Conducting Polymer Composite Films Research Articles

Flexible conductive polymer composite film with sandwich-like structure for ultra-efficient and high-stability electromagnetic interference shielding

Flexible electromagnetic interference (EMI) shielding films with the merits of light-weight, flexibility, and high EMI shielding performance are the essential materials for the consumer electronics and communication products. Herein, we construct a hybrid conductive network based on the electrospinning thermoplastic polyurethane (TPU) film loaded with different dimensional conductive fillers, including 0D FeCl3, 1D carbon nanotube (CNT) and 2D graphene nanosheet (GN) to achieve a flexible, light-weight, and ultra-efficient EMI shielding composite film. In specific, the electrospinning porous TPU film is firstly anchored by CNTs assisted by ultrasound to generate the porous TPU/CNT film. Thereafter, the as-prepared porous TPU/CNT film is loaded a GN/CNT/FeCl3 layer by vacuum-assisted filtration to generate a double-layer GN/CNT/FeCl3@TPU/CNT film. Finally, another porous TPU/CNT film is sealed onto the GN/CNT/FeCl3@TPU/CNT film by hot-pressing, which fabricates a sandwiched TPU/CNT@GN/CNT/FeCl3@TPU/CNT composite film. It is interesting to note that the composite film possesses the ultrahigh EMI shielding value (56.0 dB at 10.0 GHz) in the X-band (8.2–12.4 GHz) with high flexibility, excellent mechanical properties, long-term durability (acid-base environment resistance and stability after 1000 bends), as well as high thermal conductivity (6.53 W/(m.K)). This work proposes a simple but efficiency strategy to design the flexible EMI shielding film with ultra-high performance and outstanding durability.

MOF-Conductive polymer composite electrode as electrochemical sensor of nitrobenzene

A metal-organic framework (MOF)-conductive polymer composite film modified electrode was constructed by drop casting using PCN-222(Fe) and p3HT-p3TPA copolymer. The composite materials were characterized by diffraction, spectroscopic and electron microscopic techniques, showing the uniform distribution of MOF particles in the polymer matrix with the original MOF structure maintained. Introduction of carboxylate groups to the polymer matrix enhances interaction between polymer and MOF particles, leading to enhanced electron transfer and better water stability. The modified electrode was used for electrochemical detection of nitrobenzene in aqueous solution with the wide linear detection ranges of 0.05μM-1.00μM (0.6572 μAμM-1) and 1.00μM-100μM (0.03304 μAμM-1) as well as a low detection limit of 0.047μM.

MOF-Conductive Polymer Composite Film as Electrocatalyst for Oxygen Reduction in Acidic Media

A metal-organic framework (MOF)-conductive polymer composite film was constructed from PCN-222(Fe) nanoparticles and PEDOT:PSS solution by simple drop-casting approach. The composite film was tested as an electrocatalytic device for oxygen reduction reaction (ORR). The combination of PCN-222(Fe) MOF particles and conductive PEDOT matrix facilitates electron transfer in the composite material and improves the ORR performance of PCN-222(Fe). Levich plot and H2O2 quantification experiment show that PCN-222(Fe)/PEDOT:PSS film mainly catalyzes two-electron oxygen reduction and produces H2O2.

Enhanced electrochemical pseudocapacitance performance of poly tyramine composite on the surface of polyethylene glycol modified electrode

ABSTRACT In the present study, we introduce the first study for investigating the effect of polyethylene glycol (PEG) on the electrochemical performance of the PTy electroactive film. In this work, we applied PEG to improve electrochemical performance of PTy electroactive film. The electrochemical properties of the prepared electrodes were investigated by means of various electrochemical methods including electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV) and consecutive charge/discharge. The developed electrode in this study exhibits a specific capacity of 4200 mF.cm−2 at 5 mA.cm−2 current density while retaining 90% of the initial capacitance after 3000 cycles. Our results provide an improved conductive polymer composite film with high active surface area, ease of synthesis and high cycling stability for supercapacitors (SCs) in aqueous electrolytes.

Effect of addition of polyether amine and TiO2 nanofibers on the properties of PEO based sodium ion conducting composites

Sodium ion conducting polymer composite films have been prepared using the blend of poly (ethylene oxide) and polyetheramine (JEFFAMINE ED2003) in which sodium trifluoromethane sulfonate (NaTf) salt and varying amounts of inorganic filler (TiO2 nanofibers) have been added. The effect of TiO2 nanofibers addition has been seen in terms of improved ionic conductivity and electrochemical stability of the nanocomposite film. Highest ionic conductivity of ∼3.5 × 10⁻⁵ Scm⁻1 (at room temperature) along with an electrochemical stability up to ∼2.6 V has been obtained for PEO-Jeffamine blend based solid polymer electrolyte (SPE) with 10 wt% of NaTf salt and a small amount (0.2 wt%) of TiO2 nanofibers. A non monotonic variation in the room temperature ionic conductivity and intensity of XRD peaks has been seen for composite films with increasing concentration of TiO2 nanofibers. Uniform distribution of salt (Na, F and S) and TiO2 nanofibers in the prepared composite film has been obtained in the elemental mapping. FTIR results have given evidence of interaction between the blended polymers, salt and TiO2. The wavelength and duration of exposure of UV radiation have altered the electrical properties of film. Increase in the number of ionic charge carriers has been attained on exposure to UV radiation.

High Thermal Conductivity Polymer Composites Fabrication through Conventional and 3D Printing Processes: State‐of‐the‐Art and Future Trends

AbstractThe lifespan and the performance of flexible electronic devices and components are affected by the large accumulation of heat, and this problem must be addressed by thermally conductive polymer composite films. Therefore, the need for the development of high thermal conductivity nanocomposites has a strong role in various applications. In this article, the effect of different particle reinforcements such as single and hybrid form, coated and uncoated particles, and chemically treated particles on the thermal conductivity of various polymers are reviewed and the mechanism behind the improvement of the required properties are discussed. Furthermore, the role of manufacturing processes such as injection molding, compression molding, and 3D printing techniques in the production of high thermal conductivity polymer composites is detailed. Finally, the potential for future research is discussed, which can help researchers to work on the thermal properties enhancement for polymeric materials.

Multifunctional Thermally Conductive Composite Films Based on Fungal Tree‐like Heterostructured Silver Nanowires@Boron Nitride Nanosheets and Aramid Nanofibers

AbstractThermal conduction for electronic equipment has grown in importance in light of the burgeoning of 5G communication. It is imperatively desired to design highly thermally conductive fillers and polymer composite films with prominent Joule heating characteristics and extensive mechanical properties. In this work, “solvothermal & in situ growth” method is carried out to prepare “Fungal tree”‐like hetero‐structured silver nanowires@boron nitride nanosheet (AgNWs@BNNS) thermally conductive fillers. The thermally conductive AgNWs@BNNS/ANF composite films are obtained by the method of “suction filtration self‐assembly and hot‐pressing”. When the mass fraction of AgNWs@BNNS is 50 wt%, AgNWs@BNNS/ANF composite film presents the optimal thermal conductivity coefficient of 9.44 W/(m ⋅ K) and excellent tensile strength of 136.6 MPa, good temperature‐voltage response characteristics, superior electrical stability and reliability, which promise a wide application potential in 5G electronic devices.

Multifunctional Thermally Conductive Composite Films Based on Fungal Tree-like Heterostructured Silver Nanowires@Boron Nitride Nanosheets and Aramid Nanofibers.

Thermal conduction for electronic equipment has grown in importance in light of the burgeoning of 5G communication. It is imperatively desired to design highly thermally conductive fillers and polymer composite films with prominent Joule heating characteristics and extensive mechanical properties. In this work, "solvothermal & in situ growth" method is carried out to prepare "Fungal tree"-like hetero-structured silver nanowires@boron nitride nanosheet (AgNWs@BNNS) thermally conductive fillers. The thermally conductive AgNWs@BNNS/ANF composite films are obtained by the method of "suction filtration self-assembly and hot-pressing". When the mass fraction of AgNWs@BNNS is 50 wt%, AgNWs@BNNS/ANF composite film presents the optimal thermal conductivity coefficient of 9.44 W/(m ⋅ K) and excellent tensile strength of 136.6 MPa, good temperature-voltage response characteristics, superior electrical stability and reliability, which promise a wide application potential in 5G electronic devices.

Acoustic-assisted 3D printing based on acoustofluidic microparticles patterning for conductive polymer composites fabrication

Multifunctional composites have been widely utilized in soft robots, electronics, batteries, and biomedicine. Meanwhile, several fabrication processes have been proposed to fabricate these functional composites with desired mechanical, electrical, magnetic, and thermal properties. However, patterning functional micro/nanomaterials such as particles, dots, wires, and fibers into complex designs with high spatial resolutions in a matrix remains a technical challenge. Herein, we present an acoustic-assisted 3D printing method enabled by standing surface acoustic waves (SSAWs). The proposed SSAWs-assisted patterning method produces diverse patterning forms of micro/nanomaterials and has almost no special requirements on micro/nanomaterials properties, indicating its great versatility and compatibility. Functional materials are assembled into desired stripe-like, net-like, and dot-like patterns. Multilayer composites with different patterns in each layer are even fabricated through a layer-by-layer printing process. To further demonstrate the potential of this 3D printing method, conductive polymer composite films with programmed electrical anisotropies are printed, yielding a maximum electrical conductivity of 827 S/m. The proposed acoustic-assisted patterning method makes the 3D printing of complex functional composites with customized properties possible, pushing the wide application of functional composites forward.

Design of Fuzzy Logic Motion Detection Algorithm for the Bracelet Type Sensor Consisting of Conductive Layer-Polymer Composite Film.

To improve the motion detection performance of a bracelet-type sensor that uses only two tiny sensor modules developed using carbon-based conductive polymer composite films, a fuzzy-logic algorithm was developed in this study. A polyethylene terephthalate polymer film with a conductive layer composed of carbon paste was used as the integral material utilized for the composite film; a small sensor module composed of mechanical parts mounted on the film was developed to effectively detect the surface resistance variations of the film. A participant wore a bracelet sensor, which consisted of two sensor modules, on their forearm, and the resistance variations of the contact area between the forearm and the sensor modules corresponding to the flexion changes of the surface of the body due to muscle contraction and relaxation were detected. The surface resistance variations of the film were converted to voltage signals, which were used as inputs to the fuzzy logic algorithm to detect four consecutive motions of the forearm. The results demonstrated that the fuzzy-logic algorithm attained an accuracy of 94%. The fuzzy algorithm successfully detected four motions and the resting state of the forearms; moreover, it showed improved performance compared to previous research.

Preparation of flexible, highly conductive polymer composite films based on double percolation structures and synergistic dispersion effect

AbstractWe studied for the first time the synergistic dispersion effect of the carbon nanotube (CNT)/graphene (Gr) and polypropylene (PP)/polycarbonate (PC) (1:1) double percolation structures on conductive polymer composites (CPCs). PP/PC/CNT/Gr films with different CNT/Gr ratios are prepared by melt blending and hot pressing. Results showed that a CNT/Gr ratio of 1:1 facilitated the creation of co‐continuous double percolation structures of matrices, and the electronic conductivity reached 33.11 S/m, which was five times greater than that of the matrices containing only CNT. Results showed that the synergistic dispersion effect and the co‐continuous double percolation structures provided the matrices with conductivity through an additive effect. Meanwhile, PP/PC/CNT/Gr composite films possessed good thermal stability and hydrophobicity. They also did not exhibit thermal degradation at 300°C and had a water contact angle of 94.5°. However, PP and PC were incompatible, causing considerable brittleness of composite films macroscopically, and the films can hardly curve. To respond to this downside and improve the flexibility, a small amount of thermoplastic polyurethane (TPU) was added to the system. The presence of TPU helped combining the two materials in different phases, thereby strengthening the continuity. However, the presence of TPU adversely affected the double percolation structures and dispersion state of fillers, and subsequently decreased the conductivity.

Flexible and thin multifunctional waterborne polyurethane/Ag film for high-efficiency electromagnetic interference shielding, electro-thermal and strain sensing performances

With the rapid development of the flexible electronics industry, the range of multifunctional applications of materials has become extensive. But it is still a challenge to apply flexible materials to different fields while ensuring corresponding performance. Herein, a simple and available approach is addressed to fabricate conductive polymer composite films supported on Ag flakes and waterborne polyurethane (WPU) by spraying. The WPU/Ag films with uniform structure show outstanding flexibility and electromagnetic interference shielding effectiveness of 68.9 dB with thickness of only 50 μm, and could sustain a high standard even undergoing excessive mechanical deformations. Besides, the resulted films possess prominent electro-thermal effect, which can achieve a temperature of over 120 °C by applying a low voltage of 2 V, and the heat can be dissipated rapidly along with the connecting Ag network. Moreover, it shows a high gauge factor (229.2), good durability and reproductivity (over 1000 cycles), and rapid response time to strain (50 ms), which can be potentially used in the field of human movement monitoring and wearable electronic devices. These results indicate the multifunction of the WPU/Ag film, which could widen its practical applications after the corresponding treatment.

Dispersion of Nano-materials in Polymer Composite Materials

Polymer composites materials are the subject of extensive studies because of their novel properties compared with their constituent materials. Dispersion stability of sub-micron sized particles in the medium is important from the point of colloidal views. In the present study, dispersion of nano-materials in the matrix polymer is one of the most important problems to enhance their mechanical properties. We tackled this problem to carry out surface modification of the nano-materials, such as carbon nano tubes (CNTs), using amphiphilic polymers, polyNvinylacetamide (PNVA), synthesized thorough radical polymerization. Hydrogen bond worked between PNVA onto the modified nano-materials and hydrophilic matrix, such as polyvinyl alcohol (PVA), to enhance surface adhesions and dispersions of the nano-materials in the matrix. As a result, the mechanical properties of their composites materials were strengthened. When CNTs were used in PVA, the transparency of the composite was also increased due to improvement of their dispersions. In addition, if the CNTs formed the networks in the composites, the highly conductive and transparent polymer composite films were fabricated.

PVDF/CNF/IL composite film for shielding of microwave radiation

In this work materials have been used in the form of conducting polymer composite film for covering of different electrical and electronic equipment to provide effective electromagnetic interference (EMI) shielding. Pre localized CNF (CNF) powder will be mixed with Poly (vinylidene fluoride) (PVDF) and Ionic Liquid (IL) using solvent blending method to form a series of PVDF/CNF/IL composite films with different concentration of CNF and IL. Obtained composite films were characterized with Scanning Electron Microscopy (SEM) and Differential scanning calorimetry (DSC) for surface morphology and thermal analysis. Fabricated films were also examined for their mechanical properties. The dielectric properties of the film were measured with the help of impedance analyser. After this using dielectric properties of the films shielding effectiveness are calculated in the range of 100 KHz to 10 MHz. The fabricated film with composition of 60/10/30 exhibits the shielding effectiveness of 32 dB to 40 dB in entire frequency range and also has the elongation of 31%. The key advantage of obtained composite films is there light weight and flexibility can be used to shield small electronic equipment.

Flexible composite film for shielding of microwave radiation

Electromagnetic interference (EMI) disrupts the working of electronic devices and circuits. In this work materials have been exploited in the form of conducting polymer composite film to give effective EMI shielding properties. Pre localized Graphite(Gr) powder will be mixed with Poly vinylidene fluoride (PVDF) and Ionic Liquid (IL) using solvent blending method to form a series of PVDF/Gr/IL composite films with different concentration of Gr and IL. Obtained films were characterized with Scanning Electron Microscopy (SEM) and Differential scanning calorimetry (DSC) for surface morphology and thermal analysis. The dielectric properties of the film were measured through which shielding effectiveness of the film is calculated for both near field and far field region in the frequency range of 100 KHz to 10 MHz. The composition with 70/10/20 exhibits maximum shielding effectiveness of 35 dB, 120 dB and 40 dB for plane wave, electric field and magnetic field respectively. The fabricated films exhibit excellent EMI Shielding properties with extra advantage of low cost and flexibility.

Significant Reduction of Interfacial Thermal Resistance and Phonon Scattering in Graphene/Polyimide Thermally Conductive Composite Films for Thermal Management.

The developing flexible electronic equipment are greatly affected by the rapid accumulation of heat, which is urgent to be solved by thermally conductive polymer composite films. However, the interfacial thermal resistance (ITR) and the phonon scattering at the interfaces are the main bottlenecks limiting the rapid and efficient improvement of thermal conductivity coefficients (λ) of the polymer composite films. Moreover, few researches were focused on characterizing ITR and phonon scattering in thermally conductive polymer composite films. In this paper, graphene oxide (GO) was aminated (NH2-GO) and reduced (NH2-rGO), then NH2-rGO/polyimide (NH2-rGO/PI) thermally conductive composite films were fabricated. Raman spectroscopy was utilized to innovatively characterize phonon scattering and ITR at the interfaces in NH2-rGO/PI thermally conductive composite films, revealing the interfacial thermal conduction mechanism, proving that the amination optimized the interfaces between NH2-rGO and PI, reduced phonon scattering and ITR, and ultimately improved the interfacial thermal conduction. The in-plane λ (λ||) and through-plane λ (λ⊥) of 15 wt% NH2-rGO/PI thermally conductive composite films at room temperature were, respectively, 7.13 W/mK and 0.74 W/mK, 8.2 times λ|| (0.87 W/mK) and 3.5 times λ⊥ (0.21 W/mK) of pure PI film, also significantly higher than λ|| (5.50 W/mK) and λ⊥ (0.62 W/mK) of 15 wt% rGO/PI thermally conductive composite films. Calculation based on the effective medium theory model proved that ITR was reduced via the amination of rGO. Infrared thermal imaging and finite element simulation showed that NH2-rGO/PI thermally conductive composite films obtained excellent heat dissipation and efficient thermal management capabilities on the light-emitting diodes bulbs, 5G high-power chips, and other electronic equipment, which are easy to generate heat severely.

Influence of nanostructured VO-acetylacetonate coordination system with 2-(pyridin-4-ylmethylene) hydrazine-1-carbothioamide in pseudocapacitance performance of p-type conductive polymer composite film

ABSTRACT In this work, first, VO-acetylacetonate coordination system with 2-(pyridin-4-ylmethylene) hydrazine-1-carbothioamide (VO(acac)2L) was synthesised via sonochemical routes. Then POAP/VO(acac)2L films were fabricated through electropolymerization of poly ortho aminophenol (POAP) in the presence of VO(acac)2L and used as the active electrode of an electrochemical supercapacitor (SC) with a significant electrochemical properties improvement. X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM) was applied to characterise the structural state of the prepared samples. Also, some electrochemical methods such as electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV), and galvanostatic charge–discharge (GCD) were carried out for the system performance investigation. This work may open an avenue to develop efficient and robust nanocomposite materials for an energy storage device in an acidic medium.

Enhancement in the magnetic and electrical conductivity properties of PVA- black tea composite films

Cost-effective conducting polymer composite films were prepared from non-conducting polymer and black Tea. The films showed conducting and considerable magnetic properties. The measured coercive field, saturation magnetization and remnant magnetization values were found to be 80 Oe, 0.14 emu g−1 (at 8 kOe), and 9.0 × 10−3 emu g−1, respectively. In order to realize the high-frequency applications of these materials, dielectric properties were measured in the frequency range of 1 Hz–1 MHz. The measured dielectric permittivity (ε′) and loss tangent (tanδ) values of the composite polymer thin film were found to be 260 and 0.37 (at 1 kHz) respectively. The estimated dc conductivity (σdc) value was around 1.60 × 10−8 S cm−1.

Conductive and Stretchable Adhesive Electronics with Miniaturized Octopus‐Like Suckers against Dry/Wet Skin for Biosignal Monitoring

AbstractHigh adhesion and water resistance on skin surfaces are highly demanded properties for wearable and skin‐attachable electronics in various medical applications. Here, stretchable electronics with octopus‐like patterns (OPs) imprinted on a carbon‐based conductive polymer composite (CPC) film are presented. The bioinspired conductive suckers with dome‐like architectures are successfully exploited to sustain weight (500 g) in underwater, wherein this performance is known to be challenging. In addition, the artificial patch allows highly adhesive capabilities under both dry and wet conditions on various surfaces such as silicon (max. 5.24 N cm−2) and skin replica (max. 1.89 N cm−2) without contamination after detachment with an effortless peel‐off technique. The resulting device with low volumetric ratio of conductive carbon black presents sensitive and reliable piezoresistive responses to lateral strain and vertical pressure. By controlling the ratio of the carbon nanoplatelets in the polymeric matrix, electronic patch demonstrates both detection of electrocardiogram (ECG) and bending motions of wrist in dry and wet environments. Based on the characteristics shown in this work, the proposed electronic patch is a promising approach to realize wearable and skin‐attachable sensor devices for in vitro and in vivo monitoring of various biosignals.

Graphene and carbon black filled conductive nanocomposite films for heating element applications

Graphene has ultra-high electrical and thermal conductivity, which makes graphene as the most encouraging fillers for thermally conductive composites. Graphene and/or carbon black filled conductive polymer composite (CPC) films used as heating element are smarter than the traditional heating elements due to less environmental pollution, ease of application on many surfaces and possess the merits of lightweight. In this study, we investigated mainly the production, characterization and industrial application of graphene/carbon black reinforced styrene acrylic copolymer emulsion matrix composite films deposited on polyvinyl chloride for flexible heating element. After that, the films were dried at room temperature for 24 h in air. Structural and surface properties of the CPC films were characterized by X-ray diffraction and scanning electron microscopy. Temperature, time and voltage relation of the produced composite films were investigated. Heating and electrical properties of the CPC films were determined by using a thermal camera and 4-point probe measurement system, respectively. The electrical resistivity of the CPC films decreases from ~ 108 to 101 Ω cm with increasing the filler content or using a combination of two fillers. Graphene and carbon black filled conductive polymer composites to be considered as candidates for flexible heating element applications exhibited good electrical and heating properties thanks to synergistic effect of fillers.