Internal mutual flocculation in clay suspensions

Olphen, H. van

doi:10.1016/0095-8522(64)90033-9

Cited by 140 publications

(66 citation statements)

References 7 publications

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“…The first ever observation of this kind was done by Langmuir [21], who reported in 1938 on sols of California bentonite clay particles that, after standing for several 100 hours, separated into two distinct phases -the isotropic and nematic phase. During the last decades, there have been quite a few studies on natural and synthetic clays, investigating their phase behaviour [22][23][24][25][26], rheological [27][28][29] and structural properties [30][31][32][33]. However, in almost all of the studies, clay suspensions were found to gel rather than phase separate (I-N), as was the case with Langmuir's sample.…”

Section: Introductionmentioning

confidence: 97%

Evidence of the hexagonal columnar liquid-crystal phase of hard colloidal platelets by high-resolution SAXS

et al. 2005

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Abstract. We report Small-Angle X-ray Scattering (SAXS) measurements of the columnar phase of hard colloidal gibbsite platelets. We have been able to create large oriented domains of the columnar phase both perpendicular and parallel to the sample wall, varying the volume fraction of platelets and adding non-adsorbing polymer to the dispersion. In conjunction with the increased resolution of the SAXS setup, this allowed a detailed analysis of the columnar phase, providing unambiguous evidence for the hexagonal nature of the phase.

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Section: Introductionmentioning

confidence: 97%

Evidence of the hexagonal columnar liquid-crystal phase of hard colloidal platelets by high-resolution SAXS

et al. 2005

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“…The changes resuited from deflocculation (Michaels and Bolger, 1962;van Olphen, 1951) and aggregation (Granquist, 1959;van Olphen, 1951), which, in turn, resulted from changes in the type of interparticle association. Following van Olphen's (1963Olphen's ( , 1964 simplified model, three types of aggregates of plate-like particles of clay mineral may be distinguished: edge-face (E-F), edgeedge (E-E), and face-face (F-F). These types of aggregates apparently result form the state of balance between van der Waals attractive forces and electrostatic repulsive forces that exist between double layers having electric charge of the same sign.…”

Section: Introduction Vanmentioning

confidence: 99%

Influence of Calcium and Sodium Concentration on the Microstructure of Bentonite and Kaolin

Stawinski

Wierzchoś

García‐González

1990

Clays and clay miner.

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Abstract--The influence of added sodium and calcium nitrate electrolyte on the particle aggregates in the colloid fraction of natural bentonite and kaolin was studied. Clays were flocculated in distilled water and various electrolyte concentrations. Aggregate size was studied by sedimentation analysis; the mean radius of the aggregates was plotted against the concentrations of Na § and Ca 2 § For bentonite, the mean radii decreased with an increase of Na + and Ca 2 § concentration, reaching a minimum; and further increases in concentration led to an increase of the mean radii of the aggregates. For kaolin, an increase in Na § and Ca 2+ concentration gave rise to an increase in the mean radii of aggregates.Scanning electron micrographs showed different types of aggregates, depending on the physico-chemical conditions of a sedimentation process. In bentonite and kaolin sediments formed from a distilled water slurry, the dominant aggregate was an edge-face type. The small addition of salts to a bentonite slurry led to the formation of edge-edge-type aggregates; for kaolin edge-face-type aggregates formed, although within the microaggregate face-face associations were observed. The highest concentrations of electrolytes for sediments of both clays led to formation of compact, face-face-type aggregates.

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“…The increase of the viscosity can explain by the crystalline structure of the mineral group to which belongs the montmorillonite. In the water, the particles of bentonite which have a strong affinity for the environment in which they are scattered, form suspensions possessing a structure in house of cards [12]. They are constituted by minerals the shape of which is generally flattened.…”

Section: Rheological Measurements Of Bentonite Suspensionsmentioning

confidence: 99%

Colloidal Behavior of Aqueous Montmorillonite Suspensions in the Presence of Non-ionic Polymer

Gareche¹,

Azril²,

Saoudi³

et al. 2015

JHE

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Abstract:In this paper, we characterized at first, the rheological behavior of the bentonite suspensions and the aqueous solutions of PEO (polyethylene oxide). Then we are going to investigate the influence of this polymer in a water-based drilling fluid model (6% of bentonite suspension). The objective is to exhibit how the non-ionic polymer with molecular weight 6x10 3 g/mol. of varying concentration mass (0.7%, 1%, 2% and 3%) significantly alter the rheological properties (yield stress, viscosity, loss and elastic modulus) of the bentonite suspensions. The rheological measurements made in simple shear and in dynamic on the mixture (water-bentonite-PEO), showed rheological properties of bentonite suspensions both in the presence and absence of non-ionic polymer. The PEO presents an affinity for the bentonite particles slowing down their kinetic aggregation. The analysis by XRD (X-rays diffraction) also allowed understanding the structure of this mixture. It had revealed the intercalation between of the clay platelets on one hand, and the links bridges assured by the chains of polymer between bentonite particles beyond a critical concentration in PEO on the other hand.

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Internal mutual flocculation in clay suspensions

Cited by 140 publications

References 7 publications

Evidence of the hexagonal columnar liquid-crystal phase of hard colloidal platelets by high-resolution SAXS

Evidence of the hexagonal columnar liquid-crystal phase of hard colloidal platelets by high-resolution SAXS

Influence of Calcium and Sodium Concentration on the Microstructure of Bentonite and Kaolin

Colloidal Behavior of Aqueous Montmorillonite Suspensions in the Presence of Non-ionic Polymer

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