• Fashion & Textile Research Journal
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• v.5 no.5
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• pp.520-528
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• 2003

Chitosan was depolymerized by oxidizing agent, hydrogen peroxide ($H_2O_2$) and general properties of resulting low molecular weight chitosan(LMWC) were studied. Effect of amount of $H_2O_2$, ratio of $H_2O_2$/chitosan, and reaction temperature were investigated in preparing LMWC. In addition, the reduction of molecular weight of prepared LMWC were measured after a certain time passage. Pre-swelling treatment of starting chitosan affected uniform and mild reaction of depolymerization and increased the solubility of resulting LMWC. Prepared LMWC (Mw 100,000) showed a decrease in Mw by 25-35%. Prepared LMWC(Mw 60,000-70,000) showed a decrease in Mw by 10-15% after 7 months. Therefore, this depolymerizing process can be concluded desirable in terms of stability. In addition, yellowing of pre-swelling treated chitosan upon time passage was insignificant compared with that of untreated chitosan. Therefore, pre-swelling treatment of chitosan before depolymerization would be beneficial in terms of stability of physical state.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.21 no.1
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• pp.38-52
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• 1995

The liposomes have been developed in many drugs and cosmetics fields. In this context, it should be mentioned that MLV liposomes can be prepared standing with the main compounds of the intercellular lipids, cholesterol, palmitic acid, cholesteryl ester and lecithin, by swelling reaction. We report properties of the formation of MLV liposomes with use of the lipid base and Microfluidizer. MLV liposomes formed as multilamellar vesicles(MLV). The effect of the gelation of MLV liposomes have been on swelling reaction which have been mixed lipid with polyol and water phase at high temperature(90$\pm$5$^{\circ}C$). MLV liposomes have been prepared in incorporating alpha hydroxy acid ligrediens. Optimum condition of MLV liposomes were passed three times in the microfluidizer, particle size of the vesicles should be within 150-350nm and those confirmed by freeze-fracture electron microscopy.

• Polymer(Korea)
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• v.31 no.4
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• pp.349-355
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• 2007

Poly(N-isopropylacrylamide-co-acrylonitrile) [P(NIPAAm-co-AN)] copolymers with AN content of up to 10 mol% and their hydrogels were synthesized using water as a reaction medium, and the effects of AN unit incorporation on the critical gel transition temperature(CGTT) and swelling behaviors of the hydrogels were investigated. The CGTT of the copolymer hydrogel was $30{\sim}32\;^{\circ}C$, decreasing with increasing AN content. Below CGTT, swelling rate and equilibrium swelling ratio of the copolymer hydrogel decreased with increasing AN content. On the other hand, it exhibited faster deswelling and lower equilibrium deswelling ratio with increasing AN content above CGTT.

• Macromolecular Research
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• v.13 no.1
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• pp.45-53
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• 2005

In this study, a series of highly swelling hydrogels based on sodium alginate (NaAlg) and polymethacryl­amide (PMAM) was prepared through free radical polymerization. The graft copolymerization reaction was performed in a homogeneous medium and in the presence of ammonium persulfate (APS) as an initiator and N,N'-methylenebis­acrylamide (MBA) as a crosslinker. The crosslinked graft copolymer, alginate-graft-polymethacrylamide (Alg-g­PMAM), was then partially hydrolyzed by NaOH solution to yield a hydrogel, hydrolyzed alginate-graft-poly­methacrylamide (H-Alg-g-PMAM). During alkaline hydrolysis, the carboxamide groups of Alg-g-PMAM were converted into hydrophilic carboxylate anions. Either the Alg-g-PMAM or the H-Alg-g-PMAM was characterized by FTIR spectroscopy. The effects of the grafting variables (i.e., concentration of MBA, MAM, and APS) and the alkaline hydrolysis conditions (i.e., NaOH concentration, hydrolysis time, and temperature) were optimized systematically to achieve a hydrogel having the maximum swelling capacity. Measurements of the absorbency in various aqueous salt solutions indicated that the swelling capacity decreased upon increasing the ionic strength of the swelling medium. This behavior could be attributed to a charge screening effect for monovalent cations, as well as ionic cross-linking for multivalent cations. Because of the high swelling capacity in salt solutions, however, the hydrogels might be considered as anti-salt superabsorbents. The swelling behavior of the superabsorbing hydrogels was also measured in solutions having values of pH ranging from 1 to 13. Furthermore, the pH reversibility and on/off switching behavior, measured at pH 2.0 and 8.0, suggested that the synthesized hydrogels were excellent candidates for the controlled delivery of bioactive agents. Finally, we performed preliminary investigations of the swelling kinetics of the synthesized hydrogels at various particle sizes.

• Journal of the Korean Ceramic Society
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• v.32 no.6
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• pp.703-709
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• 1995

Octadecylenetrimethylammonium-montmorillonite as an organophilic montmorillonite intercalations complex was formed by cation exchange reaction between Na-montmorillonite and 9-octadecylenetrimethylammonium cation. After drying of this organophilic montmorillonite at $65^{\circ}C$ in high vacuum, the complexes were reacted with various swelling-solutions such as benzene, toluene, o-xylene, pyridine, $\alpha$-picoline, 2-ethyl-pyridine, 2-vinyl-pyridine and styrene, and the corresponding basal spacing obtained were 43.9$\AA$, 54.3$\AA$, 51.7$\AA$, 41.5$\AA$, 42.5$\AA$, 39.9$\AA$, 39.8$\AA$, 44.8$\AA$, respectively.

• Proceedings of the Membrane Society of Korea Conference
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• 1994.10a
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• pp.32-33
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• 1994

Poly(vinyl alcohol)(PVA) membranes crosslinked with Glutaraldehyde (GA) were prepared for the separation of acetic acid-water mixtures. For the preparation of the crosslinked membranes, dry PVA films were immersed for 2 days at 40$\circ$C in reaction solutions which contain different content of GA solution(25% GA in water), aceton and a catalyst, HCl. IR spectroscopy was employed to characterize the crosslinking reaction between hydroxyl groups in PVA and aldehyde groups in GA. Swelling measurements of the crosslinked membranes were carried out in both water and acetic acid to investigate the crosslinking density and swelling behaviour of the membranes.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.11 no.1
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• pp.40-53
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• 1998

Mast cells play an important role in the pathophysiologlcal changes observed in acute cutaneous and inflammatory diseases In order to see whether Kum-Hwang-San has an influence on mast cell- mediated immediate cutaneous reactions, the author has undertaken an animal study. Ears of mice were treated with a compound 48/80 solution topically at 30 min after the cutaneous application of Kum-Hwang-San. At each point, an ear swelling response was measured with a digimatic thickness micrometer. Ear swelling response induced by compound 48/80 was significantly suppressed dose-dependently by Kum-Hwang-San 30 min before topical application as compared with that in nonapplicated control mice, and the value returned to normal levels by 120 min. Compound 48/80- induced mast cell degranulation by Kum-Hwang-San was also remarkably decreased in accordance with the suppression in ear swelling response. Kum-Hwang-San dose-dependently inhibited histamine release from the rat peritoneal mast cells activated by compound 48/80. Another way to test acute cutaneous reaction is to induce passive cutaneous anaphylactic reaction. Kum-Hwang-San significantly inhibited passive cutaneous anaphylactic reaction activated by anti-dinitrophenyl IgE on both topical application and intradermal injection. Kum-Hwang-San also inhibited histamine release from the rat peritoneal mast cells induced by anti-DNP IgE. This study provides evidence that Kum-Hwang-San will be beneficial in the treatment of acute cutaneous diseases.

• Journal of the Korean Society of Food Science and Nutrition
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• v.23 no.2
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• pp.244-250
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• 1994

Starch phosphates were prepared by dry heating method using sodium triphosphate as a substitution reagent and their physicochemical properties were investigated with the chucheongbyeo and samkangbyeo. The solubility and swelling power of rice starches were increased by phosphorylation reaction. The solubility of the chucheongbyeo was greater than that of samkangbyeo , but the swelling power was appeared in vice versa. The transparency of raw starch was increased at the 6$0^{\circ}C$, but phosphorylated rice starch was begun to increase from 5$0^{\circ}C$. Light transmittance was higher inthe phosphorylate drice starch. The lightness of phosphyorylated rice starch decreased more than that of raw starch. Whereas the yellowness of phosphorylated rice starch increased. The temperature of initial gelatinization of the phosphorylated chucheong and samkang rice starch was shown to 5$0^{\circ}C$ and 53$^{\circ}C$, respectively. lowering 14-15$^{\circ}C$ in temperatureby the phosphorylation . The viscosity as well as by the phosphorylation reaction was raised 7.4-8.4 times, respectively. The hardness, adhesiveness, cohesiveness and texture which is rheological properties of starch gel increased by the phosphoryulation reaction. The chucheong rice starch gel was slightly higher in its rheolgocial values thanthat of the samkang rice starch gel. The rice starch particles were shown to polygonal structure, but they were deformed in the phosphorylated starch.

• Journal of Animal Science and Technology
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• v.63 no.1
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• pp.58-68
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• 2021

Several herbs including Artemisia are known to possess conceptive property. In the present study, mouse spermatozoa were incubated with ethanol extract of Artemisia vulgaris leaves. The effect of extract on acrosome exocytosis was studied by labeling spermatozoa with fluorescein isothiocyanate (FITC) peanut agglutinin and by staining with Coomassie blue. Viability and membrane integrity were studied by Trypan-blue staining and hypo-osmotic swelling test. Artemisia extract at very low concentration caused precocious acrosome reaction and loss of sperm viability. Acrosome reaction increased remarkably from 22.63% to 88.42% with increasing extract concentration from 0 to 2,000 ㎍/mL. However, the viability loss of spermatozoa was increased from 11.71% in control to 63.73% in samples treated, evaluated by Trypan-blue staining method. Membrane damage caused by the extract, evaluated by hypo-osmotic swelling test was even low, ranging from 2.27% to only 24.23%. These results indicate that Artemisia extract might block fertilization by causing precocious acrosome exocytosis in spermatozoa. A direct contraceptive effect was tested by injecting the plant extract into the vagina of female mice and then allowing them to mate with normal males. The treated female mice delivered significantly fewer litters in comparison to the control.

• Macromolecular Research
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• v.9 no.5
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• pp.253-258
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• 2001

Crosslinked poly(ethylene glycol)s (PEGs) were prepared by ultraviolet irradiation of low molar mass, liquid PEGs in the presence of benzophenone (BP) as a photoinitiator. The networks obtained have been characterized by DSC, IR, and contact angle measurements, and their water absorption and equilibrium swelling have been examined. The percent of gel formed and degree of swelling of the networks in water were dependent on the amount of BP in the reaction mixture, irradiation time and molar mass of PEG. Gel fraction yield exceeded 84%, and equilibrium swelling in water varied from 49 to 244%.