An ambipolar low band gap material based on BODIPY and EDOT

A novel donor–acceptor type conducting polymer based on BODIPY dye as acceptor and EDOT units as donor parts is synthesized electrochemically. The unique combination of BODIPY and EDOT units provides an ambipolar (n- and p-doping processes) low band gap material (4). This is the first example of p–n junction in an organic π-conjugated material where BODIPY unit is incorporated directly in the main chain. Furthermore, the polymer film exhibits electrochromic behavior upon p-doping: a color change from light violet (neutral) to indigo (oxidized).     

A new photoiniferter/RAFT agent for ambient temperature rapid and well‐controlled radical polymerization

Phenacyl morpholine‐4‐dithiocarbamate is synthesized and characterized. Its capability to act as both a photoiniferter and reversible addition fragmentation chain transfer agent for the polymerization of styrene is examined. Polymerization carried out in bulk under ultra violet irradiation at above 300 nm at room temperature shows controlled free radical polymerization characteristics up to 50% conversions and produces well‐defined polymers with molecular weights close to those predicted from theory and relatively narrow poyldispersities (M_w/M_n ～ 1.30). End group determination and block copolymerization with methyl acrylate suggest that morpholino dithiocarbamate groups were attained at the end of the polymer. Photolysis and polymerization studies revealed that polymerization proceeds via both reversible termination and RAFT mechanisms. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 3387–3395, 2008     

Photo‐Induced Cross‐Linking of Divinyl Ethers by Using Diphenyliodonium Salts With Highly Nucleophilic Counter Anions in the Presence of Zinc Halides

This study describes the use of diphenyliodonium salts with highly nucleophilic counter anions to photoinitiate the cationic cross‐linking of divinyl ethers. Both direct and indirect initiating modes are used. In the direct acting system, only a diphenyliodonium salt with a highly nucleophilic counter anion and a zinc halide are employed as initiator and activator, respectively. In the indirect systems, in addition to direct system components, photosensitive additives such as anthrecene, perylene, 2,2‐dimethoxy‐2‐phenyl acetophenone, benzophenone, and thioxanthone, which absorb the energy of the incident light and activate the iodonium salt, are used to initiate polymerization. All systems employed in this study initiated quite vigorous polymerizations.

     

Kinetic modeling of Fischer–Tropsch-to-olefins process via advanced optimization

The reaction kinetics of a Fischer–Tropsch (FT) process to produce lower olefins was modeled utilizing the experimental data produced using an in-house synthesized iron-based catalyst. Along with FT chain growth reaction that is assumed to follow alkyl mechanism, water–gas shift reaction was also taken into consideration due to its significance. Not only the rate constants but also apparent activation energies were obtained via an integrated approach utilizing multiobjective and constrained nonlinear minimization methods in order to define a model valid at a temperature range instead of a single point. The adaption of a hybrid optimization method utilizing both population- and individual-based techniques enhanced prediction accuracy compared with the case where only multiobjective genetic algorithm is used. Thanks to the developed model, the effect of process parameters on product distribution was investigated. Finally, the kinetic model was compared with Anderson–Schulz–Flory model and the deviations observed were discussed.     

Synthesis and characterization of liquid crystalline unsymmetrically substituted phthalocyanines

The synthesis of unsymmetrically substituted phthalocyanines bearing two p-tolyl-sulfonyl (tosyl)amido and six alkylthio moieties was achieved by cyclotetramerisation of two different phthalonitrile derivatives, namely 1,2-di(alkylthio)-4,5-dicyanobenzene and 4,5-dicyano-N,N′-ditosyl-o-phenylenediamine in the presence of an anhydrous metal salt and strong base. The new compounds were characterized by elemental analyses, UV/Vis, IR, NMR and mass spectra. The mesogenic properties of these new materials were studied by differential scanning calorimetry (DSC) and polarizing optical microscopy. The mesogenic properties of these compounds were compared to that of their symmetric analogous, octaalkythia substituted phthalocyanine derivatives.     

Synthesis and characterization of new mesomorphic octakis(alkylthio)-substituted lead phthalocyanines and their films

The syntheses of new octakis (alkylthio)-substituted phthalocyanines of Pb(II) (1a and 2a) are described. These compounds are very soluble in most common organic solvents. They have been fully characterized using elemental analysis, NMR, infrared and UV–Vis spectroscopy. The mesogenic properties of these new materials were studied by differential scanning calorimetry and optical microscopy. These phthalocyanine derivatives are liquid at room temperature and form columnar-hexagonal (Col_h) mesophases below −10 °C. It has been indicated that the addition of methylene bridges to the phthalocyanine (Pc) core increases the clearing point temperatures. Also, the coordination of Pb²⁺ with the phthalocyanine core decreases the clearing point temperatures and the liquid crystal phase transition temperatures. Thin films of octakis(alkylthio)-substituted Pb(II) phthalocyanines 1a and 2a were prepared by the method of spin-coating. To obtain films with an ordered structure the film of 1a was slowly cooled from room temperature down to −10 °C. Sandwich structures of the form Au/PbPc(1a)/Au were prepared for the investigation of their electrical properties. It was shown that a slowly cooled Au/PbPc(1a)/Au structure demonstrates repeatable and stable electrical switching behaviour for applied bias voltages between −1 V and +1 V.     

A set of highly water-soluble tetraethyleneglycol-substituted Zn(II) phthalocyanines: synthesis, photochemical and photophysical properties, interaction with plasma proteins and in vitro phototoxicity

Three Zn(II) phthalocyanines substituted by hydroxyl-terminated tetraethylene glycol chains have been synthesized. In order to evaluate the potential of these highly water-soluble phthalocyanines as type II-photosensitisers for photodynamic therapy, their structure-activity relationship was assessed by determining relevant photophysical and photochemical properties, such as their aggregation behaviour in aqueous buffers, their fluorescence properties and their efficiency with regard to the generation of singlet oxygen. In addition, evidence for a negligible interaction with plasma proteins in undiluted human plasma was obtained using a recently developed bioanalytical method and compared with the fluorescence quenching approach. These results combined with in vitro data regarding the phototoxicity of these phthalocyanines against HT-29 cancer cells provide evidence for the relevance of the non-peripherally substituted derivative for further in vivo investigations.     

Pre-concentration and determination of 90Sr in radioactive wastes using solid phase extraction techniques

This paper describes the use of IBC??s AnaLig^®Sr-01 molecular recognition technology product to effectively and selectively pre-concentrate, separate and recover strontium from radioactive waste samples. The use and effectiveness of AnaLig^®Sr-01 gel was successfully validated by analysis of International Atomic Energy Agency (IAEA 375) reference soil and National Physical Laboratory (NPL)?CHigh Alpha?CBeta (2003) liquid sample. The second part of this paper focuses on analysis of radioactive waste samples from nuclear power plant A1 Jaslovske Bohunice in Slovak Republic (NPP A1).     

Preparation of fluorine containing hybrid coatings: investigation of coating performance onto ABS and PMMA substrates

UV‐curable fluorinated organic–inorganic hybrid coatings were prepared by the sol–gel technique. Perfluorinated urethane modified alkoxysilane was synthesized by the reaction between perfluoro alcohol and 3‐isocyanatopropyltrimethoxysilane. The prepared formulations were applied onto poly(methyl methacrylate) (PMMA) and acrylonitrile butadiene styrene (ABS) panels and polymerized by UV‐curing. The properties of the hybrid coatings such as hardness, chemical resistance, thermal stability, surface morphology, double bond conversion, and also contact angle measurements were investigated. Contact angle measurements have shown that the addition of fluorinated silane precursor to the hybrid system improved the water repellency and increased the contact angle from 65° to 106°. Copyright © 2009 John Wiley & Sons, Ltd.     

A design study of a triple field of view 8–12 μm waveband airborne FLIR

In this work, a design study of a three field-of-view (FOV) optical system for 8–12 μm imaging using a 288×4 focal plane array detector is presented. The detector pixel size is 25 μm×28 μm. The f/# of the detector is 1.76. In order to switch the FOVs, three different optical configurations are superimposed and all three configurations are optimized. The narrow and medium FOV switching is based on movement of the second negative lens of the afocal system, whereas the wide FOV is selected by inserting a mirror between the 4th and 5th lenses of the afocal system. By inserting a switching mirror, the objective part of the first configuration is blocked out; nevertheless the afocal of the wide FOV is activated. The imager part of the layout is common for all FOVs. Diffractive and aspheric surfaces are utilized to control chromatic and all other kinds of aberrations, reducing the total lens number. The final optical designs, together with their modulation transfer function (MTF) plots, are illustrated, exhibiting excellent performance in all three FOVs. More specifically, the paper emphasizes how the displacement of compensating lenses effect the MTF of the system and how automatic movements of the lenses are used to eliminate the defocusing problem under changing environmental conditions.