• Clean Technology
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• v.22 no.4
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• pp.258-268
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• 2016

In this work, carboxymethylcellulose-based composite superabsorbent hydrogels were prepared by electron beam radiation. The composition of carboxymethylcellulose (CMC) varied from 4 wt%, 5 wt%, and 6 wt% to 7 wt% based on the amount of distilled water in the syntheses of hydrogels. Graphite oxide, reduced graphene oxide, activated carbon, and bentonite were used as additives for the synthesis of composite superabsorbent. The effect of CMC composition and the type of additives on the gel properties of the prepared hydrogels was investigated. In order to verify the functional groups in the prepared materials, Fourier transform infrared spectroscopy was used. In addition, mechanical strength, gel fraction, swelling kinetics, and equilibrium swelling ratios were measured for the prepared hydrogels. Swelling experiments were carried out in distilled water, urea solution, and physiological saline water. Prepared hydrogels were reused for 5 times, and gel fraction and swelling ratio were measured at every 24 hours. Among the prepared hydrogels, $C_{5%}GO$ and $C_{5%}rGO$ exhibited excellent mechanical property and relatively high swelling ratios for urea solution and physiological saline water with promising applicability as slow-release fertilizers.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.9 no.6
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• pp.1775-1781
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• 2008

The effects of the type of curing agent on the swelling of the natural rubber(NR) sponge applicable to the self-sealing layer of a helicopter fuel tank were investigated. The curing systems employed were peroxide and mixed ones of sulfur and peroxide. The NR compounds were prepared in a kneader and a roll-mill. The compounds were partially cured in a press at high pressure and subsequently cured fully with expansion in another press at atmospheric pressure. The apparent density of the NR sponge was measured and the cell structure was observed with scanning electron microscopy. The swelling experiments were performed at room temperature using toluene, iso-octane, and an aircraft fuel as a solvent. More rapid volume swelling of the NR sponge cured by peroxide was achieved than cured by sulfur and peroxide with similar amount of curing agent added in rubber compounds. The apparent density and cell structure of the sponge were extremely sensitive to the amount of peroxide, which influences again the swelling behavior of the NR sponge. It is important to control properly two reactions of decomposition of foaming agent and crosslinking of NR in the mold to obtain rapid swelling of the NR sponge on contact of the fuel.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1993.04a
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• pp.180-180
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• 1993

소프트하이드로겔의 합성은 IR, DSC등으로 확인되었으며, 전연성의 물성을 나타내었다. PPO 하이드로겔은 대부분 수팽윤도가 10％미만 정도로서 야굴방출시 팽윤에 의한 변형도가 낮아 부착형, 또는 이식형 조절방출성 제제에의 활용도가 기대되었으며, 약물방출은 주로 가교도/주쇄연장도에 의한 고분자 네트？의 세공크기(mesh size)에 의해 조절되었다. IPN하이드로겔의 경우는 pH의존성이 일반적이 겔보다 현저하게 나타났으며, 하유된 약물이 물성에 따른 약물방출양상을 보였다.

• Textile Coloration and Finishing
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• v.6 no.3
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• pp.37-43
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• 1994

Commercial Poly(ethylene terephthalate) (PET) filaments were treated in solvents mixtures such as benzyl alcohol/perchloroethylene(BA/PER), benzyl alcohol/trichloroethylene(BA/TRI), benzyl alcohol/ethylene chloride(BA/EC), metha nol/perchloroethylene(ME/PER), and methanol/trichloroethyle(ME/TRI). Swelling of PET in solvent mixtures showed rapidly in the middle range of mixture ratio. Contribution of swelling of each component to total swelling of binary mixtures with increasing treated time was generally showed in proportion to the mixture ratio of the each component in dependence of the extend of swelling.

• Korean Journal of Food Science and Technology
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• v.37 no.3
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• pp.418-424
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• 2005

The physicochemical properties of raw noodle flours (n = 11) commercially produced from Australian Standard White (ASW) (Group 1, n = 8) and blonds (Group 2, n = 3) of ASW and Australian hard, western white or hard red winter were investigated. Protein and ash contents were lower in Group 1. The tristimulus color values, mean particle size, flour swelling volume (FSV) and rheological parameters of farinograph and extensigraph were not different between two flour groups. Peak viscosity measured with Rapid Visco Analyzer was higher in Group 1. The protein content was positively correlated with mean particle size, dough stability and dough extensibility, and negatively correlated with FSV and peak viscosity. The FSV wag positively correlated with the peak viscosity. The rheological parameters of dough did not show any correlations with FSV and peak viscosity.

• Polymer(Korea)
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• v.34 no.2
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• pp.166-171
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• 2010

Poly(N-isopropylacrylamide)(PNIPAAm) containing polydimethylsiloxane(PDMS) block and nano clay was obtained by the polymerization of NIPAAm and [3-(methacryloylamino)propyl]trimethyl ammonium montmorillonite(MAPTAC-MMT) with PDMS-macroinitiator. The polymer was characterized with FT-IR, XRD and DSC. The addition of PDMS in the polymers did not affect the value of the lower critical solution temperature(LCST) and the glass transition temperature($T_g$) of the PNIPAAm. However, the swelling ratio decreased with increasing PDMS contents. In the case of PNIPAAm containing nano clay, the content of MAPTAC-MMT did not affect swellability, but the $T_g$ of the PNIPAAm decreased with increasing nano clay contents.

• 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.

• Journal of the Mineralogical Society of Korea
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• v.19 no.2 s.48
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• pp.123-128
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• 2006

Beidellite, a member of the dioctahedral smectite group, was synthesized hydrothermally from dickite. Organophilic [DEACOOH]-beidellite intercalation complex was formed by the cation exchange reaction between synthetic Na-beidellite and [DEACOOH]Br. The products dried in high vacuum were treated with various organic solvent such as methanol, ethanol, acetone, ether, acetonitrile and caprolactam in order to determine the swelling behaviour of the prepared complexes. After drying under high vacuum, basal spacing of [DEACOOH]-beidellite shows 15.1 ${\AA}$, and it changed to 19.4, 29.9, 15.9, 16.8, 14.8, 26.5 and 14.8 ${\AA}$ under distilled water, methanol, ethanol, acetone, ether, acetonitrile and caporlactam, respectively. Especially, the characteristics of the intercalation complexes and their swelling behavior of the synthetic beidellite and natural montmorillonite were compared.

• Polymer(Korea)
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• v.25 no.4
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• pp.545-557
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• 2001

The crosslinked films retaining cholesteric liquid-crystalline order were prepared by casting the liquid crystalline solutions of hydroxypropyl cellulose (HPC) in methanol with the two kinds of aliphatic dicarboxylic acid chlorides (succinyl chloride and suberoyl chloride). The temperature dependence on the cholesteric pitch of the crosslinked films and the swelling behavior of the films in both water and methanol were investigated. The films displayed fingerprint patterns charateristic of cholesteric liquid-crystalline phase, and their pitches, as well as HPC itself, increased with temperature. However, the pitch of all crosslinked samples was much greater than that of HPC at the same temperature and increased with increasing concentration and chain length of the crosslinker. The crosslinked samples exhibited an anisotropic swelling in both solvents. The degree of anisotropy slightly depended on the solvent and crosslinker species, but hardly on the crosslinker concentration investigated.

• The Journal of Natural Sciences
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• v.8 no.1
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• pp.145-151
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• 1995

The stretching of synthetic fibers by hot dry process is very difficult, because these fibers have high glass transition temperature at above $150^{\circ}C$. But, we used a swell-wet stretching precess; the fibers are stretched in a swelling agent such as organic solvents at lower temperature. In this study, 100% acryl fibers were uniaxially stretched with free width at $70^{\circ}C$ by swell-wet process in organic solvents. The stretchability was estimated by stretching work. This work is concerned with stretching stress and strain, and initial modulus. We found that it is a good parameter for the estimatation of high strength to the acrylic fiber. The effects of stretching conditions on the molecular orientation for high strength and mechanical properties of PAN fibers were measured.