RESUMEN
A new architecture for antireflection (AR) has been developed to break the trade-off between the optical transmittance and the electrical conduction impeding the performance of transparent conductive oxide (TCO) films. The tapered porous nanostructure with a complex continuous refractive index effectively eliminates reflections from the interfaces between air and the TCO and TCO and the substrate. Compared to the conventional TCO film, the AR TCO film exhibited the same electrical conduction, with an average transmittance of 88.7% in the 400-800 nm range, a 10.3% increase. The new AR TCO film is expected to improve the performance of various optoelectronic devices.
RESUMEN
Biological ion channels exhibiting selective and rectified ion transport properties feature nanoscale asymmetries in their physical structure, chemical composition, and charge distribution. Inspired by this, a multi-asymmetric ion-diode membrane (IDM) having a heterojunction between a positively charged anodic aluminum oxide membrane with conical macropores and a negatively charged Nafion membrane with very narrow mesopores was designed and practically fabricated in this study. Experiments and theoretical calculations demonstrated that the proposed membrane has the highest selectivity among IDMs and provides complete suppression of the concentration polarization (CP) effect limiting the current density in ion-exchange membrane electrodialysis. These findings present direct evidence that the physical and chemical design of the channel structure can provide both superior selectivity and a zero CP effect to IDMs and practical fabrication methods of IDMs for diverse, promising membrane applications.
RESUMEN
Self-aligning of a rigid hard domain nanowire inside the nanotube wall has been found for a segmented block copolymer, and applicability of the attenuated total reflection (ATR) technique of Fourier transform infrared (FTIR) spectroscopy to obtain quantitative three-dimensional orientation information of the nanowires in the nanotube has been demonstrated. The preferential orientation of a nanowire along a nanocylinder is explained in terms of the curvature of the nanotube and the persistence length of the hard domain nanowire. This observation may pave the way to new fabrication methods for the anisotropic performance of one-dimensional structures, such as electrical conductivity, piezoelectricity, and photonic properties of polymeric nanofibers and nanotubes.
RESUMEN
The polarized Fourier transform infrared-attenuated total reflection (FT-IR-ATR) technique is a very useful infrared spectroscopic method for characterizing the three-dimensional orientation of thick samples, to which the conventional transmission FT-IR method cannot easily be applied. To quantitatively analyze polarized FT-IR-ATR spectra, the dependence of the optical contact between the sample and the ATR crystal during the clamping and reclamping processes must be controlled. In this work, a new multiple peak reference (MPR) method is proposed and used to carry out a three-dimensional analysis of a poly(trimethylene 2,6-naphthalate) (PTN) polymer sample. The conventional single peak reference (SPR) analysis technique cannot be applied to such a sample due to the lack of an established reference peak. A new artificial reference band was generated by the MPR method using two different infrared bands, at 1602 cm(-1) and 917 cm(-1), in identical spectra with a combination constant of 0.95. The new artificial reference band was successfully used to calculate the three-dimensional orientation of various infrared bands of a uniaxially drawn PTN film, which has not previously been studied by three-dimensional orientation analyses using the polarized FT-IR-ATR method.
RESUMEN
Phytotoxicity and cytotoxicity of 2,4-diaminotoluene (2,4-D), 4,4'-methylenedianiline (4,4-D), and 1,6-hexanediamine (1,6-D) were investigated by observing the germination of young radish seeds and the viability of HeLa cells, respectively. 2,4-D showed the highest, 4,4-D intermediate, and 1,6-D lowest cytotoxicity. However, the phytotoxicity decreased in the order of 4,4-D > 2,4-D > 1,6-D. Contrary to the results previously reported, in the modified Sturm test the activated sludge degraded 2,4-D and 4,4-D as well as 1,6-D without any pre-acclimation. Ochrobacterium antropi was isolated for degradation of 2,4-D and 4,4-D and Pseudomonas citronellolis for 1,6-D degradation. Thielevia sp. was isolated as 2,4-D degrading fungus and Aspergillus sp. as 4,4-D and 1,6-D degrading fungus. The fungi degraded the diamines faster than the bacteria.
