Journal of the Optical Society of America B,
Journal Year:
2024,
Volume and Issue:
41(12), P. 2764 - 2764
Published: Oct. 29, 2024
This
study
introduces
a
porous
alumina
composite
structure,
incorporating
silver
on
silicon
substrate,
to
achieve
wide
range
of
color
displays.
The
structure
utilizes
the
Bragg
interference
effect
reflect
light
between
surface
and
pore
bottoms.
Fabrication
involved
magnetron
sputtering,
anodizing,
sodium
hydroxide
etching
produce
different
sizes,
depths,
film
thicknesses.
method
shifts
reflection
valleys
in
spectrum,
enabling
emission
or
absorption
across
various
wavelengths,
resulting
diverse
Experiments
reveal
that
hue
is
influenced
by
depth,
size,
thickness,
whereas
brightness
saturation
are
regulated
size
thickness.
Unlike
periodic
structural
filters
made
through
complex
methods
like
photolithography
self-assembly,
this
filter
easily
manufactured
using
simple
electrochemical
coating
techniques.
cost-effective,
simple,
controllable
ideal
for
large-scale
production
creation
high-resolution,
high-saturation
display
devices.
Small,
Journal Year:
2025,
Volume and Issue:
unknown
Published: Jan. 14, 2025
Anticounterfeiting
technologies
have
become
increasingly
crucial
due
to
the
growing
issue
of
counterfeit
goods,
particularly
in
high-value
industries.
Traditional
methods
such
as
barcodes
and
holograms
are
prone
replication,
prompting
need
for
advanced,
cost-effective,
efficient
solutions.
In
this
work,
a
practical
application
anodic
aluminum
oxide
(AAO)
membranes
presented
anticounterfeiting,
which
addresses
challenges
high
production
costs
complex
fabrication
processes.
Unlike
previous
approaches
requiring
metal
coatings
color
generation,
method
uses
commercial
foils
produce
colorful
AAO
without
layers.
Elemental
mapping
suggests
that
impurities
on
surface
contribute
enhanced
reflectivity,
aiding
photonic
crystal
formation.
A
two-step
anodization
process
creates
patterned
is
further
introduced,
with
pattern
clarity
controlled
by
time.
Additionally,
pH-responsive
film
composed
2-anilino-6-dibutylaminofluoran
(ODB-2)
thermoplastic
polyurethane
(TPU)
integrated,
enabling
dynamic
changes
under
varying
pH
conditions,
enhancing
anticounterfeiting
functionality.
This
streamlined
approach
provides
scalable
cost-effective
solution
developing
versatile
industrial
applications.
An
ideal
radiative
cooler
requires
high
emissivity
in
the
atmospheric
transparency
window
and
low
solar
energy
absorption.
Currently,
most
coolers
typically
reflect
sunlight
white,
limiting
their
aesthetics
for
various
applications.
Achieving
vibrantly
colored
poses
a
considerable
barrier,
since
colors
mostly
are
generated
by
absorbing
visible
light,
conflicting
with
demand
of
In
this
work,
we
propose
refractive
index
modulation
scheme
based
on
three-dimensional
anodic
alumina
network
(3D-AAN),
which
achieves
nonabsorbing
color-switchable
cooling
according
to
dynamic
photonic
bandgap
principle.
By
using
pulse
anodizing
selective
etching
methods,
construct
transverse
channels
inside
conventional
films,
connecting
hexagonal
vertical
form
large-scale
3D-AAN
colorful
appearance.
Outdoor
daytime
experiments
demonstrated
that
can
be
2.6
°C
lower
than
ambient
temperature
average
achieve
an
drop
7.0
silicon
substrate
under
sunlight.
Meanwhile,
tunable
color
power
achieved
reversibly
wetting
fluids.
This
provides
attractive
option
buildings
vehicles
inspires
further
development
design
cooling.
Aluminium
anodizing
in
phosphonic
acid
is
known
to
produce
anodic
aluminium
oxide
(AAO)
honeycomb
structures
with
large
interpore
distances.
However,
detailed
information
on
two-stage
and
annealing
conditions
required
for
the
crystallization
of
AAO
cell
walls
have
not
been
reported
yet.
Here,
kinetics
1
M
thermal
behaviour
resulting
studied
detail.
The
apparent
activation
energy
65
kJ
mol-1
growth
rate
reaches
15
µm
h-1
before
burning.
A
universal
approach
stable
at
high
voltages
allowing
prevent
porous
structure
rearrangement
upper
part
proposed.
It
involves
preliminary
formation
a
dense
barrier
alumina
layer
by
weak
electrolyte
second
step
acid.
pathways
obtained
are
revealed
based
differential
scanning
calorimetry,
X-ray
diffraction,
solid-state
nuclear
magnetic
resonance
techniques.
designed
program
allows
one
preserve
after
corundum
1310
°C
60
h.
possesses
stability
and,
thus,
promising
as
support
gas
sensors
fuel
cells.
