Planar microcavities containing pseudoisocyanine (PIC) J-aggregates dispersed in PVS polymer matrices are prepared and the formation of exciton-photon strong coupling states, so-called cavity-polaritons, are investigated by angle-resolved reflectivity and photoluminescence spectroscopy at room temperatures. The polarization of incident light, structure/materials of cavity mirrors and concentrations of J-aggregates are systematically changed and their optical properties are inspected in detail. Moreover, a custom-made microspectroscopy illumination system allowed us to obtain detailed angle resolved optical properties in local-area regime with diffraction-limited resolution. We confirmed the stable and well-defined formation of the polariton states even by Ag-Ag mirrors at room temperature, which is hard to achieve by present inorganic semiconductor nanostructures. Based on these findings, peculiarities of PIC-J aggregates as nano-scaled constitutions are described. We also describe briefly the optical properties of so-called fibril-shaped PIC-J aggregates associated with polariton formation as well as a possible high-density limiting case of J-aggregate-based opto-organic materials.

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Iridium (Ir) complexes with 2-arylpyridyl ligands are expected to act as highly efficient organic electroluminescent (EL) materials due to their phosphorescent properties and high internal quantum efficiency. In this study, we have prepared liquid crystal (LC)/organic EL devices containing such Ir complexes, and have investigated their EL properties. We have synthesized three 2-arylpyridines ligands containing alkyl, cyano, and fluorine groups. The ligand having alkyl and cyano groups exhibited a smectic LC phase, and the complex could be dissolved into the nematic liquid crystal: 4-pentyl-4′-cyano-biphenyl (5CB) without significant decrease in the nematic-isotropic phase transition temperature. The device using a mixture of 5CB with two of the complex having different emission wavelength showed an improvement in the EL properties. This might be caused by an energy transfer between the complexes.

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Ionic liquid/polydimethylsiloxane (IL/PDMS) gels were synthesized by hydrosilylation of divinyl-polydimethilsiloxane and polymethylhydrogenesiloxane in the presence of various ionic liquids. Since 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([EMI][TFSI]) was miscible with both DV-PDMS and PMHS, homogeneous [EMI][TFSI]/PDMS gels were obtained. The compression moduli of the [EMI][TFSI]/PDMS gels were 0.84~1.0 MPa, regardless of the [EMI][TFSI] content (10~50 wt%); such independence was similar to that of a PDMS elastomer without IL (0.85 MPa). The resistance of the [EMI][TFSI]/PDMS gel decreased with increasing the [EMI][TFSI] content; the value at 40 wt% of IL (12 GΩ) was 20 times lower than that of the PDMS elastomer (200 GΩ). The application of an electric field through Au electrodes sputtered on both sides of the 50 μm-thick gel brought about bending toward anode. The displacement at the bottom free end attained 4 mm at 100 V, which was 200 times larger than that of the PDMS elastomer without IL measured at 1000 V.

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An alicyclic tetracarboxylic dianhydride, norbornane-2-spiro-α-cyclopentanone-α´-spiro-2″-norbornane-5,5″,6,6″-tetracarboxylic dianhydride (CpODA) was synthesized from a cyclopentanone bis-spironorbornene compound by Pd-catalyzed methoxycarbonylation, followed by the ester-exchange reaction and then by the thermal dehydration ring-closure. The dianhydride was polycondensated with 1,3-bis(4-aminophenoxy)benzene in DMAc to give a poly(amic acid) having an inherent viscosity η_inh of 0.31 dL/g. The viscous solution was cast on a glass plate. The plate was heated in vacuum at 80°C and 250°C for 1 h each to be converted to the polyimide film. The film was soluble in common organic solvents such as chloroform and possessed an averaged transmittance of 89.0% in the visible light area. The polyimide has good thermal stability with the 5% weight-loss temperature at 487°C and the T_g at 290°C. The high T_g may be due to a dipole-dipole interaction between the keto groups of the polymer chains as well as to a development of rigid polyalicyclic units.

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