• Proceedings of the Korean Radioactive Waste Society Conference
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• 2006.11a
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• pp.131-132
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• 2006

• Applied Chemistry for Engineering
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• v.4 no.3
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• pp.627-636
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• 1993

Anionic acrylic resin utilizing macromer(TBMA-g-MMA) copolymer was synthesized by preparing (TBMA) macromer using anionic living polymerization, followed by graft copolymerization with MMA macromer. To control the anionic site content in graft copolymer, the relative composition((TBMA) macromer/MMA ratio) of the graft copolymer was controlled at 7/3, 10/90, 15/85, 20/80, 30/70, 40/60, 50/50 in weight content. In the course of anionic living polymerization of(TBMA) macromer, broad molecular weight distribution (1.4~1.5) was obtained by using n-butyllithium-diphenyethylene initiatior system at $-78^{\circ}C$. To introduce the double bond at the end of chain in termination step, methacryloyl chloride was reacted after insertion of benzaldehyde as capping material. Moreover, TBMA parts in graft copolymer were hydrolyzed in the presence of p-toluenesulfonic acid catalyst, and neutralization of graft copolymer with triethylamine was granted acrylic resin to anionic site. Molecular weight and molecular weight distribution of(TBMA) macromer were determined by GPC, and the hydrolysis of TBMA with neutralization of acrylic resin were determined by IR and NMR. From water dispersion and stability point of view, stable dispersion state appeared at low molecular weight(TBMA) macromer with a small TBMA content as a result of scrutiny about the relation to TBMA content and branch length for(TBMA) macromer molecular weight in graft copolymer.

• Journal of Korean Society of Environmental Engineers
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• v.36 no.4
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• pp.246-250
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• 2014

This study was carried out to investigate the anion-distribution of the famous valleys in Jeollanam-do. Sampling sites were the valley region of Eochi, Surak, Daeheungsa and Namchang. The maximum values of the anion level were 11,190~178,100 ea/mL at each site and the highest value was measured at the Surak. The mean values showed 14,060 ea/mL in Surak, 8,590 in Eochi, 8,420 in Daeheungsa and 7,020 in Namchang. For a day, the highest Concentration showed in the 5:00 a.m to 7:00 a.m and the lowest values showed in the 12:00 p.m to 14:00 p.m. According to the distance from the source, the anion tended to disappear within 7 m in Namchang and Daeheungsa. But, it influenced by 50 m in Eochi and Surak. Correlation coefficient was -0.54 with wind speed, 0.34 with humidity about the formation of anion. There was no significant correlation with wind speed in the island and longevity village where we had studied in 2009 and 2011. But there was similar correlation with humidity in the island region. Therefore, we can say that wellbeing life is walking around the valley early in the morning with no wind.

• Horticultural Science & Technology
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• v.30 no.6
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• pp.694-699
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• 2012

To examine the EC model in a culture medium, basic culture medium of Rush (2005) and EC model of Robinson and Strokes (1959) were applied analyzing the equivalence ion total amount, the EC variable of cation and anion. Following the experiential translation by Steiner (1980), 130 optimized domestic and foreign culture media for crop growth were utilized, and estimated EC model was also demonstrated. Results from basic culture medium of Rush (2005) suggests an estimated EC by equivalence ion total amount and high reliable regressive model with 0.96 y = 1.33x - 0.23 of 0.96 as value $R^2$. It was found out that the change in concentration of positive ion and anion did not differ significantly with the increase and decrease of EC, however, there occurred a slight variable range. The change brings about a bigger anion influence than the previously reported positive ion, seemingly like those based on nitride ion and sulfur ion. The above EC estimated models confirmed that with optimized 130 domestic and foreign culture media for crop growth, the value derived will be as follows: $R^2$ = 0.98 with y = 1.23x - 0.02. In addition, the contour analysis of positive ion and anion for EC, with popularly known concentration range of EC $1.5-2.5dS{\cdot}m^{-1}$ reveals an equivalent of more than $11meq{\cdot}L^{-1}$ for positive ion and $15meq{\cdot}L^{-1}$ for anion. On the other hand, the left bottom, low concentration $1.5dS{\cdot}m^{-1}$ and the right above, high concentration $2.5dS{\cdot}m^{-1}$, for both positive ion and anion existed differently in a proper culture medium concentration. This study adapted variables of both positive ion and anion of EC simultaneously, unlike in the previous culture medium by ion ratio in mutual ratio of Steiner (1980), and offers an EC model that can estimate levels or positive ion and anion in proper concentration, EC $1.5-2.5dS{\cdot}m^{-1}$, with distributed features of ions.

• Membrane Journal
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• v.19 no.2
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• pp.136-144
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• 2009

In this study, sodium dedocyl sulfate (SDS), which was anionic surfactant, was added for forming micelles to remove ferrous ions that could be contained with a small amount in industrial water. Then aggregates were formed by adsorption or binding of ferrous ions on the surface of micelles, and then rejected by ceramic membranes to remove ferrous ions. Ferrous concentration was fixed at 1mM and SDS was changed as $0{\sim}10mM$ to investigate the effect of the anionic surfactant. As a result, rejection rate of ferrous was the highest to 88.97% at 6mM. And we used ELS (Electrophoretic Light Scattering Spectrometer) to investigate particle size distribution of micellar aggregates depending on SDS concentration. Then distribution of large aggregates was the highest at 6mM. And we investigated effects of $N_2$-back-flushing time (BT) during periodic $N_2$-back-flushing on ceramic membranes. Finally optimal $N_2$-BT for NCMT-723l (pore size $0.10{\mu}m$) membrane was 20 sec.

• 한국생물공학회:학술대회논문집
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• 2000.04a
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• pp.489-492
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• 2000

The rejection of hardness in a lactate fermentation broth was investigated by NTR-729 nanofiltration membrane. Firstly, a method for determining membrane surface charge was proposed on the basis of the rejection data for NaCl, $Na_2SO_4$, $MgCl_2$, $MgSO_4$ solutions. It was found that the NTR-729 membrane was negatively charged. The rejection of $Mg^{2+}$ ions in model solution of lactate was over 80% with lactate concentrations. But the rejection of $Mg^{2+}$ ions in fermentation broth of lactate was about 40 %. This results was caused by anions paired with $Mg^{2+}$ ions. It was found that the repulsive force of monovalent anions with membrane was almost few through an experiment of a mixed solution of NaCl/ $Na_2SO_4$. So the rejection of $Mg^{2+}$ ion in a fermentation broth was lower than that in a model solution because $Mg^{2+}$ ions permeated to the membrane with various monovalent anions.

• Polymer(Korea)
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• v.33 no.5
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• pp.458-462
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• 2009

We have synthesized ABC linear triblock copolymers, i.e., polystyrene-b-poly(ethylene oxide)-b-polylactide, via sequential anionic and ring-opening polymerizations. In the first anionic polymerization step, styrene was polymerized in cyclohexane using sec-butyllithium as the initiator. Poly (styryl) lithium was hydroxylated by the addition of ethylene oxide, and the subsequent protonation with methanolic HCl. In the second anionic polymerization step, potassium naphthalenide was used to deprotonate the hydroxyl group of the PS to generate the macroinitiator of PS-$O^-K^+$. Polymerization of ethylene oxide was performed in THF and terminated with methanolic HCl. In the ring-opening polymerization step, the PS-b-PEO-$AlEt_2$ macroinitiator was prepared from an $AlEt_3$/pyridine system in THF, and the polymerization of lactide was performed at $90^{\circ}C$. The resulting block copolymers showed well-defined molecular weights and narrow molecular weight distributions as revealed by $^1H$- NMR spectroscopy and gel permeation chromatography (GPC).

• Journal of Forest and Environmental Science
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• v.15 no.1
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• pp.89-97
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• 1999

This study was carried out to obtain basic data on the kinds of aquatic insects and their living conditions in the mountain stream. The investigation was done in Bongmyung stream. Experimental Forest, Kangwon National University on aquatic insects, anions and river-bed materials. The results are as follows. 1. At every plot surveyed, diversity index, richness index and evenness index of aquatic insects appeared higher at upper stream than at lower stream in erosion control dam. 2. Anion concentrations were almost the same in plots A, B, C, D and E, but plot F at the lower stream showed 1.5 to 89 times higher concentration than the others. 3. In river-bed materials analysed, particle diameter was bigger at the upper stream than at the lower stream. At the down stream of erosion control dam showed high pebble composition ratio. 4. The number of aquatic insects showed the negative relation with the anion concentration and the positive one with the size of river-bed materials. Especially, they were affected much by the distribution chart of boulder.

• Polymer(Korea)
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• v.36 no.5
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• pp.564-572
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• 2012

A terpolymer of vinylbenzyl chloride-co-ethyl methacrylate-co-styrene (VBC-EMA-St) was prepared for membrane capacitive deionization (MCDI) by radical polymerization and amination reaction of various amination times. Nonfluoro aminated VBC-EMA-St anion-exchange membranes were characterized by Fourier transform infrared (FTIR) spectrometry. Molecular weight, polydispersity and thermal stability were obtained by gel permeation chromatography (GPC) and thermogravimetric analysis (TGA). The basic properties such as water uptake, ion exchange capacity, electrical resistance and CDI charge-discharge current were measured. The optimal values of ion exchange capacity, water uptake, electrical resistance and molecular weight of synthesized anion-exchange membrane were 1.69 meq/g, 23.7%, 1.61 ${\Omega}{\cdot}cm$ and $3.4{\times}10^4$ g/mol, respectively. As compared with conventional membrane, the pattern of cyclic charge-discharge current of synthesized anion-exchange membrane indicated efficient electrosorption and desorption.

• Journal of the Korean Chemical Society
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• v.29 no.3
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• pp.233-238
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• 1985

The non-porous and porous polystyrene divinylbenzene copolymers were prepared by the suspension polymerization method. The non-porous aminated polystyrene divinylbenzene, N-APSTDVB and the porous aminated polystyrene divinylbenzene, P-APSTDVB of 50∼100mesh size weakly basic anion exchanger were synthesized by chloromethylation followed by amination with methylamine. The functional groups of these synthesized anion exchangers were confirmed by their infrared spectra. The maximum capacity of these exchangers was 4.86meq/g. Pore volume and pore spectra were determined with a mercury porosimeter. The pore volume of P-PSTDVB increased with increasing X$_{diluent}$ at 30% of divinylbenzene. However, the pore volume of P-PSTDVB increased with increasing volume percent of divinylbenzene at constant mole fraction of diluent, X$_{diluent}$ of 0.5. The pore volume of synthesized copolymer and anion exchanger at 8% divinylbenzene and 0.5X$_{heptane}$ decreased as follows; P-PSTDVB 〉P-APSTDVB 〉N-PSTDVB. This result was attributed to the possibility that the pore volume were reduced by amination reactions. The distribution coefficients of boric acid on the N-APSTDVB anion exchanger in various concentrations of alcohol water solutions showed that as alcohol concentration increased, the distribution coefficients values decreased due to the reduced concentration of H$_2$BO$_3^-$.