studied the degree of variety of indigo for the electrochemical redox reaction in addition of reducing agent and the electrokinetic parameters. The electrokinetic parameters such asthe number of electron and the exchange rate constant were obtained by cyclic voltammetry. With increasing scan rate, the reduction currents of indigo were increased and the reduction potentials were shifted to the negative direction. As the results, the reduction processes of the indigo were proceeding to totally irreversible and diffusion controlled reaction. Also, exchange rate constant (ko) and diffusion coefficient (D0) of indigo were decreased by increasing concentration of reducing agent. We found that the less concentration, the more easily diffused and electron transferred and the product was more stable.
purpose of this study was to develop the color matching program with the excellent camouflage capacity in the near infrared range(～1100nm) including the visible light range for cotton fabrics. It was measured IR spectral reflectance in the range of 380∼1,100nm after dyed with vat dyes, and we made database for reflectance with various concentration on vat dyes which have a low reflectance value in the infrared range. The color matching algorithm that could be simulated in both the human visible light and the near infrared range was constructed by numerical analysis method using the database. In this study we also developed the dyeing conditions and dyeing process through the continuous-dyeing experiment with the vat dyes for cotton fabrics.
microspheres were prepared by thermally induced phase separation in toluene. The microsphere formation occurred by the nucleation and growth mechanism in metastable region. The effects of the polymer or pigment weight percentage and cooling rate on microsphere formation were investigated. The microsphere formation and growth were followed by the cloud point of the optical microscope measurement. The microsphere size distribution, which was obtained by particle size analyzer, became broader when the polymer concentration was higher, the pigment concentration and the cooling rate of EVA copolymer solution were lower.
combination separation system is composed of three parts, simple microfiltration unit for the pretreatment of real waste IPA, pervaporation unit with plate and frame type module(the effective membrane area 9,040㎠), and simple ultrafiltration unit as a refiner. Ultrafiltration module with hollow fiber membrane(MWCO 10,000) used to purify waste aqueous IPA solution.In addition, the flux of CMPA-K+ composite membrane for waste aqueous IPA solution was very steady-state with long experiment time(30days). And the standard deviation(σ) was 0.152 and then the coefficient of variation(CV%)was 10.82The IPA concentration on the membrane performance using pervaporation module system could be increased from 89.85wt% to more than 99.90wt% in about 8hr at operation temperature of 70℃ using the pervaporation module system.Therefore, a combination separation process system of simple filtration and pervaporation was very effective for the purpose of the IPA purification and reuse from industrial electronic components cleaning process.
order to prepare acetate nano filter for the adsorption of nicotine/tar in tobbaco, acetate nano fiber was fabricated by elecrospining from acetate solution dissolved in acetone/DMAc(2/1). Above a critical polymer concentration(15%), the nano fiber was formed. The average diameter of nano fiber was decreased with the applied voltage and increased with the feeding rate. Appropriate spinning condition was considered to be 15wt% polymer concentration, 11.25kV applied voltage, 0.6ml/h feeding rate, and 13-15cm TCD. Using the nano fiber, acetate nano filter was fabricated. It showed good nicotine/tar adsorption ability compared with general tobbaco filter. It was considered that the increase of surface area and the development of microporous structure in filter was much affected to the adsorption of nicotine/tar.
to preserve and restore the excavated cellulose fabrics as costume heritages have been carried out. In this study, in order to artificially restore an excavated cellulose fabrics, acid-treated cellulose fabrics were prepared. Three kinds of cellulose fabrics were used for an experiment. Three kinds of cellulose fabrics were treated by the acid aqueous solution for the various strength retention (100%, 80%, 60%, 40%, 20%). The fine structure and physical properties of acid treated cellulose fabrics were investigated with various techniques such as wide-angle X-ray diffraction, tensile test, weight loss, shrinkage, SEM etc. Tensile strength and strain of cellulose fabrics decreased with increasing acid treatment time. However, weight loss and shrinkage increasing slightly. The crystal diffraction intensity was not changed. SEM results of acid-treated cellulose fabrics show that the surface was damaged.
heritages of an excavated silk fabrics should be preserved without damage. In order to artificially restore the excavated silk fabrics, alkaline aqueous solution, as a simulated corpse, and two kinds of silk fabrics were used. Two kinds of silk fabrics were treated by aqueous alkaline solution according to strength retention value(100, 80, 60, 40, 20%). The fine structure and physical properties of alkaline treated silk fabrics were investigated with various techniques such as wide-angle X-ray diffraction, tensile test, weight loss, shrinkage, SEM, and yellowness. As the alkaline treatment time increased tensile strength of silk fabrics decreased. However, weight loss and shrinkage slightly increased. The diffraction intensity of β-form crystal declined and α-form crystal diffraction intensity disappeared with the treatment.