RefDoc
Haut

Faire une nouvelle recherche
Make a new search
Lancer la recherche


Titre du document / Document title

The flow characteristics of halloysite suspensions

Auteur(s) / Author(s)

THENG B. K. G. (1) ; WELLS N. ;

Affiliation(s) du ou des auteurs / Author(s) Affiliation(s)

(1) Manaaki Whenua - Landcare Research, Palmerston North, NOUVELLE-ZELANDE

Résumé / Abstract

The rheology of aqueous suspensions of Na halloysites with different particle shape has been investigated using a Haake rotary viscometer. Three halloysites from New Zealand were used : Matauri Bay (MB), Te Akatea (TA) and Opotiki (Op) which are mainly composed of thick long tubules, short thin laths, and spherules, respectively. Suspensions of the materials subsequently prepared from the MB and TA samples show a pseudoplastic consistency under shear, characterized by a steep initial rise in shear stress as shear rate increases, followed by a linear increase in stress when a certain shear rate is exceeded. The Op halloysite, on the other hand, shows Newtonian flow behaviour for which shear stress increases linearly with shear rate throughout. For MB and TA, the shear stress developed during rotor acceleration is larger than that produced during deceleration, and the corresponding flow curves enclose a hysteresis loop. As suspension pH increases, the pseudoplastic character decreases as does the amount of hysteresis. Above pH 7.5, flow approaches Newtonian and hysteresis is absent. Plots of Bingham yield value against pH at different ionic strengths (0.003, 0.03 and 0.3 M NaCl) intersect at pH 6.0 for MB and at pH 7.1 for TA. These values are identified with the point of zero charge (PZC) of the particle edge surface. The flow characteristics of halloysites may be explained in terms of the influence of particle shape, pH, electrolyte concentrations, and layer composition on particle interactions.

Revue / Journal Title

Clay minerals    ISSN  0009-8558   CODEN CLMIAF 

Source / Source

1995, vol. 30, no2, pp. 99-106 (19 ref.)

Langue / Language

Anglais

Editeur / Publisher

Mineralogical Society, London, ROYAUME-UNI  (1965) (Revue)

Mots-clés anglais / English Keywords

halloysite

;

clay minerals

;

sheet silicates

;

suspended materials

;

rheology

;

habit

;

particles

;

viscosity

;

New Zealand

;

shear stress

;

laboratory studies

;

flow mechanism

;

hysteresis

;

pH

;

electrolytes

;

electron microscopy

;

SEM data

;

Australasia

;

Mots-clés français / French Keywords

Halloysite

;

Argile minéral

;

Phyllosilicate

;

Matière en suspension

;

Rhéologie

;

Habitus

;

Matière particulaire

;

Viscosité

;

Nouvelle Zélande

;

Contrainte cisaillement

;

Essai laboratoire

;

Mécanisme écoulement

;

Hystérésis

;

PH

;

Electrolyte

;

Microscopie électronique

;

Donnée MEB

;

Pseudoplasticité

;

Australasie

;

Mots-clés espagnols / Spanish Keywords

Halloysita

;

Arcilla mineral

;

Filosilicato

;

Materia en suspensión

;

Reología

;

Hábito

;

Partícula elemental

;

Viscosidad

;

Nueva Zelandia

;

Tensión cizallamiento

;

Ensayo laboratorio

;

Mecanismo escorrentía

;

pH

;

Electrolito

;

Microscopía electrónica

;

Dato MEB

;

Australasia

;

Localisation / Location

INIST-CNRS, Cote INIST : 2996, 35400005132924.0020

Nº notice refdoc (ud4) : 3557338



Faire une nouvelle recherche
Make a new search
Lancer la recherche
Bas