Papers by Keyword: Polymer Nanocomposites

Abstract: Polymer-metal hybrid nanocomposites have garnered significant attention in recent years due to their exceptional electrical and dielectric properties, which find applications in a wide range of industries, including electronics, energy storage, and advanced materials. This review article provides a comprehensive overview of the current state-of-the-art in the field of polymer-metal hybrid nanocomposites, with a particular focus on their electrical and dielectric properties. The first section of the review delves into the synthesis and fabrication techniques employed to create these nanocomposites, highlighting the importance of controlling the dispersion and distribution of metal nanoparticles within the polymer matrix. Various approaches, such as in-situ polymerization, melt mixing, and electrospinning, are discussed in detail, along with their respective advantages and limitations.The subsequent sections explore the influence of metal nanoparticles on the electrical conductivity and dielectric constant of the nanocomposites. The role of factors such as nanoparticle size, shape, and concentration in determining these properties is thoroughly examined. Moreover, the impact of metal surface modifications and the choice of polymer matrix on enhancing electrical and dielectric performance are also addressed. In addition to discussing fundamental aspects, this review highlights practical applications of polymer-metal hybrid nanocomposites in the development of high-performance capacitors, sensors, electromagnetic shielding materials, and flexible electronics. The potential for these materials to revolutionize various technological sectors is discussed, emphasizing their role in advancing miniaturization, energy efficiency, and durability. Furthermore, the review outlines current challenges and future prospects in the field, including the need for a deeper understanding of the underlying mechanisms governing electrical and dielectric behavior in these nanocomposites. Emerging trends such as the incorporation of 2D materials and the development of multifunctional hybrid systems are also explored, hinting at exciting avenues for further research and innovation. In conclusion, polymer-metal hybrid nanocomposites offer a promising platform for tailoring electrical and dielectric properties to meet the demands of modern technology. This review serves as a valuable resource for researchers, engineers, and scientists seeking to explore the potential of these materials and drive advancements in the field of electrical and dielectric engineering.

Abstract: This paper discusses in detail Recent Trends in Tribology of Polymers, Polymer Composites and Polymer Nanocomposites, since they have certain properties unachievable with traditional materials. Important commercial materials used have been given. Some unique properties and applications of PPCs have been outlined. Carbon Nanotubes have been discussed in detail. Some explanation of the synthesis and experimental results of Cellulose-based hydrogels as reported in the literature , have been discussed in detail.

Abstract: The possibility of creating polymeric nanocomposites with desired properties can be achieved by mixing it with an appropriate nanomaterial. The carbon-based nanomaterials have an excellent combination of both physical and chemical properties which create a significant interest among the researchers to prepare an industrially useful material employing carbon based nanomaterials as the filler. The thermo-mechanical properties of materials are studied to characterize their internal state and structure. In this chapter, the thermomechanical properties of polymer-CNT nanocomposites and the various factors affecting the thermomechanical properties are discussed.

Abstract: Two types of polymeric coating were applied on an AISI 1020 steel, where one of them was reinforced by carbon nanotubes, with the objective of protection against corrosion in a medium containing saline solution, NaCl 3% wt satured with CO₂, at 75 bar and tested at 50oC and 75oC for 360 hours. Electrochemical techniques, such as Linear Polarization Resistance, (LPR), Electrochemical Impedance Spectroscopy (EIS), Tafel curves and weight loss method, were used for coating evaluation performance. Scanning Electron Microscopy (SEM), X-ray diffraction (XRD) and energy dispersive spectroscopy (EDS) were used to determine both the morphology and chemical composition of the layer formed on the analyzed surfaces. The coating adhesion to metallic surface was evaluated using pull-off test according to ASTM D4541-09. For the studied conditions, the results obtained showed that there was no adequate coating protection, occurring failures and indicating that both coatings may not be used in the tested conditions.

Abstract: This work aimed to investigate the effects of boron nitride nanotubes (BNNTs) on the mechanical and thermal properties of BNNT-polycaprolactone (PCL) nanocomposites. BNNTs were synthesized via co-precipitation and annealing process by using amorphous boron powder as a precursor. PCL-BNNT nanocomposites were prepared by using sonication and thermal curing. Their morphology, thermal and tensile properties were characterized. Morphological observation revealed that BNNTs were arbitrarily and evenly dispersed within the PCL which indicated a good dispersion of the nanotubes in polymer matrix. Both the thermal stability and mechanical properties of neat PCL were enhanced with the addition of BNNTs to polymer matrix, in particular the tensile strength of PLC was increased by 101% with the addition of 5 wt% nanofillers.

Abstract: Current work reports on evaluation of bulk mechanical properties of High Density Polyethylene (HDPE) reinforced with functionalized 1D (Multi Walled Carbon Nanotubes- (MWCNTs) and 2D (hexagonal-Boron Nitride Nanoplatelets-(h-BNNPs) fillers. Mechanical mixing and injection moulding technique was used to prepare the composites. Evaluation of bulk mechanical properties like hardness, yield stress, fracture stress, impact toughness and Young`s modulus was carried out. The optimum properties were exhibited by HDPE/0.25 MWCNT/0.1 BNNP. Hardness, yield stress, fracture stress, impact toughness and Young`s modulus was observed to increase by 93.84, 80.83, 59.23, 115 and 42.05% on comparison with pure HDPE. TEM images confirm the tubular and hexagonal morphology of MWCNT and h-BNNP. It is concluded from test results that addition of MWCNT and h-BNNP into HDPE has improvised mechanical properties.

Abstract: Present work reports on Dynamic Mechanical Thermal Analysis (DMTA) of HDPE reinforced with surface modified 0D (Nanodiamonds-NDs), 1D (Multi Walled Carbon Nanotubes-MWCNTs) and 2D (Graphite nanoplatelets-GNPs) nanofillers. Composite samples were prepared using twin screw injection moulding machine. Dynamic properties like storage, loss modulus and tan delta were investigated as a function of temperature and at constant oscillation of 1 Hz. Optimum properties were exhibited by 0.1 CNT/HDPE during a temperature swept from 30 to 110 oC. The storage modulus and loss modulus of 0.1 CNT/HDPE increased by 57 and 28% on comparison with pure HDPE. 0.1 CNT/HDPE exhibited highest ascent during tan delta evaluation confirming good damping property. TEM analysis was carried out to investigate the morphology of ND, MWCNT and GNP.

Abstract: The paper deals with the influence of environmental degradation on the change of the mechanical properties of polymer nanocomposites. The tested material was polyamide (PA) filled with nanoclay fillers Cloisite 30B, Cloisite 93A and Cloisite Na + in a volume of 2, 4 and 6 wt%. Test samples were produced by injection molding and were subjected to 540 hours and 1080 hours of UV radiation. The change of mechanical properties of PA6/MMT nanocomposite systems after the ageing in the UV chamber was studied by tensile test and Charpy impact resistance test. Article also compares structure of PA6/MMT nanocomposite.

Abstract: Despite substantial research efforts, the potential of polymer nanocomposites has still not been fully revealed, mainly due to poor control over the dispersion and alignment of nanoparticles (NPs). Since nanocomposite properties are controlled by the structural variables, it is crucial to achieve control over the NP assembly process.Self-assembly of NPs offers limited control over the NP spatial arrangement. This process results in a poorly controlled variation of simple structures such as agglomerates, clusters and dispersed NPs with the resulting structure strongly dependent a on wide range of thermodynamic parameters.On the other hand, force-assembly exploits interactions between particles induced by external force fields overcoming the thermodynamic ones. Stimulus of external electric, magnetic or electro-magnetic field is applied as the main force controlling the assembly of NPs. Understanding this process gives us the opportunity to create prescribed NP structures with controlled shape, size, and anisotropy by simple change of the force field. Precise control of structure formation on different length scales (from nanoto macro) gives us the opportunity to imitate hierarchical biological structures possessing unique balance of stiffness and toughness.Here, we report on magnetic field force assembly of Fe₃O₄ nanoparticles in the polyurethane matrix. Resulting NP chain structures were several NP wide and tens of micrometers long aligned along the magnetic force lines. Without the magnetic field, NP agglomerates of random size and shape were formed due to their self-assembly.

Abstract: Polymer nanocomposites based on polyhedral oligomeric silsesquioxanes (POSS) and their solutions and suspensions are promising systems for fundamental research which could potentially utilize self-assembly approach in designing new nanocomposite materials. Numerous applications could benefit from understanding of these systems, for instance polymer solution based paints and varnishes. This work is an initial stage of a study which aim is to link macroscale thermomechanical properties with nanoscale structures found in polymer nanocomposites. To do so, a suitable experimental protocol for preparing differently organized NPs in polymer matrix has to be find first in which both kinetic and thermodynamical parameters should be taken into account, i.e. solution casting has being investigated. The results presented here found differences between nanoparticle induced changes on rheological behavior of polystyrene solution under large amplitude oscillation shear (LAOS). High-affinity OP-POSS NPs seem to interact with PS at low loadings and form stiffened aggregates, whereas low-affinity OM-POSS NPs remained rather uninvolved. Effect of hydrodynamic forces independent of the NPs chemical nature was also observed.