• Title/Summary/Keyword: Aqueous binder

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Competitive Adsorption of Dispersant and Binder on Alumina and Its Effect on the Electrokinetic Behavior in Aqueous Media

  • Paik, Un-Gyu
    • The Korean Journal of Ceramics
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    • v.4 no.4
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    • pp.292-296
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    • 1998
  • In wet powder processing of alumina, a number of organic molecules such as dispersant and binder are used to produce the flow behavior and properties requisite for shape forming. In this study, interparticle forces of alumina particles suspended in aqueous media were controlled by suspension pH, poly (methacrylic acid) (PMAA, used as dispersant) and poly (vinyl alcohol) (PVA, used as binder). The combined adsorption isotherms of the dispersant and binder additives on alumina were determined by total organic carbon analyzer, while the adsorption of dispersant was differentiated from binder in the mixed additive system by ultraviolet spectroscopy. The electrokinetic behavior of alumina suspensions were then correlated with the adsorption characteristics of dispersant and binder onto alumina particles. It was found that the isoelectric ($pH_{iep}$) of alumina shifted from pH 8.9${\pm}$0.1 to acidic pH as PMAA concentration increased, while PVA adsorption did not affect the $pH_{iep}$ but caused a decrease in the near surface potential.

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The Effects of Suspension Composition on Defects in Aqueous Tape Casting of Alumina Ceramics

  • Shin, Hyo-Soon
    • Journal of the Korean Ceramic Society
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    • v.41 no.9
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    • pp.647-652
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    • 2004
  • In aqueous tape casting of alumina slurry systems, the relationships between the suspension compositions and the defects of the dried tapes were discussed. The suspensions compositions were controlled with the ratios of the solids, water and organics binder contents. The effects of the thickness of dried tape and kinds of binder system were also examined. In the defect free region, the apparent viscosity showed nearly same value due to the count balancing effect of solid and organic binder content on the apparent viscosity. When water content was constant, increasing solid led to decrease of organic binder content. The defect free region was narrowed with increasing of casting thickness. When linear type acrylic emulsion binders system (D1000 and D 1035) were used, defect free zone formed the belt type in the triangle of solid, water and organic binder content according to the line of constant water contents. However the defect free region was not found in the cross-link type emulsion binder system (D 1050).

Formation of Barrier ribs for PDP by Water Jet Etching of Green Tape

  • Cho, Yu-Jeong;Kim, Yong-Seog
    • 한국정보디스플레이학회:학술대회논문집
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    • 2003.07a
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    • pp.784-787
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    • 2003
  • In this study, water jet etching of aqueous green tape was attempted for processing barrier rib of plasma display panel. This process combines 1) chemical etching between water and aqueous based binder in the tape and 2) mechanical erosion by water jet. Effects of etching parameters such as pressure, temperature and aqueous binder content on the morphology of barrier ribs formed were investigated. The results demonstrated a possibility of processing barrier ribs by water jet etching.

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Influence of the Binder Types on the Electrochemical Characteristics of Si-C Composites Electrode in LIBs (Si-C 복합체 전극의 바인더 종류에 따른 전기화학적 특성 변화)

  • Jung, Sung-Hun;Ji, Mijung;Park, Geunyeong;Hong, Jongill;Choi, Byung-Hyun
    • Journal of the Korean Ceramic Society
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    • v.50 no.2
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    • pp.168-172
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    • 2013
  • This work presents the effects of binders on the electrochemical performance of Si-C composites as the anode of lithium ion batteries. PAI (polyamide-imide) was used as an organic binder, and PAN (polyacrylonitrile), PAA (polyacrylic acid) and CMC + SBR (carboxymethyl cellulose + styrene-butadiene rubber) were used as aqueous binders. As a result, stabilization time for the cell with a Si-C composite anode synthesized using aqueous binders became shorter than an organic binder. Particularly in the case of the cell using PAA binder, better performance was observed in terms of adhesion strength, initial efficiency, the volume expansion ratio, Coulombic efficiency, and capacity retention.

Polymeric Interactions of Dispersant and Binder in Aqueous Silicon Nitride Suspensions (질화규소 현탁액에서 분산제와 결합제의 상호작용연구)

  • Kim, Bong-Ho;Kim, Myong-Ho;Lee, Soo;Paik, Un-Gyu
    • 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.

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Effects of Suspension Composition on Defects in Aqueous Tape Casting of Alumina Ceramics: A Rheological Study

  • Shin, Hyo-Soon
    • Journal of the Korean Ceramic Society
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    • v.42 no.1
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    • pp.1-6
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    • 2005
  • In aqueous alumina tape casting, the effects of altering the composition of the suspensions, the binders and the casting thickness were studied. The rheological behavior of the suspensions and the defects of the dried tapes were examined and the relationships between them are discussed. The changes in the defect regions reported in the previous paper were related with the rheological properties with variations of the binder, the composition and the casting thickness. The shear thinning factor increased with the organic content and the solid content (the decrease of water content). The apparent viscosity increased with the shear thinning factor. The relation between the shear thinning factor and the log apparent viscosity was similar for all binder types. In the relation between the defect free region and the rheological properties, the defect free region became narrower with increasing casting thickness. The defect free region is independent of binder type. Therefore, the thicker tape is more difficult to produce in aqueous alumina tape casting. Knowledge of the rheological properties of the suspensions could help Predict the defect type and the possibility of defect free dried tapes.

Dispersant-Binder Interactions in Aqueous Silicon Nitride Suspensions

  • Paik, Ungyu
    • Proceedings of the Korea Association of Crystal Growth Conference
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    • 1996.06b
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    • pp.129-153
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    • 1996
  • In aqueous slurry processing of silicon nitride, the interaction of dispersant and binder on the surface of particles was studied to identify the effect of these additives on ceramic powder processing. Polymethacrylic acid (PMAA) and polyvinyl alcohol (PVA) were used as dispersant and binder, respectively. the adsorption isotherms of PMAA and PVA for the silicon nitride suspension were determined, while the adsorption of PMAA was differentiated in the mixed additive system by ultraviolet spectroscopy. These experiments were done in order to investigate the effect of these organic additives on the physicochemical properties of silicon nitride suspensions. The electrokinetic behavior of silicon nitride was subsequently measured by electrokinetic sonic amplitude (ESA). As PMAA adsorbed onto silicon nitride, the isoelectric point (pHicp) shifted from pH=6.7 to acidic pH, depending on the surface coverage of PMAA. However, adsorption of PVA did not change the pHicp of suspensions, but did decrease the surface potential of silicon nitride moderately. The rheological behavior of silicon nitride suspensions was measured to assess the stability of particles in aqueous media, and was correlated with the electrokinetic behavior and adsorption isotherm data for silicon nitride.

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The Performance Evaluation of Red Clay Binder with Polymer Aqueous Solution (고분자수용액을 첨가한 황토 결합재의 성능 평가)

  • Kim, Jin-Sung;Kim, Ho-Jin;Choi, Hyeong-Gil
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2020.11a
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    • pp.141-142
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    • 2020
  • In this study, the performance evaluation was performed by adding a polymer aqueous solution as a new additive of the red clay binder for use in the rammed earth construction method. The evaluation items were compressive strength and microstructure analysis. As a result of the experiment, the performance of the red clay binder was improved by efficiently bonding the silica particles by the polymerized polymer.

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Synthesis and Binder Application of Aqueous Polyurethanes to Nonwoven Fabrics (수성 폴리우레탄의 합성과 부직포 결합제로의 응용)

  • 김병규;김상준
    • Textile Coloration and Finishing
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    • v.5 no.3
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    • pp.188-193
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    • 1993
  • Aqueous polyurethanes(APU) were prepared from polypropylene glycol(PPG), dimethylol propionic acid(DMPA), and isophoron diisocyanate(IPDI) following a prepolymer mixing process. APUs were applied as binder for nonwoven fabrics processing. APU treated nonwoven fabrics generally showed better tear and tensile strength as compared with the untreated ones. In addition, depending on the soft segment length and crosslinking density of the PU, tear strength of APU treated fabrics was favorably compared with solvent type treated one. Similar results were obtained with microfiber nonwoven fabrics, however, the effect was less significant.

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