| 镁铝水滑石及其改性产物的表面性质的研究 |
| Surface Properties of Mg/Al-Hydrotalcite-like Compound and Its Modified Products |
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| 摘要: 采用共沉淀法制备了nMg/nAl比为2∶1镁铝水滑石(Mg/Al-HTlc)，经500 ℃焙烧后得到镁铝复合氧化物(C-HT)，并用十二烷基苯磺酸钠(SDBS)对复合氧化物进行了改性(M-HT)。通过反相气相色谱法(IGC)对Mg/Al-HTlc、C-HT和M-HT的表面性质进行了研究，定量计算了表面吸附自由能、表面能色散组分以及表面自由能特征分量。结果表明，三者的表面自由能以及色散能的大小顺序为：C-HT＞Mg/Al-HTlc＞M-HT；温度对非极性分子与Mg/Al-HTlc间的色散能影响不大，而非极性分子与C-HT和M-HT间的色散能均随温度的升高而降低；极性分子与固定相的吸附作用包括色散能和吸附自由能特征分量两部分，表面改性会使Mg/Al-HTlc的自由能特征分量降低。 |
| 关键词: 水滑石 反相气相色谱法 吸附热力学 |
| 基金项目: |
| Abstract: Magnesium-aluminum hydrotalcite-like compound(Mg/Al-HTlc)with Mg/Al molar ratio of 2 was synthesized by coprecipitation. The calcined hydrotalcite(C-HT) was obtained by calcination at 500 ℃ and then the C-HT was modified with dodecylbenzene sulfonic acid sodium salt(SDBS) to yield the modification product(M-HT). Inverse gas chromatography(IGC)was used to investigate the surface properties of the Mg/Al-HTlc, C-HT and M-HT. The surface free energy(ΔG0), the dispersive component of the surface free energy(γSd) and the specific component(ΔGsp) were estimated. The results show that the ΔG0 and γSd of the three materials have the following order: C-HT＞Mg/Al-HTlc＞M-HT. The values of γSd decrease with increasing measuring temperature for the C-HT and M-HT, but the values of γSd between non-polar probes and Mg/Al-HTlc are not affected by measuring temperature. In addition, the value of ΔG0 between the polar probes and the samples includes the dispersive component and the specific component, and the modification lowers the ΔGsp of Mg/Al-HTlc. |
| Keywords: hydrotalcite inverse gas chromatography adsorption thermodynamics |
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| 摘要点击次数: 1008 |
| 全文下载次数: 1969 |
| 张 峰,曹晓霞,倪哲明,邢方方.镁铝水滑石及其改性产物的表面性质的研究[J].无机化学学报,2009,25(2):271-277. |
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