• Textile Coloration and Finishing
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• v.10 no.3
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• pp.36-42
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• 1998

The dyeabilities of C.I. Reactive Blue 19(B19, MW ; 626), C.I. Reactive Blue 4(B4, MW ; 637) and C.I. Reactive Black 5(B5, MW : 991) were investigated. Initial dyeing rates were increased and the amount of dye on the fabric at equilibrium was decreased with temperature like other ordinary dyeing processes. Activation entropy$(\Delta{S}^*)$ was decreased because of loose bonding between dyestuffes and fiber molecules at transition state. It can be clarified that the entire reaction is exothermic and the number of molecular species at transition state becomes greater from decrease in activation enthalpy$(\Delta{H}^*)$ and the increase in activation free energy$(\Delta{G}^*)$ with temperature, respectively. The amount of B19 on the fabric at equilibrium was greater than that of B4, because B4 became unreactive towards textile substrates through hydrolysis. Due to the biggest size of the dye molecule, the reaction rate of B5 was the slowest but its difunctional group played an important role in achieving the greatest amount of dye on the fabric at equilibrium.

• Journal of Photoscience
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• v.6 no.3
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• pp.145-151
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• 1999

The use of O-carbamoyloximes as photobase generators was investigated. $\alpha$-Meth-ylbenzilydeneamino phenylcarbamate(2a) and $\alpha$-methyl benzilydeneamino cyclohexylcarbamate(2b) were prepared by the reaction of phenyl or cyclohexyl isocyanates with acetophenone oxime , respectively. Aniline, phenylhydrazine and N, N'-diphenylhydrazine were detected in thephotolysis of 2a and cyclohexylamine and cyclohexylhydrazine in the photolysis of 2b. A monomer having pendant carbamoyloxyimino groups (BGM) was prepared by the reaction fo methancryloyloxyethyl iocyanate with acetophenone oxime, and copolymerized with styrene. The BGM copolymer films turned insoluble on UV irradiation, and the degree of insolubilizationwas increased by post-baking. The photocrosslinking was thought to be due to coupling of resulting pendant aminyl radicals, and the thermal crosslinking was due to association of resulting amino and hydrazino groups by hydrogen bonding. The introduction of epoxy groups into polymer increased the degree of thermal crosslinking by post-baking.

• Bulletin of the Korean Chemical Society
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• v.22 no.7
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• pp.689-692
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• 2001

An imprinting technique with labile covalent interactions has been developed in the design of new polymer catalysts. The template monomer 2 was prepared and copolymerized with DVB or EDMA to provide the polymer with a cavity having the shape of th e transition state of the reaction as well as binding sites for the substrate and catalytic functionalities. The rate of hydrolysis of diphenyl carbonate (1) in the presence of the imprinted polymer IP-DVB-THF was found to be 120 times faster than the background uncatalyzed reaction. A Km of 32 mM and a kcat of 1.8 ${\times}$ 10-3min-1 were observed from Michaelis-Menten kinetics with the imprinted polymer IP-DVB-THF.

• Bulletin of the Korean Chemical Society
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• v.10 no.5
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• pp.443-447
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• 1989

The mechanism on the oxidative addition reaction of $(TBA)_2\;Pt(CN)_4$ with $Cl_2$ has been studied by means of extended Huckel calculations. Among two possible mechanisms, computational calculations demonstrated that the linear approach of $Cl_2$ to a $Pt(CN)_4$ moiety is more favourable than three-centered transition state. From our calculations, the most stable process is that a $Pt(CN)_4$ moiety interacts with $Cl_2$ in the linear transition state and the cleavage of Cl-Cl bond in a coordinated halogen occurred spontaneously, giving rise to a trans product by back-attacking a $Pt(CN)_4Cl$ moiety by Cl. The process consists of the comparison in the stability of each intermediate with use of bonding and potential energy.

• Journal of Powder Materials
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• v.24 no.6
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• pp.489-493
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• 2017

In this study, the surface passivation process for InP-based quantum dots (QDs) is investigated. Surface coating is performed with poly(methylmethacrylate) (PMMA) and thioglycolic acid. The quantum yield (QY) of a PMMA-coated sample slightly increases by approximately 1.3% relative to that of the as-synthesized InP/ZnS QDs. The QYs of the uncoated and PMMA-coated samples drastically decrease after 16 days because of the high defect state density of the InP-based QDs. PMMA does not have a significant effect on the defect passivation. Thioglycolic acid is investigated in this study for the effective surface passivation of InP-based QDs. Surface passivation with thioglycolic acid is more effective than that with the PMMA coating, and the QY increases from 1.7% to 11.3%. ZnS formed on the surface of the InP QDs and S in thioglycolic acid show strong bonding property. Additionally, the QY is further increased up to 21.0% by the photochemical reaction. Electron-hole pairs are formed by light irradiation and lead to strong bonding between the inorganic and thioglycolic acid sulfur. The surface of the InP core QDs, which does not emit light, is passivated by the irradiated light and emits green light after the photochemical reaction.

• Applied Chemistry for Engineering
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• v.20 no.5
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• pp.536-541
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• 2009

Plasma-polymerized acrylic acid films were deposited on Si wafer and KBr pellet by remote plasma-enhanced chemical vapor deposition (PECVD). Effects of plasma power, reaction pressure, indirect plasma method on the growth rate, chemical structure, and chemical bonding state of the films were investigated. Chemical structure and chemical state of the films were characterized by Fourier transformed infrared (FT-IR) spectroscopy and X-ray photoelectron spectroscopy (XPS) analysis and curve fitting technique. Growth rate of the film increased to a saturation value with plasma power of 100 W, but showed the maximum with reaction pressure at 300 mtorr. Whenever W/FM factor (applied energy per gas molecule) increased by increasing plasma power or lowering pressure, the fragmentation of acrylic acid molecules was promoted. From the XPS curve fitting analyses, we found that the intensity of carboxyl COO bonding peak decreased with W/FM factor, and the tendency of intensity change of carboxylic COO peak was contrary to those of ether C-O and carbonyl C=O peaks.

• Journal of the Korean Chemical Society
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• v.27 no.2
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• pp.157-164
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• 1983

N-Methylidene-2,6-diethylaniline (III) was prepared by the reaction of 2,6-diethylaniline (II) with an excess paraformaldehyde. The protons of N=$CH_2$in the compound III exhibited a second order NMR spectrum. The compound III reacted with bifunctional chlorocarbonylsulfenyl chloride(IV) to give N-(chloromethyl)-N-(2,6-diethylphenyl)-carbamoylsulfenyl chloride(V). The reaction of the compound V with various alcohols resulted in the formation of Alkyl N-(chloromethyl)-N-(2,6-diethylphenyl)-carbamoylsulfenate esters(VI${\sim}$XVI) in 71${\sim}$95% yields. The compound VI${\sim}$XVI decomposed gradually, but the thermal rearrangement of S-O bonding to S=O bonding was not found. The nucleophilic attack of an excess alcohol to the compound Ⅴ was made on both divalent sulfur and ${\alpha}$-carbon of N-chloromethyl group. The corresponding substituted products(XVII, XVIII) had considerable stability.

• Korean Journal of Food Science and Technology
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• v.33 no.6
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• pp.769-773
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• 2001

Protein content of okara and soybean were found to be 37.3% and 42.5%, respectively by micro-Kjeldahl analysis. Solubility of okara protein in phosphate buffer (pH 8) was 10% versus soy protein of 68.4%. Insolubilization of okara protein was mostly due to disulfide bonding between cysteine residues caused by excessive heat treatment during soymilk processing: hydrophobic interactions and hydrogen bondings were involved to lesser extent. Optimum extraction temperature and time were $60^{\circ}C$ and 40 min. Typical solubility profile of soy protein disappeared for okara protein though minimum solubility of the protein was around pH 3.0. Treating okara with protease was effective in solubilizing okara protein and solubility increased to 19.2%. Optimum reaction temperature and time were $80^{\circ}C$ and 50 min, respectively. Cell wall degrading enzyme did not increase solubility of the protein, however. Through enzymatic reaction okara protein could be effectively solubilized for uses as food ingredient.

• Korean Journal of Materials Research
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• v.11 no.6
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• pp.460-464
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• 2001

The ceramic diffusion coupling with the green body of calcium-doped lanthanum chromite(La$_{0.8}$Ca$_{0.2}$CrO$_3$CLC- G) and sintered calcium-doped lanthanum chromite(La$_{0.8}$Ca$_{0.2}$CrO$_3$ CLC) by Pechini's method on yttria stabilized zirconia(YSZ) plate has been investigated. The X-ray diffraction pattern of CLC sides at the reacted CLC-G/ CLC and CLC/YSZ interface were identified as La$_{1-x}$ Ca$_{x}$CrO$_3$ and the unreacted YSZ side was cubic-ZrO$_2$ at the treated condition, 1300~1500 C for 10 hr in air, respectively. The order of migration components between CLC/YSZ interface was Zr>La>>Cr>>>Ca and these changes were not dependent upon the treated conditions. The grain shape and size at the interface of CLC-G/CLC was appeared to have a uniform distribution with increasing temperature. The bonding reaction of YSZ/CLC was occurred without a large amount change of the compositions in SEM photos.os.otos.os.

• Advances in materials Research
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• v.8 no.1
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• pp.47-73
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• 2019

Joining of Mg/Ti hybrid structures by welding for automotive and aerospace applications has attracted great attention in recent years due mainly to its potential benefit of energy saving and emission reduction. However, joining them has been hampered with many difficulties due to their physical and metallurgical incompatibilities. Different joining processes have been employed to join Mg/Ti, and in most cases in order to get a metallurgical bonding between them was the use of an intermediate element at the interface or mutual diffusion of alloying elements from the base materials. The formation of a reaction product (in the form of solid solution or intermetallic compound) along the interface between the Mg and Ti is responsible for formation of a metallurgical bond. However, the interfacial bonding achieved and the joints performance depend significantly on the newly formed reaction product(s). Thus, a thorough understanding of the interaction between the selected intermediate elements with the base metals along with the influence of the associated welding parameters are essential. This review is timely as it presents on the current paradigm and progress in welding and joining of Mg/Ti alloys. The factors governing the welding of several important techniques are deliberated along with their joining mechanisms. Some opportunities to improve the welding of Mg/Ti for different welding techniques are also identified.