Montmorillonite suspensions

Middeldorp PJM, De Wolf J, Zehnder AJB, Schraa G (1997) Enrichment and properties of a 1,2,4-trichlorobenzene-dechlorinating methanogenic microbial consortium. Appl Environ Microbiol 63 1225-1229 Miller ME, Alexander M (1991) Kinetics of bacterial degradation of benzylamine in a montmorillonite suspension. Environ Sci Technol 25 240-245 Montville R, Schaffner DW (2003) Inoculum size influences bacterial cross contamination between surfaces. Appl Environ Microbiol 69 7188-7193 Mortland, MM (1970) Clay-organic complexes and interactions. Advances in Agronomy 22 75-117... 

Bowman, B.T. and Sans, W.W. Adsorption of parathion, fenitrothion, methyl parathion, aminoparathion andparaoxonby Na, Ca, and montmorillonite suspensions. SoilScL Soc. Am. J., 41 514-519, 1977. 

Fig. 12.18A shows the results of an experiment using " C-labeled paraquat adsorbed on a clay mineral (Li-montmorillonite) suspension through a soil column. When the suspension medium was distilled water, 50% of the pesticides penetrated beyond 12 cm. Under these conditions, clay remains dispersed and pestieide is readily transported through the soil. However, for a suspension medium with an electrolyte concentration of 1 mM CaCl, paraquat remains in the upper 1 cm layer. The high calcium concentration results in rapid immobilization of the clay in the soil through flocculation, and consequently little pesticide transport occurs. 

Miller, M. E. Alexander, M. (1991). Kinetics of bacterial degradation of benzylamine in a montmorillonite suspension. Environmental Science Technology, 25, 240-5. 

FIG. 11 Viscosity ( s) and light-scattering (I/Io) data for suspensions of M/Ca-montmorillonite (M = Li, Na, or K). The data for pure M-montmorillonite suspensions discussed in the text are at the extreme right in each graph [55]. 

The evidence for quasicrystal formation in suspensions of mono-valent-ion-saturated montmorillonites [23,58] indicates that wav for Na-montmorillonite should lie between 1.0 and 2.0. The viscosity data in Fig. 11 in fact lead to wav = 1.3 if the ratio of hD-values [from Eq. (30)] for Na-montmorillonite and Li-montmorillonite is equated to their ratio of av values, with av = 1.0 for Li-montmorillonite. Similarly, if the ratio of mp-values taken from Eq. (31) is equated to a ratio of av values (i.e., mp = wo wav, where wo is the mass of a unit-layer particle), then av = 1.4 0.3 on the basis of the data in Fig. 11, along with other published data on light transmission by dilute Li- and Na-montmorillonite suspensions [23]. 

Faisandier, K. et al., Structural organization of Na- and K-montmorillonite suspensions in response to osmotic and thermal stresses, Clays Clay Miner., 46, 636, 1998. 

Mungan, N. and Jessen, F.W., 1963. Studies in fractionated montmorillonite suspensions. In W.F. Bradley (Editor), Proceedings Eleventh National Conference Clays and Clay Minerals. Pergamon, New York, N.Y., pp. 282—294. 

Duran. J.D.G. et al.. Rheological and electrokinetic properties of sodium montmorillonite suspensions. 1. Rheological properties and interparticle energy of interaction, J. Colloid Interf. Sci., 229, 107, 2000. 

Some attempts eonsisting of adding ammonium sulfate to the pillared montmorillonite suspension have been reported [4,5], These preparation methods show that adding sulfate ions decreases considerably the basal spacing without developing high acidity. Other studies attempted to prepare zirconium sulfate pillared clays by adding in situ sulfate. However, the solids obtained have a low surface area, low thermal stability [6] and low sulfate to zirconium ratios [7], Earlier, we have prepared a zirconium sulfate pillared clay by in situ... 

Catalysts preparation. Intercalation solutions were prepared by addition of an ammonium sulfate solution to a fresh zirconium acetate one. The mixture was adjusted to the desired pH using a HCl solution. In another beaker, Na-montmorillonite suspension was adjusted at the same pH than the intercalation solution. 

Na-montmorillonite suspension was added dropwise to the fresh pillaring solution with different clay to zirconium ratios. The mixture was magnetically stirred for different times at 15 °C. The dispersed montmorillonite was separated by centrifugation and washed by dialysis. The resulting clay was dried overnight in oven at 120 °C. 

These generalizations arise from data such as in Table 8.3. The data were generated by saturating a montmorillonite suspension with a given ion and then measuring the quantity of that ion released when a symmetry (amount equal to the CEC) of either NH4CI or KC1 was added. 

FIGURE 10.1. Potentiometric titration of montmorillonite suspensions after treatment with NaCl-HCl solution and H-resin. (From D. G. Aldrich and J. R. Buchanan. 1958. Soii Sci. Soc. Am. Proc. 22 281-286.)... 

Measurements of the specific viscosity of a very dilute (less than 2 kg of clay per cubic meter) montmorillonite suspension can be used to determine the average thickness of the suspended clay particles if the relationship ... 

Figure 6.2. Scaled value F/Pnb of four montmorillonite suspension properties versus the charge fraction on Na" on the clay. The curves through the data points are meant only as guides to the eye.

QUASICRYSTAL FORMATION. The mixing together of Na- and Ca-montmorillonite suspensions to produce an overall charge fraction of Na" on the clay particles below 0.1 results in a very rapid (less than 1 min) formation of quasicrystals from conversion of the Na-montmorillonite particles.This rapid conversion is necessarily mediated by a redistribu- tion of the exchangeable cations such that Na ions are relocated, as required, to the external surfaces of already-formed quasicrystals that contain Ca ions on their internal surfaces. The relocation probably involves replacement by Na of Ca " already on external surfaces since the latter ions are likely to have a higher mobility than Ca " adsorbed inside a quasicrystal. 

Increasing tb may also increase viscoelastic behavior and the yield stress value. Figure 23 displays values of storage modulus G as a function of clay concentration and pH, for sodium montmorillonite suspensions aged for 200 min (12). It can be observed that the higher the clay content, the higher G. ... 

J.W Kim, S.G. Kim, H.J. Choi, M.S. Jhon, Synthesis and electrorheological properties of polyaniline-Na -montmorillonite suspensions, Macromol. Rapid Commun., 1999, 20,450. 

Tombacz, E., and M. Szekeres. 2004. Colloidal behavior of aqueous montmorillonite suspensions The specific role of pH in the presence of indifferent electrolytes. Applied Clay Science 27, no. 1-2 75-94. doi 10.1016/j.clay.2004.01.001. 

Fig. 2. The aforementioned hysteresis experienced to the highest degree at the lowest salt concentration decreases with increasing ionic strength, and almost disappears in the presence of 1 M NaCl. Apart from the first downward curves, the acid-base processes in montmorillonite suspensions under the given experimental condition can be considered as reversible equilibria.

Fig. 5 X-ray diffraction patterns of oriented montmorillonite films on a glass plate prepared from dilute montmorillonite suspensions with different pH at (around 6.5), above (around 9) and below (around 4) the pH of the point of zero charge (PZC) of the edges, where the edges of the lamellae are uncharged, and either similarly or oppositely charged compared to the faces of the particles, respectively...

Formation and mechanical properties of particle network in suspensions can be investigated by means of rheology. Here we investigated the formation of the pH-dependent structure in a montmorillonite suspension. 

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