Conductive Hybrid Films Research Articles

Facile design of structurally robust, highly conductive and well-flexible hybrid film based on MXene, cellulose nanofiber and poly (3,4-ethylenedioxythiphoenes):polystyrene sulfonate for supercapacitors

Robust, conductive and flexible electrode materials have been the focus of attention in portable, wearable electronics. However, it is still a significant challenge to achieve synergistic development of multiple properties simultaneously. Herein, we propose a combination of microscale design and nanostructures strategy to prepare MXene/cellulose nanofiber-poly (3,4-ethylenedioxythiphoenes):polystyrene sulfonate (Ti3C2Tx/CNF-PEDOT:PSS, TC-P) hybrid film by a simple in-situ polymerization and vacuum filtration process. CNF serves as the supporting skeleton of PEDOT:PSS, effectively mitigating its self-aggregation and structural deformation due to the expansion/contraction of the polymer network. And the CNF-PEDOT:PSS composite is capable to open up the interlayer space of Ti3C2Tx, which reduces the self-stacking of Ti3C2Tx nanosheets. The strong interactions among the three components enable the hybrid film electrode to possess both flexibility and high electrochemical properties. As a result, the film electrode exhibits a remarkable tensile strength of 77.4 MPa and an excellent conductivity of 162.5 S cm−1, as well as an outstanding areal specific capacitance of 896 mF cm−2 at 4 mA cm−2. Moreover, the assembled symmetric supercapacitor (SSC) device displays a large areal energy density of 62 µWh cm−2 at a power density of 800 µW cm−2 and demonstrates a long cycle life with 85.1 % capacitance retention after 10,000 GCD cycles. This study provides an effective strategy to balance mechanical flexibility and electrochemical properties, providing an inspiration to prepare flexible electrodes that are widely applied in a new generation of portable, wearable electronics.

Recyclable, ultralow-hysteresis, multifunctional wearable sensors based on water-permeable, stretchable, and conductive cellulose/PEDOT:PSS hybrid films

This study presents a method to prepare stretchable, conductive, water-permeable, and recyclable hybrid films using hydroxyethyl cellulose and PEDOT:PSS for eco-friendly sensors, with high sensitivity, low power consumption, and low hysteresis.

Flexible highly thermal conductive hybrid film for efficient radiative cooling

Radiative cooling is highly significant for carbon neutrality and sustainable development. Rapid development has been made for materials of radiative heat dissipation, applicable to sub-ambient and above-ambient cooling. However, scalable and low-cost approach for radiative cooling materials coupled with high thermal conductivity need to be further explored. Here, we present a design strategy for flexible highly thermal conductive hybrid film towards efficient radiative cooling. The proposed thermal conductive radiative cooler (TCRC) consists of interconnected polyvinylidene difluoride (PVDF) fibrous frameworks and randomly dispersed hexagonal boron nitride (h-BN) nanoplates via electrospinning and hot-pressing processes. Synergistic effects of spectral and thermal conductive properties endow the film with a high solar reflectivity of 0.92 in 250–2500 nm and a broadband mid-infrared (MIR) emissivity of 0.93 in 4–16 μm, while the thermal conductivity reaches over 10 W m−1 K−1. The radiative cooler demonstrates excellent above-ambient cooling performance (∼11 °C) with an effective cooling power of ∼80 W m−2, comparable to the most advanced reports. Besides, the film exhibits superior mechanical strength of 33 MPa and hydrophobicity with 140° contact angle. This work opens up a new avenue of radiative cooling for devices working under both above-ambient conditions.

Universal Stretchable Conductive Cellulose/PEDOT:PSS Hybrid Films for Low Hysteresis Multifunctional Stretchable Electronics.

Skin-attachable conductive materials have attracted significant attention for use in wearable devices and physiological monitoring applications. Soft, skin-like conductive films must have excellent mechanical and electrical characteristics with on-skin conformability, stretchability, and robustness to detect body motion and biological signals. In this study, a conductive, stretchable, hydro-biodegradable, and highly robust cellulose/poly(3,4-ethylene dioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) hybrid film is fabricated. Through the synergetic interplay of a conductivity enhancer, nonionic fluorosurfactant, and surface modifier, the mechanical and electrical properties of the stretchable hybrid film are greatly improved. The stretchable cellulose/PEDOT:PSS hybrid film achieves a limited resistance change of only 1.21-fold after 100 stretch-release cycles (30% strain) with exceptionally low hysteresis, demonstrating its great potential as a stretchable electrode for stretchable electronics. In addition, the film shows excellent biodegradability, promising environmental friendliness, and safety benefits. High-performance stretchable cellulose/PEDOT:PSS hybrid films, which have high biocompatibility and sensitivity, are applied to human skin to serve as on-skin multifunctional sensors. The conformally mounted on-skin sensors are capable of continuously monitoring human physiological signals, such as body motions, drinking, respiration rates, vocalization, humidity, and temperature, with high sensitivity, fast responses, and low power consumption (21 μW). The highly conductive hybrid films developed in this study can be integrated as both stretchable electrodes and multifunctional healthcare monitoring sensors. We believe that the highly robust stretchable, conductive, biodegradable, skin-attachable cellulose/PEDOT:PSS hybrid films are worthy candidates as promising soft conductive materials for stretchable electronics.

Electrically controlled mRNA delivery using a polypyrrole-graphene oxide hybrid film to promote osteogenic differentiation of human mesenchymal stem cells.

Direct messenger ribonucleic acid (mRNA) delivery to target cells or tissues has revolutionized the field of biotechnology. However, the applicability of regenerative medicine is limited by the technical difficulties of various mRNA-loaded nanocarriers. Herein, we report a new conductive hybrid film that could guide osteogenic differentiation of human adipose-derived mesenchymal stem cells (hADMSCs) via electrically controlled mRNA delivery. To find optimal electrical conductivity and mRNA-loading capacity, the polypyrrole-graphene oxide (PPy-GO) hybrid film was electropolymerized on indium tin oxide substrates. We found that the fluorescein sodium salt, a molecule partially mimicking the physical and chemical properties of mRNAs, can be effectively absorbed and released by electrical stimulation (ES). The hADMSCs cultivated on the PPy-GO hybrid film loaded with pre-osteogenic mRNAs showed the highest osteogenic differentiation under electrical stimulation. This platform can load various types of RNAs thus highly promising as a new nucleic acid delivery tool for the development of stem cell-based therapeutics.Electronic Supplementary MaterialSupplementary material (electrochemical and FT-IR analysis on the film, additional SEM, AFM and C-AFM images of the film, optical and fluorescence images of cells, and the primers used for RT-qPCR analysis) is available in the online version of this article at 10.1007/s12274-022-4613-y.

Ultraflexible transparent conductive films based on Ag nanowires for use in quick thermal response transparent heater

This work reports on the fabrication of an ultraflexible transparent conductive hybrid films via embedding silver nanowires (AgNWs) into a thin UV-curable resin film. This AgNW/UV-curable resin hybrid film exhibits excellent performance in terms of conductivity (sheet resistance: 9.9 Ω/sq.) and transparency (optical transmittance: 86.4%). After bending 1000 times at a 100 μm curvature radius or even undergoing an ultrasonication test, it still shows excellent electrical performance and negligible decay. The hybrid film has environmental endurance, and there is no significant performance degradation after being kept at high temperature (85 °C) and high humidity (85% humidity) for 60 h. Finally, the successful implementation of the hybrid film into a transparent film heater is demonstrated. The efficient Joule heating can increase the temperature of the heaters to 121 °C in ∼12 s at an input voltage of 6 V. The fast-heating characteristics at low voltages associated with its transparency and flexibility properties make the heaters a potential candidate in electrothermal applications, such as transparent soft actuators, wearable heaters, and medical thermotherapy pads.

Ingenious Method for Rapid Fabrication of a Highly Conductive Hybrid Film of Printed Cu Nanoparticle Layers Plated by Ag Nanoplates on a PET Substrate at Room Temperature

Ingenious Method for Rapid Fabrication of a Highly Conductive Hybrid Film of Printed Cu Nanoparticle Layers Plated by Ag Nanoplates on a PET Substrate at Room Temperature

Wafer-scale quasi-layered tungstate-doped polypyrrole film with high volumetric capacitance

Layered materials are particularly attractive for supercapacitors because of their unique physical, electrical and chemical properties. Here, we demonstrate a facile and scalable electrochemical deposition method for wafer-scale synthesis of quasi-layered tungstate-doped polypyrrole films (named TALPy) with controllable thickness and size. The as-prepared TALPy film exhibits a high gravimetric density and excellent volumetric capacitance, exceeding many high-performing carbon- and polymer-based film electrodes. Based on combined results of ex-situ X-ray diffraction (XRD), Raman and X-ray photoelectron spectroscopy (XPS), it is determined that TALPy stores charge through an ion intercalation process accompanied by change in oxidation states of polypyrrole backbone, which is referred as intercalation pseudocapacitance. All these results suggest the great promise of electrochemical deposition as a scalable and controllable bottom-up approach for synthesizing quasi-layered conductive organic-inorganic hybrid films for electrochemical energy storage applications with high volumetric performance.

N, P-Codoped Carbon Film Derived from Phosphazenes and Its Printing Integration with a Polymer Carpet Via "Molecular Welding" for Flexible Electronics.

Although high-performance graphene-based micro/nano flexible electronic devices have shown promising applications in numerous fields, there are still many problems in converting graphene into practical applications. Heteroatom-doped graphene materials are of huge importance because heteroatom doping can significantly change the electronic structure and introduce the active site, which benefits the integration with a promising substrate and achieves nondestructive transfer of carbon materials. Herein, we analyze in detail the pyrolysis gas composition of heteroatom-enriched phosphazenes with different structures and prepare a series of high-quality in situ N, P-codoped carbon-based films from phosphazene solid sources on a low-cost glass substrate by a convenient one-step method. The N, P-codoped carbon film shows reflectivity, good conductivity, and transparency. In addition, with the help of in situ "molecular welding", we achieve nondestructive transfer of a conductive carbon-based film from a glass substrate to promising layer-polyimide (PI) and prepare a flexible free-standing carbon/PI hybrid film with an excellent binding interface. The flexible conductive hybrid film shows excellent durability under an extremely low temperature environment and superior bending stability after 800 bending cycles. The results suggest that a phosphazene precursor is an amazing choice for constructing high-quality heteroatom-doped conductive carbon films. Besides, this work provides a promising way for nondestructive transfer of the conductive carbon-based films and large-scale preparation of large-area patterned conductive thin films.

Hybrid Perovskite Quantum Dot/Non‐Fullerene Molecule Solar Cells with Efficiency Over 15%

AbstractOrganic‐inorganic hybrid film using conjugated materials and quantum dots (QDs) are of great interest for solution‐processed optoelectronic devices, including photovoltaics (PVs). However, it is still challenging to fabricate conductive hybrid films to maximize their PV performance. Herein, for the first time, superior PV performance of hybrid solar cells consisting of CsPbI3 perovskite QDs and Y6 series non‐fullerene molecules is demonstrated and further highlights their importance on hybrid device design. In specific, a hybrid active layer is developed using CsPbI3 QDs and non‐fullerene molecules, enabling a type‐II energy alignment for efficient charge transfer and extraction. Additionally, the non‐fullerene molecules can well passivate the QDs, reducing surface defects and energetic disorder. The champion CsPbI3 QD/Y6‐F hybrid device has a record‐high efficiency of 15.05% for QD/organic hybrid PV devices, paving a new way to construct solution‐processable hybrid film for efficient optoelectronic devices.

Multilayered structural design of flexible films for smart thermal management

Intelligent materials have the ability to sense the environment and respond to their surrounding accordingly. Herein, the thermally conductive hybrid films were intellectualized by using activated shape memory composite as matrix, which endows hybrid films with active heat dissipation behavior. The obtained hybrid films not only visualize the temperature of the device by the change of shape, but also further improve thermal management abilities through the increase of contact area of the films with air in the shape changing process. The hybrid films also show high thermal conductivity because the multilayered structure was designed and constructed through the method of evaporation-induced self-assembly followed by hot-pressing technology. With the same content of graphene nanosheets, thermal conductivities of hybrid films are increased with the increase of layers. Five layered hybrid film shows the highest thermal management abilities and achieves the thermal conductivity as high as 19.37 W·m−1·K−1, which is 79.4% higher than single layered hybrid film. The structure design of hybrid films and their intellectualization opens up a new direction to improve thermal management effect of soft polymeric materials.

Preparation of Stable CuO/Boron Nitride Nanocomposite Modified Electrode for Selective Electrochemical Detection of L–Cysteine

AbstractL‐cysteine (Cys) is one of the main amino acid and its deficiency could cause several diseases and biological disorders in our body. Thus, it is important to accurately detect Cys level in biological samples. Herein, we reported a facile strategy to fabricate novel electrode material consisting of conductive hybrid film made of copper oxide‐boron nitride nanosheets (CuO/BN). Powdered X‐ray diffraction (PXRD) and Fourier transform infrared (FT‐IR) spectroscopy results confirmed the successful formation of CuO/BN hybrid nanocomposite. Next, electrochemical and electro‐catalytic properties of CuO/BN hybrid film is studied by cyclic voltammetry and amperometry. Interestingly, CuO/BN coated glassy carbon electrode (GCE) showed excellent electro‐catalytic activity towards Cys oxidation in phosphate buffer solution (0.1 M PBS). Newly developed CuO/BN film modified electrode is exhibited high oxidation peak current at lower potential of +0.45 V compared to bare GCE. CuO/BN/GCE sensor is also utilized for the detection of Cys from 1 to 10 μM and limit of detection (LOD) was found to be 0.58 μM. The selectivity of the sensor is determined by detecting 5 μM Cys in the presence of different interferent molecules. Furthermore, repeatability, reproducibility and stability of the CuO/BN/GCE sensor are also investigated. Finally, CuO/BN/GCE sensor is successfully applied to detect spiked Cys in human blood serum samples with good recovery.

A novel electrochemical sensor based on double-walled carbon nanotubes and graphene hybrid thin film for arsenic(V) detection

In this work, we demonstrate the preparation of hybrid thin films based on double-walled carbon nanotubes and graphene for electrochemical sensing applications. The hybrid films were synthesized on polycrystalline copper foil by thermal chemical vapor deposition under low pressure. This carbonaceous hybrid film has exhibited high transparency with a transmittance of 94.3 %. The occurrence of this hybrid material on the electrode surface of screen-printed electrodes was found to increase electroactive surface area by 1.4 times, whereas electrochemical current was enhanced by 2.4 times. Such a highly transparent and conductive hybrid film was utilized as a transducing platform of enzymatic electrochemical arsenic(V) sensor. The as-prepared sensor shows the linear detection of arsenic(V) in the range from 1 to 10 ppb, with a limit of detection as low as 0.287 ppb. These findings provide a promising approach to develop new multifunctional electrochemical sensing systems for environmental monitoring and biomedical diagnostics.

Elucidation of the Controversial Layer Growth Mechanism of Vapor Phase Polymerization in the Preparation of Conductive Poly(3,4‐ethylenedioxythiophene)‐SiO2 Hybrid Films

AbstractIn recent times, there have been debates to ascertain whether the growth mechanism in vapor phase polymerization is a top‐down or a bottom‐up process. The objective of the present study is to identify the formation mechanisms of the organic–inorganic hybrid film prepared in the gaseous phase on the basis of the practical importance of the hybridization of materials. To this end, poly(3,4‐ethylenedioxythiophene)‐SiO2 conductive hybrid films with different layered structures are successfully fabricated. The growth mechanism of the layered organic–inorganic conductive hybrid thin film is elucidated by investigating the variations in the morphological and chemical compositions of its surface. Additionally, a cross‐sectional analysis is performed using a scanning electron microscope‐energy dispersive X‐ray spectroscopy and X‐ray photoelectron spectroscopy. The results indicate a “bottom‐up” growth mechanism, wherein the oxidant diffused through the recently formed layer, generating novel layers; this ultimately leads to formation of the organic–inorganic conductive hybrid film. Moreover, the optoelectronic and mechanical properties of the hybrid conductive films are precisely controlled by adjusting the order of incorporation of monomers in the process and the duration of polymerization of each monomer. Thus, this study achieves the fabrication of a mechanically robust and optically enhanced conductive hybrid film.

Highly sensitive flexible pressure sensors based on graphene/graphene scrolls multilayer hybrid films

In recent years, flexible pressure sensors have attracted much attention owing to their potential applications in motion detection and wearable electronics. As a result, important innovations have been reported in both conductive materials and the underlying substrates, which are the two crucial components of a pressure sensor. 1D materials like nanowires are being widely used as the conductive materials in flexible pressure sensors, but such sensors usually exhibit low performances mainly due to the lack of strong interfacial interactions between the substrates and 1D materials. In this paper, we report the use of graphene/graphene scrolls hybrid multilayers films as the conductive material and a micro-structured polydimethylsiloxane substrate using Epipremnum aureum leaf as the template to fabricate highly sensitive pressure sensors. The 2D structure of graphene allows to strongly anchor the scrolls to ensure the improved adhesion between the highly conductive hybrid films and the patterned substrate. We attribute the increased sensitivity (3.5 kPa \begin{document}$ ^{-1} $\end{document} ), fast response time ( \begin{document}$ 50 ms), and the good reproducibility during 1000 loading-unloading cycles of the pressure sensor to the synergistic effect between the 1D scrolls and 2D graphene films. Test results demonstrate that these sensors are promising for electronic skins and motion detection applications.

From tanghulu-like to cattail-like SiC nanowire architectures: interfacial design of nanocellulose composites toward high thermal conductivity

Cattail-like H–MoS2–SiCNWs have great superiority as the thermal conductive filler for manufacturing fascinating thermal conductive CNF hybrid films.

Flexible Films for Smart Thermal Management: Influence of Structure Construction of a Two-Dimensional Graphene Network on Active Heat Dissipation Response Behavior.

In recent years, the development and wide application of micro-electronic technology brings forward high demands for active thermal management systems. However, such systems are not only costly, but also usually tethered, and need constant power to operate. To avoid such a limitation, smart thermal management systems have been developed to achieve active thermal management. Here, inspired by the temperature control principle of a butterfly, a shape memory polymer was used to endow the thermally conductive graphene-polymer hybrid film with intelligence. As the device temperature reaches 60 °C, the bud-shaped hybrid film started to bloom, which is a visually active heat dissipation process. As a result, this active process promoted the thermal management capacity of the hybrid film and increased the temperature-raising time of the light-emitting diode. Through the construction of a bilayer structure, the transmission channel for phonon transfer was optimized, which lead the hybrid film to attain a remarkable thermal conductivity of 21.83 W·m-1·K-1 with 30 wt % graphene. This graphene-polymer hybrid film shows potential application in the smart thermal management field.

Stretchable Conductive Hybrid Films Consisting of Cubic Silsesquioxane-capped Polyurethane and Poly(3-hexylthiophene).

We fabricated stretchable and electric conductive hybrids consisting of polyhedral oligomeric silsesquioxane (POSS)-capped polyurethane (PUPOSS) and doped poly(3-hexylthiophene) (P3HT). In order to realize robust films coexisting polar conductive components in hydrophobic elastic matrices, we employed POSS introduced into the terminals of the polyurethane chains as a compatibilizer. Through the simple mixing and drop-casting with the chloroform solutions containing doped P3HT and polyurethane polymers, homogeneous hybrid films were obtained. From the conductivity and mechanical measurements, it was indicated that hybrid materials consisting of PUPOSS and doped P3HT showed high conductivity and stretchability even with a small content of doped P3HT. From the mechanical studies, it was proposed that POSS promoted aggregation of doped P3HT in the films, and ordered structures should be involved in the aggregates. Efficient carrier transfer could occur through the POSS-inducible ordered structures in the aggregates.

Hybrid Conducting Composite Films Based on Polypyrrole and Poly(2‐(diethylamino)ethyl methacrylate) Hydrogel Nanoparticles for Electrochemically Controlled Drug Delivery

AbstractA 3D conductive hybrid film is fabricated based on poly 2‐(diethylamino) ethyl methacrylate (PDEA) nanoparticles with polypyrrole (PPy) as the conductive component. PDEA nanoparticles are deposited on a gold substrate by drop casting. Then, PPy is electrochemically grown through the hydrogel nanoparticles as a semi‐interpenetrating polymer network. PDEA hydrogel nanoparticles reversibly swell at low pH while PPy liberates H+ in the oxidized state. The oxidation of PPy is used to create an electrostimulated decrease in pH in the PDEA/PPy hybrid film that results in film swelling. The electrochemical properties of the hybrid conductive composite film are studied through cyclic voltammetry and electrochemical impedance spectroscopy. Doxorubicin (Dox) as model drug is encapsulated in the PDEA/PPy hybrid composite film by a pH switch. Drug electroliberation is investigated at different applied potentials from −0.65 to +0.65 V. The amount of Dox released shows a dependence on the applied potential and the duration of the electrical stimuli. The (3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide) tetrazolium reduction assay is conducted to evaluate the impact of the electrocontrolled release of Dox on the proliferation of the A549 cell line, showing a decrease in cell viability, proportional to the applied potential and its duration.

Transparent Conducting Graphene Hybrid Films To Improve Electromagnetic Interference (EMI) Shielding Performance of Graphene.

Conducting graphene-based hybrids have attracted considerable attention in recent years for their scientific and technological significance in many applications. In this work, conductive graphene hybrid films, consisting of a metallic network fully encapsulated between monolayer graphene and quartz-glass substrate, were fabricated and characterized for their electromagnetic interference shielding capabilities. Experimental results show that by integration with a metallic network the sheet resistance of graphene was significantly suppressed from 813.27 to 5.53 Ω/sq with an optical transmittance at 91%. Consequently, the microwave shielding effectiveness (SE) exceeded 23.60 dB at the Ku-band and 13.48 dB at the Ka-band. The maximum SE value was 28.91 dB at 12 GHz. Compared with the SE of pristine monolayer graphene (3.46 dB), the SE of graphene hybrid film was enhanced by 25.45 dB (99.7% energy attenuation). At 94% optical transmittance, the sheet resistance was 20.67 Ω/sq and the maximum SE value was 20.86 dB at 12 GHz. Our results show that hybrid graphene films incorporate both high conductivity and superior electromagnetic shielding comparable to existing ITO shielding modalities. The combination of high conductivity and shielding along with the materials' earth-abundant nature, and facile large-scale fabrication, make these graphene hybrid films highly attractive for transparent EMI shielding.