Medical Hydrology and Balneology: Environmental Aspects

Study of density, thermal conductivity, and ph
of mixtures of clays, seawater and
tridistilled water
Rosino J (1) , Mourelle ML (2) , Gómez CP (2)
(1) AGMA, Granada, Spain
(2) Departament of Medicine, University of A Coruña, A Coruña, Spain
jrosino@agmeam.com
Introduction and Objectives
Clay minerals with less than 2 micra grain size when mixed with water produce
a malleable paste which can be used for different purposes. Such products are
generally used in Spas and thalassotherapy centres, mainly for thermal therapeutic
uses, but are also used in aesthetic medicine and for cosmetic applications because
of their physico-chemical properties [1].
This study evaluates whether minerals with a high internal porosity such as zeolites
are suitable for preparing the abovementioned products because they offer the
possibility for later incorporation of active substances which can be gradually
released from the internal pores of zeolites. The aim of the first stage of this study
is to determine the density, thermal conductivity and pH of the several pastes obtained
from mixing clinoptiolite (zeolite) and montmorillonite with seawater and
tri-distilled water, for their possible use in thermal therapy and dermo-cosmetics.
Materials and Methods
Seawater was supplied by Quinton Labs. and tridistilled water was supplied by
CACTI. The clays used were supplied by the Spanish company “Sigma-Aldrich”.
The physico-chemical properties studied are density, thermal conductivity and
pH.
The density has been obtained using a pycnometer. Hexane and tridistilled water
have been used as calibration liquids. The technique is described in Deeds and Van
Olphen (1961) [2]. The thermal conductivity was measured by a conductivimeter
KD 2 proThermal Properties Analyzer (Decagon Devices, Inc.) [3], and pH was
measured with a pHmeter Hanna Instrument 99121 [4].
Results
The results for density obtained from the different samples are: a) 1.42g/cm3 for
clay and tri-distilled water mixtures and, b) 1.43 g/cm3 for mixtures with clay and
seawater. The values for mixtures obtained with zeolite and montmorillonite were
1.5 and 1.97 g/cm3, respectively. The thermal conductivity is 0.608 W/m•K for the
tri-distilled water mixture while that for the seawater mixture is 0.616 W/m•K. The
Balnea 432
ISBN: 978-84-669-1887-0
978-84-669-3482-4
2012, núm. 6, 432-433