Arabian Journal of Chemistry,
Journal Year:
2021,
Volume and Issue:
15(2), P. 103604 - 103604
Published: Dec. 8, 2021
Fluorescent
photochromism
has
been
applied
as
an
attractive
approach
for
the
production
of
effective
authentication
substrates
to
show
dual-mode
secure
encoding.
In
current
study,
novel
photochromic
and
fluorescent
nanocomposite
ink
was
developed
introduce
a
stamped
film
with
strong
emission
anti-counterfeiting
purposes.
Inorganic/organic
from
lanthanide-doped
aluminate
(LDA)
dispersed
in
poly(acrylic
acid)-based
binder.
To
produce
transparent
film,
LDA
must
be
well
solution.
The
effectively
onto
cellulose
documents
followed
thermal
fixation.
Homogeneous
layer
paper
surface
providing
look
ability
switch
green
beneath
ultraviolet
illustrated
by
CIE
Lab.
were
studied
photoluminescence
spectra
absorption
peak
at
364
nm,
fluorescence
band
438
nm.
induced
security
encoding
visible
light
turning
into
greenish-yellow
indicating
bathochromic
shift.
synthesized
nanoparticle
form
characterized
transmission
electron
microscopy
(TEM),
X-ray
diffraction
(XRD)
energy-dispersive
spectroscopy
(EDS).
morphological
properties
examined
infrared
(FTIR),
scan
microscope
(SEM),
EDS,
(XRF).
sheets
displayed
efficiently
reversible
without
fatigue
under
lights.
rheologies
prepared
photoluminescent
inks
mechanical
performance
investigated.
Chemical Reviews,
Journal Year:
2021,
Volume and Issue:
122(5), P. 4976 - 5067
Published: Nov. 8, 2021
Colloidal
self-assembly
refers
to
a
solution-processed
assembly
of
nanometer-/micrometer-sized,
well-dispersed
particles
into
secondary
structures,
whose
collective
properties
are
controlled
by
not
only
nanoparticle
property
but
also
the
superstructure
symmetry,
orientation,
phase,
and
dimension.
This
combination
characteristics
makes
colloidal
superstructures
highly
susceptible
remote
stimuli
or
local
environmental
changes,
representing
prominent
platform
for
developing
stimuli-responsive
materials
smart
devices.
Chemists
achieving
even
more
delicate
control
over
their
active
responses
various
practical
stimuli,
setting
stage
ready
fully
exploiting
potential
this
unique
set
materials.
review
addresses
colloids
nanostructured
We
first
delineate
driven
forces
different
length
scales.
A
concepts
equations
outlined
controlling
crystal
growth,
appreciating
importance
particle
connectivity
in
creating
responsive
superstructures.
then
present
working
mechanisms
strategies
engineering
assemblies.
The
underpinning
separation
systematically
introduced,
allowing
tuning
precise
prediction
response
external
stimuli.
Various
exciting
applications
these
summarized
with
specific
focus
on
structure-property
correlation
functional
conclude
summary
existing
challenges
provide
perspective
further
advances
next
generation.
Chemical Reviews,
Journal Year:
2021,
Volume and Issue:
121(21), P. 13013 - 13050
Published: Sept. 7, 2021
Optically
variable
devices
(OVDs)
are
in
tremendous
demand
as
optical
indicators
against
the
increasing
threat
of
counterfeiting.
Conventional
OVDs
exposed
to
danger
fraudulent
replication
with
advances
printing
technology
and
widespread
copying
methods
security
features.
Metasurfaces,
two-dimensional
arrays
subwavelength
structures
known
meta-atoms,
have
been
nominated
a
candidate
for
new
generation
they
exhibit
exceptional
behaviors
that
can
provide
more
robust
solution
anti-counterfeiting.
Unlike
conventional
OVDs,
metasurface-driven
(mOVDs)
contain
multiple
responses
single
device,
making
them
difficult
reverse
engineered.
Well-known
examples
mOVDs
include
ultrahigh-resolution
structural
color
printing,
various
types
holography,
polarization
encoding.
In
this
review,
we
discuss
mOVDs.
The
fundamentals
plasmonic
dielectric
metasurfaces
presented
explain
how
be
manipulated.
Then,
monofunctional,
tunable,
multifunctional
discussed.
We
follow
up
discussion
fabrication
needed
realize
these
mOVDs,
classified
into
prototyping
manufacturing
techniques.
Finally,
an
outlook
classification
respect
their
capacity
level.
believe
newly
proposed
concept
may
bring
about
era
anticounterfeit
leveraging
novel
concepts
nano-optics
nanotechnology.
Advanced Functional Materials,
Journal Year:
2021,
Volume and Issue:
31(52)
Published: Sept. 24, 2021
Abstract
Fluorescent
patterns
showing
the
unique
color
change
in
response
to
external
stimuli
are
of
considerable
interest
for
their
applications
anti‐counterfeiting.
However,
there
is
still
a
lack
intelligent
fluorescent
with
high‐security
levels,
presenting
dynamic
display
encrypted
information.
In
this
study,
organohydrogel
fabricated
through
two‐step
interpenetrating
technique,
leading
co‐existence
naphthalimide
moieties
(DEAN,
green‐yellow
monomer)
contained
Poly(N,N‐dimethylacrylamide)
(PDMA)
hydrogel
network
and
Polyoctadecyl
methacrylate
(PSMA)
organogel
bearing
spiropyran
(SPMA,
photochromic
monomer).
Due
heterogeneous
networks,
fluorescence
goes
continuous
from
green
yellow
red
via
resonance
energy
transfer
(FRET)
process
extension
irradiation
time.
addition,
when
H
+
introduced
into
system,
SP
units
exhibit
transformation
protonated
merocyanine
(MCH
)
rather
than
(MC)
under
UV
light,
which
inhibits
FRET
process.
By
selectively
being
treated
,
can
act
as
an
effective
platform
encrypting
secret
information,
making
them
more
difficult
forge.
Angewandte Chemie International Edition,
Journal Year:
2022,
Volume and Issue:
61(33)
Published: June 15, 2022
Though
fluorescence-tag-based
anti-counterfeiting
technology
has
distinguished
itself
with
cost-effective
features
and
huge
information
loading
capacity,
the
clonable
decryption
process
of
spatial-resolved
cannot
meet
requirements
for
high-security-level
anti-counterfeiting.
Herein,
we
demonstrate
a
spatial-time-dual-resolved
system
based
on
new
organic-inorganic
hybrid
halides
BAPPZn2
(Cly
Br1-y
)8
(BAPP=1,4-bis(3-ammoniopropyl)piperazinium,
y=0-1)
ultra-long
room-temperature
phosphorescence
(RTP).
Remarkably,
afterglow
lifetime
can
be
facilely
tuned
by
regulating
halide-induced
heavy-atom
effect
identified
naked
eyes
or
help
simple
machine
vision
system.
Therefore,
short-lived
unicolor
fluorescence
lasting-time-tunable
RTP
provide
prerequisites
unicolor-time-resolved
anti-counterfeiting,
which
lowers
decryption-device
further
provides
design
strategy
advanced
portable
technology.
Advanced Functional Materials,
Journal Year:
2021,
Volume and Issue:
31(47)
Published: Aug. 21, 2021
Abstract
Hydrochromic
materials
have
attracted
widespread
attention
in
the
fields
of
anti‐counterfeiting
because
their
ability
reversible
light
absorption
and/or
emission
properties
response
to
water.
Here,
for
first
it
is
demonstrated
that
ternary
copper
halides
Cs
3
Cu
2
I
5
nanocrystals
(NCs)
possess
excellent
hydrochromic
properties.
The
prepared
NCs
films
can
dynamically
extract
and
insert
CsI
by
exposing/removing
water
realize
conversion
between
blue‐emissive
yellow‐emissive
CsCu
.
Interestingly,
polymethyl
methacrylate
(PMMA)
coated
effectively
avoid
extraction
maintain
long‐term
stability
Further,
water‐resistant
@PMMA
are
used
as
inks
synergistically
act
on
information
achieve
multiple
encryption
effects,
which
clearly
identify
authenticate
effective
after
moisture
decryption.
Importantly,
pattern
be
re‐encrypted
invalid
evaporation.
In
addition,
has
during
repeated
encryption/decryption
cycles,
not
only
balance
accessibility
but
also
improve
security
information.
This
new
discovery
may
deepen
understanding
provide
options
design
Nano-Micro Letters,
Journal Year:
2021,
Volume and Issue:
13(1)
Published: Sept. 16, 2021
Near-infrared
(NIR),
particularly
NIR-containing
dual-/multi-mode
afterglow,
is
very
attractive
in
many
fields
of
application,
but
it
still
a
great
challenge
to
achieve
such
property
materials.
Herein,
we
report
facile
method
prepare
green
and
NIR
dual-mode
afterglow
carbon
dots
(CDs)
through
situ
embedding
o-CDs
(being
prepared
from
o-phenylenediamine)
into
cyanuric
acid
(CA)
matrix
(named
o-CDs@CA).
Further
studies
reveal
that
the
afterglows
o-CDs@CA
originate
thermal
activated
delayed
fluorescence
(TADF)
room
temperature
phosphorescence
(RTP)
o-CDs,
respectively.
In
addition,
formation
covalent
bonds
between
CA,
presence
multiple
fixation
rigid
effects
triplet
states
are
confirmed
be
critical
for
activating
observed
afterglow.
Due
shorter
lifetime
insensitiveness
human
vision
RTP
o-CDs@CA,
completely
covered
by
TADF
during
directly
observing.
The
signal,
however,
can
readily
captured
if
an
optical
filter
(cut-off
wavelength
600
nm)
being
used.
By
utilizing
these
unique
features,
applications
anti-counterfeiting
information
encryption
have
been
demonstrated
with
confidentiality.
Finally,
as-developed
was
applicable
other
kinds
CDs
achieving
or
enhancing
their
performances.
