The presence of ionic charges in a liquid crystal layer causes the generation of residual direct current (dc) voltage (Vrdc) in a liquid crystal cell. Vrdc is one of the most important factors governing the image quality of liquid crystal displays, because the existence of Vrdc causes the image sticking phenomenon. We studied the generation mechanism of Vrdc based on a model of the adsorption and desorption of the ionic charges at the interface between the liquid crystal and alignment layer. In this paper, we propose three evaluation parameters, (i) saturated residual dc voltage, (ii) time to reach its saturation state, and (iii) relaxation time during the open circuit state after applying the external dc voltage, for effective evaluation of liquid crystal and alignment layer materials from the viewpoint of the improvement of the image sticking.

Image sticking can be observed in some cases and it degrades the image quality of liquid crystal (LC) display. The image sticking is considered to be induced by generation of residual direct current voltage (Vrdc), which would be caused by the presence of ion in a LC cell. We clarified the generation mechanism of Vrdc based on a model of adsorption and desorption of the ion to and from the surface of an alignment layer at various temperatures. The experimental results indicate that these processes can be explained by the Boltzmann distribution. The analysis based on Arrehnius plots shows that the ion adsorbs to the surface of the alignment layer with weak binding such as van der Waals interaction or hydrogen bonding. This finding is effective for development of high image quality LC displays.

Residual DC voltage is one of the most important items which govern the image quality of LCD, because the existence of it causes image sticking phenomenon. However, we do not have established evaluation parameters. The generation mechanism of the residual DC voltage was analyzed based on a model of adsorption and desorption of electric charges, ions, at the interface between LC phase and alignment layer. New parameters are proposed for unified evaluation of LC and alignment materials.

No abstract

A series of anionic homopolymers, poly(sodium 2-(acrylamido)-2-methyl-1-propanesulfonate) (PAMPS) and amphiphilic copolymers of AMPS and sodium 11-(acrylamido)undecanoate (AaU), both block (PAMPS75-b-PAaUn), and random (P(AMPSm-co-AaUn)), were synthesized and their antiviral activity against Zika virus (ZIKV) was evaluated. Interestingly, while the homopolymers showed limited antiviral activity, the copolymers are very efficient antivirals. This observation was explained considering that under the conditions relevant to the biological experiments (pH 7.4 PBS buffer) the macromolecules of these copolymers exist as negatively charged (zeta potential about −25 mV) nanoparticles (4–12 nm) due to their self-organization. They inhibit the ZIKV replication cycle by binding to the cell surface and thereby blocking virus attachment to host cells. Considering good solubility in aqueous media, low toxicity, and high selectivity index (SI) of the PAMPS-b-PAaU copolymers, they can be considered promising agents against ZIKV infections.

No abstract

We have developed a long lifetime OLED display by optimizing each organic layer materials. The lifetime of the new developed blue OLED under 50 mA/cm 2 driving at 85 °C was improved more than four times compared with the previously developed OLED, and achieved longer than 1,500 hours in a real use. The developed OLED display would be useful for automotive application.

Generation mechanism of residual direct current voltage in a liquid crystal display and its evaluation parameters related to liquid crystal and alignment layer materialsGeneration of residual direct current (DC) voltage (V rDC ) induces a serious image sticking of liquid crystal (LC) displays. V rDC is generated with the ions in a LC layer adsorbing to a surface of an alignment layer under application of DC offset voltage. We clarified the adsorption and desorption of the ions to and from the surface of the alignment layer with a kinetic model proposed by us. The analysis with using the kinetic model made clear that the processes of the adsorption and desorption occur due to the thermal fluctuation followed by the Boltzmann distribution. The ions adsorb to the surface of the alignment layer by a weak binding, such as the van der Waals interaction. V C 2012 American Institute of Physics. [http://dx.