Evaluation of poly(2-hydroxyethyl methacrylate)
and poly(methyl methacrylate)-grafted
bilayers for gas separation
B. M. Maher
A. A. Babaluo
Received: 17 February 2017 /Revised: 8 May 2017 / Accepted: 1 June 2017 /Published online: 29 June 2017
Springer-Verlag GmbH Germany 2017
Abstract Thin film composites (TFCs) of poly(2-
hydroxyethyl methacrylate) (PHEMA) and poly(methyl meth-
acrylate) (PMMA) chain-tethered poly(vinylidene fluoride)-
poly(dimethylsiloxane) (PVDF-PDMS) were prepared as a
gas separation membrane. PDMS was coated on the PVDF
support using a dip coating method. PHEMA and PMMA were
then grafted on PVDF-PDMS substrate by atom transfer radical
polymerization. The PVDF-PDMS-PHEMA and PVDF-
PDMS-PMMA trilayer membranes were studied by attenuated
total reflection Fourier transform infrared spectroscopy, scan-
ning electron microscopy, atomic force microscopy, water con-
tact angle measurement, and X-ray photoelectron spectroscopy.
The results of separation tests indicated that the CO
tivity of PVDF-PDMS-PHEMA and PVDF-PDMS-PMMA
TFCs increased by ∼2and∼3 times, respectively, compared
to the solvent-extracted PVDF-PDMS support.
Keywords PVDF-PDMS support
Most studies on gas separation membranes have used dense
homogeneous films. They have important properties, like intrin-
sic gas diffusivity, solubility, and gas permeability. However, the
low flux and poor mechanical resistance restrict the capacity of
these thick films in practical industrial implementations .
Thin film composite membrane is one of the most effective
membranes for gas separation because of its asymmetric and
porous structure . The configuration of a composite mem-
brane consists of three layers, namely porous support layer,
coating layer, and selective layer [3, 4]. The coated macroporous
support is normally modified by the formation of a selective
polymer layer . The existence of a thin nonporous selective
layer over a support providing sufficient mechanical stability
guarantees high membrane permeability .
The porous support layer is expected to have a high me-
chanical strength along with an enhanced gas permeability.
The important materials utilized as supporting layer include
alumina , zeolite , polysulfone , polyamide , and
poly(vinylidene fluoride) (PVDF) . The coating layer plugs
defects in the selective layer and decreases possibility of gas
leakage through the defects. The efficiency of a composite
membrane is greatly related to coating material filling the de-
fects during the fabrication . Silicone rubber [11, 12], 4,4′-
hexafluoroisopropylidene bis(phthalic anhydride) , and
poly(aminosi1oxane)  have been applied as coating layers.
The selective top layer must be thin as far as possible to obtain
ahighflux[15, 16]. Thin polymeric films are not strong
enough to endure high gas pressure involved in gas separation
. Polymers such as polyether-block-polyamide (PEBAX)
, polyimide , polyamide , polysulfone ,
poly(methyl methacrylate) (PMMA) , and poly(ethyl
methacrylate)(PEMA) have been used as selective layers.
Electronic supplementary material The online version of this article
(doi:10.1007/s00396-017-4124-7) contains supplementary material,
which is available to authorized users.
* F. Abbasi
Institute of Polymeric Materials, Sahand University of Technology,
Faculty of Polymer Engineering, Sahand University of Technology,
Nanostructure Materials Research Center, Chemical Engineering
Department, Sahand University of Technology, Tabriz, Iran
Colloid Polym Sci (2017) 295:1595–1607