The aim of this study is to develop a mixed polyester latent crimped yarn with excellent bulkiness and stretchability. In order to achieve this goal, the thermal and physical behaviors of yarn obtained from two filaments with different shrinkabilities were investigated under various manufacturing conditions. The partially oriented yarn (POY) exhibited various thermal shrinkages under wet and dry conditions. The fabric hand value is affected by the properties of the POY and by the physical properties of the latent crimped yarns, such as linear density, tenacity, breaking strain, and shrinkage. First, the POY should be spun at speeds in the range of 3,000-3,200 m/min so as to produce a wool-like mixed PET yarn with excellent bulkiness and stretching properties. Second, the manufacturing conditions for the latent crimped yarn should be set as follows: 1) intrinsic viscosity difference between 0.15 and 0.2; 2) setting at $120^{\circ}C$; and 3) a low winding speed and high draw ratio during the spinning process. Finally, the heat roller temperature of the drawing machine should be set between $105-120^{\circ}C$ together under overfeeding conditions in order to obtain the desired wool-like mixed latent crimped yarn that exhibits excellent bulkiness and high stretchability, in accordance with the aim of this procedure.

Pressure-sensitive electronic skin (e-skin) has gained importance in the fields of prosthetics, health monitoring, sensitive tactile information display, and robotics. In particular, many previous studies have reported flexible and highly sensitive pressure sensors. Among them, e-skin devices based on CNT microfibers show wearable and excellent multimodal (pressure, temperature, humidity, and presence of chemicals) sensing capabilities However, the low sensitivity of these devices at high pressures remains a critical issue. Here, we report on highly flexbile and sensitive e-skin devices prepared by carbon nanotube (CNT) microfibers hybridized with Au flowers, which were synthesized by electrochemical methods. First, we controlled the voltage and reaction time in order to optimize the surface morphology of the CNT microfibers. Next, we fabricated capacitive pressure sensors to elucidate the impact of Au flowers on the sensing capability of the CNT microfiber-based pressure sensors, especially in high pressure regimes. The sensors based on CNT microfibers with Au flowers showed fourfold higher sensitivity than did those without the Au flowers, due to the enhanced air traps between the Au flowers. Furthermore, this morphology of CNT microfibers with Au flowers demonstrated satisfactory repeatability and durability under high pressure.

The effect of the viscosity of phosphor slurry prepared by mixing two types of silicone resins with different viscosities in various ratios on the properties of pre-formed phosphor films was investigated. The pre-formed phosphor films manufactured using these phosphor slurries were evaluated for curing characteristics, breaking strength, shear strength, and optical properties. The test results demonstrated that increasing the amount of high-viscosity silicone resin in the composite resin resulted in decreased curing reaction rate, decreased breaking strength, and correlated color temperature, whereas the viscosity and adhesion strength of the composite resin increased. Among seven different mixing ratios of the low- and high-viscosity silicone resins prepared for the composite resin, white-light emission was realized for the ratio 70:30, and the pre-formed phosphor film with this ratio exhibited high breaking strength and low adhesion strength. The breaking strength thus obtained was 24.0 MPa, the adhesion strength was 0.17 MPa, the color temperature was 5,650 K, and the two chromaticity coordinates (CIE(x, y) (1931)) were (0.3293, 0.3251).

Cellulose consists of a linear-chain polymer from 1-4-glucoside bond linked 1,4 carbon of ${\beta}$-D-glucose. Unmodified cellulose does not dissolve in water or in common organic solvents due to the presence of inter- and intra-chain hydrogen bonds. Ionic liquids, particularly, 1-ethyl-3-methylimidazolium acetate, dissolve cellulose more easily when compared to traditionally used solvents for cellulose because of directly broken of hydrogen bonds in intra and inter molecular. In addition, CNTs can also be easily dispersed in imidazolium-based ionic liquids by simple mechanical mixing. Cellulose hollow fibers filled with MWCNT were used as a precursor for carbon fibers. The cellulose/MWCNT precursor solution in the ionic liquid was prepared by air-gap spinning to improve the carbon yield and also to optimize the mechanical properties of the final cellulose-based carbon fiber. The cellulose/MWCNT hollow fibers was pyrolyzed by heating in air at $350^{\circ}C$ for 1 h 35 min. The pyrolyzed cellulose/MWCNT hollow fibers were carbonized by heating at $900^{\circ}C$ in an inert atmosphere (nitrogen). Thus-prepared cellulose/MWCNT-based carbon hollow fibers were analyzed to confirm the suitability of the carbon hollow fiber as a substitute for silicon wafer in solar cells and in semiconductor devices.

Polarimetry is a non-destructive technique that measures the degree of rotation of polarized light passing through an optically active material. Optical activity is determined by various factors, including intrinsic optical properties and residual stress. Thus, polarimetry can be used in various fields. In this study, polarimetry was used to evaluate the two-dimensional spatial uniformity of optical birefringence in an Ajinomoto build-up film. This analysis can predict the optimal cure condtitions of the film, which creates a uniform phase retardation distribution.

The purpose of this study is to improve the interfacial adhesion strength of bamboo/PBS composites by adding HDI (hexamethylene diisocyanate) as a coupling agent. Bamboo/PBS composites with HDI were fabricated by an internal mixer and a hot press machine. In addition, the effects of HDI as a coupling agent and various HDI contents on the mechanical properties of bamboo/PBS composites were investigated. Furthermore, the tensile properties, flexural properties, and Rockwell hardness of bamboo/PBS composites with HDI were evaluated. The obtained results showed that the mechanical properties of bamboo/PBS composites were improved with the addition of HDI. The morphology of fractured surfaces of bamboo/PBS composites was observed with SEM (scanning electron microscope), and the obtained SEM images showed evidence of improved interfacial adhesion between the bamboo fiber and PBS matrix. To analyze the composition change of bamboo/PBS composites, FT-IR (Fourier transform-infra red) spectroscopy was used. The FT-IR spectra of bamboo/PBS composites also showed positive effects of using HDI as a coupling agent. Finally, a comparison of various HDI contents, when all obtained results were combined, showed that bamboo/PBS composites with a HDI content of 1.5% had the most improved mechanical properties.

We compared the ability of pomegranate and gallnut extracts to protect fabrics against odors and bacteria with the deodorizing and antibacterial efficacy of two commercial deodorizing and antibacterial agents. Cotton, silk, or wool fabric was treated with pomegranate extract, gallnut extract, or one of two commercial deodorizing and antibacterial agents, F or D. The fabrics were tested for their ability to withstand the odor of ammonia, trimethylamine, acetaldehyde, or acetic acid, and their antibacterial activity against Klebsiella pneumonia and Staphylococcus aureus. We analyzed the volatile components in pomegranate extract, gallnut extract, F, and D using gas chromatography-mass spectrometry. We found more acidic volatile components in the pomegranate and gallnut extracts than in F and D. In contrast, there were more cyclo compounds in the volatile materials of F and D than in the pomegranate or gallnut extracts. The fabrics treated with pomegranate or gallnut extract showed a greater ability to withstand odors than those treated with F or D. However, the fabrics treated with F showed a greater ability to withstand acetic acid odors than did the fabric treated with pomegranate extract, gallnut extract, or D. The antibacterial properties of fabric treated with pomegranate extract, gallnut extract, and F was found to be excellent (bacteriostatic reduction rate=99.9%). These results suggest that pomegranate and gallnut extracts have strong potential to be used as multi-functional agents, with both showing excellent deodorizing and antibacterial properties.

Poly(lactic acid) (PLA)/carbon nanofiber (CNF) composites with different CNF contents (0.5 wt% and 1 wt%) were prepared by solution blending. Isothermal crystallization of the PLA/CNF composites and the pristine PLA was investigated by differential scanning calorimetry and analyzed based on the Avrami equation. The crystallization half-times of the PLA/CNF composites were smaller than that of pristine PLA, indicating that the CNF embedded in the PLA matrix enhanced the PLA crystallization rate. Avrami exponents of the PLA/CNF composites were within the range 2.3-3.0, suggesting that a mixture of two- and three-dimensional crystals was formed by heterogeneous nucleation. Polarized optical microscopy images showed that the crystalline morphology of the PLA/CNF composites looked like small grains. Tensile tests indicated that the tensile modulus and strength of the PLA/CNF composites were higher than those of pristine PLA.