Dynamics Of The Breaking Up Coagulating Structures Of The Titanium Dioxide Dispersions
DYnamics of the breaking up coagUlating structures of the titanium dioxide dispersions
V. P. Zakordonskyi, A. V. Synyts’ka, O. B. Les’kiv, M. M. Soltys
Ivan Franko National University of L’viv, Chemical Department,
Kyryla & Mefodiy Str. 6, L’viv, 79005, Ukraine,
E-mail: soltys@franko.lviv.ua
the rheological behaviour of aqueous and modificated by surfactant (sodium dodecylbenzolesulfonate) (DDBS) titanium dioxide dispersions depending on content solid phase and composition of dispersion medium has been investigated by rotational viscosimetry method.
It was shown, that exists concentration domain of sodium dodecylbenzolesulfonate, where rheological behaviour character under study systems suddenly changes. Sodium dodecylbenzolesulfonat acts as structurization agent in surfactant concentration CDDBS = 1.44´10-5 - 1.44 ´10-4 mole/l. Surfactant disclose stabilization function at CDDBS ³ CCM (CDDBS ³ 1.44´10-3 mole/l).
It was investigated that a concentration factor - a content by volume solid phase have desicive influence on the rheological behaviour of the TiO2 dispersions.
The flow character this systems ranges from quasi-Newtonian (j = 0.026) to pseudoplastic (j = 0.045 - 0.124). The rheological anomaly - of a discontinuaty rupture is characteristically for titanium dioxide dispersions with j = 0.159 - 0.191.
Modification of the surfaсe titanium dioxide particles, substantially influences on rheological behaviour character and level structurization of the in question dispersions at content by volume filler j = 0.026 - 0.124.
Analysis received results in within the scope of flow aggregating theory was shown, that dispersions are loosely-aggregated at relatively nonhigh contents of the dispersion phase j £ 0.086 (for aqueous dispersions) and j £ 0.124 (for modificated by sodium dodecylbenzolesulfonat). The breaking up of
these systems is not accompany by change of the structural organization of system elements. Higherfilled systems follow to fall in to higher-aggregation of
the small-strong solid-similar systems undepending from composition dispersion medium. The breaking up of these systems is accompany to mechanism: super-aggregates – aggregates of higher order – aggregates of a lower order.
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