Sodium bicarbonate as novel additive for fabrication of composite
nanofiltration membranes with enhanced permeability
Luhong Zhang ,
School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China
School of Chemical Engineering and Food Science, Zhengzhou Institute of Technology, Zhengzhou 450044, China
Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin 300072, China
Correspondence to: L. Zhang (E -mail: email@example.com)
Thin film composite nanofiltration membranes are frequently used to remove the residual salts from industrial wastewater.
However, these nanofiltration membranes often have relatively low fluxes that limit their practical applications. To solve the problem,
sodium bicarbonate was introduced into the composite nanofiltration membranes via interfacial polymerization of piperazine (PIP)
and 1,3,5-benzenetricarbonyl trichloride (TMC). The membrane surfaces were characterized by scanning electronic microscopy, atten-
uated total reflection Fourier transform infrared spectroscopy, electro kinetic analyzer, and contact angle goniometer. The results
showed that the addition of sodium bicarbonate generated more tiny cracks on membrane surface and decreased the zeta potential of
the membrane, which improved the permeation properties of the membrane without significantly decreasing the rejection against
four kinds of salts (Na
, NaCl, MgCl
). The addition of sodium bicarbonate provided a new possibility to improve the
permeation properties of thin film composite nanofiltration membranes.
2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46363.
composites; films; membranes; polyamides; separation techniques
Received 12 December 2017; accepted 11 February 2018
There is a large amount of wastewater with high salinity (usually
) generally in printing and
dyeing industry, often resulting in serious environmental pollu-
tion, waste of resources, as well as increase of cost.
In order to
remove the metal ions from effluents, several processes have been
applied, such as precipitation, coagulation, adsorption, ion
exchange, electro-dialysis, nanofiltration, and electro-coagulation
Among these separation methods, nanofiltration is con-
sidered to be a favorable process for water treatment especially
for divalent ion removal due to its relatively low energy con-
sumption, low operating costs, high removal efficiency, small
footprint, and ease of scale up.
Nanofiltration membrane is a kind of product between ultra-
filtration membrane and reverse osmosis membrane with a
molecular weight cutoff (MWCO) range from about 100–1000
which has been widely used in the preparation of ultra-
pure water, food, chemical, pharmaceutical, biochemical, envi-
ronmental protection, metallurgy and other fields of
concentration, and separation process.
Because of the spe-
cial property of nanofiltration membrane for detaining some
components of which molecular weight is under MWCO and
allowing low molecular weight components to permeate the
semipermeable separation layer, the preparation method is of
Compared with other kinds of nanofiltration membrane prepa-
ration methods, such as photo-grafting,
thin film composite
(TFC) membrane attracts extensive attention, which has an
active polyamide (PA) separation layer above the support mem-
The active layer has a proper rejection, which is usually
prepared by interfacial polymerization (IP) between the mono-
mers in an aqueous phase and an organic phase. The porous
membrane provides stable mechanical support, similar to a con-
ventional ultrafiltration membrane.
However, TFC nanofil-
tration membrane usually possesses a relatively low water flux,
which restrict its practical application. Therefore, making the
active layer looser is a good way to decrease the trans-
membrane pressure and increase the membrane flux with a
slight change of salt rejection.
Many factors, including solvents in organic and aqueous phase,
type and concentration of monomers, and reaction time and
temperature of the interfacial polymerization influence the mor-
phology and structure of the thin film, and then affect the per-
formance of nanofiltration membrane.
introduction of some certain additives into the aqueous solution
2018 Wiley Periodicals, Inc.
J. APPL. POLYM. SCI. 2018, DOI: 10.1002/APP.46363
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