Coagulation of Na-Montmorillonite by Inorganic Cations at Neutral pH. A Combined Transmission X-ray Microscopy, Small Angle and Wide Angle X-ray Scattering Study

被引：60

作者：

Michot, Laurent J. ^{[1
]}

Bihannic, Isabelle ^{[1
]}

Thomas, Fabien ^{[1
]}

Lartiges, Bruno S. ^{[1
]}

Waldvogel, Yves ^{[1
]}

Caillet, Celine ^{[1
]}

Thieme, Juergen ^{[2
]}

Funari, Sergio S. ^{[3
]}

Levitz, Pierre ^{[4
]}

机构：

[1] Univ Lorraine, CNRS, UMR 7360, Lab Interdisciplinaire Environm Cotinentaux, F-54501 Vandoeuvre Les Nancy, France

[2] Univ Gottingen, Inst Rontgenphys, D-37073 Gottingen, Germany

[3] HASYLAB, D-22603 Hamburg, Germany

[4] UPMC, ESPCI, CNRS, Physicochim Electrolytes Colloides & Sci Analyt U, F-75252 Paris 5, France

来源：

LANGMUIR | 2013年 / 29卷 / 10期

关键词：

AQUEOUS SUSPENSIONS; ISOTROPIC/NEMATIC TRANSITIONS; IONIC EXCHANGE; CLAY; STABILITY; FLOCCULATION; PARTICLES; NANOPARTICLES; AGGREGATION;

D O I：

10.1021/la400245n

中图分类号：

O6 [化学];

学科分类号：

0703 ;

摘要：

The coagulation of sodium montmorillonite by inorganic salts (NaNO3, Ca(NO3)(2) and La(NO3)(3)) was studied by combining classical turbidity measurements with wide-angle-X-ray scattering (WAXS), small-angle-X-ray scattering (SAXS), and transmission X-ray microscopy (TXM). Using size-selected samples, such a combination, associated with an original quantitative treatment of TXM images, provides a true multiscale investigation of the formed structures in a spatial range extending from a few angstroms to a few micrometers. We then show that, at neutral pH and starting with fully Na-exchanged samples, coagulation proceeds via the formation of stacks of particles with a slight mismatch between layers. These stacks arrange themselves into larger porous anisotropic particles, the porosity of which depends on the valence of the cation used for coagulation experiments. Face-face coagulation is clearly dominant under those conditions, and no evidence for significant face-edge coagulation was found. These structures appear to arrange as larger clusters, the organization of which should control the mechanical properties of the flocs.

引用

页码：3500 / 3510

页数：11

共 42 条

[1] Rheological determination of interaction potential energy for aqueous clay suspensions [J].