• Bulletin of the Korean Chemical Society
• /
• 제16권11호
• /
• pp.1046-1056
• /
• 1995

A topological theory has been introduced to evaluate the degree of complexation and the viscosity of polymer complexes by extending the theory of Iliopoulos and Audebert for aqueous polymer solutions. The previous theory of Iliopoulos and Audebert has offered only a semiquantitative theoretical model for polymer complex systems, whereas our present work gives a general theoretical model applicable to all the polymer complex systems. Their theories considered only the physical property term caused by the displacement of complexed points between polymer solute chains, while our theory deals with all the physical effects, caused by the displacement of complexed points entangled points in polymer solute chains. There have been predicted the characteristics of physical properties from the expression. It is exposed that the predictive values show good agreement with the experimental data for polymer complexes.

• Macromolecular Research
• /
• 제13권5호
• /
• pp.460-462
• /
• 2005

• Macromolecular Research
• /
• 제14권4호
• /
• pp.404-407
• /
• 2006

• Macromolecular Research
• /
• 제17권4호
• /
• pp.245-249
• /
• 2009

A fluorescing, copolymer(Q)-bearing, quaternary ammonium pendant was mixed with excess natural salmon sperm DNA with a molecular weight of $1.3{\times}10^6$(2,000 base pairs) to afford highly fluorescing, complex mixtures. The fluorescence life-time of the polymer Q was greatly increased when mixed with DNA: for the mixture of Q:DNA=1:750 the fast and slow decay lifetimes increased from ca. 10 to 100 ps and from 20 ps to ca. 1 ns, respectively. The enhanced fluorescence of the mixtures was ascribed to efficient compartmentalization and reduced conformational relaxation of the polymer Q by complexation with excess DNA.

• 한국섬유공학회:학술대회논문집
• /
• 한국섬유공학회 2003년도 The Korea-Japan Joint Symposium
• /
• pp.43-44
• /
• 2003

The new method for preparing hybrid fibers from aqueous solution is described. The method is based on interfacial polyionic complexation between the counter-charged polymers. Polysaccharides, chitosan and gellan, and polypeptides, poly(L-lysine) and poly(L-glutamic acid) were utilized as the components of the fibers. The chitosan-gellan and poly(L-lysine)-gellan hybrid fibers exhibited a high level biodegradability.

• 한국막학회:학술대회논문집
• /
• 한국막학회 2003년도 추계 총회 및 학술발표회
• /
• pp.51-54
• /
• 2003

• Macromolecular Research
• /
• 제15권6호
• /
• pp.581-586
• /
• 2007

Cast DNA/polyethyleneimine (PEI) blend membranes containing different amounts of DNA were prepared using acid-base interaction and characterized with the aim of understanding the polymer electrolyte membrane properties. Two different molecular weights of PEI were used to provide the mechanical strength, while DNA, a polyelectrolyte, was used for the proton transport channel. Proton conductivity was observed for the DNA/PEI membrane and reached approximately $3.0{\times}10^{-3}S/cm$ for a DNA loading of 16 wt% at $80^{\circ}C$. The proton transport phenomena of the DNA/PEI complexes were investigated in terms of the complexation energy using the density functional theory method. In the case of DNA/PEI, a cisoid-type complex was more favorable for both the formation of the complex and the dissociation of hydrogen from the phosphate. Since the main requirement for proton transport in the polymer matrix is to dissociate the hydrogen from its ionic sites, this suggests the significant role played by the basicity of the matrix.

• 한국재료학회지
• /
• 제28권3호
• /
• pp.142-147
• /
• 2018

${\beta}-Tricalcium$ phosphate (TCP) was added to $Al_2O_3$ to make a biomaterial with good mechanical properties. Using a TCP powder synthesized by a polymer complexation method, $Al_2O_3$ composites containing 30 wt% TCP were fabricated and characterized for densification, phase, microstructure, strength, and fracture toughness. With optimizing the powder preparation conditions, a high densification of 97 % was obtained by sintering at $1350^{\circ}C$ for 2 h. No reaction between the two components occurred and there was no transition to ${\alpha}-TCP$. TCP grains with a size of $2-4{\mu}m$ were well surrounded by $Al_2O_3$ grains with a size of $1{\mu}m$ or less. Strength 61(Brazilian) or 187(3-p MOR) MPa, and fracture toughness 1.7 (notched beam) or 2.5 (indentation) $MPa{\cdot}m^{1/2}$ were obtained, which are large improvements over the strength of $TCP/Al_2O_3$ composites and toughness of TCP and hydroxyapatite in previous studies.

• Journal of Pharmaceutical Investigation
• /
• 제22권2호
• /
• pp.105-113
• /
• 1992

To improve the solubility and dissolution rate of trimethoprim (TMP), which is slightly soluble drug, its inclusion complexes were prepared and studied in this experiment. Inclusion complexes of TMP with ${\beta}-cyclodextrin$ and ${\beta}-cyclodextrin$ polymer (CDPS) were prepared according to Fenyvesi method. These were compared with TMP and its physical mixture with CDPS. Water, diluted hydrochloric acid and phosphate buffer solution were used as dissolution media. And accelerated stability test was studied at $50,\;70\;and \;80^{\circ}C$. It was found that solubility and dissolution rate of inclusion complexes were increased in water. Especially, the solubility and dissolution rate of TMP was found to be markedly increased by inclusion complexation with CDPS. In stability test, ${\beta}-cyclodextrin$ inclusion complexes were more or less stable than TMP alone. This tendency was not led in CDPS. Consequently, CDPS was useful in increasing dissolution rate and stability of TMP.

• 한국전기전자재료학회논문지
• /
• 제35권3호
• /
• pp.203-214
• /
• 2022

Thermoelectric (TE) heating and cooling devices, which are able to directly convert thermal energy into electrical energy and vice versa, are effective and have exhibited a potential for energy harvesting. With the increasing consumer demands for various wearable electronics, organic-based TE composite materials offer a promise for the TE devices applications. Conductive polymers are widely used as flexible TE materials replacing inorganic materials due to their flexibility, low thermal conductivity, mechanical flexibility, ease of processing, and low cost. In this review, we briefly introduce the latest research trends in the flexible TE technology and provide a comprehensive summary of specific conductive polymer-based TE material fabrication technologies. We also summarize the manufacture for high-efficiency TE composites through the complexation of a conductive polymer matrix/inorganic TE filler. We believe that this review will inspire further research to improve the TE performance of conductive polymers.