Physics of Fluids,
Год журнала:
2023,
Номер
35(11)
Опубликована: Ноя. 1, 2023
The
charged
nanochannel
surface
and
pH-sensitive
grafted
polyelectrolyte
layer
(PEL)
play
a
critical
role
in
the
design
of
devices
aimed
at
controlling
nanofludic
flow.
They
enable
manipulation
ionic
transport
by
influencing
electric-double
(EDL)
layers
that
overlap.
Additionally,
viscoelectric
effect,
amplified
strong
EDL
electric
field,
may
enhance
activation
energy
viscosity
liquids.
Motivated
this,
we
conducted
numerical
investigation
using
finite
element
method-based
solver,
COMSOL,
to
examine
effects
effect
on
concentration-gradient-driven
chemiosmotic
flow
soft
with
inner
wall
surfaces.
It
is
important
note
positioned
between
two
reservoirs
different
pH
values
bulk-ionic
concentrations.
PEL
sensitive
protonic
association–dissociation
due
presence
carboxylic
amine
groups
monomeric
units.
In
our
study,
comprehensively
demonstrate
variations
key
variables
characterizing
underlying
These
include
changing
solute
concentration
left
side
reservoir
within
range
0.1–5
mol
m−3,
adjusting
right-side
(pHR)
3–10,
varying
coefficient.
significantly
raises
near
stronger
field
generated
left-side
resulting
from
higher
concentration.
On
other
hand,
tends
decrease
lower
pHR
remains
unaffected
changes
values.
average
velocity
shows
an
increasing–decreasing
pattern
as
enhanced.
becomes
noticeably
more
pronounced
concentrations
when
accounting
for
effect.
findings
present
study
have
practical
implications
novel
nanofluidic
devices,
frequently
employed
various
engineering
applications
control
The
challenges
of
constraints
and
imprecision
in
chemical
analysis
medical
diagnosis
are
particularly
evident
the
separation
blood
cells.
Pinched
flow
fractionation,
a
passive
microfluidic
technique,
has
gained
attention
for
its
potential
size-based
cell
separation.
Enhancing
efficiency
is
crucial,
especially
through
integration
with
external
forces
or
active
methods.
This
study
explores
use
dielectrophoresis
(DEP)
magnetophoresis
(MP)
to
separate
platelet
cells,
red
white
circulating
tumor
These
were
analyzed
both
independently
simultaneously.
To
achieve
optimal
separation,
Navier–Stokes
equations,
Newton's
second
law,
system's
electric
magnetic
fields
modeled.
Experiments
conducted
branched
microchannel
assess
impact
various
parameters,
including
buffer
rate,
pinched
section
width,
applied
voltage,
field
frequency,
intensity.
revealed
approximately
99%
under
conditions
Wp=20
μm,
Q2=1250
μl/h,
f=100
kHz,
V=3
V,
M=1.5
T.
findings
demonstrate
that
while
DEP
MP
individually
enhance
their
simultaneous
application
significantly
improves
precision,
achieving
complete
optimized
system
holds
great
promise
applications
analytical
chemistry
diagnostics,
analysis.
Analytical Chemistry,
Год журнала:
2023,
Номер
95(49), С. 18188 - 18198
Опубликована: Ноя. 29, 2023
This
research
delves
into
investigating
ion
transport
behavior
within
nanochannels,
enhanced
through
modification
with
a
negatively
charged
polyelectrolyte
layer
(PEL),
aimed
at
achieving
superior
control.
The
study
examines
two
types
of
electric
fields─direct
current
and
alternating
square,
sinusoidal,
triangular,
sawtooth
waveforms─to
understand
their
impact
on
transport.
Furthermore,
the
compares
symmetric
(cylindrical)
asymmetric
(conical)
nanochannel
geometries
to
assess
influence
overlapping
electrical
double
layers
(EDLs)
in
generating
specific
electrokinetic
behaviors
such
as
ionic
rectification
(ICR)
selectivity.
employs
finite
element
method
solve
coupled
Poisson–Nernst–Planck
Navier–Stokes
equations
under
unsteady-state
conditions.
By
considering
factors
electrolyte
concentration,
soft
charge
density,
field
type,
evaluates
performance
effects
concentration
polarization,
electroosmotic
flow
(EOF),
current,
rectification,
Notably,
accounts
for
partitioning
between
PEL
simulate
real
Findings
reveal
that
conical
due
improved
EDL
overlap,
significantly
enhance
related
characteristics
compared
cylindrical
ones.
For
instance,
ηε
=
ηD
0.8,
ημ
2,
C0
20
mM,
NPEL/NA
80
mol
m–3
conditions,
average
EOF
is
0.1
0.008
m/s,
respectively.
Additionally,
explores
selectivity
based
unveiling
potential
nanochannels
gates
or
diodes.
In
ICR
remains
unity,
lower
across
waveforms
channels.
trends
are
identified
Rf,square
>
Rf,DC
Rf,triangular
Rf,sinusoidal
Rf,sawtooth
Ssawtooth
Ssinusoidal
Striangular
SDC
Ssquare
nanochannels.
Our
control
guided
by
tailored
fields
unique
geometries,
offers
versatile
applications
Analytical
Chemistry.
includes
sample
separation,
controlled
drug
delivery,
optimized
pharmaceutical
analysis,
development
advanced
biosensing
technologies
precise
chemical
analysis
detection.
These
highlight
diverse
analytical
contributions
our
methodology,
providing
innovative
solutions
challenges
biosensing.
Physics of Fluids,
Год журнала:
2023,
Номер
35(10)
Опубликована: Окт. 1, 2023
Reverse
electrodialysis
(RED)
in
soft
nanochannels
has
emerged
as
a
promising
approach
for
energy
generation.
In
this
study,
we
investigate
production
characteristics
of
RED
and
compare
the
performance
conical
cylindrical
geometries.
The
significance
concentration
ratio
influence
charged
polyelectrolyte
layer
(PEL)
properties
are
examined
to
optimize
conversion
efficiency.
mathematical
model
includes
Nernst–Planck–Poisson
equations
creeping
flow
equation
describe
ionic
transport
fluid
within
nanochannel.
geometries
nanochannel
considered,
is
modeled
pH-dependent,
allowing
unique
interfacial
interactions.
Our
results
demonstrate
that
both
exhibit
increasing
osmotic
flows
diffusion
potentials
with
ratio.
However,
cation
transfer
number
decreases
due
reduced
selectivity
higher
concentrations.
Maximum
power
generation
increases
Remarkably,
consistently
outperform
terms
maximum
efficiency
exhibits
decreasing
trend
ratio,
highlighting
importance
utilizing
small
ratios
economical
operation.
Additionally,
denser
PELs
distinct
from
electrolyte
yield
levels
across
wide
range
ratios.
comprehensive
study
provides
valuable
insight
into
nanochannels,
emphasizing
superior
These
findings
contribute
advance
nanoscale-based
technologies
sustainable
production.
This
study
explores
electroosmotic
mixing
in
microfluidic
channel
with
predefined
surface
topology,
mainly
focusing
the
effect
of
charge-dependent
slip
length
on
underlying
dynamics.
Our
analysis
addresses
need
for
precise
control
flow
and
participating
fluids
at
microscale,
crucial
medical
biomedical
applications.
In
present
work,
we
consider
a
wavy
microchannel
non-uniform
charge
to
explore
behavior.
To
this
end,
adopting
finite-element
approach,
numerically
solve
Laplace,
Poisson–Boltzmann,
convection–diffusion,
Navier–Stokes
equations
steady-state.
The
model
is
validated
by
comparing
results
available
theoretical
experimental
data.
Through
numerical
simulations,
analyzes
patterns
microchannels,
highlighting
impact
lengths
efficiency.
For
example,
diffusive
Peclet
number
200,
efficiency
drops
from
95.5%
91.5%
when
considering
length.
It
established
that
fluid
rheology,
characterized
Carreau
behavior
index,
non-trivially
influences
field
modulation
Increased
numbers
enhance
velocity,
affecting
overall
constituent
chosen
fluidic
pathway.
instance,
increasing
0.01
1.0,
discernible
trend
emerges
higher
line
density
accelerated
velocity
within
microchannel.
also
examines
efficiency,
particularly
convective
regime
transport.
These
insights
offer
practical
guidance
designing
systems
intended
enhanced
capabilities.
Additionally,
likelihood
particle
aggregation
under
shear
forces,
vital
biological
non-Newtonian
fluids,
implications
drug
delivery,
diagnostics,
technologies.
Industrial & Engineering Chemistry Research,
Год журнала:
2024,
Номер
63(24), С. 10812 - 10824
Опубликована: Июнь 4, 2024
With
the
rapid
progress
in
micro/nanofluidics,
understanding
fundamental
mechanisms
of
ionic
transport,
fluid
behavior,
and
microsystem
dynamics
is
more
crucial
than
ever.
Given
substantial
expenses
associated
with
manufacturing
such
systems,
computational
simulations
offer
a
cost-effective
avenue
for
advancing
this
industry
sector
while
minimizing
financial
burdens.
In
context,
current
study
explores
impact
electrolyte
characteristics
by
numerically
analyzing
electroosmotic
flow
(EOF)
conical
nanochannel
featuring
charged
slippery
surfaces
coated
polyelectrolyte
layer.
Two
types
electrolytic
fluids,
namely,
water
(representing
Newtonian
fluid)
blood
plasma
non-Newtonian
fluid),
were
investigated.
The
behavior
electrolytes
was
modeled
using
Bingham–Papanastasiou
model.
governing
equations
nonlinear
model,
Poisson–Nernst–Planck
Navier–Stokes
equations,
solved
finite
element
method.
Various
parameters
including
slip
length,
surface
charge
density,
soft
layer
concentration
systematically
adjusted
to
assess
three
key
aspects:
EOF,
selectivity,
rectification.
findings
revealed
that
increasing
length
significantly
enhanced
EOF
both
electrolytes.
For
instance,
platelets
within
core
increased
1.5
times
extension
from
0
10
nm.
Additionally,
applying
positive
voltage
amplified
particularly
when
wall
charges
similar.
example,
decreasing
density
−0.02
C/m2
led
1.5-fold
increase
platelet
rising
0.028
0.042
m/s.
Scientific Reports,
Год журнала:
2024,
Номер
14(1)
Опубликована: Авг. 8, 2024
Abstract
The
PNP
nanotransistor,
consisting
of
emitter,
base,
and
collector
regions,
exhibits
distinct
behavior
based
on
surface
charge
densities
various
electrolyte
concentrations.
In
this
study,
we
investigated
the
impact
density
ion
transport
within
nanotransistors
at
different
concentrations
applied
voltages.
We
employed
a
finite-element
method
to
obtain
steady-state
solutions
for
Poisson–Nernst-Planck
Navier–Stokes
equations.
ions
form
depletion
region,
influencing
ionic
current,
analyze
influence
depth
region.
Our
findings
demonstrate
that
an
increase
in
results
deeper
zone,
leading
reduction
current.
However,
very
low
concentrations,
optimal
causes
current
reach
its
lowest
value,
subsequently
increasing
with
further
increments
density.
As
such,
$${V}_{app}=+1
\text{V}$$
Vapp=+1V
$${C}_{0}=1
\text{mM}$$
C0mM
,
increases
by
25%
when
rises
from
5
20
$$\text{mC}.{\text{m}}^{-2}$$
mC.m-2
whereas
$${C}_{0}=10
10
decreases
65%
same
This
study
provides
valuable
insights
into
their
potential
applications
nanoelectronic
devices.
