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Abstract
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The aim of this work is to explore the effects of the factors affecting the thermal conductivity
of the porous nanocomposite membranes and their performance in direct
contact membrane distillation (DCMD). The thermal conductivity models were evaluated
comprehensively for membrane material involving three-phases (filler particle, polymer
and interface). Hashemifard-Matsuura-Fauzi (HMF) and Maxwell models were the most
reliable models among three-phase and two-phase (nanocomposite material and pores)
models, respectively. Thus, the thermal conductivity of the porous nanocomposite
membrane was obtained by the combination of three-phase HMF and two-phase Maxwell
model. Finally, the performances of PTFE/Silica aerogel (SiAG) and PTFE/CaCO3 porous
nanocomposite membranes were disclosed by the heat and mass transfer model in a
DCMD system in order to study the effects of particle loading, interlayer thickness and
membrane porosity. It was concluded that both membrane thermal conductivity and the
DCMD flux approach almost the same values at the high end of interface thickness, regardless
of the thermal conductivity of the filler particle. In other words, the heat loss of
the system can be controlled by tuning the interface thickness in order to achieve a high
DCMD flux even by incorporating fillers with higher thermal conductivity rather than that
of the pure polymer. In summary, our findings revealed that next to the membrane material
and porosity, the type of the nanoparticle and interface thickness can be highlighted
as the most important parameters for controlling membrane thermal conductivity and
improving DCMD performance.
© 2023 Institution of Chemical
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