New amphiphilic block copolymers S nSz m consisting of blocks with varied degrees of polymerization, n and m, of polystyrene, S, and polystyrene carrying an amphiphilic polyoxyethylene-polytetrafluoroethylene chain side-group, Sz, were prepared by controlled atom transfer radical polymerization (ATRP). The block copolymers, either alone or in a blend with commercial SEBS (10 wt% SEBS), were spin-coated in thinner films (200-400 nm) on glass and spray-coated in thicker films ( approximately 500 nm) on a SEBS underlayer (150-200 microm). Angle-resolved X-ray photoelectron spectroscopy (XPS) measurements proved that at any photoemission angle, varphi, the atomic ratio F/C was larger than that expected from the known stoichiometry. Consistent with the enrichment of the outer film surface (3-10 nm) in F content, the measured contact angles, theta, with water (theta w > or = 107 degrees ) and n-hexadecane (theta h > or = 64 degrees ) pointed to the simultaneous hydrophobic and lipophobic character of the films. The film surface tension gamma S calculated from the theta values was in the range 13-15 mN/m. However, the XPS measurements on the "wet" films after immersion in water demonstrated that the film surface underwent reconstruction owing to its amphiphilic nature, thereby giving rise to a more chemically heterogeneous structure. The atomic force microscopy (AFM) images (tapping mode/AC mode) revealed well-defined morphological features of the nanostructured films. Depending on the chemical composition of the block copolymers, spherical (ca. 20 nm diameter) and lying cylindrical (24-29 nm periodicity) nanodomains of the S discrete phase were segregated from the Sz continuous matrix (root-mean-square, rms, roughness approximately 1 nm). After immersion in water, the underwater AFM patterns evidenced a transformation to a mixed surface structure, in which the nanoscale heterogeneity and topography (rms = 1-6 nm) were increased. The coatings were subjected to laboratory bioassays to explore their intrinsic ability to resist the settlement and reduce the adhesion strength of two marine algae, viz., the macroalga (seaweed) Ulva linza and the unicellular diatom Navicula perminuta. The amphiphilic nature of the copolymer coatings resulted in distinctly different performances against these two organisms. Ulva adhered less strongly to the coatings richer in the amphiphilic polystyrene component, percentage removal being maximal at intermediate weight contents. In contrast, Navicula cells adhered less strongly to coatings with a lower weight percentage of the amphiphilic side chains. The results are discussed in terms of the changes in surface structure caused by immersion and the effects such changes may have on the adhesion of the test organisms.

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The growth of a thermally deposited merocyanine (HB364) thin film can be modified through insertion of a transition metal oxide layer between an indium tin oxide (ITO) covered glass substrate and the dye film. Pure or V 2 O 5 modified ITO substrates result in highly crystalline HB364 films where the dye molecules adopt an edge-on orientation. Changing the transition metal oxide layer to WO 3 or MoO 3 results in a less ordered dye film with a mixed growth of edge-on and face-on orientations. Planar HB364/C 60 heterojunction (PHJ) solar cells are fabricated using the different transition metal oxides as the anode buffer layers. The devices with a pure ITO or a V 2 O 5 modified anode demonstrate the highest power conversion efficiencies up to 2.7% that also outperform HB364:C 60 bulk heterojunction (BHJ) devices (2.5%). Finally, HB364/HB364:C 60 hybrid heterojunction (HHJ) cells are fabricated showing the highest power conversion efficiency of 2.9%.

We report the synthesis of meso-ethynylphenyl BODIPYs and compare their properties with the corresponding meso-phenyl derivatives. Both types of BODIPYs carry a 2-cyano-3-acrylic acid anchoring moiety and either methyl groups or 4,4 0-dimethoxytriphenylamine (MeOTPA) donor groups at positions 3 and 5. All compounds were characterized by NMR, UV/vis and cyclic voltammetry. The MeOTPAsubstituted BODIPYs show an excellent panchromatic absorption with high molar extinction coefficients over the whole UV/vis range up to the near-IR region. The most impressive absorption was exhibited by the MeOTPA-substituted meso-ethynylphenyl BODIPY which strongly absorbs up to 1030 nm. By cyclic voltammetry measurements, all compounds were identified to be electrochemically stable in solution. Further, it was observed that the value of the LUMO level can be tuned by the meso-substituent. The HOMO level is determined by the donor substituents (À5.41 AE 0.03 eV and À4.84 AE 0.01 eV for BODIPYs with methyl groups and MeOTPA donor groups, respectively). These findings were further supported by DFT calculations. To evaluate the potential of the BODIPYs as sensitizers, the incident photon-to-current conversion efficiencies of solid-state dye-sensitized solar cells were measured. The photoaction spectra clearly show that the BODIPYs contribute to the photocurrent generation over their entire absorption region.