Showing papers on "Polymer nanocomposite published in 2015"
TL;DR: Crosslinked polymer nanocomposites that contain boron nitride nanosheets have outstanding high-voltage capacitive energy storage capabilities at record temperatures and have been demonstrated to preserve excellent dielectric and capacitive performance after intensive bending cycles, enabling broader applications of organic materials in high-temperature electronics and energy storage devices.
Abstract: Dielectric materials, which store energy electrostatically, are ubiquitous in advanced electronics and electric power systems. Compared to their ceramic counterparts, polymer dielectrics have higher breakdown strengths and greater reliability, are scalable, lightweight and can be shaped into intricate configurations, and are therefore an ideal choice for many power electronics, power conditioning, and pulsed power applications. However, polymer dielectrics are limited to relatively low working temperatures, and thus fail to meet the rising demand for electricity under the extreme conditions present in applications such as hybrid and electric vehicles, aerospace power electronics, and underground oil and gas exploration. Here we describe crosslinked polymer nanocomposites that contain boron nitride nanosheets, the dielectric properties of which are stable over a broad temperature and frequency range. The nanocomposites have outstanding high-voltage capacitive energy storage capabilities at record temperatures (a Weibull breakdown strength of 403 megavolts per metre and a discharged energy density of 1.8 joules per cubic centimetre at 250 degrees Celsius). Their electrical conduction is several orders of magnitude lower than that of existing polymers and their high operating temperatures are attributed to greatly improved thermal conductivity, owing to the presence of the boron nitride nanosheets, which improve heat dissipation compared to pristine polymers (which are inherently susceptible to thermal runaway). Moreover, the polymer nanocomposites are lightweight, photopatternable and mechanically flexible, and have been demonstrated to preserve excellent dielectric and capacitive performance after intensive bending cycles. These findings enable broader applications of organic materials in high-temperature electronics and energy storage devices.
1,324 citations
TL;DR: Recently, carbonaceous nanofillers such as graphene and carbon nanotubes (CNTs) play a promising role due to their better structural, functional properties and broad range of applications in every field as mentioned in this paper.
1,097 citations
TL;DR: Recent and in-progress state-of-the-art advancements in the application of core-shell nanoarchitecture strategies to design and prepare high-k polymer nanocomposites are summarized.
Abstract: High-k polymer nanocomposites have considerable potential in energy storage and dielectric applications because of their ease of processing, flexibility, and low cost. Core-shell nanoarchitecture strategies are versatile and powerful tools for the design and synthesis of advanced high-k polymer nanocomposites. Recent and in-progress state-of-the-art advancements in the application of core-shell nanoarchitecture strategies to design and prepare high-k polymer nanocomposites are summarized. Special focus is directed to emphasizing their advantages over conventional melt-mixing and solution-mixing methods: first, homogeneous nanoparticle dispersion can be easily achieved even in highly loaded nanocomposites; second, the dielectric constant of the nanocomposites can be effectively enhanced and meanwhile the high breakdown strength can be well-preserved; third, for nanocomposites filled with electrically conductive nanoparticles, dielectric loss can be effectively surpressed, and meanwhile a high dielectric constant can be achieved. In addition, fundamental insights into the roles of the interfaces on the dielectric properties of the nanocomposites can be probed. The last part of the article is concluded with current problems and future perspectives of utilizing the core-shell nanoarchitecture strategies for the development of high-k polymer nanocomposites.
683 citations
TL;DR: The objective of the present review is to show examples of polymer/metal composites designed to have antimicrobial activities, with a special focus on copper and silver metal nanoparticles and their mechanisms.
Abstract: Metals, such as copper and silver, can be extremely toxic to bacteria at exceptionally low concentrations. Because of this biocidal activity, metals have been widely used as antimicrobial agents in a multitude of applications related with agriculture, healthcare, and the industry in general. Unlike other antimicrobial agents, metals are stable under conditions currently found in the industry allowing their use as additives. Today these metal based additives are found as: particles, ions absorbed/exchanged in different carriers, salts, hybrid structures, etc. One recent route to further extend the antimicrobial applications of these metals is by their incorporation as nanoparticles into polymer matrices. These polymer/metal nanocomposites can be prepared by several routes such as in situ synthesis of the nanoparticle within a hydrogel or direct addition of the metal nanofiller into a thermoplastic matrix. The objective of the present review is to show examples of polymer/metal composites designed to have antimicrobial activities, with a special focus on copper and silver metal nanoparticles and their mechanisms.
556 citations
TL;DR: In this paper, a detailed study of the self-healing properties of different kinds of polymer nanocomposites utilizing a number of healing mechanisms, including the addition of several healing agents.
510 citations
TL;DR: Atomic-scale interface engineering in BaTiO3@TO2 nanofibers leads to concurrent enhancement of electric displacement and breakdown strength in poly(vinylidene fluoride) (PVDF)-based nanocomposites.
Abstract: Atomic-scale interface engineering in BaTiO3@TO2 nanofibers (TiO2 nano-fibers embedded with BaTiO3 nano-particles) leads to concurrent enhancement of electric displacement and breakdown strength in poly(vinylidene fluoride) (PVDF)-based nanocomposites. An ultrahigh energy density of ≈20 J cm(-3) is achieved with only 3 vol% nanofibers, which is by far the highest discharged energy density of PVDF-based nanocomposites.
488 citations
TL;DR: In this article, progress in developments on the use of modified natural and synthetic clays for designing polymer nanocomposites is presented, and a synopsis of the applications of these advanced, high-performance polymer nan composites are presented, pointing out gaps to motivate potential research in this field.
437 citations
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TL;DR: In this paper, the influence of the intrinsic properties of these fillers (graphene and its derivatives) and their state of dispersion in polymer matrix on the gas barrier properties of graphene/PNCs are discussed.
Abstract: Due to its exceptionally outstanding electrical, mechanical and thermal properties, graphene is being explored for a wide array of applications and has attracted enormous academic and industrial interest. Graphene and its derivatives have also been considered as promising nanoscale fillers in gas barrier application of polymer nanocomposites (PNCs). In this review, recent research and development of the utilization of graphene and its derivatives in the fabrication of nanocomposites with different polymer matrices for barrier application are explored. Most synthesis methods of graphene-based PNCs are covered, including solution and melt mixing, in situ polymerization and layer-by-layer process. Graphene layers in polymer matrix are able to produce a tortuous path which works as a barrier structure for gases. A high tortuosity leads to higher barrier properties and lower permeability of PNCs. The influence of the intrinsic properties of these fillers (graphene and its derivatives) and their state of dispersion in polymer matrix on the gas barrier properties of graphene/PNCs are discussed. Analytical modeling aspects of barrier performance of graphene/PNCs are also reviewed in detail. We also discuss and address some of the work on mixed matrix membranes for gas separation.
401 citations
TL;DR: In this article, the authors present a review of the state-of-the-art in the field of instrumented indentation of polymer nanocomposite materials and present challenges and future perspectives in the application of depth-sensing instrumentation to characterize mechanical properties.
297 citations
TL;DR: In this article, an alternating-current electric field was used to align graphene nanoplatelets (GnPs) in an epoxy polymer, and the resulting nanocomposites exhibit anisotropic properties with significantly improved electrical and thermal conductivities.
277 citations
TL;DR: In this article, the authors summarized the most recent studies on the modification of G with polymers and the subsequent synthesis and applications of high quality G-polymer nanocomposites.
TL;DR: In this article, the authors present an in-depth critical review of major experimental, simulation, and theoretical work in the field of conducting polymer nanocomposites containing rod-like particles such as carbon nanotubes and metal nanowires.
TL;DR: In this article, a transparent film for sodium-ion conduction in PEO-based solid polymer electrolyte (additionally comprising NaClO4 and nano-sized TiO2) has been fabricated for use in Na-ion batteries by using a solution casting technique.
TL;DR: The results suggest that the porosity and network structure of CNCSFD agglomerates contribute significantly to good dispersion of C NC in the PLA matrix.
TL;DR: In this paper, the types of graphene-based nanofillers and the fabrication of graphene/polymer nanocomposites are discussed. And a brief summary of the practical applications of polymeric-graphene materials along with the current trends in the field is presented to progressively show future prospects for the development of these materials.
Abstract: This paper essentially reviews the types of graphene-based nanofillers and the fabrication of graphene/polymer nanocomposites. Routes to produce graphene materials, along with the methods and modifications used to efficiently disperse graphene nanofillers within the polymer matrices are discussed. In addition, the mechanical properties, morphological, structural, electrical conductivities, electrochemical activities, thermal stabilities, and gas barrier properties are evaluated, along with the direct relationships of these properties with the graphene–polymer interactions and their dispersion in the polymer matrix. Finally, a brief summary of the practical applications of polymeric-graphene materials along with the current trends in the field is presented to progressively show future prospects for the development of these materials.
TL;DR: In this paper, the state-of-the-art progress on the use of platelet-shaped fillers for the gas barrier properties of polymer nanocomposites is summarized.
Abstract: In the field of nanotechnology, polymer nanocomposites (PNCs) have attracted both academic and industrial interest due to their exceptional electrical, mechanical and permeability properties. In this review, we summarize the state-of-the-art progress on the use of platelet-shaped fillers for the gas barrier properties of PNCs. Layered silicate nanoclays (such as montmorillonite and kaolinite) appear to be the most promising nanoscale fillers. These exfoliated nanofillers are able to form individual platelets when dispersed in a polymer matrix. The nanoplatelets do not allow diffusion of small gases through them and are able to produce a tortuous path which works as a barrier structure for gases. The utilization of clays in the fabrication of PNCs with different polymer matrices is explored. Most synthesis methods of clay-based PNCs are covered, including, solution blending, melt intercalation, in situ polymerization and latex compounding. The structure, preparation and gas barrier properties of PNCs are discussed in general along with detailed examples drawn from the scientific literature. Furthermore, details of mathematical modeling approaches/methods of gas barrier properties of PNCs are also presented and discussed.
TL;DR: Solution-processable ferroelectric polymer nanocomposites are developed as a new form of electrocaloric materials that can be effectively operated under both modest and high electric fields at ambient temperature.
Abstract: Solution-processable ferroelectric polymer nanocomposites are developed as a new form of electrocaloric materials that can be effectively operated under both modest and high electric fields at ambient temperature. By integrating the complementary properties of the constituents, the nanocomposites exhibit state-of-the-art cooling energy densities. Greatly improved thermal conductivity also yields superior cooling power densities validated by finite volume simulations.
TL;DR: BaTiO3 NWs show the best potential in improving the energy storage capability of the proposed nanocomposites, resulting from the most signficant increase of k while retaining the rather low dielectric loss and leakage current.
Abstract: High dielectric constant (k) polymer nanocomposites have shown great potential in dielectric and energy storage applications in the past few decades. The introduction of high-k nanomaterials into ferroelectric polymers has proven to be a promising strategy for the fabrication of high-k nanocomposites. One-dimensional large-aspect-ratio nanowires exhibit superiority in enhancing k values and energy density of polymer nanocomposites in comparison to their spherical counterparts. However, the impact of their intrinsic properties on the dielectric properties of polymer nanocomposites has been seldom investigated. Herein, four kinds of nanowires (Na2Ti3O7, TiO2, BaTiO3, and SrTiO3) with different inherent characteristics are elaborately selected to fabricate high-k ferroelectric polymer nanocomposites. Dopamine functionalization facilitates the excellent dispersion of these nanowires in the ferroelectric polymer matrix because of the strong polymer/nanowire interfacial adhesion. A thorough comparative study on...
TL;DR: The most recent advances in polymer nanocomposites for energy storage (i.e., electrochemical capacitors and batteries), energy saving (e.g., electrochromic devices and carbon dioxide capture), and anticorrosion (conductive and non-conductive polymer nano-coating) applications are discussed in this article.
Abstract: Polymer nanocomposites exhibit unique physicochemical properties that cannot be obtained with individual components acting alone. Polymer nanocomposites have attracted significant research interests due to their promising potential for versatile applications ranging from environmental remediation, energy storage, electromagnetic (EM) absorption, sensing and actuation, transportation and safety, defense systems, information industry, to novel catalysts, etc. In particular, polymer nanocomposites have attracted intensive research interest for solving both energy and environmental issues. This review paper mainly focuses on the most recent advances in polymer nanocomposites for energy storage (i.e., electrochemical capacitors and batteries), energy saving (i.e., electrochromic devices and carbon dioxide capture), and anticorrosion (conductive and non-conductive polymer nanocomposite anticorrosive coatings) applications.
TL;DR: It is found that the PEG[60]-PCL[40]-CNC[10] nanocomposite exhibited excellent thermo-induced and water-induced shape-memory effects in water at 37 °C (close to body temperature), and the introduction of CNC clearly improved the mechanical properties of the mixture of both PEG and PCL polymers with low molecular weights.
Abstract: In this study, we developed a thermoresponsive and water-responsive shape-memory polymer nanocomposite network by chemically cross-linking cellulose nanocrystals (CNCs) with polycaprolactone (PCL) and polyethylene glycol (PEG). The nanocomposite network was fully characterized, including the microstructure, cross-link density, water contact angle, water uptake, crystallinity, thermal properties, and static and dynamic mechanical properties. We found that the PEG[60]–PCL[40]–CNC[10] nanocomposite exhibited excellent thermo-induced and water-induced shape-memory effects in water at 37 °C (close to body temperature), and the introduction of CNC clearly improved the mechanical properties of the mixture of both PEG and PCL polymers with low molecular weights. In addition, Alamar blue assays based on osteoblasts indicated that the nanocomposites possessed good cytocompatibility. Therefore, this thermoresponsive and water-responsive shape-memory nanocomposite could be potentially developed into a new smart bioma...
TL;DR: In this article, the linear viscoelastic response of polymer nanocomposites can be quantitatively predicted by a parameter-free model in which the stress is a simple sum of contributions from the polymer matrix and the fractal NP structure linked by bridging polymer chains.
Abstract: Nanometer-sized particles that are well dispersed in a polymer melt, presumably due to strongly favorable particle–polymer interactions, can form fractal structures via polymer bridging, leading ultimately to a nanoparticle (NP) network analogous to a colloidal gel. The linear viscoelastic response of polymer nanocomposites can be quantitatively predicted by a parameter-free model in which the stress is a simple sum of contributions from the polymer matrix and the fractal NP structure linked by bridging polymer chains. The NP contribution is modeled using critical percolation, while the polymer part is enhanced by the presence of particles, owing to hydrodynamic interactions. The phase diagram at the right shows that small NPs are needed to achieve the stronger reinforcement from glassy bridges at reasonable particle loadings.
TL;DR: In this paper, ultrathin molybdenum disulfide (MoS2) nanosheets were simultaneously exfoliated and non-covalently modified by ultrasonication in an aqueous solution of chitosan.
Abstract: Polymer/graphene-analogous nanosheet composites have great potential for improving their physical and mechanical properties during the past few years. Herein, ultrathin molybdenum disulfide (MoS2) nanosheets were simultaneously exfoliated and non-covalently modified by ultrasonication in an aqueous solution of chitosan. The chitosan-modified MoS2 (CS-MoS2) nanosheets were then transferred from the aqueous solution to tetrahydrofuran by a simple solvent-exchange method for the fabrication of epoxy (EP) nanocomposites. Transmission electron microscopy and scanning electron microscopy were performed to display the homogeneous dispersion of CS-MoS2 in an EP matrix. On incorporating 2 wt% CS-MoS2 into an EP matrix, EP nanocomposites exhibited reductions of up to 43.3% and 14.6% in peak heat-release rate and total heat release derived from cone calorimeters compared to those of neat EP, respectively. Moreover, toxic volatiles, such as hydrocarbons, aromatic compounds and CO, that escaped from the flaming EP nanocomposites were decreased compared to that of neat EP, demonstrating the higher smoke safety. Combined with the analyses of char residues and thermal stability of EP nanocomposites, the reduced fire hazards of EP nanocomposites could be attributed to the nano-barrier effects of MoS2, which could effectively inhibit the release of combustible gas to support burning and restrain the effusion of volatile toxic substances that cause the majority of deaths in fires.
TL;DR: Hexagonal boron nitride nanoparticles were noncovalently modified with polydopamine in a solvent-free aqueous condition and exhibited outstanding performance in dimensional stability, dynamic-mechanical properties, and thermal conductivity, together with the controllable dielectric property and preserved thermal stability for high-temperature applications.
Abstract: Boron nitride (BN) reinforced polymer nanocomposites have attracted a growing research interest in the microelectronic industry for their uniquely thermal conductive but electrical insulating properties. To overcome the challenges in surface functionalization, in this study, hexagonal boron nitride (h-BN) nanoparticles were noncovalently modified with polydopamine in a solvent-free aqueous condition. The strong π–π interaction between the hexagonal structural BN and aromatic dopamine molecules facilitated 15 wt % polydopamine encapsulating the nanoparticles. High-performance bisphenol E cyanate ester (BECy) was incorporated by homogeneously dispersed h-BN at different loadings and functionalities to investigate their effects on thermo-mechanical, dynamic-mechanical, and dielectric properties, as well as thermal conductivity. Different theoretical and empirical models were successfully applied to predict thermal and dielectric properties of h-BN/BECy nanocomposites. Overall, the prepared h-BN/BECy nanocomp...
TL;DR: In this article, the authors present a narrative summary on the principle and methodologies for dispersion of and modification of Al2O3 NPs, along with the effects of them on the properties of polymer/Al 2O3 NCs.
TL;DR: In this paper, a new class of dielectric materials, called organic-inorganic hybrid materials, is described, which are prepared from the covalent incorporation of tantalum species into ferroelectric polymers via in situ sol-gel condensation.
Abstract: The ever-increasing demand for compact electronics and electrical power systems cannot be met with conventional dielectric materials with limited energy densities. Numerous efforts have been made to improve the energy densities of dielectrics by incorporating ceramic additives into polymer matrix. In spite of increased permittivities, thus-fabricated polymer nanocomposites typically suffer from significantly decreased breakdown strengths, which preclude a substantial gain in energy density. Herein, organic–inorganic hybrids as a new class of dielectric materials are described, which are prepared from the covalent incorporation of tantalum species into ferroelectric polymers via in situ sol-gel condensation. The solution-processed hybrid with the optimal composition exhibits a Weibull breakdown strength of 505 MV m−1 and a discharged energy density of 18 J cm−3, which are more than 40% and 180%, respectively, greater than the pristine ferroelectric polymer. The superior performance is mainly ascribed to the deep traps created in the hybrids at the molecular level, which results in reduced electric conduction and lower remnant polarization. Simultaneously, the formation of the cross-linked networks enhances the mechanical strengths of the hybrid films and thus hinders the occurrence of the electromechanical breakdown. This work opens up new opportunities to solution-processed organic materials with high energy densities for capacitive electrical energy storage.
TL;DR: In this article, a new strategy was developed to prepare high-k polymer nanocomposites with high breakdown strength by using nano-Ag decorated core-shell polydopamine (PDA) coated BaTiO3 (BT) hybrid nanoparticles.
Abstract: Flexible nanocomposites comprising of polymer and high-dielectric-constant (high-k) ceramic nanoparticles are becoming increasingly attractive for dielectric and energy storage applications in modern electronic and electric industry. However, a huge challenge still remains. Namely, the increase of dielectric constant usually at the cost of significant decrease of breakdown strength of the nanocomposites because of the electric field distortion and concentration induced by the high-k filler. To address this long-standing problem, by using nano-Ag decorated core–shell polydopamine (PDA) coated BaTiO3 (BT) hybrid nanoparticles, a new strategy is developed to prepare high-k polymer nanocomposites with high breakdown strength. The strawberry-like BT-PDA-Ag based ferroelectric polymer [i.e., poly(vinylideneflyoride-co-hexafluroro propylene), P(VDF-HFP)] nanocomposites exhibit greatly enhanced energy density and significantly suppressed dielectric loss as well as leakage current density in comparison with the nanocomposites with the core–shell structured BT-PDA. Coulomb-blockade effect of super-small nano-Ag is used to explain the observed performance enhancement of the nanocomposites. The simplicity and scalability of the described approach provide a promising route to polymer nanocomposites for dielectric and energy storage applications.
TL;DR: It is found that a sizable ECE can be generated under both modest and high electric fields, and further enhanced greatly by tailoring the morphology of the ferroelectric nanofillers such as increasing the aspect ratio of the nanoinclusions.
Abstract: The electrocaloric effect (ECE) refers to conversion of thermal to electrical energy of polarizable materials and could form the basis for the next-generation refrigeration and power technologies that are highly efficient and environmentally friendly. Ferroelectric materials such as ceramic and polymer films exhibit large ECEs, but each of these monolithic materials has its own limitations for practical cooling applications. In this work, nanosized barium strontium titanates with systematically varied morphologies have been prepared to form polymer nanocomposites with the ferroelectric polymer matrix. The solution-processed polymer nanocomposites exhibit an extraordinary room-temperature ECE via the synergistic combination of the high breakdown strength of a ferroelectric polymer matrix and the large change of polarization with temperature of ceramic nanofillers. It is found that a sizable ECE can be generated under both modest and high electric fields, and further enhanced greatly by tailoring the morpho...
TL;DR: In this article, a CNT/polymer nanocomposite of fine and well-dispersed CNT microstructure was found to enhance the EMI shielding by absorption and reduce the reflection of the EVI.
TL;DR: By designing the inorganic filler and polymer matrix, which are both relaxor ferroelectrics with the ambient-temperature phase transition and minimized hysteresis, a large ECE becomes accessible with high cooling efficiency over a broad temperature range at and near room temperature.
Abstract: Electrocaloric nanocomposites simultaneously derive high electrocaloric strength from inorganic inclusions and high dielectric strength from the polymer matrix to display a pronounced electrocaloric effect (ECE). By designing the inorganic filler and polymer matrix, which are both relaxor ferroelectrics with the ambient-temperature phase transition and minimized hysteresis, a large ECE becomes accessible with high cooling efficiency over a broad temperature range at and near room temperature.
01 Jan 2015
TL;DR: The aim of this chapter is to demonstrate the current state of development in the field of cellulose nanofibril-based nanocomposite research and application through examples.