Highly efficient single-material organic solar cells (SMOCs) based on fullerene-grafted polythiophenes were fabricated by incorporating electrospun one-dimensional (1D) nanostructures obtained from polymer chain stretching. Poly(3-alkylthiophene) chains were chemically tailored in order to reduce the side effects of charge recombination which severely affected SMOC photovoltaic performance. This enabled us to synthesize a donor− acceptor conjugated copolymer with high solubility, molecular weight, regioregularity, and fullerene content. We investigated the correlations among the active layer hierarchical structure given by the inclusion of electrospun nanofibers and the solar cell photovoltaic properties. The results indicated that SMOC efficiency can be strongly increased by optimizing the supramolecular and nanoscale structure of the active layer, while achieving the highest reported efficiency value (PCE = 5.58%). The enhanced performance may be attributed to well-packed and properly oriented polymer chains. Overall, our work demonstrates that the active material structure optimization obtained by including electrospun nanofibers plays a pivotal role in the development of efficient SMOCs and suggests an interesting perspective for the improvement of copolymerbased photovoltaic device performance using an alternative pathway.
Multifunctional
nanomaterials with the ability to respond to near-infrared
(NIR) light stimulation are vital for the development of highly efficient
biomedical nanoplatforms with a polytherapeutic approach. Inspired
by the mesoglea structure of jellyfish bells, a biomimetic multifunctional
nanostructured pillow with fast photothermal responsiveness for NIR
light-controlled on-demand drug delivery is developed. We fabricate
a nanoplatform with several hierarchical levels designed to generate
a series of controlled, rapid, and reversible cascade-like structural
changes upon NIR light irradiation. The mechanical contraction of
the nanostructured platform, resulting from the increase of temperature
to 42 °C due to plasmonic hydrogel–light interaction,
causes a rapid expulsion of water from the inner structure, passing
through an electrospun membrane anchored onto the hydrogel core. The
mutual effects of the rise in temperature and water flow stimulate
the release of molecules from the nanofibers. To expand the potential
applications of the biomimetic platform, the photothermal responsiveness
to reach the typical temperature level for performing photothermal
therapy (PTT) is designed. The on-demand drug model penetration into
pig tissue demonstrates the efficiency of the nanostructured platform
in the rapid and controlled release of molecules, while the high biocompatibility
confirms the pillow potential for biomedical applications based on
the NIR light-driven multitherapy strategy.
Materials for the treatment of cancer have been studied comprehensively over the past few decades. Among the various kinds of biomaterials, polymer-based nanomaterials represent one of the most interesting research directions in nanomedicine because their controlled synthesis and tailored designs make it possible to obtain nanostructures with biomimetic features and outstanding biocompatibility. Understanding the chemical and physical mechanisms behind the cascading stimuli-responsiveness of smart polymers is fundamental for the design of multifunctional nanomaterials to be used as photothermal agents for targeted polytherapy. In this review, we offer an in-depth overview of the recent advances in polymer nanomaterials for photothermal therapy, describing the features of three different types of polymer-based nanomaterials. In each case, we systematically show the relevant benefits, highlighting the strategies for developing light-controlled multifunctional nanoplatforms that are responsive in a cascade manner and addressing the open issues by means of an inclusive state-of-the-art review. Moreover, we face further challenges and provide new perspectives for future strategies for developing novel polymeric nanomaterials for photothermally assisted therapies.
a In this article, we report on the production by electrospinning of P3HT/PEO, P3HT/PEO/GO, and P3HT/PEO/rGO nanofibers in which the filler is homogeneously dispersed and parallel oriented along the fibers axis. The effect of nanofillers' presence inside nanofibers and GO reduction was studied, in order to reveal the influence of the new hierarchical structure on the electrical conductivity and mechanical properties. An in-depth characterization of the purity and regioregularity of the starting P3HT as well as the morphology and chemical structure of GO and rGO was carried out. The morphology of the electrospun nanofibers was examined by both scanning and transmission electron microscopy. The fibrous nanocomposites are also characterized by differential scanning calorimetry to investigate their chemical structure and polymer chains arrangements. Finally, the electrical conductivity of the electrospun fibers and the elastic modulus of the single fibers are evaluated using a four-point probe method and atomic force microscopy nanoindentation, respectively. The electrospun materials crystallinity as well as the elastic modulus increase with the addition of the nanofillers while the electrical conductivity is positively influenced by the GO reduction.
Intrinsically
conducting polymers (ICPs) are widely used to fabricate
biomaterials; their application in neural tissue engineering, however,
is severely limited because of their hydrophobicity and insufficient
mechanical properties. For these reasons, soft conductive polymer
hydrogels (CPHs) are recently developed, resulting in a water-based
system with tissue-like mechanical, biological, and electrical properties.
The strategy of incorporating ICPs as a conductive component into
CPHs is recently explored by synthesizing the hydrogel around ICP
chains, thus forming a semi-interpenetrating polymer network (semi-IPN).
In this work, a novel conductive semi-IPN hydrogel is designed and
synthesized. The hybrid hydrogel is based on a poly(
N
-isopropylacrylamide-
co
-
N
-isopropylmethacrylamide)
hydrogel where polythiophene is introduced as an ICP to provide the
system with good electrical properties. The fabrication of the hybrid
hydrogel in an aqueous medium is made possible by modifying and synthesizing
the monomers of polythiophene to ensure water solubility. The morphological,
chemical, thermal, electrical, electrochemical, and mechanical properties
of semi-IPNs were fully investigated. Additionally, the biological
response of neural progenitor cells and mesenchymal stem cells in
contact with the conductive semi-IPN was evaluated in terms of neural
differentiation and proliferation. Lastly, the potential of the hydrogel
solution as a 3D printing ink was evaluated through the 3D laser printing
method. The presented results revealed that the proposed 3D printable
conductive semi-IPN system is a good candidate as a scaffold for neural
tissue applications.
Quantum dots are of growing interest
as emissive materials in light-emitting
devices. Here first we report the formation of highly luminescent
organic capped colloidal cadmium sulfide (CdS) nanoparticles having
the highest photoluminescence quantum yield of 69% in solutions and
34% in neat thin films in the near-infrared range. Second, we also
show efficient electroluminescence in the near-infrared from solution
processed hybrid light emitting diodes (LEDs) based on such colloidal
CdS quantum dots embedded in an organic semiconductor matrix forming
a nanocomposite active layer. We also discuss the device structure
and role of the doped active layer in efficiency improvement. With
optimized active layer thickness and concentration of QDs, the device
exhibits an external electroluminescence quantum efficiency of 0.62%
at a peak emission wavelength of 760 nm, providing a route to solution
processable flexible light sources for biosensors and medicine.
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