ACS Applied Polymer Materials,
Journal Year:
2024,
Volume and Issue:
6(11), P. 6864 - 6874
Published: June 5, 2024
Thermally
induced
crystal
structure
changes
in
semicrystalline
polymers
involve
solid-to-solid
transition
or
melting
of
the
starting
form
followed
by
recrystallization
into
different
forms.
Understanding
such
crystal-to-crystal
transitions
controlling
chain
mobility
amorphous
chains
is
rarely
studied.
Herein,
we
chose
poly(3-hydroxybutyrate)
(PHB)
to
investigate
temperature-induced
structural
bulk
and
aerogel
samples
present
role
on
reorganization
during
heating.
Aerogels
PHB
were
prepared
freeze-drying
thermoreversible
gels
films
hot
pressing
pellets.
Both
aerogels
crystallized
α
form.
We
observed
a
major
upon
heating
prior
was
not
melt-crystallized
speculate
that
enhanced
tie
are
between
lamellar
crystals
triggered
conformational
change
from
T2G2
helical
all-trans
conformation
(T′TT̅′T̅)
within
lattice
resulted
(α
+
β)
transition.
Journal of Materials Chemistry C,
Journal Year:
2024,
Volume and Issue:
12(21), P. 7775 - 7783
Published: Jan. 1, 2024
An
ice
dissolution-normal
pressure
drying
strategy
based
on
graphite
nanosheet
was
proposed
to
prepare
porous
PVDF
foams,
which
own
exceptional
microwave
absorption
(RL
max
=
−57.68
dB,
EAB
6.86
GHz)
and
compression
strength
(300.9
kPa).
Soft Science,
Journal Year:
2025,
Volume and Issue:
5(1)
Published: Jan. 18, 2025
Heterointerface
engineering
has
drawn
considerable
interest
in
tuning
interfacial
polarization
and
promoting
impedance
matching.
Therefore,
it
become
a
key
strategy
for
optimizing
electromagnetic
wave
(EMW)
absorption.
This
comprehensive
review
primarily
focused
on
the
EMW
absorbing
strategies
of
polymer-based
materials,
emphasizing
critical
developments
heterointerface
engineering.
A
possible
mechanism
materials
was
proposed,
synergism
multi-components,
microstructure
design,
Key
innovations
structural
design
such
as
porous
structure,
multilayered
segregated
structure
are
explored,
highlighting
their
contributions
to
enhancing
Also,
highlights
latest
research
progress
advanced
conductive
insulating
with
desirable
absorption
performance;
fabrication
methods,
structures,
properties,
mechanisms
were
elucidated
detail.
challenges
presented
followed
by
some
future
perspectives.
Advanced Materials,
Journal Year:
2024,
Volume and Issue:
36(24)
Published: April 10, 2024
Abstract
Designing
nanocomposite
hydrogels
with
oriented
nanosheets
has
emerged
as
a
promising
toolkit
to
achieve
preferential
performances
that
go
beyond
their
disordered
counterparts.
Although
current
fabrication
strategies
via
electric/magnetic
force
fields
have
made
remarkable
achievements,
they
necessitate
special
properties
of
and
suffer
from
an
inferior
orientation
degree
nanosheets.
Herein,
facile
universal
approach
is
discovered
elaborate
MXene‐based
highly
oriented,
heterogeneous
architecture
by
virtue
supergravity
replace
conventional
fields.
The
key
such
leverage
bidirectional,
force‐tunable
attributes
containing
coupled
orthogonal
shear
centrifugal
field
for
steering
high‐efficient
movement,
pre‐orientation,
stacking
MXene
in
the
bottom.
Such
synergetic
effect
allows
yielding
high‐orientation
MXene‐rich
layer
(orientation
degree,
f
=
0.83)
polymer‐rich
layer.
authors
demonstrate
high‐orientation,
deliver
extraordinary
electromagnetic
interference
shielding
effectiveness
55.2
dB
at
12.4
GHz
yet
using
super‐low
0.3
wt%,
surpassing
most
hydrogels‐based
materials.
This
versatile
supergravity‐steered
strategy
can
be
further
extended
arbitrary
including
MoS
2
,
GO,
C
3
N
4
offering
paradigm
development
nanocomposites.
Lightweight
flexible
piezoelectric
devices
have
garnered
significant
interest
over
the
past
few
decades
due
to
their
applications
as
energy
harvesters
and
wearable
sensors.
Among
different
piezoelectrically
active
polymers,
poly(vinylidene
fluoride)
its
copolymers
attracted
considerable
attention
for
conversion
high
flexibility,
thermal
stability,
biocompatibility.
However,
orientation
of
polymer
chains
self-poling
under
mild
conditions
is
still
a
challenging
task.
Herein,
anisotropic
fluoride-co-trifluoroethylene)
(PVDF-TrFE)/MXene
aerogel-based
generators
with
highly
oriented
MXene
fillers
are
fabricated.
The
unidirectional
freezing
hybrid
solution
facilitates
strain-induced
alignment
nanosheets
along
solvent
crystal
growth
direction
robust
interactions
between
(O–H/F
groups)
PVDF-TrFE
(F–C/C–H
groups).
Consequently,
this
process
fosters
development
abundant
electroactive
β
crystals
preferred
characteristics,
leading
formation
intrinsic
self-oriented
dipoles
within
aerogel.
As
result,
properties
fully
harnessed
without
any
complex
poling
process,
resulting
in
an
open-circuit
voltage
around
40
V
loading
3
wt
%
aerogel,
which
2-fold
higher
than
that
corresponding
isotropic
aerogel
where
randomly
aligned.
Furthermore,
developed
nanogenerator
was
demonstrated
tactile
sensor
showed
sensitivity
9.6
V/N
lower
forces
(less
2
N)
1.3
force
regime
(2
N
<
10
N).
strategy
adopted
here
not
only
provides
enhancement
crystalline
form
but
also
paves
avenue
toward
developing
self-powered
using
polymers.
