• Fibers and Polymers
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• 제5권2호
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• pp.95-104
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• 2004

A series of superabsorbents based on acrylic acid (AA), sodium acrylate, 2-acrylamido-2-methylpropane sulphonic acid, N,N'-methylene bis-acrylamide (MBA) were prepared by inverse suspension polymerization. These hydrogels were further crosslinked on the surface with polyethylene glycol-600 (PEG-600). The water absorbency or swelling behaviors for these xerogels in water and 0.9% saline solutions, both under free condition and under load were investigated. Absorption characteristics of these hydrogels were found to depend on nature and concentration of crosslinker in the system. It was also found that the saline absorption was significantly improved as the incorporation of AMPS in the polymer was increased. The surface crosslinking introduced in the polymers was found to improve the absorption under load characteristics without lowering the free water absorption capacities of the polymer to a considerable extent.

• 한국전기화학회:학술대회논문집
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• 한국전기화학회 2001년도 연료전지심포지움 2001논문집
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• pp.189-192
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• 2001

In order to prepare the proton-conducting membrane with lower cost and higher ionic conductivity than commercialized one, the concept of incorporating the nitrogen acid to polymer backbone, is proposed. The synthesis, thermal, and temperature-variable impedance/electrical conductivity studies of poly (p-tolunesulfonylamido acrylate) are reported. This polymer can be prepared by reacting poly (acryloyl chloride) with ptolunesulfonamide and cast into homogeneous membranes. Thermogravimetric analysis (TGA) shows that the polymer is thermally stable up to about $200^{\circ}C$ and Differential scanning calorimetry (DSC) illustrates that the glass transition occur at around $67^{\circ}C$. The ionic conductivity measured by dielectric spectroscopy is in the range of $10^{-5}\;S/cm$ in dry atmosphere that it can be a candidate for the membrane of PEMFC or DMFC.

• Proceedings of the Korean Institute of Building Construction Conference
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• 한국건축시공학회 2018년도 추계 학술논문 발표대회
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• pp.193-194
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• 2018

In this study, various materials such as epoxy material, urethane material, cement material, and acrylic material are used to solve the water leakage occurring in underground structures. However, in the reality that the durability is insufficient and the effect is insufficient, it is aimed to improve the repairing effect by using acrylics. As a second study, it is confirmed that leachate can be used as a repair material by considering long time under water stability, elongation range test, fatigue resistance test, tube stability test, damage recovery performance ana temperature stability considering leakage environment for polyacrylate. In addition, this material is applied to Expansion Joint to perform leakage repair, and to verify the effect of repairing leakage by monitoring and visual observation of concrete humidification.

• Journal of the Regional Association of Architectural Institute of Korea
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• 제20권6호
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• pp.55-61
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• 2018

This study improved the water repair materials of the polyacrylic system applied to concrete structures by controlling expansion, strengthening water resistance, and improving cohesiveness. The improved polyacrylate repair materials were evaluated against the existing products to verify their performance and level of improvement, and applied on-site to the concrete structures that are leaking the improved water. The verification method measured the presence of water leaks and the moisture content of concrete inside. Moisture levels were measured for two months before and after material installation, and at least 0.8 - 1.7% of humidity was reduced after installing polyacrylic resin, and no leakage was found.

• Korean Chemical Engineering Research
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• 제52권5호
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• pp.553-557
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• 2014

Sulfonated polypropylene (S-PP) is prepared by sulfuric acid-acetone aldol condensation reaction of polypropylene (PP) separator to yield hydrophilic separator surface with a moderate amount of $-SO_3H$ groups. Activated carbon supercapacitor is also fabricated adopting the S-PP separator coated with potassium polyacrylate (PAAK) hydrogel polymer electrolyte. As a result, the hydrophilic surface of S-PP separator involves better physical and electrochemical properties such as decrease in contact angle, improvements of wettability, electrolyte uptake, and ionic conductivity to give higher specific capacitance and long cycle-life.

• Journal of Korean Society of Environmental Engineers
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• 제33권9호
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• pp.677-685
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• 2011

The reverse osmosis membrane processes have several operational problems. Fouling by inorganic scale occurs on membrane surface due to increases in concentrations over solubility by retaining ions on feed side of the membrane. Inorganic scales could be controlled by antiscalants or acid addition. In this study, three antiscalants having different characteristics were selected and evaluated on efficiency of $CaCO_3$ scale control. The $CaCO_3$ scale was inhibited by the antiscalants : 0.4 mg/L for SHMP, 0.6 mg/L for Spectra Guard, and 3 mg/L for Flocon 150 N. Increasing concentration factors of simulated sea water resulted in increases in antiscalant doses for the scale control. The increases in doses were positively proportional to the concentrate factors used in this study. Spectra Guard, one of the polyacrylate type antiscalants, was the most effective to control $CaCO_3$ scale. The antiscalants with the different scale inhibition time and doses implied the different control mechanisms.

• Analytical Science and Technology
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• 제26권1호
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• pp.34-41
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• 2013

Split-flow thin cell (SPLITT) fractionation (SF) is a rapid separation technique capable of separating colloidal particles or macromolecules into two or more fractions. SF allows fractionations in a preparative scale as sample is fed continuously. Generally SF uses a thin ribbon-like channel equipped with two flow stream splitters at the inlet and outlet of the channel. Thus there exist two flow inlets and two flow outlets at the top and bottom of the inlet and outlet of the channel, respectively. There are two operating modes in SF, conventional mode and full-feed mode (FFD). Although the resolution in the FFD mode is lower than that in the conventional mode, FFD mode has some merits. The design of the channel and operation are simpler in the FFD mode, as it does not require the feeding of the solvent. Thus there is no flow stream splitter at the channel inlet, and only one pump is needed, unlike the conventional mode, where two pumps are required for the feedings of the sample and the solvent separately. Also the sample is not diluted in the FFD mode as there is no solvent feeding, which is important for fractionation samples with low colloidal concentrations such as environmental samples. For some of environmental samples, pre-concentration is often required. In this study, a new large-scale splitter-less FFD-SF channel was implemented, where there is no splitter at the outlet as well as at the inlet of the channel. It was possible to build the channel in a much larger dimension than conventional ones, allowing much higher sample throughput (TP). The new channel was tested and optimized with polyurethane (PU) latex beads, and then applied to large-scale separation of Polyacrylate (PA).

• Journal of the Society of Cosmetic Scientists of Korea
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• 제33권3호
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• pp.159-163
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• 2007

The relationship between texture and rheological properties of mascara(oil-in-water emulsion) was analyzed in this study. The final mascara product and gelling agents(2.0 wt%) used therein, such as hydroxyethylcellulose(HC), carboxymethylcellulose(CMC), hectorite, sodium magnesium silicate (SMS), hydroxyethyl acrylate/sodium acryloyldimethyl taurate copolymer(HS), and polyacrylate 13/polyisobutene/polysorbate 20 (PPP), were measured for rheological properties. As a result, HS and PPP showed the highest adhesiveness which were related to the volumizing effect of mascara. The viscosities of HC, SMS, and HS were measured at the stress range of $1{\sim}1,000s^{-1}$. SMS, with the lowest storage modulus range of $100{\sim}1,000s^{-1}$, affected the mascara in terms of smooth texture. The results of this study suggest that the rheology of gelling agents used influences the final texture of the mascara.

• The Korean Journal of Pesticide Science
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• 제9권3호
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• pp.262-267
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• 2005

In order to commercialize Paenibacillus sp. AC-1 and to minimize its harmful side effects, four granular formulations were prepared using AC-1 powder, adjuvant, and carrier and then their physicochemical properties of the formulations were investigated. Out of the carriers tested, the best one was talc for the formulation. Viable cells was stabilized during the formulating process. Viable cells in the granules formulated with Paenibacillus sp. AC-1 powder were stabilized at storage temperature range ($4{\sim}50^{\circ}C$) after 12 weeks. The release rate of viable cells from granules into water under a static condition were eluted over 90% in 7 hours and breakdown rates of particle were 100% in 1 day. Among the tested formulations, granular formulation comprising of 20% of Paenibacillus sp. AC-1 powder, 7% of polycarboxylate as surface active agent, 1% of sodium polyacrylate as adjuvant, the rest as carrier showed to be best.

• Applied Chemistry for Engineering
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• 제20권2호
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• pp.201-207
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• 2009

The hydrogenation reaction of methyl dodecanoate for the synthesis of 1-dodecanol has been carried out in the presence of a copper chromite catalyst. The catalysts were synthesized by ceramic method, co-precipitation, and improved co-precipitation method and the particles were characterized by SEM and XRD. Also, the products of the reaction were assigned by GC, GC/MSD and NMR. The particles synthesized by each method showed (1) a spherical shape with the size of 3.2 to $7.0{\mu}m$, (2) an agglomerated spherical shape with the size of 50 to 500 nm and (3) a spherical shape with smaller particle size, respectively. Especially, in order to control the size of particles, the particles were synthesized in various dispersant solutions as Span 80, polyacrylate, and polyethyleneglycols (PEGs). The particles synthesized in PEG (Mw = 4000) solution showed the smallest particle size of 30 to 50 nm and the regularity of the particle size distribution. Our experimental results elucidated that the activity of catalyst for hydrogenation increases with decreasing the size of catalyst particle. The highest yield of dodecanol in the hydrogenation reaction was 95.5% when copper chromite synthesized in the PEG solution was used as a catalyst in the optimized reaction condition.