• Proceedings of the Polymer Society of Korea Conference
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• 2006.10a
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• pp.259-259
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• 2006

PAU is the block copolymer consists of a small amount of a small amount of poly(${\gamma}-methyl-L-glutamate$) (PMLG) and the polyurethane. The urethane segments are hydrophobic and then strongly interact with the other hydrophobic materials such as PTFE, and the PMLG segments with the ${\alpha}-helix$ structure possess the cytocompatibility. Therefore, PAU can be easily coated onto the PTFE fiber and acts as an artificial extracellular matrix with the high cytocompatibility Results shows, the immobilization, cultured and functions of porcine hepatocytes is greatly improved.

• Macromolecular Research
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• v.11 no.1
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• pp.2-8
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• 2003

The self-assembly of polymers can lead to supramolecular systems and is related to the their functions of material and life sciences. In this article, self-assembly of Langmuir-Blodgett (LB) films, polymer micelles, and polymeric nanoparticles, and their biomedical applications are described. LB surfaces with a well-ordered and layered structure adhered more cells including platelet, hepatocyte, and fibroblast than the cast surfaces with microphase-separated domains. Extensive morphologic changes were observed in LB surface-adhered cells compared to the cast films. Amphiphilic block copolymers, consisting of poly(${\gamma}$-benzyl L-glutamate) (PBLG) as the hydrophobic part and poly(ethylene oxide) (PEO) [or poly(N-isopropylacrylamide) (PNIPAAm)] as the hydrophilic one, can self-assemble in water to form nanoparticles presumed to be composed of the hydrophilic shell and hydrophobic core. The release characteristics of hydrophobic drugs from these polymeric nanoparticles were dependent on the drug loading contents and chain length of the hydrophobic part of the copolymers. Achiral hydrophobic merocyanine dyes (MDs) were self-assembled in copolymeric nanoparticles, which provided a chiral microenvironment as red-shifted aggregates, and the circular dichroism (CD) of MD was induced in the self-assembled copolymeric nanoparticles.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.07a
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• pp.1047-1049
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• 2001

The displacemant current measuring system used for detecting the dynamic behavior of monolayers at the air-water interface is described. It basically consists of a film balance, a pair of electrodes connected to each other through a sensitive ammeter. Here, one electrode is suspended in air and the other electrode is placed in the water. With Maxwell-displacement-current-measuring method, the phase transitions of Poly-${\gamma}$ -benzyl D-glutamate(PBDG) on a water surface were detected. Measured surface pressure, displacement current and dipole moment of monolayers of PBDG on the water surface. We measured analyzed displacement current that occur when differed temperature. Could know that displacement current is proportional in increase of temperature and great as experiment result.

• Proceedings of the KIEE Conference
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• 2002.07c
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• pp.1413-1415
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• 2002

The Displacement current measurement system used in this experiment because detecting the dynamic behavior of monolayers at the air-water interface is possible. It basically consists of a film balance, a pair of electrodes connected to each other through a sensitive ammeter. Here, one electrode is suspended in air and the other electrode is placed in the water. PBLG phase transformation measured by Maxwell-displacement-current-measurement method in surface of the water. Measured (surfacc pressure, displacement current and dipole moment) of monolayers of PBLG on the water surface. We measured displacement current that occur when changed temperature(15, 20, 25$^{\circ}$ ) and the compression speed(30, 40, 50(mm/min)). From the result, it is known that curren generated in the range of high surface pressur compression velocity and temperature become faste.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.11a
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• pp.362-365
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• 2002

This paper, experiment manufactures device of Metal/Poly-${\gamma}$ Benzyl $_D$-GlutamateOrganic Films/Metal structure using PBDG and I-V properties and C-F properties. The I-V characteristic is measured that approve voltage from 0 to +2[V] of device and the distance between electrode is larger, could know that small current flow and thin film could know that had insulation property. C-F characteristic has each other affinity between the polarization amount and frequency. Permittivity of MIM device could know by dipole that is voluntary polarization of LB film that polarization is happened. The capacitor properties of a thin film is better as the distance between electrodes is smaller.

• Proceedings of the KIEE Conference
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• 2002.11a
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• pp.150-152
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• 2002

This paper, experiment manufactures device of Metal/Poly-$\gamma-Benzyl\;_D-Glutamate$ Organic Films/Metal structure using PBDG and I-V properties and C-F properties. The I-V characteristic is measured that approve voltage from 0 to +2[V] of device and the distance between electrode is larger, could know that small current flow and thin film could know that had insulation property. C-F characteristic has each other affinity between the polarization amount and frequency. Dielectric constant of MIM device could know by dipole that is voluntary polarization of LB film that polarization is happened. The capacitor properties of a thin film is better as the distance between electrodes is smaller.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.07b
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• pp.723-726
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• 2002

We give pressure stimulation into organic thin films and then manufacture a device under the accumulation condition that the state surface pressure is 10[mN/m]. In processing of a device manufacture, we can see the process is good from the change of a surface pressure for organic thin films and transfer ratio of area per molecule. The structure of manufactured device is Au/Poly-$\gamma$ Benzyl $_D$-Glutamate/Al; the number of accumulated layers is 1, 3, 5 and 7. Also, we then examined of the MIM device by means of I-V. The I-V characteristic of the device is measured from 0 to +2[V]. We determined electrochemical measurement by using cyclic voltammetry with a three-electrode system. LB film accumulated by monolayer on an ITO. In the cyclicvoltammetry, An Ag/AgCl reference electrode, a platinum wire counter electrode and LB film-coated ITO working electrode measured in $LiBF_4$ solution, stable up to 0.9V vs. Ag/AgCl.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.08a
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• pp.101-104
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• 2002

Abstract We give pressure stimulation into organic thin films and then manufacture a device under the accumulation condition that the state surface pressure is 10[mN/m]. In processing of a device manufacture, we can see the process is good from the change of a surface pressure for organic thin films and transfer ratio of area per molecule. The structure of manufactured device is Au/Poly-${\gamma}$ Benzyl $_D$-Glutamate/Al; the number of accumulated layers is 1, 3, 5 and 7. Also, we then examined of the MIM device by means of I-V. The I-V characteristic of the device is measured from 0 to +2[V]. We determined electrochemical measurement by using cyclic voltammetry with a three-electrode system. LB film accumulated by monolayer on an ITO. In the cyclicvoltammetry, An Ag/AgCl reference electrode, a platinum wire counter electrode and LB film-coated ITO working electrode measured in $LiBF_4$ solution, stable up to 0.9V vs. Ag/AgCl.

• Bulletin of the Korean Chemical Society
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• v.8 no.4
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• pp.318-324
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• 1987

Experimental results for viscous flow of poly (${\gamma}$ -methyl L-glutamate) solutions have been published elsewhere. The data of $[{\eta}]^f / [{\eta}]^0$ are expressed by the following equation, $\frac{[{\eta}^f]}{[{\eta}^{\circ}]}=1-\frac{A}{\eta^\circ}{1-\frac{sin^{-1}[{\beta}_2(f/{\eta}_0)\;{e}xp\;(-c_2f^2/{\eta}_0^2kT)]}{{\beta}_2f/{\eta}_0}$ (A1) where $[{\eta}]^f\; and\; [{\eta} ]^0$ are the intrinsic viscosity at shear stress f and zero, respectively, $ A{\equiv}lim\limits_{C{\rightarrow}0}[(1/C)(X_2/{\alpha}_2)({\beta}_2/{\eta}_0)],{\eta}_0$ viscosity of the solvent, ${\beta}_2$ is the relaxation time of flow unit 2, $c_2$ is a constant related to the elasticity of flow unit 2. The theoretical derivation of Eq.(A1) is given in the text. The experimental curves of $[{\eta}]^f / [{\eta}]^0$ vs. log f are compared with the theoretical curves calculated from Eq.(A1) with good results. Eq.(A1) is also applied to non-biopolymeric solutions, and it was found that in the latter case $c_2 = 0.$ The reason for this is explained in the text. The problems related to non-Newtonian flows are discussed.

• Bulletin of the Korean Chemical Society
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• v.8 no.4
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• pp.332-335
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• 1987

This paper is a continuation of our previous $paper,^1$ and deals with Eq.(1) (see the text), which was theoretically derived in the $paper,^1$$ [{\eta}]^f\; and\; [{\eta}]^0$ is the intrinsic viscosity at stress f and f = O, respectively. Equation (1) predicts how $[{{\eta}}]^f / [{\eta}]^0$ changes with stress f, relaxation time ${\beta}_2$ of flow unit 2 and a constant $c_2$ related with the elasticity of molecular spring of flow unit 2. In this paper, Eq.(1) is applied to a biopolymer, e.g., poly (${\gamma}$-benzyl L-glutamate), and nonbiopolymers, e.g., polyisobutylene, polystyrene, polydimethylsiloxane and cellulose triacetate. It was found that the $c_2$ factor is zero for non-biopolymers while $c_2{\neq}0$ for biopolymers as found $previously.^1$ Because of the non-Newtonian nature of the solutions, the ratio $[{{\eta}}]^f / [{\eta}]^0$ drops from its unity with increasing f. We found that the smaller the ${\beta}_2,$ the larger the $f_c$ at which the viscosity ratio drops from the unity, vice versa.