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Conflict of Interest: In relation to this article, we declare that there is no conflict of interest.

Publication history: Received February 1, 2008
Accepted April 3, 2008

This is an Open-Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/bync/3.0) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

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졸 합성시 숙성이 γ-Al2O3 입자의 표면특성에 미치는 영향

Effects of Surface Characterization of γ-Al2O3 Particles by Aging in the Sol Preparation

유승준 곽동희 김형기¹ 황운연¹ 박형상¹ 윤호성² 장희동^2†

Seung-Joon Yoo Dong-Heui Kwak Hyung-Ki Kim¹ Un-Yeon Hwang¹ Hyung-Sang Park¹ Ho-Sung Yoon² Hee Dong Jang^2†

서남대학교 환경화학공학부, 590-711 전북 남원시 광치동 720 ¹서강대학교 화공생명공학과, 121-742 서울시 마포구 신수동 1번지 ²한국지질자원연구원 자원활용소재연구부, 305-350 대전광역시 유성구 과학로 92

Faculty of Environmental and Chemical Engineering, Seonam University, 720 Gwangchi-dong, Namwon-city, Chonbuk-province, Korea ¹Division of Chemical and Biomolecular Engineering, Sogang University, C.P.O. Box 1142, Seoul 100-611, Korea ²Division of Minerals Utilization and Materials, Korea Institute of Geology Mining & Materials, Gwahang-no 92, Yuseong-gu, Daejeon 305-350, Korea

hdjang@kigam.re.kr

Korean Chemical Engineering Research, June 2008, 46(3), 545-549(5), NONE Epub 7 July 2008

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Abstract

γ-AlO(OH) 졸 입자 뿐만 아니라 소성처리된 γ-Al2O3 입자의 표면특성을 γ-AlO(OH) 졸 제조시 숙성단계에 의하여 조절하였다. 연구결과, γ-AlO(OH) 졸 입자의 등전점은 숙성 증가에 따라 pH 9.25에서 pH 8.70까지 감소하였으며 γ-Al2O3 입자의 경우는 pH 9.90에서 pH 8.86까지 감소하였다. 숙성에 따른 γ-Al2O3 입자의 산, 염기 특성을 고찰한 결과, γ-Al2O3 입자의 산량은 숙성시간의 증가에 따라 0.1367 mmol/g에서 0.0783 mmol/g까지 감소하였으며, Hammett 산성도함수 Ho는 4.8 이상의 산세기를 보였다. 한편 γ-Al2O3 입자의 염기량은 숙성시간의 증가에 따라 0.4399 mmol/g에서 0.3074 mmol/g 까지 감소하였다. 따라서 졸-겔법에 의한 γ-Al2O3 제조시 숙성공정이 산, 염기점의 양을 포함한 표면특성을 조절할 수 있는 중요 공정변수임을 제시하였다.

The surface characteristics of calcined γ-Al2O3 particles as well as γ-AlO(OH) sol particles were controlled by aging in the boehmite sol preparation. As a result of the study, the IEPs of γ-AlO(OH) particles were decreased from pH 9.25 to pH 8.70 and those of the calcined γ-Al2O3 particles were decreased from pH 9.90 to pH 8.86 by the increase of the aging times. As a result of the acidic and basic characterization of the calcined γ-Al2O3 particles by the aging, the amount of acid sites was decreased from 0.1367 mmol/g to 0.0783 mmol/g by the increase of the aging times and Hammett acidity, Ho was showed the acidic strength of 4.8 or above. On the other hand, the amount of basic sites was decreased from 0.4399 mmol/g to 0.3074 mmol/g by the increase of the aging times. Based on these results, we proposed the fact that the aging step in the sol-gel process was an important step to control the surface characterization of γ-Al2O3 particles including acidity and basicity.

Keywords

γ-AlO(OH) Aging γ-Al2O3 Surface Characterization Acidity

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