Control of 伪-Calcium Sulfate Hemihydrate Morphology Using Reverse Microemulsions

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• 作者：Bao Kong ; Baohong Guan ; Matthew Z. Yates ; Zhongbiao Wu
• 刊名：Langmuir
• 出版年：2012
• 出版时间：October 9, 2012
• 年：2012
• 卷：28
• 期：40
• 页码：14137-14142
• 全文大小：385K
• 年卷期：v.28,no.40(October 9, 2012)
• ISSN：1520-5827

文摘

Alpha calcium sulfate hemihydrate (伪-HH) is an important class of cementitious material and exhibits considerable morphology-dependent properties. In the reverse microemulsions of water/n-hexanol/cetyltrimethylammonium bromide (CTAB)/sodium dodecyl sulfonate (SDS), the morphology and aspect ratio of 伪-HH are successfully controlled by adjusting the mass ratio of CTAB/H₂O and the concentration of SDS. As the ratio of CTAB/H₂O is increased from 1.3 to 4.5, the crystal length decreases from 120 to 150 渭m to 0.5鈥?.2 渭m with the corresponding aspect ratio reduced sharply from 180 to 250 to 2鈥?. With increasing SDS concentration, the crystal morphology gradually changes from submicrometer-sized long column to rod, hexagonal plate, and even nanogranule. The preferential adsorption of CTAB on the side facets and SDS on the top facets contributes to the morphology control. This work presents a simple, versatile, highly efficient approach to controlling the morphology of 伪-HH on a large scale and will offer more opportunities for 伪-HH multiple applications.