Hybrid Polymer Nanocomposites Research Articles

Temperature-Dependent Synergistic Effect of Multi-Walled Carbon Nanotubes and Graphene Nanoplatelets on the Tensile Quasi-Static and Fatigue Properties of Epoxy Nanocomposites.

Even though the characteristics of polymer materials are sensitive to temperature, the mechanical properties of polymer nanocomposites have rarely been studied before, especially for the fatigue behavior of hybrid polymer nanocomposites. Hence, the tensile quasi-static and fatigue tests for the epoxy nanocomposites reinforced with multi-walled carbon nanotubes (CNTs) and graphene nanoplatelets (GNPs) were performed at different temperatures in the study to investigate the temperature-dependent synergistic effect of hybrid nano-fillers on the studied properties. The temperature and the filler ratio were the main variables considered in the experimental program. A synergistic index was employed to quantify and evaluate the synergistic effect of hybrid fillers on the studied properties. Experimental results show that both the monotonic and fatigue strength decrease with increasing temperature significantly. The nanocomposites with a MWCNT (multi-walled CNT): GNP ratio of 9:1 display higher monotonic modulus/strength and fatigue strength than those with other filler ratios. The tensile strengths of the nanocomposite specimens with a MWCNT:GNP ratio of 9:1 are 10.0, 5.5, 12.9, 23.4, and 58.9% higher than those of neat epoxy at −28, 2, 22, 52, and 82 °C, respectively. The endurance limits of the nanocomposites with this specific filler ratio are increased by 7.7, 26.7, 5.6, 30.6, and 42.4% from those of pristine epoxy under the identical temperature conditions, respectively. Furthermore, the synergistic effect for this optimal nanocomposite increases with temperature. The CNTs bridge the adjacent GNPs to constitute the 3-D network of nano-filler and prevent the agglomeration of GNPs, further improve the studied strength. Observing the fracture surfaces reveals that crack deflect effect and the bridging effect of nano-fillers are the main reinforcement mechanisms to improve the studied properties. The pullout of nano-fillers from polymer matrix at high temperatures reduces the monotonic and fatigue strengths. However, high temperature is beneficial to the synergistic effect of hybrid fillers because the nano-fillers dispersed in the softened matrix are easy to align toward the directions favorable to load transfer.

Effect of secondary filler properties and geometry on the electrical, dielectric, and electromagnetic interference shielding properties of carbon nanotubes/polyvinylidene fluoride nanocomposites

AbstractHybrid polymer nanocomposites based on polyvinylidene fluoride (PVDF) as the matrix, carbon nanotubes (CNTs) as the primary conductive filler, and metal nanoparticles as secondary fillers were fabricated by melt mixing. Secondary nanofillers with different geometry and properties (nickel nanowire (NiNW), silver nanowire (AgNW), nickel nanoparticle (NiNP), and silver nanoparticle (AgNP) were selected to investigate the effect of geometry and properties of secondary filler on the hybrid polymer nanocomposites' properties. Electrical conductivity, electromagnetic interference (EMI) shielding effectiveness, and complex microwave properties of the fabricated hybrid nanocomposites were studied in X‐band frequency (8.2–12.4 GHz). The hybrid nanocomposites containing CNT/AgNW demonstrated superior conductivity and EMI shielding compared to individual fillers such as CNT, AgNW, NiNW, AgNP, NiNP, or hybrid system such as CNT/NiNW. The novelty of the present study lies in the unique synergy arising from the combination of nanofillers with similar geometry and high electrical conductivity, which resulted EMI shielding effectiveness as high as 27 dB for a shield with only 1.1 mm thickness. The EMI shielding mechanisms, including negative permittivity were studied and explained in details in the manuscript.

An efficient homogenization scheme for analyzing the elastic properties of hybrid nanocomposites filled with multiscale particles

Designing material requires the establishment of structure–property relationships for multiscaled nanoparticle/microparticle-reinforced polymer hybrid nanocomposites. This fundamental task is the first step in developing a reliable new method. In the present study, two micromechanical analytical models are proposed to develop an efficient homogenization scheme, in the case of calculating elastic properties for a multiscaled hybrid nanocomposite consisting of silica nanoparticles and glass microparticles embedded in the epoxy matrix. In the small scale, we consider homogenous interphase surrounding the nanoparticle which the first model takes into consideration. In the small scale, considering the thickness of this interphase as variable and characteristic length scale, the influence of nanoparticle size on the overall elastic properties is calculated. In the large scale, an interface model of homogenization is proposed; this model too calculates the elastic properties of the overall nanocomposite as a function of inclusion size in microsize representative volume elements. In the large scale, the existence of surface stress and strains is a result of “sticking” behavior of the matrix to the inclusion surfaces. By combining these two models, we can determine the effective elastic properties of a hybrid nanocomposite as a function of nanoparticle size, microscale inclusion size, interphase thickness, and volume fractions. The model predictions are in good agreement with the experimental data provided in the literature.

Functional Polymer Hybrid Nanocomposites Based on Polyolefins: A Review

For the last twenty years, polymer hybrid nanocomposites have enjoyed unflagging interest from numerous scientific groups and R&D departments, as they provide notable enhancement of properties, even at low nanofillers’ content. Their performance results from many factors, the most important of which is the uniform distribution in the entire volume of the matrix, that still is very challenging, but is the right choice of two types of nanoparticles that can lead to an increase of dispersion stability and even more uniform distribution of fillers. The incorporation of two types of nanofillers, especially when they differ in aspect ratio or chemical nature, allows to additively reduce the price of the final composite by replacing the more expensive filler with the cheaper one, or even synergistically improving the properties, e.g., mechanical, thermal, and barrier, etc., that can extend their usage in the industry. Despite numerous review papers on nanocomposites, there is no review on how the introduction of a hybrid system of nanofillers affects the properties of polyolefins, which are the most commonly used engineering plastics. This review deeply focuses on the structure–properties relationship of polyolefins-based hybrid nanocomposites, especially based on two types of polyethylenes (low-density polyethylenes (LDPE) and high-density polyethylenes (HDPE)) and polypropylene.

New Hybrid Polymer Nanocomposites Based on Polyvinylidene Fluoride and CdS/ZnS Nanoparticles: Structure and Dielecric Properties

The structure and dielectric properties of new hybrid polymer nanocomposites based on polyvinylidene fluoride (PVDF) and CdS and ZnS nanoparticles (NPs) have been studied. It was established that ZnS and CdS NPs, when added at low concentrations, define the structure of the host polymer matrix, and new polar groups and stable charge traps arise, which, in turn, leads to an increase in the dielectric permittivity and polarizing ability of the nanocomposites based on PVDF + CdS/ZnS NPs. As the NP concentration is increased, the NPs start to behave like a separate dispersion phase, and the conductivity of nanocomposites grows as the content of this phase increases, which results in the nanocomposite’s polarizing ability gradually diminishing.

Polymers in gearbox production

Technological progress spurs the creation of new machine designs, the development of new highly advanced technologies, as well as the introduction of new materials, including polymeric ones, that meet the economic and ecological criteria. An analysis of the literature reveals that there are few works outlining the rules for the design of machine components using polymeric materials, including composites and nanocomposites. This article is a review of the literature on the use of polymer matrix thermoplastic composites (PA6 – polyamide 6, PA66 – polyamide 66 and POM – polyoxymethylene) in toothed transmission systems. The presented examples demonstrate the production of hybrid polymer nanocomposites with addition of inorganic fillers and their application in the manufacture of machine components, including gears.

Compressive Strength Evaluation of Nanodiamond/ MWCNT/Graphene Reinforced Novel Hybrid Polymer Nano Composites

Because of the inherent brittleness property of monolithic epoxy, it fails to prevent crack propagation and is hence vulnerable to the catastrophic failure. Nano-fillers, such as CNT/Graphene (GnP)/Nanodiamond (NDs) and other carbonaceous materials increase its ability to withstand crack propagation thus its fracture strength propitiously improved. This paper studies compressive properties of MWCNT/GnP/NDs on epoxy based composite material. A static uniaxial compression test was conducted in order to study the effect of these fillers on the compressive stress-strain behaviour of such composites. In this study, the MWCNT/GnP/NDs are added individually as 0.2 wt% and for the hybrid composite, 0.1 wt. % of NDs is added separately along with 0.1 wt% of MWCNT and GnP to the epoxy matrix. The bonding between MWCNT/GnP/NDs with the epoxy matrix is confirmed by microscopic observations. The results showed that the individual addition of 0.2 wt% of MWCNT/GnP/NDs, improves the compressive strength whereas the hybrid composite produced a declining trend. The reverse trend was also observed for the modulus value of the above mentioned composite materials.

Synergy studies on polyurethane–carbon black, multi-walled carbon nanotube-based heterogeneous electroactive shape memory nanocomposite system

This paper describes a multi-filler synergy study that was carried out for multi-walled carbon nanotubes (MWCNTs) and carbon black (CB) filler systems in polyurethane (PU) resin, and the individual contributions of the fillers were evaluated. The hybrid nanocomposite was found resistant to ultraviolet radiation and exhibited a high glass transition temperature enabling it suitable for space applications. The contributions of individual fillers in the hybrid system were compared with the binary nanocomposites of respective fillers and the advantages of hybrid system are also highlighted. The synthesized hybrid polymer nanocomposite (PU + CB + MWCNT) was found to have superior thermal, electrical and mechanical properties even at a very low content of reinforcements and a percolation threshold of 5% CB and 0.15% MWCNT combination was also observed. Shape memory effect of the hybrid system was evaluated and compared with binary systems. A faster recovery time of 41 s was observed for a combination of 5% CB and 0.25% MWNT against 50 s for 25% CB alone upon thermal actuation. On electrical actuation, the hybrid nanocomposite system was observed to have a three-fold faster recovery compared to the binary systems of CB alone. The hybrid system proves to be a reliable choice for replacing an expensive single reinforcement system of MWCNTs.

Modification of tamarind fruit shell powder with in situ generated copper nanoparticles by single step hydrothermal method

Tamarind fruit shell powder (TFSP) with particle size of < 50 µm (obtained from cleaned tamarind fruit shells) was modified with in situ generated copper nanoparticles (CuNPs) by simple one step hydrothermal method. The modified TFSP was characterized by scanning electron microscope (SEM), Fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD), thermogravimetric analysis (TGA) and antibacterial tests. The generated stable CuNPs on the surface of the modified TFSP were spherical in shape with an average size of 88 nm. The FT-IR spectroscopy analysis indicated the involvement of the functional groups of the TFSP in the generation and stabilization of the CuNPs. The XRD analysis indicated the presence of both CuNPs and Cu2O nanoparticles in the modified TFSP. The thermal analysis indicated the presence of 5.6 wt% of copper nanoparticles as calculated from the difference of residual char content between the unmodified and modified TFSP. The modified TFSP with in situ generated CuNPs exhibited obvious antibacterial activity against both the Gram negative and Gram positive bacteria and hence can be considered as low cost filler in the preparation of antibacterial polymer hybrid nanocomposites for packaging and medical applications.

The Multi-objective Optimization Design Approach for Carbon Fiber Hybrid Nanocomposites Containing NanoClay and NanoZnO Particles by Using OptiComp

This paper presents the multi-objective design optimization of Carbon Fiber-Reinforced Polymer hybrid nanocomposites by OptiComp. The use of nanoparticles not only improves the interface strength but also significantly improves stress and hence the propagation of strain in composite laminates, which ultimately improves the stiffness of the composite laminate. The OptiComp is the comprehensive generic procedure for design optimization of the composites. With the utilization of OptiComp, the discrete form Variable thickness approach (VTA) used in this study can discover the minimum laminate thickness, and for maximum stiffness in one step instead of two-step method. The Max stress theory and Tsai-Wu theory as constraints for the current study in optimization are performed using a direct value coding genetic algorithm. It is found that the CFRP nanocomposites up to 2 to 3 wt% range of nanoparticles can be designed for max. stiffness and min. weight.

Tunable β-phase crystals, degree of crystallinity, and dielectric properties of three-phase PVDF/PEO/SiO2 hybrid polymer nanocomposites

Polymer nanocomposites (PNCs) are key materials in the advances of flexible-type microelectronic devices based on polymer engineering and technology. In this study, three-phase hybrid PNC films of poly(vinylidene fluoride)/poly(ethylene oxide) (PVDF/PEO) blend dispersed with amorphous silica (SiO2) nanoparticles were prepared and characterized by different spectroscopic techniques. The results reveal that the increase of SiO2 contents decreases the degree of crystallinity and relative fraction of PVDF β-phase crystals, and considerably modifies the spherulitic morphology of PVDF/PEO blend matrix. The dielectric spectroscopy of frequency range 20 Hz–1 MHz confirms a dominant contribution of interfacial polarization at low frequencies and a significant hindrance to the PEO chain segmental dynamics. Furthermore, the dielectric permittivity of these films increases linearly up to 5 wt% loading of nanofiller. The tunable structural and dielectric properties of the PVDF/PEO/SiO2 films with SiO2 concentration confirm them technologically appealing polymeric nanodielectrics for energy storage and organoelectronic device applications.

Polymerization-Induced Self-Assembly (PISA) and “Host–Guest” Complexation-Directed Polymer/Gold Nanocomposites

Polymer and inorganic hybrid nanocomposites are of increasing interest for a wide variety of applications; however, the preparation of these nanocomposites often requires cumbersome procedures, esp...

Synthesis and Characterization of Polypyrrole-Antimony (III) Oxide Hybrid Polymer Nanocomposites

Synthesis and Characterization of Polypyrrole-Antimony (III) Oxide Hybrid Polymer Nanocomposites

Carbon nanotube/ZnO nanowire/polyvinylidene fluoride hybrid nanocomposites for enhanced electromagnetic interference shielding

AbstractLightweight and flexible materials with high conductivity and low thickness are highly desirable for electromagnetic interference (EMI) shielding applications. Developing hybrid nanostructured materials, which combine the properties of their constituents, is an excellent strategy to create highly effective EMI shields. In this study, we report a hybrid polymer nanocomposite composed of carbon nanotube (CNT) and ZnO nanowire (ZnONW) for EMI shielding applications. We found that the combination of a conductive filler (CNT) and a dielectric filler (ZnONW) with a similar geometry is an effective method to fabricate nanocomposites with enhanced EMI shielding. We achieved high average shielding effectiveness of 27.3 dB (with a maximum of 41 dB at 10.2 GHz) for a sample of CNT:ZnONW (5.0:2.5 wt%) with only 1.1 mm thickness, which is among the best‐reported values in the literature for polymer nanocomposites with similar filler loading and thickness. This performance originates from the excellent electrical conductivity and dielectric properties of hybrid nanocomposites, combined with the geometry of ZnO nanowire. A comparison of the shielding properties of the developed hybrid nanocomposites with the literature implies that they are promising functional materials in the world of EMI shielding applications.

Multifunctional hybrid polymer nanocomposites for automotive‐battery packaging

AbstractGlobal sales of new electric vehicles (EV) already passed a million units last year. Lithium‐ion battery packs are composed of cells and assembly of modules. Nevertheless, the development of light‐weighted with high oxygen and moisture barrierability remains one of the untouched issues in battery technology. This study aimed to fabricate multifunctional hybrid nanocomposites for barrier films for Li‐ion battery packs on electric vehicles applications. The synthesized carbon supported MgO nanoparticles (hereafter referred to as CSMO) were dispersed in high density polyethylene (HDPE) polymer to satisfy several requirements for EV battery packs. The loading amount of MgO was achieved up to 22 wt % of carbon, and the size distribution was in the range of 50 to 100 nm. The hybrid nanocomposites were characterized by water‐vapor transmission rate (WVTR), various spectroscopic methods, thermo‐gravimetric analysis and elemental analysis. Mechanical properties were also tested. The extremely low WVTR value of CSMO/HDPE composites below 0.5 mgm−2 day−1 is the lowest value among any other gas barrier films reported in the literature. Suitable mechanical properties were also achieved. The newly proposed multifunctional hybrid nanocomposites would be very promising for barrier films on automotive packaging applications.

Developing a nested micromechanical model to predict the relaxation moduli of graphene nanoplatelets/carbon fiber reinforced hybrid nanocomposites

A nested analytical method, a product of combining two micromechanical models is developed in this study. The proposed micromechanical method predicts the relaxation properties of polymer hybrid nanocomposites containing linearly visco-elastic matrix, transversely isotropic elastic carbon fibers, and graphene nanoplatelets. Calculations performed in this model are of two scales. The small scale, which is the domain of epoxy resin and graphene nanoplatelet interactions, and the large scale, which assumes the small scale as a homogenized isotropic matrix. In the large scale, the prescribed matrix is then reinforced by the unidirectional CFs. Each scale calculation gives the properties of the underlying material. Secant moduli and the field fluctuation techniques are adopted in this study. Resulting explicit formulae allows one to calculate the overall relaxation moduli of the graphene nanoplatelet/carbon fiber-reinforced polymer hybrid nanocomposites. By comparing the data obtained by experiments and the results extracted by the proposed micromechanical approach, the accuracy of the model becomes apparent. Addition of graphene nanoplatelets into the fibrous composites leads to an improvement in the relaxation properties of the hybrid nanocomposites. Also, the elastic properties of graphene nanoplatelet/carbon fiber-reinforced epoxy hybrid nanocomposites are reported. The role of graphene nanoplatelet agglomeration, frequently encountered in real engineering situations, in the mechanical response of unidirectional hybrid nanocomposites is examined. The effects of volume fraction of graphene nanoplatelets and CFs on the overall mechanical properties are investigated.

Hybrid polymer nanocomposites as EMI shielding materials in the X-band

Electromagnetic interference (EMI) is a phenomenon where one electromagnetic field interacts with another, generating disturbances in both the fields. The electromagnetic interference (EMI) issue is of grave concern due to a rampant increase in wireless devices and increased sensitivity of electronic gadgets. Conductive polymer nanocomposites have been extensively used as an alternative to metals used traditionally for EMI shielding applications. In this paper, the influence of the EMI shielding effectiveness (SE) of the epoxy nanocomposites containing varying quantities of carbon black and magnetite (Fe3O4). The results indicate that addition of magnetic filler (i.e, Fe3O4) increases the shielding effectiveness of the nanocomposites in the X-band. Microstructural characterization of the epoxy nanocomposites using scanning electron microscopy revealed good filler dispersion in the matrix. Mechanical testing on the composites reveals that the Young’s modulus increased with the filler content. This method of increasing the EMI shielding properties of polymer by employing both conductive and magnetic fillers will be useful for other systems as well and will open further avenues for research in this direction.

An insight into mechanical properties of polymer nanocomposites reinforced with multidimensional filler system: A state of art review

The advent of polymer nanocomposites and hybrid polymer nanocomposites had widened the scope of neat polymers by enhancing their mechanical and other properties. It had further extended its areas of applications from engineering to biomedical and other application of prominence. The current discussion is primarily focused on different application area of nanofillers and their role in improvising the mechanical properties of neat polymer. A systematic study of available literatures presents that the synergy between polymer matrix fillers and its dispersion in matrix material resulted in improvised mechanical properties. A critical review of different application area and preparation technique is also presented.

Dielectric dispersion and electrical conductivity of amorphous PVP–SiO2 and PVP–Al2O3 polymeric nanodielectric films

The biodegradable hybrid polymer nanocomposite (PNC) films comprising silica (SiO 2 ) and alumina (Al 2 O 3 ) nanoparticles as inorganic nanofillers and the poly(vinyl pyrrolidone) (PVP) as organic host matrix (i.e., PVP– x wt% SiO 2 and PVP– x wt% Al 2 O 3 for x = 0, 1, 3 and 5) have been prepared by aqueous solution-casting method. X-ray diffraction (XRD) study reveals that these nanocomposite materials are highly amorphous. The dielectric spectroscopy of these different nanofiller concentrations PNC films has been carried out in the frequency range from 20 Hz to 1 MHz at a fixed temperature and also for 3 wt% nanofillers containing PNC films with the temperature variation. The results confirm that the complex dielectric permittivity of these hybrid films is influenced by the interfacial polarization in the low frequency range of 20 Hz to 1 kHz, whereas in the high frequency range up to 1 MHz permittivity is mainly governed by the molecular polarization and remains almost independent of the frequency. These SiO 2 and Al 2 O 3 nanofillers containing PNC films at fixed temperature display anomalous behaviour of dielectric permittivity and ac electrical conductivity with the increase of nanofiller concentration, but these parameters significantly enhance at low frequencies with the increase of temperature of the films. The electric modulus spectra of Al 2 O 3 containing PNC film exhibit relaxation peaks below 100 Hz at higher temperatures which attribute to the interfacial polarization relaxation process. The frequency independent dielectric permittivity and significantly low loss of these PNC materials at radio frequencies confirm their suitability as polymeric nanodielectric (PND) substrate and insulator in the design and fabrication of biodegradable electronic devices and electrical components.

Numerical investigation of the mechanical properties of a novel hybrid polymer composite reinforced with graphene and MXene nanosheets

This paper presents a numerical investigation of the elastic properties of a novel hybrid polymer composite reinforced with graphene and MXene nanosheets. A finite element computational model was developed to analyze the mechanical properties of a new polymer hybrid composite reinforced with MXene and graphene taking into account the properties of the 2D nanosheets, different aspect ratios, placement options and volume fractions of nanoreinforcements, as well as the interaction effects between the nanofillers and the surrounding polymer matrix. Using the developed numerical model, the influences of the interface layer properties, MXene and graphene aspect ratio, alignment and volume fraction on the orthotropic mechanical properties of the proposed novel hybrid polymer nanocomposites were determined. The results suggest that MXenes along with graphene nanosheets show considerable promise in the development of novel nanoengineered high-strength multifunctional composite materials, as well as provides insight for future design of such materials.