Surface chemistry and rheological behaviour of titania pigment suspensions

被引:94
作者
Morris, GE [1 ]
Skinner, WA [1 ]
Self, PG [1 ]
Smart, RS [1 ]
机构
[1] Univ S Australia, Ian Wark Res Inst, Mawson Lakes, SA 5095, Australia
基金
澳大利亚研究理事会;
关键词
titania; titanium dioxide; pigments; rheology; surface chemistry;
D O I
10.1016/S0927-7757(98)00631-1
中图分类号
O64 [物理化学(理论化学)、化学物理学];
学科分类号
070304 ; 081704 ;
摘要
The influence of pH and surface chemical state on rheological behaviour was investigated for variations of silica- and alumina-coated, aluminium-doped titania pigment suspensions. The variation in rheological properties correlates with the change in the pigment surface properties, determined from electrophoresis measurements, atomic concentrations, chemical states and modified Auger parameters derived from X-ray photoelectron spectroscopy (XPS). Pigment suspensions exhibited a maximum yield stress and viscosity at or near the isoelectric point (iep). At a pH where the magnitude of the zeta potential of the titania pigment is high, a low-viscosity, dispersed suspension was obtained. The pH of the maximum yield value of the pigment suspension increases with increasing aluminium hydroxyl group density and decreases with increasing silicon hydroxyl group density. Low-viscosity pigment dispersions were obtained with increasing aluminium surface concentration and further reduced with an increase in the silicon surface concentration. Pigment particle attractions are chiefly dictated by van der Waals forces and heteroaggregation. The pigment aggregate strength therefore depends upon the Hamaker constant of the heterogeneous pigment based on the proportion of the respective surface groups. (C) 1999 Elsevier Science B.V. All rights reserved.
引用
收藏
页码:27 / 41
页数:15
相关论文
共 34 条