水熱法合成三八面體滑鎂皂石之研究

Study of hydrothermal synthesis of trioctahedral stevensite

李雅茹(Ya-Ru Li)

指導教授 ： 余炳盛

國立臺北科技大學/工程學院/資源工程研究所/碩士(2008年)

https://doi.org/10.6841/NTUT.2008.00385

摘要

膨潤石為最常見的層狀矽酸鹽類礦物之一，由於其層間表面帶負電，因而具有一些特殊的性質，故在工業上也廣泛的使用，例如：石油鑽井、鑄造、冶金 、建材、化工、食品、紡織等各行業均有應用。
本研究以水熱法合成三八面體膨潤石，根據其結構化學式Na2x(Al2(1-x)Mg2x□)Si4O10(OH)2探討不同配比、pH值、起始原料及反應時間與產物的關係。
研究結果顯示在鹼性溶液，鎂含量Mg0.8~0.9時可形成三八面體滑鎂皂石相； pH值為5、8時，鎂含量為Mg0.7~0.9其合成滑鎂皂石之效果較佳。因其b軸及c軸方向晶體為短程有序的關係，使用二氧化矽當作矽源所合成出來的效果比使用矽酸鈉的效果更佳，由於矽酸鈉須溶解於水中，經水熱反應後晶體必須經過成核階段後才開始成長，晶體生長在c軸方向堆疊較慢，故滑鎂皂石之晶體結構在c軸方向的堆疊不明顯，如增加反應時間有助於滑鎂皂石在c軸方向的堆疊排列。根據SEM-EDS和ICP-AES化學元素分析結果得知三八面體滑鎂皂石中以SiO2和MgO含量為主，因而得知八面體層中陽離子的位置以鎂離子為主。

關鍵字

水熱法 ； 三八面體鎂膨潤石 ； 滑鎂皂石

並列摘要

Smectites are one of the most common groups of phyllosilicates. Due to Smectites negative charge on the surface of interlayers, which cause special properties, the substance is widely used in the following industries: oil drilling, casting , metallurgy , building materials , the chemical industry, food science, and textile engineering .
In this study, trioctahedral smectite was synthesized, using a hydrothermal method. Different Mg/Al ratio, starting materials, pH value and reaction times were discussed, based on the structural formula of smectite Na2x(Al2(1-x)Mg2x□)Si4O10(OH)2.
The results indicated that the trioctahedral stevensite was synthesized with Mg/Al ratio 0.8-0.9 in alkaline solution. Better crystallization was obtained at Mg/Al ratio 0.7-0.9 and pH value 5 and 8. Furthermore, crystal is a short- range order along axis b and axis c, thus silicon dioxide is better than sodium silicate as a silicon source. Sodium silicate must dissolve in water. Moreover, crystal growth under hydrothermal conditions, takes place after nucleation, resulting in slower stacking rates on axis c. Therefore, stacking on axis c is unobvious in the structure of stevensite. It can be improved by extending the reaction time. SEM-EDS and ICP-AES elements analysis have shown that silicon dioxide and magnesium oxide are the major components of trioctahedral stevensite. We know that magnesium ion mainly occupies the octahedral layer cationic site.

並列關鍵字

Hydrothermal synthesis ； trioctahedral magnesium smectite ； stevensite

參考文獻

[2] O.Yu. Golubeva, E.N. Korytkova, V.V. Gusarov, “Hydrothermal Synthesis of Magnesium Silicate Montmorillonite for Ploymer-Clay Nanocomposites”, Russian Journal of Applied Chemistry, vol.78,no.1, 2005, pp.28~35

[3] O.Yu. Golubeva, and V.V. Gusarov, “Layered Silicates with a Montmorillonite Structure: Preparation and Prospects for the Use in Polymer Nanocomposites ”, glass Physics and Chemistry, vol.33,no.3, 2007, pp.237~241

[4] S.W. Bailey, “Summaryo f recommendationso f AIPEA nomenclaturec ommitteeo n clay minerals” American Mineralogist, vol. 65,1980, pp. l~7

[5] S. Guggenheim and R.T. Martin, “Definition of clay and clay mineral: joint report of the AIPEA and CMS Nomenclature Committees ”,Clay minerals,vol.30, 1995, pp257~259

[7] M. Reinholdt, J. Miehe-Brendle, L. Delmotte, R.Le Dred and M.-H. Tuilier, “Fluorine Route Synthesis of montmorillonites Containing Mg or Zn and Characterization by XRD, Thermal Analysis, MAS NMR and EXAFS Spectroscopy”, European Journal of Inorganic Chemistry, vol.11, 2001, pp. 2831-2841