The electrooptical characteristics of carbon nanotube-doped liquid crystal (LC) devices were investigated. Two complementary operation modes of the liquid crystal cells were fabricated. The measured results reveal that anisotropic carbon nanosolids modify the dielectric anisotropy and the viscosity of the liquid crystal carbon nanotube mixture, hence significantly modifying the threshold voltage and the switching behavior of a liquid crystal device. Doping a small amount of carbon nanotubes into the liquid crystal mixture is effective in improving the electrooptical characteristics of an LC device when the employed LC mixture is viscous.

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We investigate p-type doping in ZnO prepared by metal-organic chemical vapour deposition with dimethylhydrazine (DMHy) as the nitrogen dopant source. Results obtained by x-ray photoelectron spectroscopy show that DMHy exhibits a narrow temperature window from 500 to 550 °C for efficient nitrogen incorporation and that nitrogen doping is critically influenced by growth conditions, e.g. the N/Ga flux ratio in growth. Within an appropriate N/Ga flux ratio range, p-type ZnO can be realized. The effect of the N/Ga flux ratio on the conductivity conversion of ZnO is reported. The extrinsic nitrogen acceptor level is calculated to be about 160 meV from low-temperature photoluminescence spectra.

A transient reorientation of liquid crystals in azo-dye-doped liquid crystals (ADDLCs) is observed by the improved attenuated total reflection leading a pump light into a coupling prism, namely, pumped ATR experiment. The evanescent wave of the pump light induces the photoexcitation of azo dye at the limited effective depth, and the evanescent wave of the probe light detects the dynamic behavior in real time. The time response of the photoexcitation in ADDLCs in the pumped ATR experiment is less than 2ms and it is believed that the reaction occured in the local region of 100nm.

An international intercomparison involving eight national metrology institutes (NMIs) was conducted to establish their current measurement capabilities for determining five selected congeners from the brominated flame retardant classes polybrominated diphenyl ethers and polybrominated biphenyls. A candidate reference material consisting of polypropylene fortified with technical mixtures of penta-, octa- and decabromo diphenyl ether and decabromo biphenyl, which was thoroughly assessed for material homogeneity and stability, was used as study material. The analytical procedures applied by the participants differed with regard to sample pre-treatment, extraction, clean-up, employed calibrants and type of calibration procedure as well as regarding analytical methods used for separation, identification and quantification of the flame retardant congeners (gas chromatography coupled to an electron capture detector (GC-ECD), gas chromatography-mass spectrometry in the electron ionisation mode (GC-EI-MS), gas chromatography-mass spectrometry in the electron capture negative ionisation mode (GC-ECNI-MS), and liquid chromatography-inductive coupled plasma-mass spectrometry (LC-ICP-MS)). The laboratory means agreed well with relative standard deviations of the mean of means of 1.9%, 4.8%, 5.5% and 5.4% for brominated diphenyl ether (BDE) 47, 183 and 209 and for the brominated biphenyl (BB) congener 209, respectively. For BDE 206, a relative standard deviation of 28.5% was obtained. For all five congeners, within-laboratory relative standard deviations of six measurements obtained under intermediate precision conditions were between 1% and 10%, and reported expanded measurements uncertainties typically ranged from 4% to 10% (8% to 14% for BDE 206). Furthermore, the results are in good agreement with those obtained in the characterization exercise for determining certified values for the flame retardant congeners in the same material. The results demonstrate the state-of-the-art measurement capabilities of NMIs for quantifying representative BDE congeners and BB 209 in a polymer. The outcome of this intercomparison (pilot study) in conjunction with possible improvements for employing exclusively calibrants with thoroughly assessed purity suggests that a key comparison aiming at underpinning calibration and measurement capability (CMC) claims of NMIs can be conducted.