Carmody Onuma, Frost Ray L, Kristóf János, Kokot Serge, Kloprogge J Theo, Makó Eva
Inorganic Materials Research Program, Queensland University of Technology, 2 George Street, GPO Box 2434, Brisbane Queensland 4001, Australia.
Appl Spectrosc. 2006 Dec;60(12):1414-22. doi: 10.1366/000370206779321472.
Studies of kaolinite surfaces are of industrial importance. One useful method for studying the changes in kaolinite surface properties is to apply chemometric analyses to the kaolinite surface infrared spectra. A comparison is made between the mechanochemical activation of Kiralyhegy kaolinites with significant amounts of natural quartz and the mechanochemical activation of Zettlitz kaolinite with added quartz. Diffuse reflectance infrared Fourier transform (DRIFT) spectra were analyzed using principal component analysis (PCA) and multi-criteria decision making (MCDM) methods, the preference ranking organization method for enrichment evaluations (PROMETHEE) and geometrical analysis for interactive assistance (GAIA). The clear discrimination of the Kiralyhegy spectral objects on the two PC scores plots (400-800 and 800-2030 cm(-1)) indicated the dominance of quartz. Importantly, no ordering of any spectral objects appeared to be related to grinding time in the PC plots of these spectral regions. Thus, neither the kaolinite nor the quartz are systematically responsive to grinding time according to the spectral criteria investigated. The third spectral region (2600-3800 cm(-1), OH vibrations), showed apparent systematic ordering of the Kiralyhegy and, to a lesser extent, Zettlitz spectral objects with grinding time. This was attributed to the effect of the natural quartz on the delamination of kaolinite and the accompanying phenomena (i.e., formation of kaolinite spheres and water). The mechanochemical activation of kaolinite and quartz, through dry grinding, results in changes to the surface structure. Different grinding times were adopted to study the rate of destruction of the kaolinite and quartz structures. This relationship (i.e., grinding time) was classified using PROMETHEE and GAIA methodology.
高岭土表面的研究具有工业重要性。研究高岭土表面性质变化的一种有用方法是对高岭土表面红外光谱进行化学计量分析。对含有大量天然石英的基拉伊赫吉高岭土的机械化学活化与添加石英的采特利茨高岭土的机械化学活化进行了比较。使用主成分分析（PCA）和多准则决策（MCDM）方法、富集评估偏好排序组织方法（PROMETHEE）和交互式辅助几何分析（GAIA）对漫反射红外傅里叶变换（DRIFT）光谱进行了分析。在两个主成分得分图（400 - 800和800 - 2030 cm⁻¹）上对基拉伊赫吉光谱对象的清晰区分表明了石英的主导地位。重要的是，在这些光谱区域的主成分图中，没有任何光谱对象的排序似乎与研磨时间有关。因此，根据所研究的光谱标准，高岭土和石英都没有系统地对研磨时间作出响应。第三个光谱区域（2600 - 3800 cm⁻¹，OH振动）显示，基拉伊赫吉光谱对象以及在较小程度上采特利茨光谱对象随着研磨时间有明显的系统排序。这归因于天然石英对高岭土分层及伴随现象（即高岭土球和水的形成）的影响。通过干磨对高岭土和石英进行机械化学活化会导致表面结构发生变化。采用不同的研磨时间来研究高岭土和石英结构的破坏速率。这种关系（即研磨时间）使用PROMETHEE和GAIA方法进行了分类。
