Hybrid Composite Films Research Articles

Thermoelectric devices with polymer/zeolite hybrid composite films for conversion of heat to electricity

Here we report that organic/inorganic hybrid composite films, consisting of poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) and zeolite Y (Zy), can efficiently convert heat to electricity in the horizontal device geometry. The PEDOT:PSS/Zy (PPZy) hybrid composite films were prepared from corresponding aqueous solutions at various Zy contents (up to 50 wt%). The PPZy solutions exhibited an increased viscous state with a maximum at Zy = 30 wt%, indicating strong interactions between PEDOT:PSS and Zy components. All devices with the PPZy composite films could convert heat to electricity and showed higher thermoelectric (TE) performances than those with the pristine PEDOT:PSS films. The TE devices with the PPZy films (Zy = 30 wt%) delivered an output power of 8.8 pW with a power factor of 0.76 μW/mK2, which is ca. 20 times higher than those with the pristine PEDOT:PSS films. The flexible TE devices, which were fabricated on poly(ethylene naphthalate) (PEN) film substrates, exhibited robust TE performances even after 5000 bending cycles. The present approach of hybrid composite films based on zeolite particles may contribute to further TE performance improvement for flexible and wearable TE devices.

Creation of spin switching in graphene oxide-based hybrid film materials with an anionic Fe(III) 5Cl-salicyaldehyde-thiosemicarbazone complex.

The present article describes the synthesis of hybrid composite film materials formed during the self-assembly process through non-covalent interactions of graphene oxide (GO) nanosheets with salt 1, represented by an anionic spin-crossover complex [FeIII(5Cl-thsa)2]- (5Cl-thsa - 5-chlorosalicylaldehyde thiosemicarbazone) and the organic tetraethylammonium cation [Et4N]+. The insertion of the salt 1 molecules into the interlayer space of GO nanosheets with the subsequent formation of a hybrid material GO-1 was observed. The film of the hybrid material GO-1 was characterized by scanning electron and confocal laser microscopy, EDX and XPS analysis, IR, Raman and 57Fe Mössbauer spectroscopy, dc magnetic measurements, and powder X-ray diffraction. Comparison of the magnetic properties of salt 1 and a film of the hybrid material GO-1 demonstrated a significant influence of the GO nanosheets matrix on the completeness of spin transition and showed a slight shift of the hysteresis loop by 1 K in the temperature range of 200-230 K. DFT calculations showed an important role of the organic cation [Et4N]+ in the process of adsorption of the spin-crossover anion [FeIII(5Cl-thsa)2]- on the GO nanosheet surface.

Boosting thermoelectric performance of PEDOT: PSS/Bi2Te3 hybrid films via structural and interfacial engineering

In this work, we synthesized poly(3,4-ethylenedioxythiophene): poly (styrene sulfonate) (PEDOT: PSS) and PEDOT: PSS/Bi2Te3 hybrid composite film using a spin coating method. The maximum Seebeck coefficient (22 μVK−1) and power factor (57.18 μWm-1 K−2 around 300 K) were achieved at 0.4 wt% Bi2Te3. The electrical conductivity (σ) reached a maximum of 1467 Scm−1 at 300 K for 0.6 wt% Bi2Te3, which is more than three times higher than that of pure PEDOT: PSS. Two critical components contribute to the improved electrical transport performance, as identified by XRD, Raman spectroscopy, XPS, AFM, and SEM. First, the conductive polymer undergoes a structural transformation from a benzenoid to a quinoid configuration, enhancing conductivity. This transformation is due to the interaction between the π bonds of PEDOT: PSS and the Van der Waals forces between the tellurium (Te) atom layers of Bi2Te3. Second, the interfacial barrier between PEDOT: PSS and Bi2Te3 creates an energy-filtering effect that increases the Seebeck coefficient.

Enhancing thermal consistency and stability of quantum dots through encapsulation: A study on microscale-structured hybrid for WLEDs

Quantum dots (QDs) are regarded as highly potential materials for color conversion in light-emitting diodes (LEDs) and display technologies owing to their distinctive and outstanding optical characteristics. Nevertheless, the energy transfer process occurring among various colored QDs, known as Förster resonance energy transfer (FRET), results in a notable redshift in fluorescence emission, restricting the precise control of photoluminescence spectra in fabricated devices. This study presents a dual-impact technique to enhance the stability of CdSe/ZnS colloidal QDs while also preventing the FRET process. This is achieved by encapsulating the QDs within silica (SiO2) and ethylene-vinyl acetate (EVA) films. The research features two distinct encapsulation methods: enveloping multiple QDs within a SiO2 matrix (MQD) and adsorbing QDs onto SiO2 spheres as a shell (SQD and SQDS). Those hybrid structures are successfully fabricated with their nanostructure, chemical composition, and optical properties extensively analyzed. Moreover, the photo-physical properties of QDs/SiO2/EVA hybrid composite films and their impact on blue lightemitting diodes (LEDs) and White-LEDs have been conducted. Among those formulations explored, the MQD/EVA films stand out, displaying natural sunlight color emission with a color temperature of 4214 K, a color coordinate at (0.37, 0.37), and significant improvements in chromatic and thermal stability under high driving power. The successful integration of high-molecular-weight polymers and SiO2 coatings highlights the effectiveness of this approach in producing robust, high-quality QD-polymer film composites, making them ideal candidates for display technologies.

Hybrid Ethylcellulose Polymeric Films: Ag(I)-Based Components and Curcumin as Reinforcing Ingredients for Enhanced Food Packaging Properties.

Bio-active ethylcellulose (EC) polymeric films have been obtained by incorporating curcumin (curc) and Ag(I)-based compounds, known for their antioxidant and antimicrobial activity, respectively, within the polymeric matrix. The recently reported Ag(I) coordination polymer, in both its structural forms (α-[(bpy)Ag(OTf)]∞ and β-{[(bpy)Ag][OTf]}∞), and the [(bpy)Ag(OTf)]∞-curc polymeric co-crystal (bpy=2,2'-bipyridine; OTf=trifluoromethanesulfonate) have been selected as Ag(I) species. The hybrid composite films have been prepared through the simple solvent casting method and characterized through Powder X-Ray Diffraction (PXRD), Differential Scanning Calorimetry (DSC) and Fourier Transform Infrared (FTIR) spectroscopy, Scanning Electron Microscope (SEM), UV-vis spectroscopy. The deep investigation of the film samples highlighted the non-inert behaviour of EC towards these specific active ingredients. Antimicrobial tests showed that EC films embedding the Ag(I)-based compounds present good antimicrobial performance, in particular against Staphylococcus aureus, used as a model of Gram-positive bacteria. In addition, Silver migration tests, performed on the Ag(I)-incorporating EC films, evidenced low values of silver release particularly in the case of the EC films incorporating [(bpy)Ag(OTf)]∞-curc.

Surface Embedded Metal Nanowire-Liquid Metal-Elastomer Hybrid Composites for Stretchable Electronics.

Both liquid metal (LM) and metallic filler-based conductive composites are promising stretchable conductors. LM alloys exhibit intrinsically high deformability but present challenges for patterning on polymeric substrates due to high surface tension. On the other hand, conductive composites comprising metallic fillers undergo considerable decrease in electrical conductivity under mechanical deformation. To address the challenges, we present silver nanowire (AgNW)-LM-elastomer hybrid composite films, where AgNWs and LM are embedded below the surface of an elastomeric matrix, using two fabrication approaches, sequential and mixed. We investigate and understand the process-structure-property relationship of the AgNW-LM-elastomer hybrid composites fabricated using two approaches. Different weight ratios of AgNWs and LM particles provide tunable electrical conductivity. The hybrid composites show more stable electromechanical performance than the composites with AgNWs alone. In particular, 1:2.4 (AgNW:LMP w/w) sequential hybrid composite shows electromechanical stability similar to that of the LM-elastomer composite, with a resistance increase of 2.04% at 90% strain. The sequential approach is found to form AgIn2 intermetallic compounds which along with Ga-In bonds, imparts large deformability to the sequential hybrid composite as well as mechanical robustness against scratching, cutting, peeling, and wiping. To demonstrate the application of the hybrid composite for stretchable electronics, a laser patterned stretchable heater on textile and a stretchable circuit including a light-emitting diode are fabricated.

Advanced hydrostable, recyclable and degradable cellulose hybrid films as renewable alternatives to synthetic plastics

Strong, tough and sustainable materials are in high demand in various engineering applications. We demonstrate a potential sustainable hybrid film made from natural cellulose and a biobased slurry. Through a simple and scalable approach, cellulose can be processed into an advanced material with over 2.8 and 9.2-fold increase in dry strength and toughness after curing and a 728-fold increase in wet strength, respectively. In addition, these hybrid composite films display an outstanding antioxidant activity surpassing 90 %, along with excellent ultraviolet radiation shielding and thermal insulation properties. Further, the hybrid films can be fabricated by integrating all-natural materials and still guarantee their unique functionality. We also demonstrate the feasibility of a circular bioeconomy by recycling the hybrid film using a green, deep eutectic solvent to fabricate a recycled hybrid film that displays excellent mechanical and optical properties. When recycling is unsuitable or economical, the hybrid film can naturally degrade in the soil under 6 months. These encouraging findings suggest the promise of cellulose hybrid films as a renewable, low-cost, tough, and strong material with the potential to replace nonrenewable synthetic plastics and products.

Synergy Unleashed: Piezo–Tribo Hybrid Harvester for Sustainable Power Generation Toward Augmented and Virtual Reality Applications

Recently, piezo–tribo hybrid nanogenerators are developed using the synergistic effect. Exploration of multi‐crystalline piezoelectric materials adds the advantage of mechanically to electrically converting hybrid systems. On the way, the multi‐crystalline 0.3Ba0.7Ca0.3TiO3–0.7BaSn0.12Ti0.88O3 (BCST) materials are characterized by the structural, vibrational, and ferroelectric properties. The synergistic effect‐based polydimethylsiloxane/BCST hybrid composite film is prepared for multi‐energy harvesting. The triboelectric nanogenerator produces a maximum output voltage of 210 V. The hybrid device obtains the maximum output performance of 326 V. The harvested energy is used to charge commercial capacitors and power low‐power electronics. The signal processing and analysis unit is constructed for monitoring or functioning in real‐time finger movement. In the future, this kind of system can be coupled with augmented and virtual reality applications.

Room-Temperature NH3 Gas Surface Acoustic Wave (SAW) Sensors Based on Graphene/PPy Composite Films Decorated by Au Nanoparticles with ppb Detection Ability.

Exhaled human breath analysis has great potential for the diagnosis of diseases in non-invasive way. The 13C-Urea breath test for the diagnosis of Helicobacter pylori infection indicates the ammonia concentration of 50-400 ppb in the breath. This work successfully developed a surface acoustic wave (SAW) resonator based on graphene/polypyrrole composite films decorated by gold nanoparticles (AuNPs-G/PPy) with sensitivity and selectivity to detect ammonia in parts-per-billion concentrations, which is promising for the accurate diagnosis of H. pylori infection. XRD, EDS, and SEM characterized the AuNPs-G/PPy nanocomposites, providing comprehensive insights into their structural, compositional, and morphological properties. The gas-sensing capabilities of the fabricated SAW sensors were extensively investigated, focusing on their response to NH3 gas at ambient temperature. The concentration of ammonia gas was effectively quantified by monitoring the frequency shift of the SAW device. Notably, our developed SAW sensor demonstrated outstanding sensitivity, selectivity, repeatability, and reproducibility for 50-1000 ppb NH3 in dry air. The excellent sensing performance of the AuNPs-G/PPy hybrid composite film can be attributed to the synergistic effects of graphene's superior conductivity, the catalytic properties of gold nanoparticles, and the conductivity sensitization facilitated by electron-hole recombination on the polypyrrole surface.

A temperature and electric field responsive flexible hybrid composite film containing CsxWO3 nanocrystals for energy efficient smart window

Smart windows, which can dynamically adjust solar radiation transmittance in accordance with people's requirements and the ambient temperatures, play an important role in solving the problem of energy consumption in buildings. However, the polymer-dispersed liquid crystals, one of the representatives of smart window, are generally only optically modulated in the visible region, but not sensitive to the near-infrared light region, which has a thermal effect. Herein, we reported a hybrid composite film with both light and heat management by introducing inorganic CsxWO3 nanocrystals into the organic PDLC system. The optical modulation effect of this film covers the solar irradiation in the range of 400–2500 nm, including visible light and invisible near-infrared light. In addition, the optical state of the film could be switched between transparent and opaque by electric field when the temperature was below the phase transition temperature (45 °C), while the film remained transparent when the temperature was above the phase transition temperature. Simultaneously, about 60% to 95% of the NIR irradiation range of 800–2500 nm can be screened under the variations of the thermal and electric fields due to the local surface plasmon resonance of the CsxWO3 nanocrystals. The thermal insulation effect demonstrated by the model house fitted with this film gives it the potential to be used in energy-efficient smart windows.

Green interconnected network structure of chitosan-microcrystalline cellulose-lignin biopolymer film for active packaging applications

As an excellent alternative to petroleum-based food packaging materials, a novel green hybrid composite film with an excellent interconnected network structure was successfully fabricated by integrating chitosan (chi), microcrystalline cellulose (MCC), and lignin nanoparticles (LNP), including the desired amount of plasticizer glycerol (gly). Overall, 36 combinations were developed and investigated for superior biocomposite film formation. Among the various concentration ratios, the 40:35:25 chi-MCC-gly film provided well-organized film formation, good physicochemical properties, mechanical stability, efficient water contact angle, reduced water solubility, and lower water vapor permeability (11.43 ± 0.55 × 10−11 g.m−1.s−1.Pa−1). The performance of the chi-MCC-gly film further enhanced by the homogeneous incorporation of ∼100 nm LNP. With 1 % LNP addition, the tensile strength of the film increased (28.09 MPa, 47.10 % increase) and the water vapor permeability reached a minimum of 11.43 × 10−11 g.m−1.s−1.Pa−1, which proved the impact of LNP in composite films. Moreover, the films showed excellent resistance to thermal shrinkage even at 100 °C and exhibited nearly 100 % UV blocking efficiency at higher LNP concentrations. Interestingly, the green composite films extended the shelf life of freshly cut cherry tomatoes to seven days without spoilage. Overall, the facile synthesis of strong, insoluble, UV-blocking, and thermally stable green composite films realized for food packaging applications.

Design and fabrication of CoS2/graphene hybrid composite film sensor for NO2 gas-sensing performance

Design and fabrication of CoS2/graphene hybrid composite film sensor for NO2 gas-sensing performance

Designed hybrid organic−inorganic nanocomposite film based on synergistic effect of conducting polymer and keggin type polyoxometalate clusters

The exchange of electrical charges between a chemical reaction center and an external electrical circuit is critical for many advanced technological applications. From this perspective, "wiring” of polyoxometalates (POM) which is highly redox-active molecular metal oxide anions to conductive polymers (CPs) will be of great importance. Herein, POM-CP-based organic-inorganic hybrid composite film has been prepared electrochemically from mixtures of Keggin-type POM clusters (K7-xNaxPW11O39∙14H2O) and a triazine cored carbazole derivative. Incorporating POM clusters into cross-linked CPs has led to hybrid material with not only value-adding properties but also synergistic effects. When optical and electrical properties of the composite films prepared from different feed ratios have been examined, it has been observed that the incorporation of POM clusters into the conductive polymer structure has led to a decrease in the onset potential, response time, and bandgap as well as an increase in the optical contrast, stability, and charge capacity of the CPs.

Improvement of the Shielding Effectiveness of PMMA/MWCNTs/Ag Hybrid Composite for X-Band Application

Herein, the PMMA/MWCNT/Ag hybrid composite films are prepared by solvent casting method to be used in an electrical application. The AC conductivity and dielectric characteristics have been investigated at room temperature. The electrical conductivity of the hybrid composite reaches a percolation critical concentration of 2.14×10-4 S/cm by Ag doping. For all PMMA/MWCNT/Ag hybrid composites, the frequency-dependent dielectric constant decreases as the frequency area widens. As the concentrations of MWCNT and Ag increase, the AC conductivity exhibits an increasing trend. The MWCNT and Ag content was found to significantly affect the SE of the given composites. A high electromagnetic (EM) shielding efficiency (SE) was achieved between 8.2 and 12.4 GHz (X-band). The highest EM attenuation of 18 dB at 12 GHz was achieved using 0.5 wt% MWCNT and Ag. The thermal analysis of the formed PMMA/MWCNT/Ag hybrid composites showed that exothermic reactions with the greatest weight loss took place between 200°C and 300°C. FESEM show that PMMA/MWCNT/Ag hybrid composites had uniform dispersion of the carbon nano tube and silver particles within the PMMA matrix .

MXenes (Ti3C2Tx) incorporated polyimide nanohybrid composite films

In this study, polyimide (PI)/MXene hybrid composite films as electromagnetic interference (EMI) shielding materials were fabricated using MXene (Ti3C2Tx) as a filler. The PI/MXene nanohybrid composite films were fabricated by casting an aqueous solution containing water-soluble poly (amic acid) ammonium salt (PAS) and MXene colloid, followed by thermal imidization. PI/MXene hybrid composite films with different contents (1.36 wt. % ∼ 20 wt. %) were prepared. The PI/MXene hybrid composite films showed high EMI shielding effectiveness up to 159 dB/mm as well as low moisture contents, controlled dielectric constants, improved thermal stability, and low coefficients of thermal expansion.

Nano-SiO2-modified xylan-PVOH-based composite films: Mechanical and barrier properties investigation

Hemicellulose from a wide range of sources and abundant reserves shows good biocompatibility, degradability, and renewability. Because of its low degree of polymerization and a large amount of hydroxyl groups, hemicellulose-based films exhibit low strength and tend to be hydrophilic, which hinders some potential applications. Therefore, hemicellulose-based films with improved strength and barrier properties are needed. In this study, nano-SiO2 was incorporated into polyvinyl alcohol/xylan matrix for the purpose of preparing an inorganic-organic hybrid composite film with elevated mechanical and barrier performance. The addition of nano-SiO2 can serve this purpose. A 1% nano-SiO2 loading resulted in an increase of contact angle of the composite film from 89.6° to 110.4°, an increase of the tensile strength from 11.2 to 14.8 MPa, and a decrease of oxygen permeability from 1.83 to 0.27 (cm3⋅µm)/(m2·d·kPa), which corresponds to a contact angle that was increased by 23%, tensile strength increased by 32%, and oxygen permeability decreased by 85%. These results indicated that the nano-SiO2 modified xylan film might have great application prospects as a barrier film in food packaging.

Effect of corn husk fibre loading on thermal and biodegradable properties of kenaf/cornhusk fibre reinforced corn starch-based hybrid composites

This paper documents the thermal and biodegradation behaviour of kenaf/cornhusk fiber reinforced corn starch-based hybrid composites film (CS/K–CH) produced by solution casting method. To develop both components as biodegradable hybrid composite, this research used corn starch as matrix, kenaf fiber and cornhusk fibre as a filler. Changes in physical structure and weight from the soil burial test were measured using Mettler Toledo digital balance ME. Films produced from physically blended corn starch reinforced kenaf biocomposites films (CS/K) biocomposite film had faster biodegradation and lost 96.18% of weight within 10 days compared with corn starch hybrid composites that only lost 83.82% of total weight. It was observed that the control film, CS/K biocomposite film was completely degraded after 10 days, meanwhile it took 12 days for hybrid composite films to be fully degrade. The thermal properties such as TGA and DTG were also measured. Addition of corn husk fiber significantly improve the film's thermal properties. Glass transition temperatures of corn starch hybrid films were significantly lowered when cornhusk compositions were increased from 0.2% wt to 0.8% wt. Importantly, the current work has demonstrated that hybrid films made of corn starch can be a suitable biodegradable material for substitute synthetic plastic.

Electrocatalytic performance of cobalt oxide and hybrid composite thin films of cobalt Oxide@Polyaniline for oxygen evolution reaction

Water splitting is the process in which oxygen evolution reaction is prominent. This can be done by the most affordable technique using an electric field (electrochemical method). Keeping this in mind, we have synthesized novel hybrid composite thin films of Co3O4@PANI, to overcome the deficient electrochemical performance of solo Co3O4. The electrocatalytic performance of cobalt oxide and hybrid composite material for oxygen evolution reaction is studied. Cobalt oxide is deposited by the SILAR method, and hybrid composite material is prepared via different methods like electrochemical deposition and SILAR. Morphology, charge transfer resistance, and phase of material are studied with Scanning Electron Microscopy (SEM), Electrochemical Impedance Spectroscopy (EIS) and X-ray diffraction (XRD) respectively. The hybrid composite Co3O4@PANI electrocatalyst manifests high catalytic activity with 258 mV overpotential at 10 mA cm−2 current while solo Co3O4 shows deficient catalytic activity with 323 mV overpotential at 10 mA cm−2 which is examined by Linear swap voltammetry (LSV) and 16.28 mV dec-1 is Tafel slope. This hybrid combination also shows excellent stability for 10 hrs for OER in 1 M NaOH.

Dielectric constant enhancement of poly 4-vinylphenol (PVPh) via graphene flakes incorporation through electrospray atomization for energy storage.

We report on the fabrication of hybrid composite poly 4-vinlyphenol (PVPh)/graphene thin film via cost-effective electrospray atomization deposition technique. Thin films fabricated through manipulating deposition technique in two different ways which are blending and layer by layer (LBL). For investigation of PVPh/graphene hybrid composite dielectric behavior in comparison to PVPh; three asymmetric MIS thin film capacitors were fabricated, where dielectric thin films (i) PVPh and (ii & iii) hybrid composite thin films PVPh/graphene (blended and LBL) were sandwiched between electrodes i.e. indium tin oxide (ITO) and p-type semiconductor poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS). The dielectric properties of the thin films were characterized for frequencies 1 to 100 kHz while utilizing the MIS thin film capacitors. The capacitance obtained at 1 kHz frequency for PVPh/graphene (LBL) dielectric layer at the voltage range ±10 volts was 8.5 mF cm-2 while for blended PVPh/graphene thin film the capacitance at the voltage range ±3 volts was 0.40 μF cm-2 and for pristine PVPh as dielectric layer the capacitance at voltage range ±1 volts was 1.45 μF cm-2. Similarly, even at higher frequencies up to 100 kHz, the PVPh/graphene (LBL) showed stable behavior. Thus, the composite PVPh/graphene (LBL) thin film has a better dielectric nature compared to the composite PVPh/graphene (blended) thin film, even at higher frequencies with larger operational voltage window. This distinguishing nature of the composite PVP/graphene (LBL) is attributed to increase in dielectric constant due to graphene flakes in between PVPh. For the thin films LBL and blended PVPh/graphene, the calculated dielectric constant at 10 kHz is 6.7 and 0.023 while at 100 kHz it is 2 and 0.0167, respectively.

Green and Facile Synthesis of Hybrid Composites with Ultralow Dielectric Properties from Water-Soluble Polyimide and Dual-Porous Silica Nanoparticles

Here, we proposed an eco-friendly synthetic method for synthesizing hybrid composites with ultralow dielectric properties at high frequencies up to 28 GHz for true 5G communication from aqueous aromatic polyimide (PI) polymers and dual-porous silica nanoparticles (DPS). The "one-step" water-based emulsion template method was used to synthesize the macroporous silica nanoparticles (MPS). A substantially negative ζ potential was produced along the surface of MPS by the poly(vinylpyrrolidone)-based chemical functionalization, enabling excellent aqueous dispersion stability. The water-soluble poly(amic acid) (PAA), as a precursor to PI, was also "one-step" polymerized in an aqueous solution. The MPS were dispersed in a water-soluble PAA matrix to create the hybrid composite films using an entirely water-based approach. The compatibility between the PAA matrix and MPS was elucidated by investigating relatively diverse end-terminated PAAs (with either amine or carboxyl group). It was also discovered that, during a thermally activated imidization reaction, the MPS are in situ converted into the DPS with macro- and microporous structures (with a surface area of 1522.4 m2/g). The thermal, dielectric, mechanical, and morphological characteristics of each composite film were examined, while the amount of DPS in the PI matrix varied from 1 to 20 wt %. With the addition of 5 wt % DPS as an optimum condition, it showed ultralow dielectric properties, with the Dk and Df being 1.615 and 0.003 at a frequency of 28 GHz, respectively, and compatible mechanical properties, with the tensile strength and elastic modulus being 78.2 MPa and 0.32 GPa, respectively. These results can comprehensively satisfy various physical properties required as a substrate material for 5G communication devices.