Environmental Science & Technology,
Journal Year:
2022,
Volume and Issue:
56(19), P. 14069 - 14079
Published: Sept. 20, 2022
Nanofiltration
(NF)
membranes
are
playing
increasingly
crucial
roles
in
addressing
emerging
environmental
challenges
by
precise
separation,
yet
understanding
of
the
selective
transport
mechanism
is
still
limited.
In
this
work,
underlying
mechanisms
governing
selectivity
polyamide
NF
membrane
were
elucidated
using
a
series
monovalent
cations
with
minor
hydrated
radius
difference.
The
observed
single
cation
was
neither
correlated
nor
hydration
energy,
which
could
not
be
explained
widely
accepted
model
or
ion
dehydration
theory.
Herein,
we
employed
an
Arrhenius
approach
combined
Monte
Carlo
simulation
to
unravel
that
transmembrane
process
would
dominated
its
pairing
anion,
if
anion
has
greater
energy
barrier,
due
constraint
anion-cation
coupling
transport.
Molecular
dynamics
simulations
further
revealed
distinct
structure
primary
origin
barrier
difference
cations.
having
larger
incompressible
after
partial
through
subnanopores
induce
more
significant
ion-membrane
interaction
and
consequently
higher
barrier.
Moreover,
validate
our
proposed
mechanisms,
grafting
modification
toward
enlarging
dominant
ions
achieved
3-fold
enhancement
separation
efficiency.
Our
work
provides
insights
into
ionic
species
membranes.
Environmental Science & Technology,
Journal Year:
2022,
Volume and Issue:
56(18), P. 12811 - 12827
Published: Sept. 1, 2022
Nanofiltration
(NF)
membranes
have
been
widely
applied
in
many
important
environmental
applications,
including
water
softening,
surface/groundwater
purification,
wastewater
treatment,
and
reuse.
In
recent
years,
a
new
class
of
piperazine
(PIP)-based
NF
featuring
crumpled
polyamide
layer
has
received
considerable
attention
because
their
great
potential
for
achieving
dramatic
improvements
membrane
separation
performance.
Since
the
report
novel
Turing
structures
that
exhibited
an
order
magnitude
enhancement
permeance
(
Science
2018,
360
(6388),
518−521),
number
published
research
papers
on
this
emerging
topic
grown
exponentially
to
approximately
200.
critical
review,
we
provide
systematic
framework
classify
morphologies.
The
fundamental
mechanisms
fabrication
methods
involved
formation
these
morphologies
are
summarized.
We
then
discuss
transport
solutes
how
phenomena
could
simultaneously
improve
permeance,
selectivity,
antifouling
applications
highlighted,
future
opportunities/needs
identified.
insights
review
guidance
further
development
high-performance
tailored
wide
range
applications.
Advanced Materials,
Journal Year:
2022,
Volume and Issue:
34(21)
Published: March 3, 2022
Ultrathin
membranes
are
at
the
forefront
of
membrane
research,
offering
great
opportunities
in
revolutionizing
separations
with
ultrafast
transport.
Driven
by
advanced
nanomaterials
and
manufacturing
technology,
tremendous
progresses
made
over
last
15
years
fabrications
applications
sub-50
nm
membranes.
Here,
an
overview
state-of-the-art
ultrathin
is
first
introduced,
followed
a
summary
fabrication
techniques
emphasis
on
how
to
realize
such
extremely
low
thickness.
Then,
different
types
membranes,
categorized
based
their
structures,
that
is,
network,
laminar,
or
framework
discussed
focus
interplays
among
structure,
methods,
separation
performances.
Recent
research
development
trends
highlighted.
Meanwhile,
performances
current
for
representative
(gas
liquid
separation)
thoroughly
analyzed
compared.
Last,
challenges
material
design,
structure
construction,
coordination
given,
order
fully
potential
facilitate
translation
from
scientific
achievements
industrial
productions.
Environmental Science & Technology,
Journal Year:
2022,
Volume and Issue:
56(4), P. 2656 - 2664
Published: Feb. 3, 2022
Interlayered
thin-film
nanocomposite
(TFNi)
membranes
have
been
shown
to
achieve
enhanced
water
permeance
as
a
result
of
the
gutter
effect.
Nevertheless,
some
studies
report
impaired
separation
performance
after
inclusion
an
interlayer.
In
this
study,
we
resolve
competing
mechanisms
transport
in
transverse
direction
vs
that
normal
direction.
To
enable
easy
comparison,
carbon
nanotube
(CNT)-incorporated
TFNi
with
identical
polyamide
rejection
layer
but
different
interlayer
thicknesses
were
investigated.
While
increasing
thickness
CNT
facilitates
(therefore
improving
effect),
it
simultaneously
increases
its
hydraulic
resistance
An
optimal
13.0
±
0.7
L
m–2
h–1
bar–1,
which
was
more
than
doubled
over
control
membrane
6.1
realized
at
moderate
thickness,
resulting
from
trade-off
between
these
two
mechanisms.
demonstrate
reduced
fouling
and
improved
reversibility
for
without
interlayer,
can
be
attributed
uniform
flux
distribution.
The
fundamental
revealed
study
lay
solid
foundation
future
development
toward
properties
antifouling
ability.
