2024-03-29T13:58:38Z
https://meral.edu.mm/oai
oai:meral.edu.mm:recid/611
2021-12-13T05:01:08Z
1582963739756:1582967007954
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Study of ionic surfactants binding to humic acid and fulvic acid by potentiometric titration and dynamic light scattering
Min Min Yee
Miyajima, Tohru
Takisawa, Noboru
The binding of anionic surfactant, sodium dodecyl sulfate (SDS) with Aso humic acid (AHA) has been
studied by potentiometric titration and dynamic light scattering (DLS) methods at two pH regions and
ionic strengths that is pH 9.18 (ionic strength 0.03 moldm−3) and pH 3.98 (ionic strength 0.10 moldm−3).
At pH 9.18 and low ionic strength no binding is observed between SDS and AHA in the investigation
by both methods, whereas some interaction is observed at pH 3.98 and at high ionic strength by DLS
measurement since electrostatic repulsion is suppressed by counterions at this solution condition. The
binding between cationic surfactant, dodecyltrimethyl–ammonium ion (DTMA+) with Aso fulvic acid
(AFA) and AHA has also been investigated by potentiometric titration and DLS methods and compared
with the binding of dodecylpyridinium ion (C12Py+). The binding ofDTMA+ ions with AFAorAHAisweaker
than that of C12Py+ ions, presumably due to steric hindrance of headgroup of DTMA+ ions and due to
higher attractive binding of C12Py+ ions induced by – interaction between aromatic rings. The hydrodynamic
diameter of DTMA+–AFA/DTMA+–AHA aggregates is smaller than that of C12Py+–AFA/C12Py+–AHA
aggregates.
2009
http://hdl.handle.net/20.500.12678/0000000611
https://meral.edu.mm/records/611