Blachier C, Michot L, Bihannic I, Barrès O, Jacquet A, Mosquet M
Laboratoire Environnement et Minéralurgie, Pôle de l'eau, UMR 7569, Nancy Université, CNRS15 Avenue du Charmois, 54 500 Vandoeuvre lès Nancy, France.
J Colloid Interface Sci. 2009 Aug 15;336(2):599-606. doi: 10.1016/j.jcis.2009.04.021. Epub 2009 Apr 14.
This work aims at a better understanding of the interaction between a polycationic quaternary amine polymer (F25) and three different clay minerals: montmorillonite, illite, and kaolinite. For this, adsorption isotherms of F25 on the clay surfaces were measured together with the evolution of the CEC along the isotherm, which revealed that cation exchange plays an important role in the adsorption process. These first results were confirmed by XRD measurements on dried powders that are evidence in the case of montmorillonite of the presence of polymer in the interlayer spaces. In addition, the evolution of the short range structure of clay minerals suspensions on polymer adsorption was followed by WAXS experiments. Polymer intercalation was observed while the structure of the resulting stacking appeared to change slightly along the polymer adsorption isotherm. Diffuse reflectance infrared measurements revealed that significant conformational changes occur on polymer adsorption onto montmorillonite surfaces. Furthermore, adsorption above the CEC is observed which involves a charge reversal of clay mineral surfaces, the zero charge being reached for an adsorbed amount corresponding to the CEC. Finally, flocculation was discussed compared to adsorption amounts and zeta potential measurements, confirming that optimum flocculation concentration is reached for noncharged particles.
这项工作旨在更好地理解聚阳离子季铵聚合物（F25）与三种不同粘土矿物（蒙脱石、伊利石和高岭土）之间的相互作用。为此，测量了F25在粘土表面的吸附等温线以及沿等温线阳离子交换容量（CEC）的变化，结果表明阳离子交换在吸附过程中起重要作用。这些初步结果通过对干粉的X射线衍射（XRD）测量得到证实，在蒙脱石的情况下，XRD测量证明了层间空间中存在聚合物。此外，通过广角X射线散射（WAXS）实验跟踪了聚合物吸附时粘土矿物悬浮液短程结构的变化。观察到聚合物插层现象，同时所得堆积结构似乎沿聚合物吸附等温线略有变化。漫反射红外测量表明，聚合物吸附到蒙脱石表面时会发生显著的构象变化。此外，观察到在阳离子交换容量以上的吸附，这涉及粘土矿物表面的电荷反转，当吸附量达到阳离子交换容量时达到零电荷。最后，结合吸附量和zeta电位测量对絮凝进行了讨论，证实了对于不带电颗粒达到了最佳絮凝浓度。
