• Analytical Science and Technology
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• v.27 no.1
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• pp.27-33
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• 2014

This study described about preparation of the cross-linked silk fibroin (SF) film by ${\gamma}$-irradiation of the casted SF film, which is fabricated from aqueous solution regenerated via fibers of cocoons and their application as supports for human cell culture. The properties of cross-linked SF film were evaluated by FT-IR spectroscopy, contact angle, solubility to water, thermal analysis, surface area analyzer, and morphology via scanning electron microscopy (SEM). The cross-linked SF films were not dissolved in water and exhibited the rough surface morphology, large surface area, and good thermal properties. The human fibroblast cell (CCD-986sk) and embryo kidney-ft cell were well growed on the surface of cross-linked SF film supports prepared by ${\gamma}$-irradiation. The cross-linked SF film prepared by ${\gamma}$-irradiation can be used as biomaterials for human cell culture.

• Macromolecular Research
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• v.14 no.2
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• pp.205-208
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• 2006

A polymeric film of a biodegradable poly(1,5-dioxepan-2-one) (PDXO) was formed on a gold surface by a combination of the formation of self-assembled monolayers (SAMs) presenting hydroxyl groups and the surface-initiated, ring-opening polymerization (SI-ROP) of 1,5-dioxepan-2-one (DXO). The SI-ROP of DXO was achieved by heating a mixture of $Sn(Oct)_2$, DXO, and the SAM-coated substrate in anhydrous toluene at $55^{\circ}C$. The resulting PDXO film was quite uniform. The PDXO film was characterized by polarized infrared external reflectance spectroscopy, X-ray photoelectron spectroscopy, time-of-flight secondary ion mass spectrometry, atomic force microscopy, ellipsometry, and contact angle goniometry.

• Journal of the Korean Chemical Society
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• v.14 no.3
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• pp.263-269
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• 1970

A theory of surface tension developed by using the approximation that the surface of liquids consists of a monomolecular layer has been applied to the molten salts (NaCl, KCl, NaBr, KBr) and the strong electrolyte solutions. By considering that the ionic forces are the long-range forces and with the use of the partition functions developed, the surface tension of molten salts and strong electrolyte solutions has been calculated. The results show good agreement between theory and experiment at various temperatures and over a wide concentration ranges (0.1-4.0m)

• KIEE International Transactions on Electrophysics and Applications
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• v.11C no.3
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• pp.81-84
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• 2001

The trans and cis forms of N-alkyl-4-styrylpyridinium derivatives (CnSP: n= 4, 8, 12, 16) were successfully synthesized and purified. The derivatives of styrylpyridinium cause photoisomerization when they are illuminated with UV light. The pressure-area isotherms of CnSP and their derivatives were studied to reveal the effect of alkyl chain length. The photoisomerization of CnSP monolayers at the air/water interfaces was indirectly studied by measuring surface tension changes with photoirradiation on the water surface. The characteristics of CnSP were furthermore studied with UV-vis, surface pressure-area isotherms, surface potential-area isotherms, Brewster Angle Microscopy (BAM) at the air/water interface, and optical diffraction efficiency on the ultrathin films.

• Carbon letters
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• v.27
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• pp.12-17
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• 2018

We fabricated a Li-S battery with post-treated carbon nanotube (CNT) films which offered better support for sulfur, and investigated the effect of the surface properties and pore structure of the post-treated CNT films on Li-S battery performance. Post-treatments, i.e., acid treatment, unzip process and cetyltrimethylammonium bromide (CTAB) treatment, effectively modified the surface properties and pore structure of the CNT film. The modified pore structure impacted the ability of the CNT films to accommodate the catholyte, resulting in an increase in initial discharge capacity.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.08a
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• pp.136-136
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• 2013

High-resolution photoemission spectroscopy (HRPES) measurements were collected and density functional theory (DFT) calculations were conducted to track the coverage dependent variation of the absorption structure of 2-thiophenecarboxaldehyde (C4H3SCHO: TPCA) on the Ge(100) surface at room temperature. In an effort to identify the most probably adsorption structures on the Ge(100) surface, we deposited TPCA molecules at a low coverage and at a high coverage and compared the differences between the electronic features measured using HRPES. The HRPES data provided three possible adsorption structures of TPCA on the Ge(100) surfaces, and DFT calculations were used to determine the plausibility of the structures. HRPES analysis, corroborated by DFT calculations, indicated that an S-dative bonded structure was the most probable adsorption structure at relatively lower coverage levels, the [4+2] cycloaddition structure was the second most probable structure, and the [2+2]-C=O cycloaddition structure was the last probable structure on the Ge(100) surfaces at relatively higher coverage levels.

• Bulletin of the Korean Chemical Society
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• v.15 no.11
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• pp.933-939
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• 1994

Using an atom superposition and electron delocalization molecular orbital (ASED-MO) method, we have investigated the vibrational and chemisorptive properties of adsorbates on a Pt(100) surface during CO oxidation. The calculated vibrational stretching frequency for a predicted structure of $[CO{\cdot}{\cdot}{\cdot}O]^*$ complex is 1642 $cm^{-1}$. The CO bond stretches by 0.05 ${\AA}$ when adsorbed on one-fold site, and is tilted by 30 ${\AA}$ from the surface normal. We find the decrease in CO vibrational frequency on going from the one-fold to the high coordination sites. Binding at the two-fold site is predicted to be favored for $Pt_{18}(100)$ and at the 1-fold site for $Pt_{23}(100)$. From the calculations of the steric interactions, we have found that pre-adsorbed oxygen modifies the surface so that CO is adsorbed on the one-fold site ordered in a $(\sqrt{2}{\times}{\sqrt}{2})R45^{\circ}$. Our results are in good agreement with recent experimental findings of Hong et al. [J.Phys. Chem. 1993, 97, 1258].

• Bulletin of the Korean Chemical Society
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• v.12 no.5
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• pp.520-524
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• 1991

Stainless steel 304 2B and BA are oxidized in 2.5 M $CrO_3/$ 5.0 M $H_2SO_4$ solution, and elemental composition and oxidized state of the surface region is analyzed as a function of the surface depth using X-ray photoelectron spectroscopy. It is found that Fe and Cr are preferentially oxidized and diffuse outward following the oxidation. Element Ni, the third major component of the steel is not oxidized and remains deep under the surface. It is also found that the oxidized Fe dissolves considerably into the solution thereby enriching the gas-oxide interface with Cr.

• Bulletin of the Korean Chemical Society
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• v.15 no.12
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• pp.1093-1097
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• 1994

The interaction of oxygen molecule with Ni44(111) model surface to which the molecule approaches is studied by calculating the relevant DOS and COOP with the tight-binding EHT method. It is found that the dissociative adsorption of oxygen takes place as a result of electron transfer from the Ni d${\pi}$ orbital to the antibonding 1${\pi}_g$ orbital of the oxygen molecule. This finding is noteworthy to contrast with the case of Ni(100) surface in which the electron transfer takes place from the Ni d${\delta}$ orbital of the nickel surface.

• Bulletin of the Korean Chemical Society
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• v.12 no.6
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• pp.635-643
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• 1991

The adsorption of methanethiol on a Ag(100) surface has been studied with Extended Huckel calculation in the cluster approximation of the substrate. Since it has been known that methanethiol is chemisorbed dissociatively on silver surface by rupture of S-H bond, the methanethiolate radical is taken as adsorbate. Of the various adsorption sites, the 4-fold hollow site is preferred. The methanethiolate radical is mainly adsorbed via its 2e orbital. The charge transfer from metal to this level leads to the C-S bond weakening, which is consistent with the red shift of C-S stretching mode in surface enhanced Raman (SER) spectrum.