• Textile Coloration and Finishing
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• v.35 no.2
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• pp.121-127
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• 2023

In this study, a comprehensive investigation was conducted on the morphological and property changes of laser-induced nanocarbon (LINC) as a function of laser process parameters. LINC was formed on the surfaces of polyimide films with different backbone structures under various process conditions, including laser power, scan speed, and resolution. Three different forms of LINC electrodes (i.e., continuous 3D porous graphene, wooly nanocarbon fibers, line cut) were formed depending on the laser power and scan speed. Furthermore, heteroatom doping induced from the chemical structure of the polyimide during laser patterning was found to be effective in modifying the electrical properties of LINC electrodes. The LINC surfaces exhibited different microstructures depending on the laser beam resolution under constant laser power and scan speed, allowing for controllable surface wettability. The correlation between the chemical structure of the polymer substrate, laser process parameters, and carbonized surface properties in this study is expected to be utilized as fundamental understanding for the manufacturing of next-generation carbon-based electronic devices.

• Applied Chemistry for Engineering
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• v.27 no.4
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• pp.415-420
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• 2016

To enhance electrochemical performances of anode materials, the surface of coal tar pitch (CTP) was modified by incorporating heteroatoms through chemical treatment with phosphoric acid ($H_3PO_4$). The prepared anode materials with modified CTP was analyzed by XRD, FE-SEM and XPS. The electrochemical performances of modified CTP were investigated by constant current charge/discharge test, rate performance, cyclic voltammetry and impedance tests using the electrolyte of $LiPF_6$ dissolved in the mixed organic solvents (ethylene carbonate : dimethyl carbonate = 1 : 1 vol% + vinylene carbonate 3 wt%). The coin cell using modified CTP ($H_3PO_4/CTP$ = 3 : 100 in weight) has better initial capacity and initial efficiency (489 mAh/g, 82%) than those of other composition coin cells. Also, it was found that the capacity retention was 86% after 30 cycles and the rate capability was 87% at 2 C/0.1 C.

• Environmental Analysis Health and Toxicology
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• v.15 no.4
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• pp.139-145
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• 2000

The Flavin-containing monooxygenase (FMOs) (EC1.14.13.8) are NADPH-dependent flavoenzymes that catalyze oxidation of soft nucleophilic heteroatom centers in a range of structurally diverse compounds, including foods, drugs, pesticides, and other xenobiotics. In humans, FMO3 is quantitatively a major human liver monooxygenase. In the present study, the baculovirus expression vector system was used to overexpress human FMO3 in insect cells for catalytic studies. Six commercially available organic selenium compounds were examined for substrate activity with microsomes isolated from Spodoptera frugiperda (Sf)9 cells infected with human FMO3 recombinant baculovirus. While none of the aromatic heterocyclic selenides tested showed detectable activity, all dialkyl- and alkylaryl-selenides free from ionic groups catalyzed the NADPH- and O$_2$-dependent oxidation. Kinetic constants demonstrate that (based on Km) dialkyl-and alkylaryl- selenides are better substrates for human FMO3 than analogous nitrogen or sulfur compounds .

• Environmental Analysis Health and Toxicology
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• v.16 no.2
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• pp.97-102
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• 2001

The flavin-containing monooxygenases(FMOs) (EC1.14.13.8) are NADPH0dependent flavoenzymes that catalyze oxidation of soft nucleophilic heteroatom centers in a range of structurally diverse compounds, including foods, drugs, pesticides, and other xenobiotics. In humans, FMO3 is quantitatively a major human liver monooxygenase. In the present study, the baculovirus expression vector system was used to overexpress human FMO3 in sect cells for stalytic studies. Microsomes isolated from Spodoptera frugiperda(Sf)9 cells infected with human FMO3 recombinant baculovirus catalyzed the NADPH-and O$_2$-dependent oxidation of methimazole, thiourea, and phenylthiourea. However there was no detectable activity with 1, 3-diphenylthiourea or larger thiocarbamides. Microsomes from control Sf9 cells were devoid of methimazole or thiourea S-oxygenase activity. 1, 3-diphenylthiourea is apparently completely excluded from the catalytic site, these amines drugs are probably approaching the upper size limits of xenobiotics accepted by human FMO3. The substrate specificity of this iosform in humans appears considerably more restriceted than that of pig, guinea pig, rat or rabbit FMO3.

• Journal of Energy Engineering
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• v.26 no.3
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• pp.97-104
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• 2017

In this study, waste tire rubbers were pyrolyzed in a lab-scale pyrolysis plant equipped with a fluidized bed reactor in a temperature ranges of $450-650^{\circ}C$. The main object of this work is to investigate the properties of pyrolysis oil with reaction temperatures and the behavior of sulfur in the products when waste polypropylene was added for co-pyrolysis. The maximum yield of oil was about 52wt.% at the reaction temperature of $456^{\circ}C$. From GC-MS analysis, the pyrolysis oils consisted mainly of limonene, toluene, xylene, styrene, trimethylbenzene, methylnaphthalenes and some heteroatom(sulfur and nitrogen)-containing compounds. The addition of waste polypropylene resulted in decrease in sulfur contents of the pyrolysis oils.

• Journal of the Korean Chemical Society
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• v.36 no.4
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• pp.485-495
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• 1992

The viscosities of organic compounds (alcohols, acetates, alkanes, acids, substituted $NH_2$) in liquid states, gas states and the binary mixtures of n-alkane / 1-chloroalkane were calculated by molecular modeling techniques. The molecular descriptors of molecular modeling technique are Molecular connectivity indices, Wiener indices and ad hoc descriptors, which can encode the information of compound properties about the effect of size, branching, cyclization, unsaturation, heteroatom content, polarizability, and so on. The successful results among method have been Molecular connectivity indices, binary mixtures of n-alkane / 1-chloroalkane, Wiener indices for gas state and ad hoc descriptor for liquid states. Also we obtained the regression equations for viscosities using molecular modeling indices for gas, liquid states and binary mixtures of n-alkane / 1-chloroalkane. The calculated viscosity values for organic compounds are in good agreement with experimental results.

• Polymer(Korea)
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• v.38 no.5
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• pp.682-686
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• 2014

To prepare transparent acrylic pressure sensitive adhesives (PSAs), terpolymer syrups were photopolymerized from 2- ethylhexyl acrylate and 2-hydroxyethyl acrylate with third monomer having different chemical structure. After polymerization, 1,6-hexanediol diacrylate as a crosslinker and a photoinitiator were added and then UV-irradiated to prepare the PSAs. The adhesion performances and optical characteristics of the PSAs were investigated. Their adhesion performance was dependent on the composition of monomers in the polymer chain but optical properties were maintained at a suitable level. The PSAs prepared by bulky and heteroatom-containing monomers such as IBOA, THFA, and ACMO showed better adhesion performance than others.

• Proceedings of the Korean Vacuum Society Conference
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• 2000.02a
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• pp.170-170
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• 2000

Synthetic polymers such as polyimide, polycarbonate, and poly(methyl methacrylate) are long chain molecules which consist of carbon, hydrogen, and heteroatom linked together chemically. Recently, polymer surface can be modified by using a high energy ion beam process. High energy ions are introduced into polymer structure with high velocity and provide a high degree of chemical bonding between molecular chains. In high energy beam process the modified polymers have the highly crosslinked three-dimensionally connected rigid network structure and they showed significant improvements in electrical conductivity, in hardness and in resistance to wear and chemicals. Polyimide films (Kapton, types HN) with thickness of 50~100${\mu}{\textrm}{m}$ were used for investigations. They were treated with two different surface modification techniques: Plasma Source Ion Implantation (PSII) and conventional Ion Implantation. Polyimide films were implanted with different ion species such as Ar+, N+, C+, He+, and O+ with dose from 1 x 1015 to 1 x 1017 ions/cm2. Ion energy was varied from 10keV to 60keV for PSII experiment. Polyimide samples were also implanted with 1 MeV hydrogen, oxygen, nitrogen ions with a dose of 1x1015ions/cm2. This work provides the possibility for inducing conductivity in polyimide films by ion beam bombardment in the keloelectronvolt to megaelectronvolt energy range. The electrical properties of implanted polyimide were determined by four-point probe measurement. Depending on ion energy, doses, and ion type, the surface resistivity of the film is reduced by several orders of magnitude. Ion bombarded layers were characterized by Time-of-Flight Secondary Ion Mass Spectrometry (TOF-SIMS), XPS, and SEM.

• Journal of the Korean Chemical Society
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• v.27 no.5
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• pp.330-339
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• 1983

The CNDO/2 and STO-3G calculations were performed on nitrogen, oxygen, and sulfur compounds in order to examine the effect of interactions between two nonbonding (n) orbitals in the same molecule separated by N intervening $\sigma$ bonds based on the PMO approach. Calculated basis level energies, energy splittings, and interaction energy changes for both chain and cyclic model compounds were qualitatively compared with the corresponding predictions derived from perturbational formalism for n-n orbital interactions and successfully explained in terms of the derived energy expressions. In general, through-space interaction term could be neglected in the N and O systems. And the calculated results were explained simply by through-bond interaction term. As a result, through-bond interaction placed n- below n+ for odd systems and n+ below n- for even systems. Also energy splittings in odd systems were larger than those in even systems. However, in the cases of cis-ethylene diamine and o-phenylene diamine(conformer VI in Table 4), through-space interaction term was found to be substantial and the opposing effects of through-space and through-bonds interactions were observed. Finally it was found that the interactions between two n orbitals on S atoms always had some contribution of the destabilizing through-space interaction term. This result was consistent with the fact that the lone pair lobes of third elements were larger in size than those of the second period elements.