Ion-beam irradiation(IB) on HfO2 surface induced high-performance liquidcrystal(LC) driving at a 1-V threshold with vertical alignment of liquid crystals(LC). The high-k materials Atomic layer deposition was used to obtain LC orientation on ultra thin and high-quality films of HfO2 layers. To analyze surface morphological transition of HfO2 which can act as physic alignment effect of LC, atomic force micro scopy images are employed with various IB intensities. The contact angle was measured to elucidate the mechanism of vertical alignment of LC on HfO2 with IB irradiation. Contact angle measurements show the surface energy changes via IB intensity increasing.
The ion-beam irradiated lanthanum zinc oxide (LZO) films were conducted as liquid crystal (LC) alignment layer to achieve uniform and homogeneous alignment of LC molecules. Polarized optical microscopy and the pre-tilt angle measurements revealed the alignment characteristics of LC molecules on the LZO film surface. Physical characteristics of the LZO film surface were analyzed by field emission scanning electron microscope and atomic force microscopy. The strong ion-beam irradiation on the LZO film changed surface rougher than before and induced physical anisotropic characteristics. Chemical composition of the LZO film was investigated by X-ray photoelectron spectroscopy and it was revealed that the ion-beam irradiation induced the breakage of the metal-oxide bonds. Due to this, anisotropic dipole moment which related with van der Waals force between LC molecules and alignment layer was induced. Because of this, LC molecules were anchored to the LZO film surface to achieve uniform LC alignment. Collecting the capacitance-voltage curve, residual DC of the LC cell with the LZO films was measured and it was verified that the LC cell with the LZO film had a nearly zero residual DC. Therefore, the ion-beam irradiated LZO film is an efficient method as an LC alignment layer
In this study, enhanced cation exchange capacity of polystyrene (PS) electrospun fibers by electron beam irradiation was investigated. PS spinning solutions were prepared by dissolving 25 wt% PS in 75 wt% mixed solvents (dimethylacetamide (DMAc)/tetrahydrofuran (THF)) at the ratio of 33/67% v/v with divinylbenzene (DVB; 0, 1, 2 phr) as crosslink agent. The PS electrospun fibers were carried out at doses of 0 (control), 100 and 200 kGy. The ion exchange capacity (IEC) of PS electrospun fibers depend on the DVB concentration and irradiation dose. The PS electrospun fiber with DVB 1 phr at dose of 150 kGy showed the maximum IEC of 4.670 mmol/g.
Nematic liquid crystal (NLC) alignment effects on SiOF layers via ion-beam(IB) irradiation for four types of incident energy were successfully studied. The effect of fluorine addition on silicon oxide film properties as a function of SiOF₄/O₂gas flow ration was investigated. The SiOF thin film exhibits good chemical and the thermal stability of the SiOF thin film were sustained as function of the NLC alignment until 200℃. Also, the response-time characteristics of aligned LCD based on SiOF film were studied.
Radiation technologies have been widely used in mutation breeding of crops. Although gamma-radiation has been predominantly applied in radiation breeding, ion beam irradiation is recently emerging as a methodology highly effective in induction of mutations that are useful for plant breeding. Therefore, we investigated the biological effects caused by irradiation of two types of ion beams, which were proton and ion beams, respectively, in pepper. In the evaluation of survival rate, LD50 values were between 300 and 350 Gy, 30 and 40 Gy in irradiation of proton and carbon beams, respectively, while LD50 for gamma-ray was determined to be between 50 and 100 Gy. Growth traits including shoot length, root length, and root width were also examined in pepper seedlings according to does of proton and carbon ion beams to estimate biological effectiveness of each radiation. The result was applied in the construction of pepper mutant population which will be used to develop pepper breeding materials containing novel characteristics.