• Journal of the Korean Applied Science and Technology
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• v.29 no.2
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• pp.278-285
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• 2012

Effects of ion species on the expansion behavior of Poly(styrene sufonic acid)(PSSA) hydrogel were investigated in aqueous solution of selected anions, cations and hydrophobic ions. The deexpansion extent of Poly(stylene sulfonic acid) gel follow the sequence $SCN^-$<$Br^-$<$Cl^-$<$F^-$ in low concentration solutions due to the destabilization of anions to hydrogen bond between ${SO_3}^-$ and water. The deexpansion in cations followed the sequence of counterion interactions between ${SO_3}^-$ and cations. It was discussed the effects of ions on the hydrogen bonding through ${SO_3}^-$ and phenyl ring in salt solutions. Other interactions, such as the cation-${\pi}$ interaction, hydrophobic interaction, and dispersion force, contributed to the ion specific swelling of PSSA hydrogel.

• Polymer(Korea)
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• v.32 no.6
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• pp.587-592
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• 2008

High molecular weight poly(vinyl alcohol) (PVA) hydrogel to be expected as a candidate material for the wound-dressing was successfully prepared by electron beam (EB) irradiation. To produce PVA hydrogels with various gel fractions, degrees of swelling in water, gel strengths, and elongations, two different number-average degrees of polymerization [($P_n$)s] of PVA were adapted such as 1700 and 4000, and the PVA solution concentration and irradiation dose of EB were controlled to range of 5 $\sim$ 20% and 30 $\sim$ 100 kGy, respectively. The gel fraction and strength of PV A hydrogel were increased with increasing molecular weight of PVA, solution concentration, and irradiation dose of EB. On the contrary, the degree of swelling and elongation of PVA hydrogel were decreased. The thermal property and crystallinity related to degree of crosslinking of PVA hydrogel were examined by the analyses of differential scanning calorimetry and X-ray diffraction.

• Journal of the Korean Graphic Arts Communication Society
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• v.21 no.1
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• pp.11-20
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• 2003

Equilibrium swelling curves of N-isopropyl acrylamide(NIPA) gel and its ionized copolymer gels were obtained as a function of temperature. Discontinuous volume changes of the gels were observed. Phase transition temperature was increased with the ionized counter parts of the gels. Equilibrium swelling of ionized copolymer gel cylinder was found to depend strongly on their diameters. Crosslinking density of NIPA gel was adjusted by increasing N,N'-methylenebisacrylamide(BIS). Phase transition temperature was increased with the crosslinking density.

• Journal of the Korean Graphic Arts Communication Society
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• v.21 no.1
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• pp.81-90
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• 2003

To understand the thermoresponsive volume phase transition of an N-isopropyl acrylamide(NIPA) gel on water, the solubility parameter of neutral NIPA gel was determined by swelling the gel with various solvents. Water was found not to be a good solvent for NIPA gel. Equilibrium swelling curves of NIPA gel were respectively obtained by immersing in pure water, ethanol, n-propanol and some mixed solvents. On adding a small amount of alcohols to water, volume phase transition of NIPA gel in water was changed. Phase transition temperature of this gel was decreased with the increase of the carbon number of alcohol.

• Journal of the Korean GEO-environmental Society
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• v.7 no.4
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• pp.25-34
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• 2006

Portland cement and sodium silicate are widely used as the main components of the injection, which are used to prevent flow and improve ground condition. The main problem of the injection material is the leaching of the sodium hydroxite and silicate due to the limited reaction with the cement. This paper studies the effect of cement hydration retarder on the compressive strength of the sodium silicate - cement gel. A series of tests, including digital-type testing machine, X-ray diffraction and scanning electron microscope are performed. Results clearly demonstrate that the sodium tripolyphosphate, which is the cement hydration retarder in the test, significantly improves the initial strength of the homogel.

• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.8
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• pp.965-970
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• 2017

The objective of this study was to evaluate the effects of gelatin type (powder vs. hydrated) with or without transglutaminase (TGase) on the physicochemical and textural properties of low-fat model sausages (LFS). Treatments included LFS (control), LFS with hydrated-gel form of gelatin (1%), and LFS with powder form of gelatin (1%). Yellowness values of LFS with any type of gelatin were higher than those without gelatin (P<0.05). Moisture content (%) of LFS containing powder form of gelatin (1%) was higher than those with hydrated-gel form of gelatin or control (P<0.05). Expressible moisture (EM, %) of LFS with hydrated-gel form of gelatin was lower than those with powder form of gelatin (P<0.05). Thus, sausages with hydrated-gel form of gelatin showed better functional properties as compared to those with powder form of gelatin. To elucidate the interaction between gelatin and TGase in meat product, five actual sausages were manufactured: reference [konjac flour (KF), carrageenan (CN), and soy protein isolate], control (KF and CN alone), TRT1 (KF and CN, TGase 1%), TRT2 (KF and CN, gelatin 1%), and TRT3 (KF and CN, TGase 1%+gelatin 1%). EM (%) of sausages with TGase alone was higher than those of other treatments (P<0.05). Most textural properties of TRT3 were higher than those of other treatments. Thus, TRT3 showed better functional properties than those with single addition. In conclusion, a combination of TGase and gelatin could be used to manufacture LFSs with improved functional and textural properties.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.41 no.3
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• pp.201-208
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• 2015

Organogels are semi-solid systems that consist of an apolar solvent as the liquid phase within a three-dimensional networked structure. In this study, we developed a stable and skin penetration-enhanced Lecithin Organogel (LO) containing genistein, which is one of the poorly soluble active ingredients in both polar and apolar phase. After screening of various components (type of gelators, organic and aqueous phase), hydrogenated lecithin (HL), sunflower oil (SO), dipropylene glycol (DPG), and polyethylene glycol (PEG) were mainly used in this formulation. Phase ternary diagram was employed for optimization of the composition in the LO. The formulated LO were evaluated for its organoleptic characteristics, stability, pH, rheology, phase transition temperatures, microscopic analysis and skin penetration. The optimized stable LO system can be utilized as an effective and stable cosmetic formulation that can carry poorly soluble active ingredients at high concentration for topical dermal delivery.

• Journal of Biomedical Engineering Research
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• v.8 no.1
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• pp.13-28
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• 1987

Crosslinked poly(2-hydroxyethylmethacrylate) has been prepared by polymerizing 2-hydroxyethyl methacrylate(HEMA) with crosslinkers such as ehyleng glycol dime- thacrylate(EGDMA), tetraethylene glycol dimethacrylate(TEGDMA), tetraethylene glycol diacrylate(TEGDA), divinyl benzene(DVB), and N, N-methylenebisacry- lamide(MAB) in the presence of initiator $\alpha$ , $\alpha$ -azobisisobutyronitrile at 60。C, The synthesized copolymers were identified by FT-lR spectrophotomether. The swelling properties of the crosslinked copolymers in various solvents such as water, methanol, ethanol, n-propanol, and n-butanol were investigated at different temperatures. The thermal properties of the crosslinked coplymers were also measured by differential scanning calorimetry(DSC) and thermogravimetry(TG)

• Proceedings of the Korean Fiber Society Conference
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• 2001.10a
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• pp.324-325
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• 2001

Poly(vinyl alcohol) (PVA) is useful for biomaterials such as contact lens, drug delivery system, and biological tissues, because of good biocompatibility and no toxicity. Particularly, hydrogels have unique position in biomaterial fields because of their high water contents.[1-2] Because atactic PVA (a-PVA) is very weak in water, a-PVA need to be chemically crosslinked with crosslinking agent such as glutaradehyde to prepare PVA hydrogels with high water-resistance and good physical properties.[3] (omitted)

• Radioisotope journal
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• v.21 no.4
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• pp.46-54
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• 2006

Biocompatible and biodegradable hydrogels based on carboxymethyl cellulose(CMC) and polyethyleneglycol(PEG) were prepared far physical barriers for preventing surgical adhesions. These interpolymeric hydrogels were synthesized by a gamma irradiation crosslinking technique. The 1Scmxl.Scm of cecal serosa and adjacent abdominal wail were abraded with bane burr until tbe serosal surface was disrupted and hemorrhagic but not perforated. and the serosa of tbe cecum was sutured to the abdominal wall in 5mm apart from the injured sire. The denuded cecum was covered with either CMC/PEG hydrogels or solution from CMC/PEG hydrogel. Control rat serosa was not covered. Two weeks later. the rats were sacrificed and adhesion was scored on a 0-5 scale. No treatment showed the significantly higher incidence of adhesions than either CMC/BEC hydrogels or solution from CMC/PEG hydrogel. In conclusion, these studies demonstrate that CMC/BEG hydrogels have a function of prevention of intra abdominal adhesion in a rat model.