Front Cover: The image shows the polarizing optical microscopy image of a cholesteric liquid crystal medium. The structural chirality of the cholesteric liquid crystal results when an achiral polythiophene derivative bearing the azobenzene moiety is dissolved in the cholesteric liquid crystal. The chiral polymer thus obtained shows light-driven chiroptic modulation through the photo-isomerization of the azobenzene group in the substituent. Further details can be found in the article by H. Goto^* and R. Ohta on page 2071.

Understanding the principles of charge generation and recombination in organic solar cells is a prerequisite for future material development and device optimization. Optical probes, especially transient absorption spectroscopy, are valuable tools to study the dynamics of excited states such as excitons and charges, over a wide-range of timescales. New insights from recent studies may help to guide the future material development without having to rely on entirely empirical strategies for device optimization.

The imprint of structural chirality and photo-induced chiroptic modulation: Dissolving achiral polythiophene derivatives bearing the azobenzene moiety, which have been synthesized in an isotropic toluene solution, in a cholesteric liquid crystal (Ch*LC) medium within the liquid crystal temperature range imparts chirality. The resultant polymers show light-driven chiroptic modulation.

The synthesis, characterization and photopatterning behavior of alternating fluorene cooligomers is described. Different comonomers such as TPD, bithiophene and benzothiadiazole were alternatingly incorporated into the oligofluorene chain and the electrooptical properties were compared to their randomly linked counterparts. Photopatterning experiments reveal that under optimized conditions lateral resolutions of 600nm are possible.

Hydrogen bonding increases the planarity of the backbones of aromatic hydrazide-based extended polymers, while suitable side chains provide solubility. As a result, such polymers can self-assemble into vesicular structures or gelate organic solvents of both low and high polarity.

An induced large-scale alignment of the parallel cylinder morphology of the polystyrene -block-polyethylene oxide thin film via treatment in a saturated benzene vapor that flows parallel to the film surface is realized. The enhanced alignment in the vapor-flow is attributed to a vapor-flow-induced shearing effect of the polymer film. The semicrystalline PEO block forms cylinders that initiate a growth rate with a favorable perpendicular orientation of the PEO crystalline stems with respect to the cylinder axis.

Detailed studies regarding the correlation between the UCST and the copolymer composition, polymer concentration and the presence of electrolytes for aqueous solutions of the homopolymer of N-acryloylglycinamide (NAGA), bearing H-donor and H-acceptor sites, and a UCST copolymer system based on H-donor NAGA and H-acceptor N-acetylacrylamide (NAcAAm) monomers are reported.

Thermal diffusivity along the out-of-plane direction ( D_⟂) in polyimide (PI) blend films containing silver nano particles is investigated. Micro phase-separated structures with a “vertical double percolation (VDP)” morphology are spontaneously formed in the films, and the blend films exhibit significantly higher D_⟂ than that of mono phase homo-PI films. These results indicate that the VDP structure functions as an effective thermal conductive pathway.

A general approach to construct a one-dimensional face-to-face alignment of porphyrin/fullerene nanowires has been developed. The nanowires display regular one-dimensional linear arrays with lengths in the range 50–300nm and could have potential applications in photoelectronic devices, organic solar cells, etc.

By choosing the amount of ⁱBu₃Al or Et₃Al added, the values of alternating ethylene/norbornene (EN) copolymers are widely controlled from 25 000 to 209 000g·mol⁻¹ accompanied with an increase in the polymer yields by the use of [Ph₂C(Flu)(3-MeCp)]ZrCl₂ (1) combined with methylaluminoxane (MAO) in toluene.

A series of π-conjugated polymers consisting of isothianaphthene and dialkoxy-p-phenylene units have been synthesized. The polymers assume an interdigitation-type self-assembled packing structure in the solid state, and molecularly align on the surface of the Pt plate. UV-Vis data have been elucidated on the basis of the π-stacked assembly of the polymers. The polymers undergo electrochemical p-doping at about 0.2V versus Ag⁺/Ag, and a p-doped polymer film showed a moderate electrical conductivity of 182S·cm⁻¹.

The determination of conformation and molar mass distribution of polyelectrolytes is a difficult analytical task. Online coupling of a separation procedure and a scattering method in the form of field-flow fractionation and small-angle X-ray scattering is used for characterization of a PAA mixture.

ATRP equilibrium constants, K_ATRP, and ATRP activation rate coefficients, k_act, are measured up to 2500 bar by online-FT-NIR/VIS spectroscopy for several binary Cu^I/Cu^II ligand–alkyl bromide systems. The activation volume, ΔV^‡_act, is close to the reaction volume, ΔV_R, that is obtained from the pressure dependence of K_ATRP. Both quantities reflect the characteristics of ligand complexation.