We have reported drastic enhancement of photoluminescence of chiral Eu(III) complex (Eu(D-facam)₃) in 1-butanol by cooperating effect of tetramethylammonium cation with specific counter anions of chloride and acetate. In this study, based on such unusual luminescence improvement, solvent effect of this luminescence enhancement was further investigated by comparing a series of primary alcohols with straight alkyl chains (carbon number, n : 1∼6) including methanol, ethanol, 1-propanol, 1-butanol, 1-pentanol and 1-hexanol. In the case of both anions, notable alcoholic solvent effect on luminescence properties of Eu(D-facam)₃ were observed upon coexistence with tetramethylammonium citation. Interestingly, in 1-pentanol, Eu(D-facam)₃ achieved a superior luminescence enhancement above 500 times and induced circular polarized luminescence (g_lum=-0.69) by the interaction with tetramethylammonium acetate. On the contrary, the luminescence of Eu(D-facam)₃ decreased by addition of tetramethylammonium acetate the in the methanol. The unusual optical behavior would be attributed to structural change of Eu(D-facam)₃ induced by the interaction of tetramethylammonium and specific anions in alcoholic solution. The strength of their interactions would be affected by polarity of the alcoholic solvents, leading to huge dependence of the luminescence intensity on the alcohol species.

Jetting stability of thermal printheads is difficult to be predicted, since the thermal printhead makes scorch on the heater because of boiling inks on the heater for jetting.

In order to prevent scorching of the heater, it is effective to increase the surface potential of the pigment particles, but the conventional measurement method cannot eliminate the effect of Brownian motion of the particles.

Therefore, we developed a new method for measuring the zeta potential distribution, which eliminates the effect of Brownian motion. We also found that there is a linear relationship between the new index ζ_2% and the jetting durability. In addition, the relationship between the index of ζ_2% and the jetting durability can be interpreted based on the classical DLVO (Derjaguin-Landau-Verwey-Overbeek) theory.

These results suggest that the jetting durability can be predicted by measuring the physical properties for the development of new inks for thermal heads.

Significant improvement in the power conversion efficiency of organic photovoltaics has been made in the last decade. Ternary blend OPVs (organic photovoltaics), in which three organic semiconductors are blended to absorb wide range of the incident light, have shown to be an important strategy for improving the efficiency. Here, we show a ternary blend OPV system that used a high-crystalline polymer and a fullerene derivative as the host binary blend system and a nonfullerene n-type material as the third component. It was found that even with a small amount of the third component, optical absorption can be enhanced by the optical interference effect, which significantly boosted the efficiency of the ternary blend cell compared to the binary blend cell.

Chemical doping of polymeric semiconductors involves the electron transfer between the host polymer and guest dopant, representing a host-guest binary system. The successful introduction of functional dopant molecules or ions into an interstice of crystalline polymers improves the doping level. A metallic state with degenerated, coherent electrons is realized particularly via anion exchange doping. The resulting high doping level and enhanced conductivity could allow an in-depth understanding of electronic states in polymeric semiconductors, and may possibly open up opportunities for exploring novel functionalities of conductive polymers.

This review describes the current status and future challenges of ion-conductive polymers. Ion-conductive materials are essential in various electronic devices such as lithium-ion batteries, fuel cells, and electrochromic devices etc. First, various applications using ion conductive materials and their required properties are introduced. Next, the characteristics of various ion conductive materials, including not only organic but also inorganic materials, and their highest ionic conductivities are outlined. Then, the ion conductive mechanism of the polymer electrolytes are explained. Through the introduction of the representative polymer-salt complexes and single ion conductors (polyionic liquids), one can understand the factors for controlling the ionic conductivity (Glass transition temperature, Effects of plasticizers and inorganic fillers).

Antistatic agents are additives used to avoid problems plastics have with static electricity, and are used in various fields such as home appliances, office equipment, construction materials, electronic component carrier materials, and the medical field. In addition, its application is increasingly expanding to prevent electrostatic discharge (electrostatic discharge, ESD) due to the recent miniaturization of electronic components. Antistatic agents include low-molecular-weight antistatic agents and high-molecular-weight antistatic agents. Unlike low-molecular-weight types, polymer-type antistatic agents are alloyed with plastics and thus have a semipermanent antistatic effect. This paper introduces the characteristics of polymer-type antistatic agents and explains their differences from low-molecular-weight antistatic agents, using PELECTRON, a polymer-type antistatic agent developed and marketed by our company, as a specific example.

Polymers are superior electrical insulating material but also are thermal insulators. Most of conventional polymers are hard to transmit the heat, then polymers are generally used as composites containing ceramics powders to improve their low thermal conductivities. Recently, several journals have published the articles about the high thermal conductive polymers themselves, not composites. One is about the widely used thermoplastic polymer, polyethylene by ultra-drawn nano-fiber, which has the high thermal conductivity of 104Wm^-1K^-1 like conductive metals. The other is a thermosetting polymer used in electronics devices, especially in mesogenic epoxy resin, shows the high thermal conductivity of 5.8Wm^-1K^-1 to cross-plane direction in the interface on the substrate by controlling higher order structure. These thermal conductivities have achieved by controlling the higher order structures of polymers. In this article, the latest technologies of controlling the higher order structures of polymers to increase the thermal conductivities would be explained.

Polysilsesquioxanes have been considerably utilized various materials for industrial applications, because of their excellent thermal, mechanical, optical and electrical properties, as well as, their processability using a wide variety of silane compounds as raw materials. Although molecular structures of the polysilsesquioxanes are supposed to significantly affect their properties, completely control the structures of the products at the molecular level is difficult in the case of general sol-gel method. Therefore, the correlation between structures and properties is also still unclear due to the difficulty of their structural analysis. Use of cage silsesquioxane frameworks as element-blocks has been demonstrated to be an efficient method for designing well-defined silsesquioxane materials at molecular level structures. This review focuses the potential of cage silsesquioxane based element-block materials as functional materials, especially for ionic conductive, latent heat storage, thermal conductive, and UV-resistant materials.

To develop new useful biodegradable polymers from easily available raw materials, various copolyesters were designed and synthesized, and their properties and biodegradability were evaluated. Triblock copolymers, PLLA-b-P(CL-r-DLLA)-b-PLLA, consisting of poly(L-lactide)(PLLA)and poly(ε-caprolactone-r-DL-lactide)(P(CL-r-DLLA))blocks, showed excellent properties as thermoplastic elastomers. Triblock copolymers consisting of PLLA and aliphatic polyesters synthesized by the polycondensation of 3-methyl-1,3-propanediol and aliphatic dicarboxylic acids showed high biodegradability in seawater. Sequence-controlled copolyesters composed of terephthalic acid, ethylene glycol, and hydroxy acid such as glycolic acid and L-lactic acid with high melting point and biodegradability in seawater were developed. Sequence-controlled poly(ester-amide)s composed of diol, dicarboxylic acid, and γ-aminobutyric acid components showed improved thermal stability compared to polyamide 4, and the poly(ester-amide)s containing short diols and aliphatic dicarboxylic acids showed high biodegradability.

Moth-eye technology, which is one of the leading technologies to reduce the light reflection on the surface, has attracted attention because of its possibility of achieving excellent low reflection at low cost. Moth-eye Film, which has a structure that imitates the nano-protrusion structure formed on the surface of the moth's eyes, is used for electronic display devices that take advantage of its ultra-low reflection characteristics. In addition, various new proposals have been made for non-display applications that utilize unique surface properties. The lotus leaf effect caused by the nanostructure, that is, the antifouling film using superhydrophobicity, the antifogging film using superhydrophilicity, the 3D cell culture sheet and antibacterial sheet have been developed as applications to the bio/medical field. This paper introduces moth-eye's antifouling properties, antifogging properties, antibacterial properties, and antiviral properties that are in increasing demand due to the epidemic of COVID-19.