Original scientific paper

A Light Scattering and Electron Microscope Examination of Monodispersed Metal Iodate Hydrosols

M. J. Herak ; Institute »Ruder Boskovic«; Department of Physical Biochemistry, »Andrija Stampar« School of Public Health, Faculty of Medicine; Laboratory of Physical Chemistry, Faculty of Science, University of Zagreb, Zagreb, Croatia, Yugoslavia
J. Kratohvil ; Institute »Ruder Boskovic«; Department of Physical Biochemistry, »Andrija Stampar« School of Public Health, Faculty of Medicine; Laboratory of Physical Chemistry, Faculty of Science, University of Zagreb, Zagreb, Croatia, Yugoslavia
M. M. Herak ; Institute »Ruder Boskovic«; Department of Physical Biochemistry, »Andrija Stampar« School of Public Health, Faculty of Medicine; Laboratory of Physical Chemistry, Faculty of Science, University of Zagreb, Zagreb, Croatia, Yugoslavia
M. Wrischer ; Institute »Ruder Boskovic«; Department of Physical Biochemistry, »Andrija Stampar« School of Public Health, Faculty of Medicine; Laboratory of Physical Chemistry, Faculty of Science, University of Zagreb, Zagreb, Croatia, Yugoslavia

Abstract

Monodispersed lanthanum and lead iodate hydrosols were prepared and their properties examined by means of light scattering, electron and light microscopy, and measurements of rate of deposition of particles. The sols exhibited brilliant colour bands of higher order Tyndall spectra indicating the presence of spherical particles very uniform ill sizes. Lead iodate sols, otherwise very unstable, could be stabilized by simple filtration through filter paper. This was accompanied by reversal of charge carried by the particles. The growth of lanthanum iodate was much slower. Angular distribution of light scattered by metal iodates showed typical features of monodispersed systems with spherical particles several hundred millimicrons in radius. This was confirmed by electron microscopy. Particles of a typical lanthanum iodate sol were about 700 mμ in radius, and those of lead iodate about 860 mμ. The variations in particle sizes from different preparations were considerable, and could be explained by the uncontrolled influence of the direct mixing of reacting solutions. A tentative mechanism of the formation of monodispersed metaliodate hydrosols was proposed.

Keywords

Hrčak ID:

245377

URI

https://hrcak.srce.hr/245377

Publication date:

8.5.1959.

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