• Journal of the East Asian Society of Dietary Life
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• v.6 no.2
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• pp.213-219
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• 1996

Addition of reducing agents during extrusion markedly affected physical and chemical properties of wheat flour and gluten extrudates. Expansion at the die was increased for wheat flour and gluten extrudates. Organic materials containing sulfur were evaporated as a flavor from gluten at the die and total sulfur contents were decreased. Physical shape was different for gluten extrudates without reducing agents. It was difficult to form the long strand of gluten extrudate without cooling die. Hydroquinone accelerated cell breakdown and produced more irregular shape of extrudate. However, addition of cysteine decreased the cell breakdown and produced the long strand of gluten extrudates. Chemical reactions of reducing agents such as cysteine and hydroquinone were different for high content (＜80%) of wheat gluten. It was assumed that reducing agents donated hydrogen to inhibit the formation of disulfide crosslinking, decreased the dough strength and produced the broken cell and irregular shape of extrudates. Whereas, cysteine reacted as a binder as well as reducing agent and formed long strands. The evidence of reaction of reducing agents was shown from the fact that non-protein disulfide was increased and protein disulfide was slightly decreased from cysteine added gluten extrudate.

• Bulletin of the Korean Chemical Society
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• v.29 no.1
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• pp.61-68
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• 2008

High initial (2 minutes after iv injection) brain-uptake of PET agents is required to deliver the agent to binding sites in brain tissue but, for quantification of the specific binding, relatively rapid washout of free and non-specifically bound PET agents from the brain (30 minutes after injection) also is required. In order to compare the physicochemical properties of the PET agents which are responsible for early brain-uptake and rapid washout, respectively, chemometric analysis on brain-uptake of PET agents was performed via a classical VolSurf approach. According to the PCA and PLS results, high 2-30 min brain-uptake ratio seems to be related to the large hydrophobic regions in the PET agents which are not confined to a particular surface.

• Textile Coloration and Finishing
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• v.13 no.6
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• pp.413-427
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• 2001

In this studs, we synthesized durable antistatic agents with acrylic monomers for preventing the electrification of static electricity which is one of defects of polyester fabrics. Also we synthesized quaternary ammonium salts which give antistatic property and crosslinking agents which make antistatic agents adhere to fiber. The treatment of synthesized antistatic agents on polyester fabric carried out at the condition of various concentrations, treatment times and temperatures. The antistatic property, handle characteristics and other properties of treated and untreated polyester fabrics were also investigated.

• Korean Chemical Engineering Research
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• v.49 no.3
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• pp.348-351
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• 2011

In this research, we developed a sensor system which can easily detect several chelating agents using polydiacetylene(PDA) vesicles. In comparison to other sensors, PDA based sensor has several advantages. First, detection method is much simpler and faster because it does not require any labeling step in the experiment procedure. Second, significant color-transition from blue to red based upon external stimulus allows us the detection by naked eyes. Finally, it is also possible to perform quantitative analysis of the concentration of the chelating agent by measuring the colorimetric response. In this paper, five types of chelating agents were used, including EDTA, EGTA, NTA, DCTA and DTPA. Among them, EDTA and DCTA triggered especially strong color-transition. In conclusion, this study has led to a successful development of a color transition-based PDA sensor system for easy and rapid detection of chelating agents.

• Clean Technology
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• v.11 no.3
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• pp.129-139
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• 2005

Fluoride-type cleaning agents such as TFEA (2,2,2-trifluoroethanol) and HFE (hydrofluoroether) are noticed to be next generation cleaning agents alternative to CFCs since they do not destruct ozones in the stratosphere due to no containment of chloride in the molecule, have lower global warming potential compared to HFCs and HCFCs, and are thermally stable compounds. Thus, the physical properties and cleaning agents were measured and compared with those of CFC-113, 1,1,1-TCE and HCFC-141b which are ozone destruction substances. They were also compared and evaluated with those of IPA and methanol which are currently employing as alternative cleaning agents. And TFEA-based cleaning agents consisted of TFEA and alcohols or HFEs were formulated, their physical properties and cleaning abilities were measured and their utilization as alternative cleaning agents was evaluated. As a result, TFEA and HFEs have lower cleaning ability for their removal of various soils compared to chloride-type cleaning agents, but theyshow excellent cleaning ability for Fluoride-type soils. And it is observed that the formulated cleaning agents of TFEA and alcohols or HFEs caused to increase cleaning ability of flux and unsoluble cutting oil more than 100% compared to their individual component. Therefore, the fluoride-type cleaning agents are expected to be utilized for development of environmental-friendly non aqueous cleaning agents with excellent cleaning ability if they are formulated with proper solvents or additives.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.32 no.3
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• pp.65-74
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• 2000

This study was carried out to acquire basic data necessary for the use of rice-straw chemical pulp. It investigated the proper bleaching conditions when rice-straw chemical pulps(alkaline sulfite-Na2S2O4 pulp) were bleached with the various kinds of bleaching agents. And physical properties of bleached pulps were tested. The results of this study were as follows; 1, The proper conditions of chlorine sequence were determined to be 4% concentration of chlorine 25$^{\circ}C$ of reaction temperature and 50 minutes of reaction time. 2. For calcium hypochlorite sequence the proper conditions of chemical concentration reac-tion temperature and reaction time were 3% 25$^{\circ}C$ and 20 minutes respectively. 3. For chlorine dioxide sequence the proper conditions were 1% concentration of chlorine dioxide 70$^{\circ}C$ of reaction temperature and 2hr. of reaction time. 4. The proper conditions of hydrogen peroxide sequence were 1.5% concentration of hydro-gen peroxide 70$^{\circ}C$ of reaction temperature and 1hr. of reaction time respectively. 5. When the rice-straw chemical pulp were bleached with four kinds of bleaching agents methioned above in the proper conditions respectively brightnesses were the order of chlorine dioxide calcium hypochlorite, chlorine, hydrogen peroxide. And strengthes of pulps bleached with chlorine dioxide and hydrogen peroxide were higher than those of pulps bleached with other bleaching agents.

• Textile Coloration and Finishing
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• v.33 no.1
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• pp.1-9
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• 2021

This study aims to prepare the fabric with detoxification properties against chemical warfare agent by the simple treatment. For this purpose, polypropylene non-woven fabric(PP) was treated with polyethyleneimine(PEI) and guanidinylated PEI and detoxification properties of the guanidinylated PEI treated PP were evaluated using diisopropylfluorophosphate(DFP), as a chemical warfare agent simulant, and compared with the untreated and PEI treated PP. The half-lives of DFP on guanidinylated PEI treated PP and untreated PP were 334 min and 714 min, respectively. The half-life of DFP with guanidinylated PEI treated PP was 53.22% shorter than with untreated PP. This result shows that guanidine group in guanidinylated PEI treated PP was acted as a base catalyst for hydrolysis of DFP and decreased half-life of DFP. Therefore, it is expected that guanidinylated PEI treatment can be an simple pathway to prepare the detoxification fabric material for protective clothing against chemical warfare agents.

• Membrane and Water Treatment
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• v.9 no.5
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• pp.335-342
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• 2018

Micelle-Enhanced Ultrafiltration (MEUF) is a membrane separation processes that improving ultrafiltration process with the formation of micelles of the surface active agents. Surface active agents are widely used to improve membrane processes due to the ability to trap organic compounds and metals in the treatment of industrial waste water. In this study, surface active agents are used to improve micelle-enhanced ultrafiltration (MEUF) to reduce chemical oxygen demand (COD), total dissolved solid (TDS), turbidity and clogging the membrane in dairy wastewater treatment. Three important operational factors (anionic surface active agent concentration, pressure and pH) and these interactions were investigated by using response surface methodology (RSM) and Box-Behnken design. Results show that due to the concentration polarization layer and increase the number of Micelles; the anionic surface active agent concentration has a negative effect on the flux and has a positive effect on the elimination of contamination indices. pH, and the pressure have the greatest effect on flux. On the other hand, it could be stated that these percentages of separation are in the percentages range of Nano-filtration (NF). While MEUF process has higher flux than NF process. The results have been achieved at lower pressure while NF process needs high pressure, thus making MEUF is the replacement for the NF process.

• Journal of Electrochemical Science and Technology
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• v.10 no.2
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• pp.244-249
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• 2019

SiO has a high theoretical capacity as a promising anode material candidate for high-energy-density Li-ion batteries. However, its practical application is still not widely used because of the large volume change that occurs during cycling. In this report, an active material containing a mixture of SiO and graphite was used to improve the insufficient energy density of the conventional anode with the support of multidimensional conducting agents. To relieve the isolation of the active materials from volume changes of SiO/graphite electrode, two types of conducting agents, namely, 1-dimensional VGCF and 0-dimensional Super-P, were introduced. The combination of VGCF and Super-P conducting agents efficiently maintained electrical pathways among particles in the electrode during cycling. We found that the electrochemical performances of cycleability and rate capability were greatly improved by employing the conducting agent combinations of VGCF and Super-P compared with the electrode using only single VGCF or single Super-P. We investigated the detailed failure mechanisms by using systematic electrochemical analyses.

• Elastomers and Composites
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• v.58 no.4
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• pp.208-215
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• 2023

In this study, the properties of polyurethane-polydimethylsiloxane (PU-PDMS) hybrid foams containing different types and contents of physical blowing agents (PBAs) were investigated. Two types of blowing agents, namely physical blowing agents and thermally expandable microspheres (TEM), were applied. The apparent density was measured using precisely cut foam samples, and the pore size was measured using image software. In addition, the microstructure of the foam was confirmed via scanning electron microscopy and transmission electron microscopy. The thermal conductivities related to the microstructures of the different foams were compared. When 0.5 phr of the hydrocarbon-based PBA was added, the apparent density and pore size of the foam were minimal; however, the pore size was larger than that of neat foam. In contrast, the addition of 3 phr of TEM effectively reduced both the apparent density and pore size of the PBAs. The increase in resin viscosity owing to TEM could enhance bubble production stability, leading to the formation of more uniform and smaller pores. These results indicate that TEM is a highly efficient PBA that can be employed to decrease the weight and pore size of PU-PDMS hybrid foams.