Two-Photon Absorbing Block Copolymer as a Nanocarrier for Porphyrin: Energy Transfer and Singlet Oxygen Generation in Micellar Aqueous Solution

A novel amphiphilic water-soluble 2PA-chromophore-containing block copolymer was designed and synthesized. Micelles (nanostructures) were generated in the aqueous solution using the block copolymer and characterized using dynamic light scattering (DLS) and atomic force microscopy (AFM). We demonstrated that hydrophobic porphyrin could be incorporated into aqueous solution with the assistance of micelles. The results from DLS showed that the average diameters are in the range of 59−77 nm. Efficient energy transfer (as high as 96%) from the 2PA chromophore to porphyrin was observed in micellar aqueous solution even though the donor and acceptor were not covalently bonded. Furthermore, the energy transfer contributes to the efficient generation of the singlet oxygen (by a factor of 2.6 at 800 nm) from the porphyrin guest molecules

Diels−Alder “Click Chemistry” for Highly Efficient Electrooptic Polymers

Diels−Alder “Click Chemistry” for Highly Efficient Electrooptic Polymer

Surface Modification of a Polyimide Gate Insulator with an Yttrium Oxide Interlayer for Aqueous-Solution-Processed ZnO Thin-Film Transistors

We report a simple approach to modify the surface of a polyimide gate insulator with an yttrium oxide interlayer for aqueous-solution-processed ZnO thin-film transistors. It is expected that the yttrium oxide interlayer will provide a surface that is more chemically compatible with the ZnO semiconductor than is bare polyimde. The field-effect mobility and the on/off current ratio of the ZnO TFT with the YO_<i>x</i>/polyimide gate insulator were 0.456 cm²/V·s and 2.12 × 10⁶, respectively, whereas the ZnO TFT with the polyimide gate insulator was inactive

High birefringent reactive discotic liquid crystals based on asymmetrical triphenylene with phenyl-acetylene moieties

<p>Triphenylene (TP)-based liquid crystals, a category of discotic liquid crystals (DLCs), are easy to synthesise, thermally stable and can undergo self-assembly. A new DLC compound, 2,7,10-tris[4-(6-acryloyloxyhexyloxy)benzoate]-3,6,11-tris[(4-hexylphenyl)ethynyl]-triphenylene, was obtained with a 49% yield using catechol as a starting material and features acetylene groups on its TP core. This material can form films with high birefringence through its cross-linkable acrylate ends. Here, we synthesised this new compound and characterised it using nuclear magnetic resonance spectroscopy, mass spectrometry and elemental analysis. The thermal behaviour was also investigated using differential scanning calorimetry and polarised optical microscopy. This new asymmetric TP-based DLC compound exhibited a nematic liquid-crystalline phase between −20 and 170°C and formed an optical anisotropic film with a high birefringence (Δ<i>n</i> = 0.21–0.25).</p

Enhanced Performance of Solution-Processed Organic Thin-Film Transistors with a Low-Temperature-Annealed Alumina Interlayer between the Polyimide Gate Insulator and the Semiconductor

We studied a low-temperature-annealed sol–gel-derived alumina interlayer between the organic semiconductor and the organic gate insulator for high-performance organic thin-film transistors. The alumina interlayer was deposited on the polyimide gate insulator by a simple spin-coating and 200 °C-annealing process. The leakage current density decreased by the interlayer deposition: at 1 MV/cm, the leakage current densities of the polyimide and the alumina/polyimide gate insulators were 7.64 × 10^–7 and 3.01 × 10^–9 A/cm², respectively. For the first time, enhancement of the organic thin-film transistor performance by introduction of an inorganic interlayer between the organic semiconductor and the organic gate insulator was demonstrated: by introducing the interlayer, the field-effect mobility of the solution-processed organic thin-film transistor increased from 0.35 ± 0.15 to 1.35 ± 0.28 cm²/V·s. Our results suggest that inorganic interlayer deposition could be a simple and efficient surface treatment of organic gate insulators for enhancing the performance of solution-processed organic thin-film transistors

Ultralarge and Thermally Stable Electro-Optic Activities from Supramolecular Self-Assembled Molecular Glasses

A series of molecular engineered organic glasses have been prepared to exploit the use of complementary Ar−ArF interactions to improve poling efficiency. These self-organized molecular glasses have also been used as host in the binary chromophore system to further improve the number density of chromophores and r33 values. Ultrahigh r33 values (up to 327 pm/V at the wavelength of 1310 nm) and good temporal stability could be achieved in these materials