알루미나 몰드를 이용한 K+-β"-Al2O3 튜브의 Slip Casting과 슬러리의 분산 특성

정우영; 김우성; 임성기; Woo-Young Chung; Woo-Sung Kim; Sung-Ki Lim

Journal of the Korean Industrial and Engineering Chemistry, Vol.14, No.4, 397-402, June, 2003

Export Citation

알루미나 몰드를 이용한 K⁺-β^"-Al₂O₃ 튜브의 Slip Casting과 슬러리의 분산 특성

Slip Casting of K⁺-β^"-Al₂O₃ Tube using Alumina Mold and Dispersion Properties of Slurry

정우영^†, 김우성 , 임성기

건국대학교 신소재공학과, 서울 143-701

Woo-Young Chung^†, Woo-Sung Kim , and Sung-Ki Lim

Department of Materials Chemistry and Engineering, Konkuk University, Seoul 143-701, Korea

E-mail:

초록

Slip casting방법을 이용하여 고체 산화물 전해질로 사용되고 있는 이온 전도체인 K⁺-β^"-Al₂O₃ tube를 성형하였다. K₂O-LiO₂-Al₂O₃ 삼성분계로부터 제조된 순수한 K⁺-β^"-Al₂O₃ 분말과 메탄올 용매를 혼합하여 슬러리를 만들었다. 튜브 성형시 기존의 석고 몰드 사용의 단점인 첨가물의 함유와 몰드에서의 분리의 어려움을 제거하기 위하여 알루미나 몰드를 사용하였다. pH 변화에 따른 슬러리 내 입자들의 최적 분산 조건을 연구하였다. 슬러리는 메탄올을 용매로 하여 고체의 함량을 40 wt%로 하였을 때 최적의 K⁺-β^"-Al₂O₃ tube를 성형할 수 있었다. 이 슬러리에 대하여 HCl을 사용하여 pH와 입자크기 및 제타 전위에 따른 슬러리의 안정성을 연구하였다. K⁺-β^"-Al₂O₃는 메탄올을 용매로 HCl을 첨가 하였을 때 pH 6.2 이하에서 제타 전위가 높고 입자간 반발력으로 인한 안정한 분산을 형성하였다. 분석된 casting 조건들과 함께 알루미나 몰드를 사용하여 K⁺-β^"-Al₂O₃ tube를 성공적으로 성형하였다.

Super ionic conductor, K⁺-β^"-Al₂O₃ tube, which is commonly used as a solid oxide electrolyte, was formed using a slip casting method. Pure K⁺-β^"-Al₂O₃ powder obtained from K₂O-LiO₂-Al₂O₃ ternary system was mixed with methanol as the solvent to prepare the casting slurry. Alumina powder was used for mold material, since the conventional gypsum mold has problems in the tube preparation: penetration of impurity into product and removal of product out of mold. The optimal dispersion condition of the particles according to pH-change in the slurry was analyzed. 40 wt% of solid contents with methanol as the solvent showed the optimal condition for forming K⁺-β^"-Al₂O₃ tube. Additionally, the stability of slip was studied by measuring the pH, particle size and zeta potential of the slurry using HCl as the dispersant. At conditions below pH of 6.2, the slurry showed higher zeta potential causing strong inner-particle repulsion to maintain stable dispersion. With the analyzed casting conditions, the K⁺-β^"-Al₂O₃ tube was formed successfully using the alumina mold.

Keywords:K⁺-β"-Al₂O₃ tube;slip casting;alumina mold;dispersion stability;zeta potential

[References]

Farrington GC, Briant JL, Proceeding of the International Conference on Fast Ion Transport in Solid Electrodes and Electrolytes, 395, Lake Geneva, Wisconsin (1979)
Paik UG, Ceramics(Korea), 8, 218 (1993)
Reed JS, Principles of Ceramic Processing 2nd Ed., John Wiley & Sons, Inc., 507 (1995)
Richerson DW, Modern Ceramic Engineering, Marcel Dekker, Inc. (1982)
Rivier M, Pelton AD, Ceram. Bull., 57, 183 (1978)
Jung YG, Choi SC, Mater. Lett., 37, 312 (1998)
Park JG, Lim DG, Kim IT, Kim YH, J. Korean Ceram. Soc., 28, 1019 (1991)
Fisher ML, Lange FF, J. Am. Ceram. Soc., 83, 1861 (2000)
Tsetsekou A, Agrafiotis C, Milias A, J. Eur. Ceram. Soc., 21, 363 (2001)
Kim BH, Kim MH, Lee S, Paik UG, J. Korean Ceram. Soc., 32, 901 (1995)
Kim WS, Lim SK, J. Korean Ind. Eng. Chem., 12(3), 312 (2001)
vanZyl A, Thackeray MM, Duncan GK, Kingon AI, Mater. Res. Bull., 28, 145 (1993)
Schaefer GW, Dekroon AP, Aldinger F, Solid State Ion., 81(1-2), 43 (1995)
Vold RD, Vold MJ, Colloid and Interface Chemistry, Addison-Wesley Publishing Company (1983)
Hunter RJ, Foundations of Colloid Science, Vol. 1, Clarendon Press, Oxford (1987)
Hunter RJ, Zeta Potential in Colloid Science, Academic Press (1981)
de Kroon AP, Schafer GW, Aldinger F, Chem. Mater., 7, 878 (1995)
Ham CH, Lim SK, Lee CK, Yoo SE, J. Korean Ind. Eng. Chem., 10(7), 1086 (1999)

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[1] Farrington GC, Briant JL, Proceeding of the International Conference on Fast Ion Transport in Solid Electrodes and Electrolytes, 395, Lake Geneva, Wisconsin (1979)

[2] Paik UG, Ceramics(Korea), 8, 218 (1993)

[3] Reed JS, Principles of Ceramic Processing 2nd Ed., John Wiley & Sons, Inc., 507 (1995)

[4] Richerson DW, Modern Ceramic Engineering, Marcel Dekker, Inc. (1982)

[5] Rivier M, Pelton AD, Ceram. Bull., 57, 183 (1978)

[6] Jung YG, Choi SC, Mater. Lett., 37, 312 (1998)

[7] Park JG, Lim DG, Kim IT, Kim YH, J. Korean Ceram. Soc., 28, 1019 (1991)

[8] Fisher ML, Lange FF, J. Am. Ceram. Soc., 83, 1861 (2000)

[9] Tsetsekou A, Agrafiotis C, Milias A, J. Eur. Ceram. Soc., 21, 363 (2001)

[10] Kim BH, Kim MH, Lee S, Paik UG, J. Korean Ceram. Soc., 32, 901 (1995)

[11] Kim WS, Lim SK, J. Korean Ind. Eng. Chem., 12(3), 312 (2001)

[12] vanZyl A, Thackeray MM, Duncan GK, Kingon AI, Mater. Res. Bull., 28, 145 (1993)

[13] Schaefer GW, Dekroon AP, Aldinger F, Solid State Ion., 81(1-2), 43 (1995)

[14] Vold RD, Vold MJ, Colloid and Interface Chemistry, Addison-Wesley Publishing Company (1983)

[15] Hunter RJ, Foundations of Colloid Science, Vol. 1, Clarendon Press, Oxford (1987)

[16] Hunter RJ, Zeta Potential in Colloid Science, Academic Press (1981)

[17] de Kroon AP, Schafer GW, Aldinger F, Chem. Mater., 7, 878 (1995)

[18] Ham CH, Lim SK, Lee CK, Yoo SE, J. Korean Ind. Eng. Chem., 10(7), 1086 (1999)