Original scientific paper

Solid/Liquid Equilibria in Aqueous Systems of Dodecyl Benzene Sulphonate and Alkaline Earth Ions

Đurđica Težak ; Laboratory of Physical Chemistry, Faculty of Science, University of Zagreb, P.O.B. 163, YU-41001, Zagreb, Croatia, Yugoslavia
Franjo Strajnar ; Laboratory of Physical Chemistry, Faculty of Science, University of Zagreb, P.O.B. 163, YU-41001, Zagreb, Croatia, Yugoslavia
Dušanka Šarčević ; Laboratory of Physical Chemistry, Faculty of Science, University of Zagreb, P.O.B. 163, YU-41001, Zagreb, Croatia, Yugoslavia
Ognjen Milat ; Institute of Physics of the University of Zagreb, P.O.B. 304, YU-41001 Zagreb, Croatia, Yugoslavia
Mirko Stubičar ; Institute of Physics of the University of Zagreb, P.O.B. 304, YU-41001 Zagreb, Croatia, Yugoslavia

Abstract

SolubUi.ty/ precipitability boundaries and the morphology of
solid pha ses were investigated and equilibria cons t ants calculated
for Mg, Ca, Sr, Ba - dodecyl benzene sulphonate salts. The
experimental methods of tyndallometry, polari ~ing microscopy
and X-ray diffraction gave consistent results. The measurements
were performed at 293 K.
The so,lubilLty of MCDBS)2 salts decreased in the order
Mg > Ca > Sr >Ba; pK0sp were calcula ted to be: (10.80±0.07)
for MgCDBSh, (10.48±0.07) for Mg(DBS)2 (for DBS dimer) ,
(11.23±0.03) for CaCDBSh, (12.00±0.08) for Sr(DBSh, (12.4 ± 0.2)
for Ba(DBSh
It is demonstrated that at least two prec:ipitated phases can
be obtained : a partially ·ordered phase, probably belonging to
the smectic A liquid crysta.1, while the other phase appears to
be a solid crystal.

Keywords

Hrčak ID:

194174

URI

https://hrcak.srce.hr/194174

Publication date:

15.2.1984.

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