sulfated complexes exhibit superior optical properties, cellular uptake, and intracellular staining over their hydroxylated analogs. A toxicity assay confirms the highly improved cytocompatibility of the polymer‐wrapped SWNTs toward surfactant‐solubilized SWNTs. In microscopy studies the complexes allow for the direct imaging of the SWNTs' cellular uptake via the PBI and SWNT emission using the 1st and 2nd optical window for bioimaging. These findings render the polymer‐SWNT complexes with nanometer size, dual fluorescence, multiple charges, and high cytocompatibility as valuable systems for a broad range of fluorescence bioimaging studies.     

微波诱导氧化处理北系染料废水

为达到采用微波诱导氧化工艺(MIOP)处理北系染料废水的目的,分别考察了活性炭种类、活性炭用量、微波辐射时间、微波功率、H₂O₂用量和pH值等因素对处理效果的影响.结果表明,6 g活性炭与50 mL北系废水混合,在微波功率为480?W,辐射时间6 min,H₂O₂用量2.0 mL,FeSO₄用量0.07 g,pH=3的条件下,对废水COD的去除率达到98.95%.微波诱导氧化、活性炭吸附和单独微波辐射3种不同工艺的对比实验表明,微波诱导氧化有明显的优越性,且不会对环境造成二次污染.动力学研究表明,该氧化过程符合一级动力学规律,反应速率常数K=0.086 min^-1,反应半衰期t_1/2=8.06 min.     

有机P－N结太阳能电池的研究

有机Ｐ－Ｎ结太阳能电池的研究董长征，王维波，蓝闽波，任绳武，肖绪瑞，周庆复，许慧君（华东理工大学，上海２００２３７）（中国科学院感光化学研究所，北京１００１０１）关键词有机太阳能电池，酞菁，红近年来，以有机化合物作为光电转换材料的研究报道很多￣［１～...