ACS Applied Materials & Interfaces,
Journal Year:
2024,
Volume and Issue:
16(25), P. 32748 - 32761
Published: June 11, 2024
Layer-by-layer
(LbL)
self-assembly
of
oppositely
charged
polyelectrolytes
(PEs)
is
usually
performed
on
a
conventional
ultrafiltration
base
substrate
(negative
zeta
potential)
by
depositing
cationic
PE
as
first
layer.
Herein,
we
report
the
facile
and
fast
formation
high
performance
molecular
selective
membrane
nonelectrostatic
adsorption
anionic
polyvinylidene
fluoride
(PVDF,
potential
−17
mV)
followed
electrostatic
LbL
assembly.
Loose
nanofiltration
membranes
have
been
prepared
via
both
concentration-polarization
(CP-LbL,
under
applied
pressure)
driven
(C-LbL,
dipping)
self-assembly.
When
layer
poly(styrene
sodium)
sulfonic
acid,
assembled
contains
free
−SO3–
groups
exhibits
higher
rejection
Na2SO4
lower
MgCl2.
The
reversal
salt
occurs
when
quaternized
polyvinyl
imidazole
(PVIm-Me).
(five
layers)
PStSO3Na
shows
several
dyes
(97.9
to
>99.9%),
NaCl
dye
separation
factor
(52–1800),
antifouling
compared
PVIm-Me
(97.5–99.5%
rejection,
∼40–200).
However,
C-LbL
requires
longer
time
or
concentration
reach
close
CP-LbL
membranes.
exhibit
excellent
pressure,
pH
(3–12),
(60
g
L–1)
stability.
This
work
provides
an
insight
for
construction
low
fouling
high-performance
fractionation
based
sequence.
