Page 346 - IJB-9-1

International Journal of Bioprinting High-performance electrospun PVDF/AgNP/Mxene fiber

Transparent electrodes, which are often used for MXenes have garnered widespread attention due to their
organic light-emitting diodes (OLEDs) , touch screens, distinctive electrical and mechanical characteristics,
[47]
and thin-film silicon solar cells, have thrived along with which make them ideal for supercapacitors, lithium-ion
the advancements in smartphone technology . Although (Li-ion) batteries [70,71] , and use in various applications ,
[72]
[48]
indium tin oxide (ITO) has been the predominant including strain sensors, energy storage [73,74] , catalysis ,
[49]
[75]
material in transparent electrodes, it is a brittle material electromagnetic interference (EMI) shielding , and
[76]
that requires a vacuum environment for production, healthcare [76–78] . MXene is an attractive alternative for
making its thin-film fabrication process costly and nanocomposites engineering due to its nanometer-
energy-consuming. Furthermore, the limited interfacial scale dimensions, huge aspect ratio, and great electric
area between the molecular chains of PVDF and typical conductivity. While the majority of published works have
conductive fillers poses a challenge to achieving adequate focused on improving dielectric, electrochemical, and
filler–dipole interactions and increasing dipole polarization thermoelectric characteristics, a number of studies have
during the electrospinning of piezoelectric PVDF or its looked into MXene’s capacity to modulate the piezoelectric
copolymers. The incorporation of conductive fillers into capabilities of piezoelectric polymers because of its
polymer solutions has the potential to increase the intensity exceptional conductivity, layer structure, and active surface.
of the electric field, thus resulting in an increase in the Nevertheless, it is important to select an appropriate
polarization of polymer dipoles at a constant voltage [50–53] . matrix to achieve high levels of flexibility, porosity, and
Several conductive active nanofillers have been employed permeability. Research has revealed that combining an
to build conductive networks on various substrates, such MXene with PVDF would result in a composite with high
as graphene (rGO) , carbon nanotubes (CNTs) , permittivity and compatibility. Since conductive fillers and
[55]
[54]
AgNPs , MXene , and silver nanowires (AgNWs) , a high dielectric constant can improve the piezoelectric
[56]
[57]
[58]
showing excellent conductivity and transmissivity; all of properties of a polymer, it is anticipated that MXenes would
which have been developed as alternatives to ITO [59,60] . be excellent materials for increasing the piezoelectric
The use of nanocomposites strategy, with an emphasis capabilities of PVDF and its copolymers [79–81] . MXene can
on the inclusion of conductive nanofillers, represented promote the formation of the piezoelectric phase, bring
by graphene and carbon nanotubes [53,61] , is a direct about a high interfacial coupling effect, and provide an
approach to improving piezoelectricity, and therefore the improved piezoelectric response in PVDF, much like the
sensitivity of PVDF. By using a small amount of conductive conductive reinforcements, represented by graphene and
nanofillers, it is possible to increase the piezoelectric phase carbon nanotubes. Additionally, it should be highlighted
development, produce strong interfacial coupling effects, that MXene nanosheets have a stronger reinforcing effect
and preserve the high flexibility of PVDF, all of which are than graphene and carbon nanotubes at the same loading
useful for increasing the sensitivity of nanocomposites. amount. For instance, the maximum reported piezoelectric
Silver is an attractive material on account of its coefficient d of MXene/PVDF hybrid film is 43 pC/N,
33
antibacterial properties, electrical conductivity, and compared to that of carbon nanotubes/PVDF, which
relatively low cost. Although AgNPs have enormous is 23 pC/N. Meanwhile, it has been discovered that the
surface areas that are rich in electrons, their vulnerability to presence of MXene nanosheet improves the mechanical
oxygen (O ) prevents them from being employed directly. performance, i.e., the young’s modulus, of PVDF. MXene/
2
A biocompatible and reducible PVDF has been created PVDF hybrid films have a greater voltage sensitivity Sv of
to prevent the oxidation of AgNPs and enhance their up to 0.0480 V/N in detecting force when compared to
electrical stability [62,63] . Furthermore, AgNPs have been traditional PVDF-based force sensors (Sv = 0.0221 V/N)
widely used as fillers in polymer matrices in view of their due to their outstanding piezoelectric response and high
[82]
excellent ability to improve the crystal β-phase structure Young’s modulus .
of PVDF [64,65] . A β-phase content of approximately 80% The intercalated MXene in composite nanofibers is
can be achieved with the addition of AgNPs to PVDF. The spread out evenly, which not only solves the problem
interaction between electron-rich AgNPs and the F atoms of MXene aggregation but also enables the composite
in PVDF increases the piezoelectricity and the β-phase materials to self-reduce AgNPs in situ. More importantly,
content, resulting in electrically conductive particles in wearable electronics incorporating MXene/AgNP
nanofibers upon electrospinning, and thereby improving composites have significant EMI shielding properties,
polarization [62,65–69] . allowing them to protect the human body from potentially
MXenes are novel two-dimensional (2D) materials dangerous electromagnetic radiation. A new generation
displaying excellent aqueous dispersion and electrical of multipurpose wearable electronic devices based on
conductivity as well as abundant surface functional groups. MXene/AgNP materials is expected to be launched [83–86] .

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Volume 9 Issue 1 (2023)olume 9 Issue 1 (2023) 338 https://doi.org/10.18063/ijb.v9i1.647