• Title/Summary/Keyword: Thixotropic

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Thixotropic Properties of Polyacrylamide Hydrogels with Various Synthetic Conditions (합성조건에 따른 Polyacrylamide 수화 겔의 흐름변성 성질)

  • Kim, Nam-Jeong
    • Journal of the Korean Chemical Society
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    • v.50 no.6
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    • pp.447-453
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    • 2006
  • of synthetic conditions and water content on rheological properties of polyacrylamide hydrogels were studied. The non-Newtonian flow curves of polyacrylamide hydrogels were obtained by using a cone-plate rheometer. The rheological parameters were obtained by applying non-Newtonian equation to the flow curves for polyacrylamide hydrogels. The polyacrylamide hydrogels are shear thinning under increasing shear rate modes which result in thixotropic behavior. These flow properties are controlled by the characteristics of flow units and the interaction among the flow segments.

Collodial Properties and Acid Consuming Capacity of Hydrous Aluminum Oxide Suspension (제산제 알루미나수화물의 콜로이드성과 제산능)

  • 이계주;이기명
    • YAKHAK HOEJI
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    • v.35 no.4
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    • pp.277-282
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    • 1991
  • Rheological, colloidal and micromeritical properties were followed to investigate aging mechanisms of hydrous aluminum oxide suspension using Zeta-meter systems, BET adsorption apparatus, Master sizer and electronmicroscope. The results indicate that hydrous aluminum oxide suspension revealed plastic flow with thixotropy. The viscosity, thixotropy and yield value were increased with increasing concentration. During aging process, the viscosity and thixotropic index were increased by an addition of glycerin, however, sorbitol stabilized aging process of the suspension being accompanied with growth of particle size and reduction in specific surface area, pore area and pore volume, and consistency. Diminution of adsorptive power of the particles was also protected by addition of sorbitol to hydrous aluminum oxide suspension. From these results, one of aging mechanism of hydrous aluminum oxide suspension assumed growth and/or crystallization of colloidal particles in aqueous suspension.

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Non-Newtonian Rheological Properties of Poly(vinyl alcohol) hydrogel (Poly(vinyl alcohol) hydrogel의 비 뉴톤 유변학적인 성질)

  • Kim, Nam-Jeong
    • Elastomers and Composites
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    • v.44 no.3
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    • pp.323-328
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    • 2009
  • The rheological properties of complex materials such as polymer melts show complicated non-Newtonian flow phenomena when they are subjected to shear flow. These flow properties are controlled by the characteristics of flow units and the interactions among the flow segments. The non-Newtonian flow curves of poly(vinyl alcohol) hydrogel were obtained in various concentrations and temperatures by using a cone-plate rheometer. By applying non-Newtonian flow equation to the flow curves for PVA hydrogel samples, the rheological parameters were obtained. The PVA hydrogel samples are shear thinning under increasing shear rate modes which result in thixotropic behavior.

Development of Transparent Dielectric Paste for PDP

  • Kim, Hyung-Jong;Kyoung Joo;Auh, Ken-Ho
    • Proceedings of the Korea Association of Crystal Growth Conference
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    • 1998.09a
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    • pp.79-83
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    • 1998
  • Plasma display panel is a potential candidate for HDTV, due to the fact hat the expansion of screen size is much easier using thick film technology. In this study, transparent dielectric materials using lead borosilicate glasses is developed, which satisfy the requirements of dielectrics for PDP. Paste is made of this glass composition. The paste has thixotropic behavior suitable for screen printing. The paste shows more thixotropic behavior as the particle size decrease. After firing, cross sectional area was analyzed by SEM. The void of fired thick film was removed using bimodal particle system. The dielectric showed good adhesion characteristics.

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Segregation resistance of high fluidity concrete depending on addition method of thixotropy-inducing materials (고유동 콘크리트의 고요변성 부여 물질 혼합방법에 따른 재료분리 방지 여부)

  • Kim, Young-Ki;Lee, Yu-Jeong;Heo, Jun-Ho;Han, Dongyeop
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2022.11a
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    • pp.113-114
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    • 2022
  • The aim of the research is to evaluate the segregation resistivity of the mixture conditions by changing the PVA and borax solutions for thixotropic property on concrete mixture. Since the water addition caused by producing solutions of PVA and borax induces segregation of the concrete mixture, the unit water was reduced by replacing the water amount for PVA and borax solution. By replacing the water from PVA and borax solutions, the segregation was prevented with prefixed concrete mix design and thixotropic properties were also occurred.

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Thixotropic Properties of Gelatinized Rice Starch Solutions (쌀 전분 호화액의 틱소트로픽 성질)

  • Kim, Ju-Bong;Kim, Young-Suk;Lee, Shin-Young;Pyun, Yu-Ryang
    • Korean Journal of Food Science and Technology
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    • v.16 no.4
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    • pp.451-456
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    • 1984
  • Rheological properties of gelatinized rice starch solutions were investigated with Brookfield rotational viscometer. The 8% starch solution showed thixotropic behavior with yield stress. The alkali gelatinized starch was more thixotropic than the thermal gelatinized one. The time dependent characteristics of starch solutions followed Tiu's model. The value of rate constant $(a_1)$ in Tiu's model increased linearly with shear rate, and was exponentially dependent on concentration and temperature. Temperature dependency of rate constant and apparent viscosity followed Arrhenius type equation and the activation energy were about 14.3 and 6.8 Kcal/g mole, respectively. The $a_1-value$ was found to be useful to evaluate changes in structaral decay on the shearing time of gelatinized rice starch solutions.

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