Hierarchical electrodes with superior cycling performance using porous material based on cellulose nanofiber as flexible substrate.

The development and application of flexible electrodes with extended cycle life have long been a focal point in the field of energy research. In this study, positively charged polyethylene imine (PEI) and conductive polymer poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) with negative charge were alternately deposited onto a cellulose nanofiber (CNF) porous material utilizing pressure gradient-assisted layer-by-layer (LbL) self-assembly technology. The flexible substrate, characterized by a three-dimensional porous structure reinforced with stiff CNF, not only facilitated high charge storage but also enhanced the electrode's cycling life by reducing the volume changes of PEDOT:PSS. Furthermore, the exceptional wettability of PEI by the electrolyte could promote efficient charge transport within the electrode. The electrode with 10 PEI/PEDOT:PSS bilayer exhibits a capacitance of 63.71 F g-1 at the scan rate of 5 mV s-1 and a remarkable capacitance retention of 128 % after 3000 charge-discharge cycles. The investigation into the nanoscale layers of the LbL multilayer structure indicated that the exceptional cyclic performance was primarily attributed to the spatial constraints imposed by the rigid porous substrate layered structure on the deformation of PEDOT:PSS. This work is expected to make a significant contribution to the development of electrodes with high charge storage capacity and ultra-long cycling life.

Development of an Elastin-like Polypeptide-Based Nucleic Acid Delivery System Targeted to EGFR+ Bladder Cancer Cells Using a Layer-by-Layer Approach.

Nucleic acid (NA)-based therapies are revolutionizing biomedical research through their ability to control cellular functions at the genetic level. This work demonstrates a versatile elastin-like polypeptide (ELP) carrier system using a layer-by-layer (LbL) formulation approach that delivers NA cargos ranging in size from siRNA to plasmids. The components of the system can be reconfigured to modulate the biochemical and biophysical characteristics of the carrier for engaging the unique features of the biological target. We show the physical characterization and biological performance of LbL ELP nucleic acid nanoparticles (LENNs) in murine and human bladder tumor cell lines. Targeting bladder tumors is difficult owing to the constant influx of urine into the bladder, leading to low contact times (typically <2 h) for therapeutic agents delivered via intravesical instillation. LENN complexes bind to bladder tumor cells within 30 min and become rapidly internalized to release their NA cargo within 60 min. Our data show that a readily adaptable NA-delivery system has been created that is flexible in its targeting ability, cargo size, and disassembly kinetics. This approach provides an alternative path to either lipid nanoparticle formulations that suffer from inefficiency and physicochemical instability or viral vectors that are plagued by manufacturing and immune rejection challenges. This agile ELP-based nanocarrier provides an alternative route for nucleic acid delivery using a biomanufacturable, biodegradable, biocompatible, and highly tunable vehicle capable of targeting cells via engagement with overexpressed cell surface receptors.

Layer-by-layer assembly of a [Fe-(pyrazine){Pd(CN)4}] spin crossover thin film.

[Fe-(pyrazine){Pd(CN)4}] (pyrazine = pz) thin films were fabricated using a layer-by-layer assembly approach, a method known to be tunable, versatile, and scalable, since thin films are better-suited for industrial applications. In this study, [Fe-(pz){Pd(CN)4}] powder was synthesized, and the results obtained from a vibrating sample magnetometer verified the presence of an abrupt hysteresis loop with widths of 45 K centered around 300 K, indicating good cooperativity. Super conducting quantum interference device magnetometry results indicated a slow spin transition with temperature but with evidence of hysteresis for thin film samples. X-ray absorption analysis provided further support of the spin crossover behavior but differs from the magnetometry because the spin state transition at the surface differs from the bulk of the thin film. X-ray photoelectron spectroscopy provided some insight into issues with the film deposition process and multiplex fitting was used to further support the claim that the surface of the film is different than the bulk of the film.

An investigation of functionalized chitosan and alginate multilayer conformal nanocoating on mouse beta cell spheroids as a model for pancreatic islet transplantation.

Multilayer conformal coatings have been shown to provide a nanoscale barrier between cells and their environment with adequate stability, while regulating the diffusion of nutrition and waste across the cell membrane. The coating method aims to minimize capsule thickness and implant volume while reducing the need for immunosuppressive drugs, making it a promising approach for islet cell encapsulation in clinical islet transplantation for the treatment of Type 1 diabetes. This study introduces an immunoprotective nanocoating obtained through electrostatic interaction between quaternized phosphocholine-chitosan (PC-QCH) and tetrahydropyran triazole phenyl-alginate (TZ-AL) onto mouse ß-cell spheroids. First, successful synthesis of the proposed polyelectrolytes was confirmed with physico-chemical characterization. A coating with an average thickness of 540 nm was obtained with self-assembly of 4-bilayers of PC-QCH/TZ-AL onto MIN6 ß-cell spheroids. Surface coating of spheroids did not affect cell viability, metabolic activity, or insulin secretion, when compared to non-coated spheroids. The exposure of the polyelectrolytes to THP-1 monocyte-derived macrophages lead to a reduced level of TNF-α secretion and exposure of coated spheroids to RAW264.7 macrophages showed a decreasing trend in the secretion of TNF-α and IL-6. In addition, coated spheroids were able to establish normoglycemia when implanted into diabetic NOD-SCID mice, demonstrating in vivo biocompatibility and cellular function. These results demonstrate the ability of the PC-QCH/TZ-AL conformal coating to mitigate pro-inflammatory responses from macrophages, and thus can be a promising candidate towards nanoencapsulation for cell-based therapy, particularly in type 1 diabetes, where the insulin secreting ß-cells are subjected to inflammation and immune cell attack.

Hierarchical Incorporation of Reduced Graphene Oxide into Anisotropic Cellulose Nanofiber Foams Improves Their Thermal Insulation.

Anisotropic cellulose nanofiber (CNF) foams represent the state-of-the-art in renewable insulation. These foams consist of large (diameter >10 µm) uniaxially aligned macropores with mesoporous pore-walls and aligned CNF. The foams show anisotropic thermal conduction, where heat transports more efficiently in the axial direction (along the aligned CNF and macropores) than in the radial direction (perpendicular to the aligned CNF and macropores). Here we explore the impact on axial and radial thermal conductivity upon depositing a thin film of reduced graphene oxide (rGO) on the macropore walls in anisotropic CNF foams. To obtain rGO films on the foam walls we developed liquid-phase self-assembly to deposit rGO in a layer-by-layer fashion. Using electron and ion microscopy, we thoroughly characterized the resulting rGO-CNF foams and confirmed the successful deposition of rGO. These hierarchical rGO-CNF foams show lower radial thermal conductivity (λr) across a wide range of relative humidity compared to CNF control foams. Our work therefore demonstrates a potential method for improved thermal insulation in anisotropic CNF foams and introduces versatile self-assembly for postmodification of such foams.

Complex Sequence-Defined Heteropolymers Enable Controlled Film Growth in Layer-By-Layer Assembly.

Digitally-encoded poly(phosphodiesters) (d-PPDE) with highly complex primary structures are evaluated for layer-by-layer (LbL) assembly. To be easily decoded by mass spectrometry (MS), these digital polymers contain many different monomers: 2 coding units allowing binary encryption, 1 cleavable spacer allowing controlled MS fragmentation, and 3 mass tags allowing fragment identification. These complex heteropolymers are therefore composed of 6 different motifs. Despite this strong sequence heterogeneity, it is found that they enable a highly controlled LbL film formation. For instance, a regular growth is observed when alternating the deposition of negatively-charged d-PPDE and positively-charged poly(allyl amine hydrochloride) (PAH). Yet, in this approach, the interdistance between consecutive coded d-PPDE layers remains relatively small, which may be an issue for data storage applications, especially for the selective decoding of the stored information. Using poly(sodium 4-styrene sulfonate) (PSS) as an intermediate non-coded polyanion, it is shown that a controlled interdistance between d-PPDE layers can be easily achieved, while still maintaining a regular LbL growth. Last but not least, it is found in this work that d-PPDE of relatively small molecular weight (i.e., significantly smaller than those of PAH and PSS) still enables a controlled LbL assembly.

Cephalopods' Skin-Inspired Design of Nanoscale Electronic Transport Layers for Adaptive Electrochromic Tuning.

Cephalopods can change their skin color by using high-speed electron transduction among receptors, neural networks, and pigmentary effectors. However, it remains challenging to realize a neuroelectrical transmission system like that found in cephalopods, where electrons/ions transmit on nanoscale, which is crucial for fast adaptive electrochromic tuning. Inspired by that, hereby an ideal, rapidly responsive, and multicolor electrochromic biomimetic skin is introduced. Specifically, the biomimetic skin comprises W18O49 nanowires (NWs) that are either colorless or blue, Au nanoparticles@polyaniline (Au NPs@PANI) ranging from green to pink, and a flexible conductive substrate. As the applied voltage changes from 0.4 V to -0.7 V and back to 0 V, the color of the biomimetic skin transforms from green to blue and ultimately to pink. This color change is attributed to the electrically induced redox reaction of Au NPs@PANI and W18O49 NWs, triggered by the transfer of electrons and ions. Furthermore, the high versatility and adaptability of electrical stimulus enable the creation of a highly interactive electrochromic biomimetic skin system through the integration of sensitive acoustic sensors, providing a perfect environment-responsive platform. This work provides a biomimetic multicolor electrochromic skin that depends on electron/ion transfer on nanoscale, expands potential uses for camouflage skin.

Heparan Sulfate-Collagen Surface Multilayers Support Serum-Free Microcarrier Culture of Mesenchymal Stem Cells.

The increasing cost of high-volume cultures and dependence on serum and growth factor supplementation limit the affordability of mesenchymal stromal cell (MSC) therapies. This has spurred interest in developing strategies that support adherent cell expansion while reducing raw material costs. Culture surfaces coated with sulfated glycosaminoglycans (GAGs), specifically heparan sulfate (HS), are an alternative to prolong growth factor retention in cell cultures. Unlike heparin, recombinant HS (rHS) offers strong binding affinity for multiple growth factors and extracellular matrix components, such as collagen I, without undesirable anticoagulant effects or xenobiotic health risks. The potential of rHS as a factor reservoir in MSC cultures remains underexplored. This study investigated the impact of rHS on the growth and anti-inflammatory properties of undifferentiated bone marrow MSCs in both planar and microcarrier-based cultures. It was hypothesized that rHS would enable MSC growth with minimal growth factor supplementation in a sulfation level-dependent manner. Cell culture surfaces were assembled via the layer-by-layer (LbL) method, combining alternating collagen I (COL) and rHS. These bilayers support cell adhesion and enable the incorporation of distinct sulfation levels on the culture surface. Examination of pro-mitogenic FGF and immunostimulatory IFN-γ release dynamics confirmed prolonged availability and sulfate level dependencies. Sulfated surfaces supported cell growth in low serum (2% FBS) and serum-free (SF) media at levels equivalent to standard culture conditions. Cell growth on rHS-coated surfaces in SF was comparable to that on heparin-coated surfaces and commercial surface-coated microcarriers in low serum. These growth benefits were observed in both planar and microcarrier (µCs) cultures. Additionally, rHS surfaces reduced ß-galactosidase expression relative to uncoated surfaces, delaying cell senescence. Multivariate analysis of cytokines in conditioned media indicated that rHS-containing surfaces enhanced cytokine levels relative to uncoated surfaces during IFN-γ stimulation and correlated with decreased pro-inflammatory macrophage activity. Overall, utilizing highly sulfated rHS with COL reduces the need for exogenous growth factors and effectively supports MSC growth and anti-inflammatory potency on planar and microcarrier surfaces under minimal factor supplementation.

Multifunctional piezoelectric surfaces enhanced with layer-by-layer coating for improved osseointegration and antibacterial performance.

Implant failure is primarily caused by poor osseointegration and bacterial colonization, which demands readmissions and revision surgeries to correct it. A novel approach involves engineering multifunctional interfaces using piezoelectric polyvinylidene fluoride (PVDF) materials, which mimic bone tissue's electroactive properties to promote bone integration and provide antibacterial functionality when mechanically stimulated. In this study, PVDF films were coated with antibacterial essential oil nanoparticles and antibiofilm enzymes using a layer-by-layer (LBL) approach to ensure antibacterial properties even without mechanical stimulation. The experimental results confirmed the LBL build-up and demonstrated notable antibiofilm properties against Pseudomonas aeruginosa and Staphylococcus aureus while enhancing pre-osteoblast cell proliferation under mechanical dynamic conditions in a bioreactor that replicated the real-life environment of implants within the body. The findings highlight the potential of PVDF-coated surfaces to prevent biofilm formation and boost cell proliferation through the piezoelectric effect, paving the way for advanced implantable devices with improved osseointegration and antibacterial performance.

Polypeptide-based multilayer nanoarchitectures: Controlled assembly on planar and colloidal substrates for biomedical applications.

Polypeptides have shown an excellent potential in nanomedicine thanks to their biocompatibility, biodegradability, high functionality, and responsiveness to several stimuli. Polypeptides exhibit high propensity to organize at the supramolecular level; hence, they have been extensively considered as building blocks in the layer-by-layer (LbL) assembly. The LbL technique is a highly versatile methodology, which involves the sequential assembly of building blocks, mainly driven by electrostatic interactions, onto planar or colloidal templates to fabricate sophisticated multilayer nanoarchitectures. The simplicity and the mild conditions required in the LbL approach have led to the inclusion of biopolymers and bioactive molecules for the fabrication of a wide spectrum of biodegradable, biocompatible, and precisely engineered multilayer films for biomedical applications. This review focuses on those examples in which polypeptides have been used as building blocks of multilayer nanoarchitectures for tissue engineering and drug delivery applications, highlighting the characteristics of the polypeptides and the strategies adopted to increase the stability of the multilayer film. Cross-linking is presented as a powerful strategy to enhance the stability and stiffness of the multilayer network, which is a fundamental requirement for biomedical applications. For example, in tissue engineering, a stiff multilayer coating, the presence of adhesion promoters, and/or bioactive molecules boost the adhesion, growth, and differentiation of cells. On the contrary, antimicrobial coatings should repel and inhibit the growth of bacteria. In drug delivery applications, mainly focused on particles and capsules at the micro- and nano-meter scale, the stability of the multilayer film is crucial in terms of retention and controlled release of the payload. Recent advances have shown the key role of the polypeptides in the adsorption of genetic material with high loading efficiency, and in addressing different pathways of the particles/capsules during the intracellular uptake, paving the way for applications in personalized medicine. Although there are a few studies, the responsiveness of the polypeptides to the pH changes, together with the inclusion of stimuli-responsive entities into the multilayer network, represents a further key factor for the development of smart drug delivery systems to promote a sustained release of therapeutics. The degradability of polypeptides may be an obstacle in certain scenarios for the controlled intracellular release of a drug once an external stimulus is applied. Nowadays, the highly engineered design of biodegradable LbL particles/capsules is oriented on the development of theranostics that, limited to use of polypeptides, are still in their infancy.

Fabrication of Fully Positively Charged Layer-by-Layer Polyelectrolyte Nanofilms with pH-Dependent Swelling Properties.

Nanofilms fabricated by layer-by-layer (LbL) assembly from polyelectrolytes (PEs) are important materials for various applications. However, PE films cannot retain the charges along the polymer chains during fabrication, resulting in a low charge density. In this study, the preparation of LbL nanofilms with preserved positive charges via a controllable and efficient approach was achieved. To fabricate fully positively charged (FPC) LbL nanofilms, a polycation, poly-l-lysine, was partially grafted with azide and alkyne groups. Through copper-catalyzed azide-alkyne cycloaddition and the LbL procedure, nanofilms were fabricated with all of the individual layers covalently bonded, improving the pH stability of the nanofilms. Because the resulting nanofilms had a high charge density with positive charges both inside and on the surface, they showed unique pH-dependent swelling properties and adsorption of negatively charged molecules compared with those of traditional polyelectrolyte LbL nanofilms. This kind of FPC nanofilm has great potential for use in sensors, diagnostics, and filter nanomaterials in the biomedical and environmental fields.

"Target-and-release" nanoparticles for effective immunotherapy of metastatic ovarian cancer.

Immunotherapies such as checkpoint inhibitors (CPI) are effective in treating several advanced cancers, but these treatments have had limited success in metastatic ovarian cancer (OC). Here, we engineered liposomal nanoparticles (NPs) carrying a layer-by-layer (LbL) polymer coating that promotes their binding to the surface of OC cells. Covalent anchoring of the potent immunostimulatory cytokine interleukin-12 (IL-12) to phospholipid headgroups of the liposome core enabled the LbL particles to concentrate IL-12 in disseminated OC tumors following intraperitoneal administration. Shedding of the LbL coating and serum protein-mediated extraction of IL-12-conjugated lipids from the liposomal core over time enabled IL-12 to disseminate in the tumor bed following rapid NP localization in tumor nodules. Optimized IL-12 LbL-NPs promoted robust T cell accumulation in ascites and tumors in mouse models, extending survival compared to free IL-12 and remarkedly sensitizing tumors to CPI, leading to curative treatments and immune memory.

A polyoxometalate/chitosan-Ti3C2Tx MXene nanocomposite constructed by electrostatically mediated strategy for electrochemical detecting L-tryptophan in milk.

L-tryptophan (L-Trp) is crucial for human metabolism, and its imbalance or deficiency can lead to certain diseases, such as insomnia, depression, and heart disease. Since the body cannot synthesize L-Trp and must obtain it from external sources, accurately monitoring L-Trp levels in food is essential. Herein, a nanocomposite film based on polyoxometalate (P2Mo17V), Ti3C2Tx MXene, and chitosan (Cs) was developed through a green electrostatically mediated layer-by-layer self-assembly strategy for electrochemical detection of L-Trp. The composite film exhibits fast electron transfer and remarkable electrocatalytic performance for L-Trp with a wide linear range (0.1-103 µM), low limit of detection (0.08 µM, S/N = 3), good selectivity, reproducibility, and repeatability. In milk sample, the recoveries of L-Trp were from 95.78% and 104.31%. The P2Mo17V/Cs-Ti3C2Tx electrochemical sensor not only provides exceptional recognition and detection capabilities for L-Trp but also shows significant potential for practical applications, particularly in food safety and quality control.

Spray-assisted layer-by-layer deposition of quaternized chitosan/tannic acid for the construction of multifunctional bio-based nonwoven dressings.

Gauze wound dressings have received considerable attention due to their cost-effectiveness, excellent mechanical properties, and widespread applications. However, their inability to actively combat microorganisms and effectively scavenge free radicals results in suboptimal wound management. In this study, a novel nonwoven-based gauze dressing coated with quaternized chitosan/tannic acid (QCS/TA), based on electrostatic interaction and hydrogen bonding, was successfully prepared using a spray-assisted layer-by-layer assembly method. The bio-based nonwoven dressing, assembled with multiple interlacing bilayers, demonstrated outstanding antimicrobial properties, eliminating 99.99 % of Staphylococcus aureus (S. aureus) and 85 % of Escherichia coli (E. coli). Compared to the pristine nonwoven dressing, the QCS/TA-coated nonwoven dressing scavenged >85 % of the surrounding radicals within 2 h. Additionally, the nonwoven dressing exhibits excellent coagulation properties. Notably, the facile spraying procedure preserved most of the softness and breathability of the nonwoven substrate. After the deposition of seven bilayers, the bending stiffness and drape coefficient increased by only 37.63 % and 3.85 %, respectively, while the air permeability and moisture permeability reached 1712 mm/s and 3683.58 g/m2/d, respectively. This bio-based nonwoven dressing, derived from safe and non-toxic ingredients, holds promise as the next generation of multifunctional gauze dressings.

Sequential Self-Assembly of Polystyrene-block-Polydimethylsiloxane for 3D Nanopatterning via Solvent Annealing.

This study aims to develop a strategy for the fabrication of multilayer nanopatterns through sequential self-assembly of lamella-forming polystyrene-block-polydimethylsiloxane (PS-b-PDMS) block copolymer (BCP) from solvent annealing. By simply tuning the solvent selectivity, a variety of self-assembled BCP thin-film morphologies, including hexagonal perforated lamellae (HPL), parallel cylinders, and spheres, can be obtained from single-composition PS-b-PDMS. By taking advantage of reactive ion etching (RIE), topographic SiO2 monoliths with well-ordered arrays of hexagonally packed holes, parallel lines, and hexagonally packed dots can be formed. Subsequently, hole-on-dot and line-on-hole hierarchical textures can be created through a layer-by-layer process with RIE treatment as evidenced experimentally and confirmed theoretically. The results demonstrated the feasibility of creating three-dimensional (3D) nanopatterning from the sequential self-assembly of single-composition PS-b-PDMS via solvent annealing, providing an appealing process for nano-MEMS manufacturing based on BCP lithography.

Enhanced filtration membranes with graphene oxide and tannic acid for textile industry wastewater dye removal.

A novel modification technique employing a layer-by-layer (LbL) self-assembly method, integrated with a pressure-assisted filtration system, was developed for enhancing a commercial polyethersulfone (PES) microfiltration (MF) membrane. This modification involved the incorporation of tannic acid (TA) in conjunction with graphene oxide (GO) nanosheets. The effectiveness of the LbL method was confirmed through comprehensive characterization analyses, including ATR-FTIR, SEM, water contact angle (WCA), and mean pore size measurements, comparing the modified membrane with the original commercial one. Sixteen variations of PES MF membranes were superficially modified using a three-factorial design, with the deposited amount of TA and GO as key factors. The influence of these factors on the morphology and performance of the membranes was systematically investigated, focusing on parameters such as pure water permeability (PWP), blue corazol (BC) dye removal efficiency, and flux recovery rate (FRR). The membranes produced with the maximum amount of GO (0.1 mg, 0.55 wt%) and TA as the inner and outer layers demonstrated remarkable FRR and significant BC removal, exceeding 80%. Notably, there was no significant difference observed when using either 0.2 (1.11 wt%) or 0.4 mg (2.22 wt%) in the first layer, as indicated by the Tukey mean test. Furthermore, the modified membrane designated as MF/TA0.4GO0.1TA0.4 was evaluated in the filtration of a simulated dye bath wastewater, exhibiting a BC removal efficiency of 49.20% and a salt removal efficiency of 27.74%. In conclusion, the novel PES MF membrane modification proposed in this study effectively enhances the key properties of pressure-driven separation processes.

Trafficking through the blood-brain barrier is directed by core and outer surface components of layer-by-layer nanoparticles.

Drug-carrying nanoparticles are a promising strategy to deliver therapeutics into the brain, but their translation requires better characterization of interactions between nanomaterials and endothelial cells of the blood-brain barrier (BBB). Here, we use a library of 18 layer-by-layer electrostatically assembled nanoparticles (NPs) to independently assess the impact of NP core and surface materials on in vitro uptake, transport, and intracellular trafficking in brain endothelial cells. We demonstrate that NP core stiffness determines the magnitude of transport, while surface chemistry directs intracellular trafficking. Finally, we demonstrate that these factors similarly dictate in vivo BBB transport using intravital imaging through cranial windows in mice. We identify that hyaluronic acid surface chemistry increases transport across the BBB in vivo, and flow conditions are necessary to replicate this finding in vitro. Taken together, these findings highlight the importance of assay geometry, cell biology, and fluid flow in developing nanocarriers for delivery to the brain.

Over 18.2% efficiency of layer-by-layer all-polymer solar cells enabled by homoleptic iridium(III) carbene complex as solid additive.

The vertical phase distribution of active layers plays a vital role in balancing exciton dissociation and charge transport for achieving efficient polymer solar cells (PSCs). The layer-by-layer (LbL) PSCs are commonly prepared by using sequential spin-coating method from donor and acceptor solutions with distinct solvents and solvent additives. The enhanced exciton dissociation is expected in the LbL PSCs with efficient charge transport in the relatively neat donor or acceptor layers. In this work, a series of LbL all-polymer solar cells (APSCs) were fabricated with PM6 as donor and PY-DT as acceptor, and triplet material m-Ir(CPmPB)3 is deliberately incorporated into PY-DT layer to prolong exciton lifetimes of active layers. The power conversion efficiency (PCE) of LbL APSCs is improved to 18.24% from 17.32% by incorporating 0.3 wt% m-Ir(CPmPB)3 in PY-DT layer, benefiting from the simultaneously enhanced short-circuit current density (JSC) of 25.17 mA cm-2 and fill factor (FF) of 74.70%. The enhancement of PCE is attributed to the efficient energy transfer of m-Ir(CPmPB)3 to PM6 and PY-DT, resulting in the prolonged exciton lifetime in the active layer and the increased exciton diffusion distance. The efficient energy transfer from m-Ir(CPmPB)3 to PM6 and PY-DT layer can be confirmed by the increased photoluminescence (PL) intensity and the prolonged PL lifetime of PM6 and PY-DT in PM6 + m-Ir(CPmPB)3 and PY-DT + m-Ir(CPmPB)3 films. This study indicates that the triplet material as solid additive has great potential in fabricating efficient LbL APSCs by prolonging exciton lifetimes in active layers.

Layer-by-Layer-Processed All-Polymer Solar Cells with Enhanced Performance Enabled by Regulating the Microstructure of Upper Layer.

The layer-by-layer (LBL) fabrication method allows for controlled microstructure morphology and vertical component distribution, and also offers a reproducible and efficient technique for fabricating large-scale organic solar cells (OSCs). In this study, the polymers D18 and PYIT-OD are employed to fabricate all-polymer solar cells (all-PSCs) using the LBL method. Morphological studies reveal that the use of additives optimizes the microstructure of the active layer, enhancing the cells' crystallinity and charge transport capability. The optimized device with 2% CN additive significantly reduces bimolecular recombination and trap-assisted recombination. All-PSCs fabricated by the LBL method based on D18/PYIT-OD deliver a power conversion efficiency (PCE) of 15.07%. Our study demonstrates the great potential of additive engineering via the LBL fabrication method in regulating the microstructure of active layers, suppressing charge recombination, and enhancing the photovoltaic performance of devices.

Structure engineering of nickel silicate/carbon composite with boosted electrochemical performances for hybrid supercapacitors.

In the wake of the carbon-neutral era, the exploration of innovative materials for energy storage and conversion has garnered increasing attention. While nickel silicates have been a focal point in energy storage research, their application in supercapacitors (SCs) has been relatively underreported due to poor conductivity. A newly designed architecture, designated as rGO@NiSiO@NiO/C (abbreviated for reduced graphene oxide (rGO), nickel silicate (NiSiO), nickel oxide/carbon (NiO/C)), has been developed to enhance the electrochemical performance of NiSiO. The incorporation of inner rGO provides structural support for NiSiO, enhancing conductivity, while the outer NiO/C layer not only boosts conductivity but also safeguards NiSiO from structural degradation and electrolyte dissolution. This architecture eliminates multi-phase mixtures, facilitating rapid electron/mass transfer kinetics and accelerating electrochemical reactions, resulting in exceptional electrochemical properties. The rGO@NiSiO@NiO/C architecture achieves a specific capacitance of 324F·g-1 at 0.5 A·g-1, with a superb cycle performance of âˆ¼ 91 % after 10,000 cycles, surpassing state-of-the-art nickel silicates. Furthermore, the hybrid supercapacitor (HSC) device incorporating the rGO@NiSiO@NiO/C electrode attains an areal capacitance of 159 mF·cm-2 at 2.5 mA·cm-2, a retention ratio of âˆ¼ 98 % after 10,000 cycles, and an energy density of 0.68 Wh·m-2 (26.7 Wh·kg-1) at 3.4 W·m-2 (343.8 W·kg-1). This study presents a layer-by-layer approach for constructing transition metal silicates/C architectures to enhance their electrochemical performance.