Yao Ming, Liu Zi-yang, Wang Kai-xiong, Zhu Miao-qin, Sun Hong-jie
College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310029, China.
Guang Pu Xue Yu Guang Pu Fen Xi. 2005 Jun;25(6):870-3.
FTIR was employed in the structure analysis of the saponites with an ideal chermical formula [Si6.5Al1.5]IV [Mg6]VI O20(OH)4 the starting gel synthesized by microwave-hydrothermally under different pressures (1 x 10(5), 5 x 10(5), 1.5 x 10(6), 2.5 x 10(6) and .5 x 10(6) Pa). It was found that low frequency absorption region in infrared spectrum was sensitive to the crystallization of the product and the amorphous materials produced in synthesis of saponite under the radiation of microwave. The absorptions belong to amorphous materials were decreased with increasing pressure. Saponite synthesized at 3.5 x 10(6) Pa showed no amorphous absorptions (1240, 90-602 cm(-1)), indicating the purity and quality of the synthetic mineral. It was worthy to note that Si(AI)-O stretching vibration infrared absorption could be regarded as an index in assessing the quality of synthetic 2:1 trioctahedral smectite sample with the same chemical compositions. With the increasing pressure, this strong vibration shifted to low frequency (1022, 1020, 1016, 1016, 1005 cm(-1)) in the medium frequency of the whole infrared spectrum. Since the sensitivity, easiness and simplicity, this infrared index would be meaningful in practical saponite-related minerals analysis. In addition, powder X-ray diffraction and scanning electronic microscopy were employed in charactering the saponite synthesized by microwave-hydrothermal method in this work.
傅里叶变换红外光谱（FTIR）被用于对理想化学式为[Si6.5Al1.5]IV [Mg6]VI O20(OH)4的皂石进行结构分析，该皂石由起始凝胶在不同压力（1×10⁵、5×10⁵、1.5×10⁶、2.5×10⁶和3.5×10⁶帕）下通过微波水热法合成。研究发现，红外光谱中的低频吸收区域对产物的结晶以及微波辐射下皂石合成过程中产生的无定形物质敏感。随着压力增加，属于无定形物质的吸收峰降低。在3.5×10⁶帕下合成的皂石没有无定形吸收峰（1240、90 - 602厘米⁻¹），表明合成矿物的纯度和质量。值得注意的是，Si(Al)-O伸缩振动红外吸收可被视为评估具有相同化学成分的合成2:1三八面体蒙脱石样品质量的一个指标。随着压力增加，这种强振动在整个红外光谱的中频区域向低频移动（1022、1020、1016、1016、1005厘米⁻¹）。由于其灵敏度、简便性，该红外指标在实际的皂石相关矿物分析中具有重要意义。此外，在本工作中还采用粉末X射线衍射和扫描电子显微镜对微波水热法合成的皂石进行表征。
