Ternary Nanocomposite Films Research Articles

Improvement of antibacterial activity of AgNPs@PVA-PVP ternary nanocomposite films followed by gamma-ray irradiation treatment for biomedical applications

Our study investigates the influence of several doses of gamma rays on the antibacterial behavior of nanocomposite of silver nanoparticles (AgNPs) doped in a blend of poly (vinyl alcohol) (PVA)-Polyvinyl Pyrrolidone (PVP). AgNPs@PVA-PVP nanocomposite films have been fabricated by laser ablation method, and then the synthesized films were subjected to various gamma ray’s doses. X-ray diffraction (XRD) data shows a diffraction peak at 2θ = 38° assigned to the existence of AgNPs. Ultraviolet–visible (UV-Vis) results confirm the characteristic peak of silver nanoparticles at 425 nm. The cell viability and antibacterial behavior results confirmed the enhancement in the performance of AgNPs@PVA-PVP composite after irradiated to gamma rays. These values of cell viability have been raised by increasing the dose of gamma rays to 94.5±6.5 % for dose at 70 kGy gamma rays. The values of the inhibition zone of microorganisms were enhanced by raising the doses of gamma rays to 19.5±0.5 and 21.3±0.6 against E. coli and S. aureus respectively specifically for nanocomposite with gamma dose 70 kGy. Thus, the improved antibacterial activity of AgNPs@PVA-PVP nanocomposite could be used in biomedical applications.

In-situ polymerized boehmite/ cashew gum/ polyvinyl alcohol/ polypyrrole blend nanocomposites with tunable structural, electrical, and mechanical properties for enhanced energy storage applications

This study describes the successful synthesis of boehmite (BHM) nanofiller-reinforced ternary blend nanocomposite films composed of polyvinyl alcohol (PVA), cashew gum (CG), and polypyrrole (PPy) using in-situ polymerization with water as the environmentally friendly solvent. The blend nanocomposites were characterized using Fourier-transform infrared spectroscopy (FTIR), field emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). FTIR analysis revealed chemical bonding between BHM and the biopolymer matrix at1071 cm-1. FE-SEM images exhibited a uniform distribution of BHM nanofillers within the CG/PVA/PPy matrix, particularly at a 10 wt% concentration. The addition of BHM significantly enhanced the thermal stability and the glass transition temperature of the nanocomposites. The temperature-sensitive AC conductivity, activation energy, and dielectric properties were examined using an impedance analyzer. AC conductivity analysis revealed reduced activation energy (1.277 × 10⁻5 eV at 7 wt% BHM) and increased dielectric constant (from 565.28 to 4411.22). The ternary blend nanocomposite demonstrated a significant 60.2 % increase in tensile strength, reflecting enhanced force resistance, while hardness values ranged from 26 to 30, classifying the films as soft and flexible. Overall, the study highlights significant enhancements in the morphological, electrical, thermal, dielectric, and mechanical properties of the nanocomposite films, emphasizing their promising potential for energy storage applications.

Unleashing the potential: Multifunctionality of PVDF-HFP based ternary nanocomposite films - magnetoelectric, energy harvesting and impact sensing performance

Multifunctional materials are proving to be highly promising for advancing various technologies, including magneto-mechano-electric energy harvesting devices and flexible sensors. This study focused on synthesizing a polyvinylidene fluoride-hexafluoropropylene-metal-oxide-layered silicate nanocomposite system using a cost-effective solution casting technique. The performance of the system was evaluated in terms of magnetoelectric behaviour, energy harvesting capabilities, and impact sensing. The nanocomposite films demonstrated a peak-to-peak voltage of 12.2 V with a filler loading of 15 wt% and an applied force of 9 N, along with a magnetoelectric coupling coefficient of 20.6 mVcm−1Oe−1. The device's ability to scavenge biomechanical energy during body movements like foot stamping, arm bending, finger flexing, and wrist bending was successfully verified. Furthermore, rigorous durability testing was conducted through repeated energy harvesting studies, proving the device's practicality and resilience. Notably, the developed device powered up six LEDs and a digital clock, while the impact sensor exhibited a linear relationship between output voltage and impact force. These findings highlight the remarkable potential of the polyvinylidene fluoride-hexafluoropropylene-metal-oxide-layered silicate nanocomposite system for multifunctional applications in various technological fields.

Synergistic effect of combining metallic and mineral nanoparticles on the improvement of the performance of active poly(butylene adipate‐co‐terephthalate) packaging films

AbstractActive ternary nanocomposite films based on poly(butylene adipate‐co‐terephthalate) (PBAT), ZnO nanoparticles (NPs), and cloisite (C15A, C30B) were fabricated through solvent casting. The structural and morphological characteristics of these hybrid metal‐oxide‐clay nanocomposites were analyzed using Fourier transform infrared spectroscopy, X‐ray diffraction, atomic force microscopy, and UV‐visible spectrophotometry. Due to the synergistic effect resulting from the combination of ZnO and cloisites, PBAT‐based nanocomposite films have demonstrated a significant improvement in their mechanical and barrier properties. Hardness recorded increase of 87.75% and 41.05%, while Young's modulus showed improvement of 218.13% and 102.68% for PBAT/ZnO/C15A and PBAT/ZnO/C30B films, respectively, compared to the pure PBAT matrix. Additionally, an enhancement in water vapor barrier properties was estimated at 81.28% for PBAT/ZnO/C15A film and 90.88% for PBAT/ZnO/C30B, in comparison with the PBAT alone. Furthermore, the incorporation of clay into the PBAT/ZnO matrix led to a notable slowdown in the release rate of Zn2+ ions, mainly attributed to the entrapment of ZnO NPs within the Cloisite galleries. As these particles dissolve into Zn2+ ions, they undergo a gradual diffusion process through the clay sheets. In addition, the simultaneous presence of both types of nanofillers exhibited a more pronounced antibacterial effect compared to that induced by ZnO NPs alone. However, it is noteworthy that antibacterial performance was closely linked to the type of clay used. Indeed, the PBAT/ZnO/C15A film demonstrated complete inhibition of in vitro bacterial growth within just 3 to 4 days, whereas the PBAT/ZnO/C30B film did not exhibit the same level of effectiveness.Highlights Development of active PBAT/ZnO/clay packaging films. ZnO NPs entrapped in clay galleries yielded slow Zn2+ ion diffusion. Synergistic combination of ZnO and Cloisite NPs exhibits strong antibacterial activity. The antibacterial performance is directly linked to the type of clay used.

Optical and structural properties of graphene oxide-incorporated polyvinylpyrrolidone/copper ternary nanocomposites (PVP/Cu/GO) films

Novel ternary nanocomposite films based on polyvinylpyrrolidone copper nanoparticles graphene oxide (PVP/Cu/GO) were prepared using electrochemical deposition technique on Fluorine doped tin oxide (FTO) substrate. This facile and effective approach has been proven to be very useful for the fabrication of inexpensive, high-performance electrochemical devices. To achieve uniform deposition of the nanocomposite films, the three components of the nanocomposites were mixed under controlled conditions. The impact of different GO loading on the PVP/Cu/GO composites was measured using UV–visible spectroscopy, X-Ray Diffraction (XRD) spectroscopy, SEM, EDX, and four-point probe techniques to evaluate their optical, structural, morphological, compositional, and electrical properties, respectively. UV-visible analysis shows that the optical band gap (Eg) of the nanocomposite decreased from 3.51 to 2.02 eV with increasing GO loading. All of the nanocomposites showed UV absorbance of ≈450 nm. According to the XRD results, the GO materials were very well dispersed in the PVP/Cu/GO composites, while also revealing the crystalline nature of the nanocomposites. The SEM results revealed spherical-shaped grains of the deposited films, while the EDX results revealed the major elements deposited. Four-point probe analysis of the nanocomposites revealed slight increase in conductivity with low GO content, thus confirming the semiconducting properties of the nanocomposites with the GO content. The obtained results herein shows that the PVP/Cu/GO nanocomposites are successfully synthesized with attractive physiochemical properties suitable for the fabrication of organic electronic devices and photovoltaic devices.

Preparation and characterization of lignin nanoparticles and chitin nanofibers reinforced PVA films with UV shielding properties

Environmental pollution of non-degradable packaging and the increasing demand for biodegradable food packaging materials are driving research on the design and development of multifunctional polyvinyl alcohol (PVA)-based films. However, binary PVA blends are not suitable to satisfy the requirements for mechanical properties, thermal stability, hydrophobicity and UV-barrier properties of food packaging materials. Herein, ternary nanocomposite films have been fabricated by incorporating sustainably renewable chitin nanofibers (ChNF) and biomass-based lignin nanoparticles (LNPs) into the biodegradable PVA. Results suggest that addition of 5 wt% ChNF and 1 wt% LNPs improves the films toughness appreciably along with superior thermal stability and surface hydrophobicity. More importantly, these nanocomposite films are transparent but could shield 95% of the UVB (275–325 nm) and UVC (200–275 nm) radiation. The outcome is deemed to aid developing novel PVA-based for biodegradable food packing materials and UV-shielding biomaterials, and it provides a way to solve the pollution of non-degradable plastics. • Successfully incorporated chitin nanofibers and lignin nanoparticles in the PVA films. • Mechanical properties and UV barrier properties of PVA films improved substantially. • PVA based UV shielding films have been developed.

Improved Physical, thermal, and conductivity strength of ternary nanocomposite films of PVDF/PMMA/GO NPs for electrical applications

Polymer nanocomposites samples polyvinylidene fluoride/Polymethyl methacrylate (PVDF/PMMA) mixed with various concentrations of graphene oxide nanoparticles (GO NP's) were created using solution casting and ultrasonic-assisted solution casting processes. The characteristics of the manufactured polymer samples were studied using XRD, FTIR, TEM, TGA, and DSC. The AC conductivity, dielectric constant, and dielectric loss of PVDF/PMMA-GO nanocomposites were examined as a function of GO concentrations. XRD analysis demonstrates the semicrystalline PVDF/PMMA and shows that the doped PVDF/PMMA films have a lower crystallinity degree (Xc) than the pure blend. The interaction between the GO ions and the PVDF/PMMA matrices is demonstrated by significant fluctuations in the FTIR spectra. TEM revealed that the GO nanoparticles were produced in spherical and cubic shapes, with an average size of 18.6 nm. The energy gap of nanocomposite films reduced as the GO NP's concentration in the polymer mix increased, decreasing from 4.24 eV to 3.71 eV for the indirect transition. The PVDF/PMMA exhibits a single glass transition temperature (Tg) according to the DSC study, showing that the PVDF and PMMA are miscible. The melting point of the nanocomposite films increased from 244.39 °C to 251.56 °C, increasing their thermal stability. Thermogravimetric analysis (TGA) curves showed that the PVDF/PMMA polymeric matrix had increased thermal stability. Dielectric constant and loss analyses have been performed to gain a better knowledge of charge storage properties and conductivity relaxation. The highest ionic conductivity of PVDF/PMMA blended with 0.08 wt. GO NP's is ~7.23 × 10–5 S/cm. These findings are expected to have a considerable effect on a wide range of applications, such as polymer solar cells, nanoelectronics, polymer organic semiconductors, and energy storage.

Tailoring of ternary nanocomposite films of poly(vinyl alcohol)/AgAlO2@reduced graphene oxide: An active material for flexible supercapacitors

Poly(vinyl alcohol) (PVA)/silver aluminium oxide (AgAlO2)@reduced graphene oxide (rGO) nanocomposites (NCs) as flexible supercapacitor electrodes were fabricated via an eco-friendly and scalable solution casting approach. The crystallinity and morphological characteristics of the developed NCs were characterized by using X-ray diffraction (XRD), Raman spectroscopy and scanning electron microscopy (SEM). The thermal properties were analysed by thermal gravimetric analysis (TGA). The electrochemical performance of PVA/AgAlO2@rGO NCs as a supercapacitor electrode material was investigated by cyclic voltammetry (CV) studies. PVA/AgAlO2@rGO NCs showed wide operating potential windows (1.2 ​V) which can greatly enhance their capacitive behaviour. The highest specific capacitance obtained was 273.4 ​F ​g−1 in the case of 2 ​wt % AgAlO2@rGO loaded PVA NC as compared to pristine PVA (6.04 ​F ​g−1). These NCs exhibited superior performance with the energy density (13.8 Whkg−1) and power density (150 ​W ​kg−1) at 0.5 ​A ​g−1 respectively. PVA/AgAlO2@rGO NCs exhibited the negligible equivalent series resistance and charge transfer resistance as an indication of excellent charge propagation at the interface between an electrolyte and an electrode. The NCs showed good capacity retention of 86.18% even after 1000 cycles. The NCs comprising of AgAlO2 NPs exhibited better specific capacitance than reduced graphene oxide incorporated PVA NCs, thus constituting a new approach for fabricating supercapacitors electrodes.

Fabrication of noble metal (Au, Ag, Pt)/polythiophene/reduced graphene oxide ternary nanocomposites for NH3 gas sensing at room temperature.

Room temperature NH3 gas sensors composed of noble metal (Au, Ag or Pt)/polythiophene/reduced graphene oxide (Au, Ag or Pt/PTh/rGO) ternary nanocomposite films were fabricated using a simple one-pot redox reaction. The surface morphology and composition of Au, Ag or Pt/PTh/rGO ternary nanocomposite films were analyzed using Fourier transform infrared spectroscopy, X-ray diffraction (XRD) and scanning electron microscopy (SEM). Compared with Ag/PTh/rGO and Pt/PTh/rGO ternary nanocomposite films, obviously bright Au nanoparticles were observed on the surface of the massive lamination PTh film which wrapped the rGO, and encapsulated Au nanoparticles were observed in the Au/PTh/rGO film. Comparative gas sensing results showed that the Au/PTh/rGO ternary nanocomposite film had the highest response compared with Ag/PTh/rGO and Pt/PTh/rGO ternary nanocomposite films at room temperature, especially when the testing concentration of NH3 gas was below 5 ppm. The Au/PTh/rGO ternary nanocomposite film also had a fast response time and good reproducibility. The combination of the high catalytic activity of naked Au nanoparticles and the formation of effective carrier transfer channels by encapsulated Au nanoparticles was responsible for the improved response of the Au/PTh/rGO ternary nanocomposite film.

Initiating a Stretchable, Compressible, and Wearable Thermoelectric Generator by a Spiral Architecture with Ternary Nanocomposites for Efficient Heat Harvesting

AbstractThermoelectric generators (TEGs) based on organic/inorganic nanocomposites have made great achievements in recent years, while rational design of flexible TEGs to harvest energy via cross‐plane heat flux remains a great challenge. Herein, flexible poly(3,4‐ethylenedioxytiophene)‐tosylate/Te/single‐walled carbon nanotubes (PEDOT‐Tos/Te/SWCNTs) ternary nanocomposite films with unique layered structure are synthesized, exhibiting an optimized power factor of 131.9 ± 8.5 µW m–1 K–2 that is ≈120 times of that of the pristine PEDOT‐Tos. A spiral architecture is subsequently proposed to assemble the nanocomposite films into 3D TEGs, resulting in device‐level flexibility, stretchability, and compressibility. The spiral‐like TEGs can realize efficient heat‐to‐electricity conversion through cross‐plane heat flux, and large output powers of 7.04 and 9.59 µW are achieved for the TEG prototypes with 10 p‐type legs and 5 pairs of p‐n couples, respectively, under a temperature difference of 80 K, surpassing most reported TEGs using Te‐based composites. They can also provide stable energy output upon multiple stretching and compressing cycles. Furthermore, the spiral‐like TEGs are demonstrated versatile applications to harvest human body heat on wrist, and to generate electricity via the temperature difference induced by hot water or liquid nitrogen. This work offers a promising route to exploit thermoelectric composites for flexible and wearable applications.

Absorption-dominant microwave shielding properties of Sn0.2Fe2.8O4-graphite-PVDF ternary nanocomposite films

Absorption-dominant microwave shields are in high demand for mitigating the effect of electromagnetic interference (EMI) on devices and the environment. In this paper, we describe the development of absorption enhanced ternary nanocomposites and their EMI shielding capability. Polymer based shields have been fabricated by dispersing conducting graphite and magnetic spinel ferrite Sn0.2Fe2.8O4 nanoparticles in electroactive polymer polyvinylidene fluoride. Shielding effectiveness (SE) values in the expected range of 10–30 dB in the X-band region, were achieved with as low as 30–50 wt% of pristine graphite and 1–10 wt% of Sn0.2Fe2.8O4. The industrial standard of 99% shielding (SE ⩾ 20 dB) was obtained with 50 wt% of graphite. The composites exhibit absorption as the dominant mechanism of shielding. The percentage SE due to absorption is about 70% and is tuned upwards by the increase in ferrite concentration. The composites were characterized by x-ray diffraction and vibrating sample magnetometry; thermal analysis confirms their stability. The thin, flexible films fabricated by the simple and cost-efficient technique of solution casting will be extremely valuable as wrap-on shields for X-band microwave attenuation.

Exploring the bone regeneration potential of bio-fabricated nano-titania reinforced polyvinyl alcohol / nano-cellulose based composite film

A significant rise in bone-related defects affects the quality of life which impels researchers to facilitate the new approaches for bone regeneration. Herein, we have explored the bioactive nature of nano-titania for its utilization in bone tissue engineering. The titania-doped ternary nanocomposite film (PVA/NC-TiO2) was prepared by the fusion of Polyvinylalcohol (PVA), nano-cellulose (NC), and TiO2 (0.01 wt%) nanoparticles via sol-gel casting and compared with its binary nanocomposite film (PVA/NC). The simple and low-cost synthesis of these nanocomposite films, together with remarkable bioactive and thermo-mechanical properties, makes them a good candidate for their applications in human bone regeneration. The fabricated nanocomposite films were characterized through Fourier transform infra-red, Ultra-violet spectroscopy, and X-ray diffraction analysis to study complex formation and intermolecular interactions between the molecular entities.The SEM and TEM micrographs revealed the smooth surface of the developed binary and ternary nanocomposite films along with homogenous particle distribution. The thermo-mechanical stability was significantly improved when the nanocomposite film was modified with TiO2 nanoparticles indicating an enhancement of intermolecular interactions in PVA/NC-TiO2 film as compared to PVA/NC film. The Dynamic mechanical analysis results show higher storage modulus and glass transition temperature for PVA/NC-TiO2 film (9131.26 MPa, 74.3 °C) than PVA/NC film (7588 MPa, 64.3 °C). A comparative analysis of nanocomposite films revealed that PVA/NC-TiO2 film exhibited a thick and more uniformed layer of Ca–P mineral on its surface than PVA/NC film when incubated in Simulated Buffer Saline. The low loading of TiO2 nanoparticles resulted in a positive reinforcement effect on the bioactivity of the PVA/NC-TiO2 film (cell viability higher than 80%, hemolysis less than 1.7%) which provides an effective gateway for polymer nanocomposites in the dynamic orthopedic application by serving a better bone template for the regeneration of bone tissue.

Barrier, rheological, and antimicrobial properties of sustainable nanocomposites based on gellan gum/polyacrylamide/zinc oxide

AbstractIn this study, we used a solution casting method to prepare gellan gum (G)‐based ternary nanocomposite films containing polyacrylamide (P) and zinc oxide (ZnO) nanoparticles. All composites were prepared using the chemical cross‐linker N,N‐methylenebisacrylamide. The nanocomposites were characterized using Fourier transform infrared (FTIR) spectroscopy, X‐ray diffraction, and scanning electron microscopy. Attenuated total reflectance FTIR revealed strong hydrogen bonding interactions among gellan gum, polyacrylamide, and ZnO, which enhanced the physiochemical, thermal, and mechanical properties of the GPZnO nanocomposites. The addition of ZnO nanoparticles increased the glass transition temperature (Tg: 181.8–196.3°C), thermal stability (T5%: 87.8–96.5°C), and char yield (23.9–29.1%) of the GP composite films, as well as their the tensile strength (from 33.5 to 43.8 MPa) and ultraviolet (UV) blocking properties (~99.2% protection against UVB [280–320 nm]). ZnO significantly influenced the rheological properties of the GP composite. The prepared GP and GPZnO nanocomposites exhibited shear thinning behavior and their viscosities decreased when there is an increase in shear rate. Storage and loss modulus increased with frequency with the addition of ZnO nanoparticles. The GPZnO films exhibited reduced hydrophilicity, moisture content, and water barrier properties compared with the GP film. The GPZnO nanocomposites exhibited effective antimicrobial activity against six different pathogens. The prepared GPZnO films could be useful in biodegradable packaging applications.

Effect of TiO2 nanoparticles on energy transfer mechanism in ternary nanocomposite conjugated polymer blend

The effect of TiO2 nanoparticles (NPs) on the energy transfer mechanism from poly(9,9-dioctylfluorene-2,7-diyl) (PFO) to poly(2-methoxy-5(2-ethylhexyl)1,4-phenylenevinylene (MEH-PPV) and to poly 9,9-dioctylfluorene-alt-benzothiadiazole (F8BT), and from F8BT to MEH-PPV was investigated. The binary and ternary nanocomposite thin films were spin-coated on glass substrate after prepared by the solution blending method. The intensity enhancement, the red-shift in the emission spectra and the enhancement in electrical properties, after the NPs added to the ternary blend, confirmed improvements in both the electron-hole recombination and the energy transfer efficiency. To recognize the effect of the NPs on the energy transfer mechanism, the emission and absorption spectra of three nanocomposite binary blends were recorded. The donor and acceptor contents in the blends were kept constant, while the NPs content was varied. Förster radius (Ro) and distance between donor and acceptor molecules (RDA) were calculated and found to be affected by the NPs addition. Successfully, the mechanism of the NPs effect was explained. Several observations indicated that the NPs addition into the blend enhanced the Förster resonance energy transfer (FRET), while obstructed the Dexter energy transfer mechanism. In addition, the measured Commission International d′Eclairage (CIE) coordinates confirmed that the emitted color from the blends can be simply controlled via the NPs addition.

Enhanced antimicrobial and physical properties of poly (butylene adipate‐co‐terephthalate)/zinc oxide/reduced graphene oxide ternary nanocomposite films

The development of biodegradable packaging materials is important to mitigate the negative environmental impact of plastic waste. This study focuses on enhancing antimicrobial and physical properties of poly(butylene adipate-co-terephthalate) biodegradable film by incorporated with zinc oxide (ZnO)/reduced graphene oxide (rGO). The resulting nanocomposite films were characterized to evaluate its functional properties and antibacterial activity. The ZnO/rGO nanocomposite can improved the mechanical and thermal properties of the PBAT nanocomposite films. In addition, the migration of Zn ions from the PBAT/ZnO/rGO nanocomposite films were considered safe under the criteria established by European plastic regulation (EU) standards. The PBAT/ZnO/rGO nanocomposite films also showed excellent antibacterial activity against Escherichia coli (81.32%) and Staphylococcus aureus (82.44%). The results of this study suggest that PBAT/ZnO/rGO nanocomposite films is effective as a biodegradable active material for food packaging applications.

Construction of ternary core-shell Fe3O4@BaTiO3/PVDF nanocomposites with enhanced permittivity and breakdown strength for energy storage

Introducing conductive nanoparticles into ferroelectric polymers gives rise to significant enhancement of permittivity (ε), making these composites practically promising for energy storage devices. However, the breakdown strength (EB) of such composites is reduced with few exceptions, which limits high-performance applications. Here we study the energy storage behavior of well-designed Fe3O4@BaTiO3 core-shell nanoparticle/poly(vinylidene fluoride) (PVDF) nanocomposites in which conductive Fe3O4 nanoparticles (NPs) are coated by ferroelectric BaTiO3 (BT), together with the PVDF matrix, forming the ternary nanocomposite films with high energy storage performance. Notably, the permittivity is enhanced by increasing the volume fraction of the Fe3O4@BT NPs, reaching 38 with 2 vol% Fe3O4@BT NPs and remaining low dielectric loss (~0.066). In particular, the nanocomposites exhibit moderate breakdown strength (~430 kV/mm), which is attributed to the “voltage dispersion layer” (the BaTiO3 shell) between the polymer matrix and Fe3O4 NPs. The finite element simulation substantiates the experimental results and further confirms the positive correlation of the breakdown strength and the permittivity of the “voltage dispersion layer”. With the synergistic effect of both breakdown strength and electric displacement, a remarkable energy density (16 J/cc, at 430 kV/mm) is obtained.

Interfacial architecting with anion treatment for enhanced thermoelectric power of flexible ternary polymer nanocomposites

Flexible ternary thermoelectric nanocomposite films with unique interfacial architectures are developed by sequential electrochemical polymerization and subsequent anion treatment. These nanocomposites exhibit high power factors over 500 μW m−1 K−2.

Poly (3,4-ethylenedioxythiophene)/ polypyrrole/ carbon nanoparticle ternary nanocomposite films with enhanced thermoelectric properties

The different impacts of graphene (GNS) and multi-walled carbon nanotube (MWCNT) on the polypyrrole (PPy)-based composites systems have been investigated. PPy/GNS and PPy/MWCNT binary composites were firstly obtained by in situ polymerization. Then poly(3,4-ethylenedioxythiophene): poly (styrene sulfonate) (PEDOT: PSS) was employed to prepare PEDOT: PSS-PPy/GNS (PGNS) and PEDOT: PSS-PPy/MWCNT (PMWCNT) ternary nanocomposite films. PGNS films exhibit uniform layered structure and possess better crystallinity than PMWCNT composites films. Structural analyses reveal that PPy/GNS interact stronger with PEDOT chains, and PEDOT molecular has greater effect on the π-π conjugated structure of PPy/GNS than that of PPy/MWCNT. In particular, when the mass ratio of PPy/GNS to PEDOT: PSS was 70%, PGNS composites show excellent thermoelectric performance with the maximum power factor at room temperature of 82.22 μW/mK2, which is among the highest value of PPy/GNS-based composites, and the optimal power factor of 55.28 μW/mK2 goes to PMWCNT films when the mass ratio of PPy/MWCNT to PEDOT: PSS was 5%.

Fabrication of a highly sensitive flexible humidity sensor based on Pt/polythiophene/reduced graphene oxide ternary nanocomposite films using a simple one-pot method

A novel, flexible humidity sensor based on ternary nanocomposite films of Pt nanoparticles, polythiophene, and reduced graphene oxide (Pt/polythiophene/RGO) was fabricated using a simple one-pot redox synthesis. First, 2-thiophene methanol (2-TPM) was allowed to react with PtCl42– ions via an oxidative polymerization process, which released electrons that simultaneously reduce the PtCl42– ions and GO to Pt nanoparticles and RGO, respectively. The effects of the amounts of added PtCl42– ions and RGO on the electrical, flexibility, and humidity-sensing properties of the Pt/polythiophene/RGO ternary nanocomposite films were investigated. The Pt/polythiophene/RGO ternary nanocomposite films were characterized by using the Fourier transform infrared spectroscopy (FTIR), Raman, atomic force microscopy (AFM), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). A Pt/polythiophene/RGO ternary nanocomposite film containing 30 mg of Pt and 0.1 g of RGO exhibited the greatest flexibility, sensitivity, and long-term stability. This flexible humidity sensor also demonstrated a wide range of working humidities, an acceptable linearity, a small hysteresis, a short response/recovery time, and a weak temperature dependence. We used complex impedance spectra to explain the humidity-sensing mechanism of the flexible sensor based on Pt/polythiophene/RGO ternary nanocomposite films and thus found that the ions (H3O+) in this system dominate the conductance process of the sensor.

Specific interactions and charge transport in ternary PVDF/polyaniline/MWCNT nanocomposite films

This paper reveals the specificity of morphology, structure and electrical properties of the new compression-molded ternary nanocomposite films based on polyaniline (PANI) doped with plasticizing dopant dodecylbenzenesulfonic acid (DBSA) and multi-walled carbon nanotubes (MWCNT), which are distributed in the dielectric matrix of polyvinylidene fluoride (PVDF). We find that this specificity appears not only due to sum of the properties of the components but also to their physical-chemical interactions. The strong influence of such interactions on the nanocomposites properties is well confirmed by Raman spectroscopy analysis of oxidation level, quantity of polarons, bipolarons and phenazine defects of the doped PANI component in binary PVDF/PANI and ternary PVDF/PANI/MWCNT nanocomposite films with 1 wt% or 10 wt% of MWCNT. Based on conductivity measurements of these films in a wide temperature range (4.2–300 K) we conclude that mechanisms of their conductivity depend on both the specific interactions and the MWCNT content. The effect of MWCNT on the electrical properties of ternary nanocomposites is more pronounced at low temperatures.