• Journal of the Korean Ceramic Society
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• v.31 no.12
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• pp.1467-1474
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• 1994

The effects of the dispersion, drying, and binder burning-out on the green-microstructures of gelcasted alumina were studied. The slip consisting of 55 vol% alumina powder and 5 wt% organic materials was well-dispersed by adding 0.28 wt% polyelectrolyte polymer. Green bodies were dried at >85% relative humidity at room temperature. Green-microstructures were observed to be depended on the heating rate during binder burnout. Constant drying rate was not observed in drying process of gelcasted alumina. Sintered body showed its relative density higher than 99% when it was sintered at 1$600^{\circ}C$ for 2 hours.

• Journal of the Korea Institute of Building Construction
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• v.8 no.5
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• pp.85-91
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• 2008

Prepacked concrete has recently been used in the special constructions fields such as underwater concrete work, heavy-weight concrete work, underground structure work, partial repair works for damaged reinforced concrete structures. and polymer-modified mortars have been employed as grouting mortars for the prepacked concrete. The purpose of this study is to recommend the optimum mix design of polymer-modified grouting mortars for prepacked concrete. Polymer-modified mortars using SBR and EVA emulsions as admixture of grouting mortars for prepacked concrete are prepared with various mix proportions such as sand-binder ratio, fly ash replacement ratio, polymer-binder ratio. and tested for flowability, viscosity of grouting mortars, bleeding ratio, expansion ratio, flexural and compressive strengths of grouting mortars and compressive and tensile strengths of prepacked concretes. From the test results, it is apparent that polymer-modified mortars can be produced as grouting mortars when proper mix design is chosen. We can design the mix proportions of high strength mortars for prepacked concrete according to the control of mix design factors such as type of polymer, polymer-binder ratio, sand-binder ratio and fly ash replacement ratio. Water-binder ratio of plain mortars for a constant flowability value are in the ranges of 43% to 50%. SBR-modified mortar has a little water-binder ratios compared to those of plain mortar, however, EVA-modified mortar needs a high water-binder ratio due to a high viscosity of polymer dispersion. The expansion and bleeding ratios of grouting mortars are also controlled in the proper value ranges. Polymer-modified grouting mortars have good flexural. compressive and tensile strengths, are not affected with various properties with increasing fly ash replacement to cement and binder-sand ratio. In this study, SBR-modified grouting mortar with a polymer-binder ratio of 10% or less, a fly ash replacement of 10% to cement and a sand-binder ratio of 1.5 is recommended as a grouting mortar for prepacked concrete.

• Journal of the Korean Ceramic Society
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• v.32 no.8
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• pp.901-908
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• 1995

In aqueous slurry processing of silicon nitride, the interaction of dispersant and binder used as polymeric processing additives on the silicon nitride particle surface was studied to identify the effect of these processing polymeric additives on the ceramic powder processing. The adsoprtion isotherm study of anionic organic molecule as dispersant and nonionic organic molecules as binder of silicon nitricde was studied to investigate the effect of these processing organic additives on the physicochemical properties of silicon nitride particles. As anionic molecule adsorbed onto silicon nitrice surface, the IEP of silicon nitride shifted toward acidic pH and changed the stability of silicon nitride particle. However, the adsorption of binder as nonionic organic molecule onto silicon nitride surface did not changed the IEP but caused the decrease of electrostatic potentials of silicon nitride. These distinctive adsorption behaviors of organic additives on silicon nitride particles can be closely correlated to the stability of silicon nitride particles suspended in aqueous media.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.11a
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• pp.455-456
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• 2007

Optically transparent, highly conductive coating have been major theme of thin film science efforts for some years. In this work, t-MWNT(thin Multi-walled Carbon Nanotubes) are acid treated, then the stable dispersion of t-MWNTs in polar solvent such as alcohols, was achieved by sonication. The transparent conducting films are prepared using the one component solution of t-MWNT/epoxy binder via spray coating on glass substrate. The characterization of acid treated t-MWNTs was performed by Raman spectrometer. The opto-electrical properties of conducting films are analyzed by the binder concentration, and the effect of co-solvent on the compatibility and dispersibility of one component t-MWNT/epoxy binder solutions are discussed.

• Journal of the Korean Applied Science and Technology
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• v.10 no.1
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• pp.49-55
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• 1993

Ground Calcium Carbonate, among paper coating pigments, will influence less dispersant demand, less binder demand, increase coating solids from 58% to 70%, which means high speed coating, less shrinkage during drying, less energy consumption, more uniform coverage of fibers. The quality point of view of Ground Calcium Carbonate, brightness, particle size, Particle size distribution, hardness, impurities content are important. More important factors of Ground Calcium Carbonate which influence the paper coating process are dispersion mechanisms and their effects. The study was made to investigate the effect of Ground Calcium Carbonate dispersion by sodium salt of polyacrylate dispersant composition and dispersion condition. Basic tests such as physical, optical and chemical were perfumed, and dispersion effects were investigated by different conditions. The results showed that the type of dispersant affected the dispersion effects, and the Ground Calcium Carbonate has critical dispersant demand.

• Corrosion Science and Technology
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• v.22 no.6
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• pp.447-456
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• 2023

In this work, we performed a comparative study examining two coatings on Ti Gr.1 for use in fuel cell bipolar plates. The coatings consisted of carbon black as the conductor along with acrylic polymer and Ti Sol-Gel binder as the binder. Ti Sol-Gel that had precipitated as TiO₂ in areas impregnated between carbon black gaps, thereby acting as a binder for carbon black and serving as a polymer coating. Neither of the coatings peeled off during the 90° bend test to check formability. The contact resistance of the TiO₂ coating was found to be lower than that of the polymer binder coating. Moreover, due to coating shrinkage (denser) that occurred during the heat treatment process, the TiO₂ binder coating showed almost the same level of corrosion resistance, as measured by potentiostatic and EIS tests, despite being thinner than the polymer coating. However, both the polymer binder coating and the TiO₂ binder coating had many pores and irregularities internally (around 10 ~ 100 nm) and on the surface (0.1 ~ 2 ㎛). We considered that these pores and irregularities contributed to the lower corrosion resistance.

• Journal of Hydrogen and New Energy
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• v.31 no.3
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• pp.276-283
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• 2020

Alcohol-based solvents including ethanol (EtOH) and tert-butyl alcohol (TBA) are investigated instead of isopropanol (IPA), which is a common solvent for polytetrafluoroethylene (PTFE), as an alternative solvent for preparing the catalyst slurry with PTFE binder. As a result, the performance at 0.2 A/㎠ from the single cells from using catalyst slurries based on EtOH and TBA showed very similar value to that from the slurry using IPA, which implies the EtOH and TBA can be used as a solvent for the catalyst slurry. It is also confirmed by the very close values of the total resistance of the membrane electrode assemblies from the slurries using different solvents. In the energy dispersive spectrometry (EDS) image, the shape of crack and dispersion of PTFE are changed according to the vapor pressure of the solvent.

• Journal of the Korean Ceramic Society
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• v.39 no.5
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• pp.446-451
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• 2002

Zirconia/alumina mixture powder was spray-dried various degree of dispersion, type of dispersants and powder content in the slurry. The quality of the granule was determined by observation of the granule shapes after spray drying and fracture of intergranular boundaries during pressing. Defect-free granules were obtained from the powders that formed weak flocs in the slurry. The granules, spray-dried from the slurry containing 32.5 vol% powder mixture and PVP as binder, were fractured completely during shaping and the sintered specimens showed a density of 99.7% and a flexural strength of 850 MPa.

• Journal of the Korean Ceramic Society
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• v.37 no.7
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• pp.721-725
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• 2000

In this study, the dispersion stability of nano-sized CeO2 particles, synthesized by hydrothermal method in aqueous was evaluated from observing the surface potential behavior of CeO2 particle synthesized by solid state reaction. The isoelectric point(IEP) of nano-sized CeO2 synthesized by hydrothermal synthesis was found to be pH 9 contrary to the isoelectric point of micro-sized CeO2 synthesized by solid state reaction at pH 6.7. IEP was shifted to pH 2.0 as the addition of D-3019 from 0.1 to 1.0 wt%. The surface potential of CeO2 particles synthesized by hydrothermal synthesis was reduced as the addition of B-1001 used as a binder without change of IEP because the absorption of B-1001 polymer on the CeO2 particles shifted the shear plane of CeO2 particles outward away from the surface. This surface potential behavior was well correlated with the dispersion stability of slurry.

• Journal of the Korean Electrochemical Society
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• v.19 no.3
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• pp.107-113
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• 2016

In this study, an anion-exchange ionomer solution was prepared by grinding poly(2,6-dimethyl-1,4-phenylene oxide) (PPO) in liquid nitrogen for solid alkaline fuel cells (SAFCs). Type of quaternized PPO (QPPO) solutions was controlled by grinding time. The ionomer binder solutions were characterized in terms of dispersity, particle size, and electrochemical properties. As a result, ionomer binder solutions using grinded polymer showed higher dispersion and smaller particle size distribution than that using non-grinded polymer. The highest ionic conductivity and IEC of the membrane recast by using BPPO-G120s were $0.025S\;cm^{-1}$ and $1.26meq\;g^{-1}$, respectively.