(401ao) The Effects of SiO2 and Zeolite 4A/SiO2 on the Transport Behavior of CO2 and CH4 through Polydimethylsiloxane Nanocomposite Membranes

The Effects of SiO₂ and Zeolite 4A/SiO₂ on the
Transport Behavior of CO₂
and CH₄ through Polydimethylsiloxane
Nanocomposite Membranes

Abstract

Emmanuel O. Ogbole, Jianzhong Lou,
Shamsuddin Ilias

Polymeric membrane-based gas separation provides
energy-efficient unit operation in the process  industry. Polydimethylsiloxane (PDMS) is one of the common polymers used for
developing mixed matrix membranes (MMMs) for gas separation as it offers one of the highest
permeability coefficients for a wide range of gas species, modest selectivity, good
material compatibility with inorganic materials, etc.  Single-filler and double-fillers mixed matrix
membranes were prepared with polydimethylsiloxane (PDMS) and different weight
percent of SiO₂ and zeolite 4A/SiO₂. The effects of the
single filler (SiO₂) and double-fillers (zeolite 4A/SiO₂)
on the transport behaviors of CO₂ and CH₄ through the
nanocomposite membranes were investigated. Permeability of CO₂ and
CH₄ through the neat PDMS membrane and the PDMS mixed matrix
membranes (MMMs) were experimentally measured. CO₂ andCH₄
permeability were theoretically predicted using Maxwell model. Scanning
electron microscopy (SEM) images and visual
observation showed that SiO₂ enhanced
the uniform dispersion of zeolite 4A in the double-filler-PDMS membrane. The
incorporation of SiO₂ nanoparticles and
zeolite 4A/SiO₂ disrupted the PDMS polymer chains packing
arrangement; thereby, altering the performance of MMMs and the transport
behavior of the gases in the single filler (SiO₂-PDMS) MMMs
and double filler (zeolite 4A/SiO₂-PDMS). The experimental permeability
measurements of CO₂ and CH₄ through the (SiO₂-PDMS)
MMMs showed a measure of deviation from the theoretical model. The 2.5wt%
zeolite 4A/2.5wt%SiO₂-PDMS MMM exhibited significant average CO₂/CH₄
selectivity improvement over the neat membrane and other MMMs from 3.09 to 4.89.