Showing papers on "Polymer nanocomposite published in 2014"
TL;DR: This first report (to the authors' knowledge) on MXene composites of any kind, shows that adding polymer binders/spacers between atomically thin MXenes layers or reinforcing polymers with MXenes results in composite films that have excellent flexibility, good tensile and compressive strengths, and electrical conductivity that can be adjusted over a wide range.
Abstract: MXenes, a new family of 2D materials, combine hydrophilic surfaces with metallic conductivity Delamination of MXene produces single-layer nanosheets with thickness of about a nanometer and lateral size of the order of micrometers The high aspect ratio of delaminated MXene renders it promising nanofiller in multifunctional polymer nanocomposites Herein, Ti 3 C 2 T x MXene was mixed with either a charged polydiallyldimethylammonium chloride (PDDA) or an electrically neutral polyvinyl alcohol (PVA) to produce Ti 3 C 2 T x /polymer composites The as-fabricated composites are flexible and have electrical conductivities as high as 22 × 10 4 S/m in the case of the Ti 3 C 2 T x /PVA composite film and 24 × 10 5 S/m for pure Ti 3 C 2 T x films The tensile strength of the Ti 3 C 2 T x /PVA composites was significantly enhanced compared with pure Ti 3 C 2 T x or PVA films The intercalation and confinement of the polymer between the MXene flakes not only increased flexibility but also enhanced cationic intercalation, offering an impressive volumetric capacitance of ∼530 F/cm 3 for MXene/PVA-KOH composite film at 2 mV/s To our knowledge, this study is a first, but crucial, step in exploring the potential of using MXenes in polymer-based multifunctional nanocomposites for a host of applications, such as structural components, energy storage devices, wearable electronics, electrochemical actuators, and radiofrequency shielding, to name a few
1,545 citations
TL;DR: Self-aligned in situ reduced graphene oxide (rGO)/polymer nanocomposites with the engineered structure and properties present high performance electromagnetic interference shielding with a remarkable shilding efficiency of 38 dB.
Abstract: Nanocomposites that contain reinforcements with preferred orientation have attracted significant attention because of their promising applications in a wide range of multifunctional fields. Many efforts have recently been focused on developing facile methods for preparing aligned graphene sheets in solvents and polymers because of their fascinating properties including liquid crystallinity and highly anisotropic characteristics. Self-aligned in situ reduced graphene oxide (rGO)/polymer nanocomposites are prepared using an all aqueous casting method. A remarkably low percolation threshold of 0.12 vol% is achieved in the rGO/epoxy system owing to the uniformly dispersed, monolayer graphene sheets with extremely high aspect ratios (>30000). The self-alignment into a layered structure at above a critical filler content induces a unique anisotropy in electrical and mechanical properties due to the preferential formation of conductive and reinforcing networks along the alignment direction. Accompanied by the anisotropic electrical conductivities are exceptionally high dielectric constants of over 14000 with 3 wt% of rGO at 1 kHz due to the charge accumulation at the highly-aligned conductive filler/insulating polymer interface according to the Maxwell-Wagner-Sillars polarization principle. The highly dielectric rGO/epoxy nanocomposites with the engineered structure and properties present high performance electromagnetic interference shielding with a remarkable shilding efficiency of 38 dB.
1,011 citations
TL;DR: In this article, the authors discuss various assembly techniques available for effectively incorporating the strong and flexible graphene-based components into polymer matrices by utilization of weak and strong interfacial interactions available in functionalized graphene sheets.
918 citations
TL;DR: Halloysite nanotubes (HNTs) have been used extensively in polymer nanocomposites as mentioned in this paper, where they have shown high tensile and flexural strength, elastic moduli, and improved toughness.
722 citations
TL;DR: Concurrent improvements in dielectric constant and breakdown strength are attained in a solution-processed ternary ferroelectric polymer nanocomposite incorporated with two-dimensional boron nitride nanosheets and zero-dimensional barium titanate nanoparticles that synergistically interact to enable a remarkable energy-storage capability.
Abstract: Concurrent improvements in dielectric constant and breakdown strength are attained in a solution-processed ternary ferroelectric polymer nanocomposite incorporated with two-dimensional boron nitride nanosheets and zero-dimensional barium titanate nanoparticles that synergistically interact to enable a remarkable energy-storage capability, including large discharged energy density, high charge-discharge efficiency, and great power density.
429 citations
TL;DR: In this article, a chemically reduced graphene oxide (RGO)/poly(diallylimethyammonium chloride) (PDDA) nanocomposite film sensor with high-performance humidity properties was reported.
Abstract: Chemically reduced graphene oxide (RGO)/poly(diallylimethyammonium chloride) (PDDA) nanocomposite film sensor with high-performance humidity properties was reported in this paper. The film sensor was fabricated on flexible polyimide substrate with interdigital microelectrodes structure. By the layer-by-layer nano self-assembly approach, graphene oxide and PDDA were exploited to form hierarchical nanostructure, and then was partially reduced via solution-based chemically reduction for obtaining both conductivity and chemically active defect sites. The effect of hydrobromic acid treatment on the conductivity properties of PDDA/GO film was examined, further verifying the advantage of hydrobromic acid reduction. The humidity sensing properties of the presented nanocomposite film sensor, such as repeatability, hysteresis, stability, response–recovery characteristics, were investigated by exposing to the wide relative humidity range of 11–97% at room temperature. As a result, the sensor exhibited not only excellent sensing behavior to humidity, but also fast response–recovery time and good repeatability, highlighting the unique advantages of layer-by-layer nano self-assembly for film sensors fabrication. As last, the possible humidity sensing mechanism of the proposed sensor was discussed in detail.
419 citations
TL;DR: A review of the state-of-the-art research on the use of graphene, GO, and rGO for barrier applications, including few-layered graphene or its derivatives in coated polymeric films and polymer nanocomposites consisting of chemically exfoliated GO and reduced graphene oxide (rGO) nanosheets, and their gas-barrier properties is presented in this article.
Abstract: Currently, there is great interest in graphene-based devices and applications because graphene has unique electronic and material properties, which can lead to enhanced material performance. Graphene may be used in a wide variety of potential applications from next-generation transistors to lightweight and high-strength polymeric composite materials. Graphene, which has atomic thickness and two-dimensional sizes in the tens of micrometer range or larger, has also been considered a promising nanomaterial in gas- or liquid-barrier applications because perfect graphene sheets do not allow diffusion of small gases or liquids through its plane. Recent molecular simulations and experiments have demonstrated that graphene and its derivatives can be used for barrier applications. In general, graphene and its derivatives can be applied via two major routes for barrier polymer applications. One is the transfer or coating of few-layered, ultrathin graphene and its derivatives, such as graphene oxide (GO) and reduced graphene oxide (rGO), on polymeric substrates. The other is the incorporation of fully exfoliated GO or rGO nanosheets into the polymeric matrix. In this article, we review the state-of-the-art research on the use of graphene, GO, and rGO for barrier applications, including few-layered graphene or its derivatives in coated polymeric films and polymer nanocomposites consisting of chemically exfoliated GO and rGO nanosheets, and their gas-barrier properties. As compared to other nanomaterials being used for barrier applications, the advantages and current limitations are discussed to highlight challenging issues for future research and the potential applications of graphene/polymer, GO/polymer, and rGO/polymer composites. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 39628.
388 citations
TL;DR: In this paper, a multilayer-structured 0-3 nanocomposite was proposed to achieve high energy densities and low dielectric losses in modern electronic and electrical power systems.
Abstract: Dielectric materials with high electric energy densities and low dielectric losses are of critical importance in a number of applications in modern electronic and electrical power systems. An organic–inorganic 0–3 nanocomposite, in which nanoparticles (0-dimensional) are embedded in a 3-dimensionally connected polymer matrix, has the potential to combine the high breakdown strength and low dielectric loss of the polymer with the high dielectric constant of the ceramic fillers, representing a promising approach to realize high energy densities. However, one significant drawback of the composites explored up to now is that the increased dielectric constant of the composites is at the expense of the breakdown strength, limiting the energy density and dielectric reliability. In this study, by expanding the traditional 0–3 nanocomposite approach to a multilayered structure which combines the complementary properties of the constituent layers, one can realize both greater dielectric displacement and a higher breakdown field than that of the polymer matrix. In a typical 3-layer structure, for example, a central nanocomposite layer of higher breakdown strength is introduced to substantially improve the overall breakdown strength of the multilayer-structured composite film, and the outer composite layers filled with large amount of high dielectric constant nanofillers can then be polarized up to higher electric fields, hence enhancing the electric displacement. As a result, the topological-structure modulated nanocomposites, with an optimally tailored nanomorphology and composite structure, yield a discharged energy density of 10 J/cm3 with a dielectric breakdown strength of 450 kV mm–1, much higher than those reported from all earlier studies of nanocomposites.
354 citations
TL;DR: A novel type of polymer nanocomposite (NC) hydrogel with extraordinary mechanical properties at low inorganic content is prepared and investigated, and their elongation at break can exceed 4000%.
Abstract: A novel type of polymer nanocomposite (NC) hydrogel with extraordinary mechanical properties at low inorganic content is prepared and investigated. The NC hydrogels consist of isethionate-loaded layered double hydroxide/polyacrylamide (LDH-Ise/PAM) - with LDH-Ise being used because of its swelling properties - and no conventional organic crosslinker. The NC hydrogels exhibit an unusual hierarchical porous structure at the micro- and nanometer scales, and their elongation at break can exceed 4000%.
273 citations
TL;DR: In this article, the effect of using hexagonal boron nitride (h-BN) nanosheets on the thermal conductivity of polymer composites has been investigated by liquid exfoliation of bulk h-BN flakes.
256 citations
TL;DR: In this article, the static and dynamic properties of poly(2-vinylpyridine)/silica nanocomposites are investigated by temperature modulated differential scanning calorimetry, broadband dielectric spectroscopy (BDS), small-angle X-ray scattering (SAXS), and transmission electron microscopy.
Abstract: The static and dynamic properties of poly(2-vinylpyridine)/silica nanocomposites are investigated by temperature modulated differential scanning calorimetry, broadband dielectric spectroscopy (BDS), small-angle X-ray scattering (SAXS), and transmission electron microscopy. Both BDS and SAXS detect the existence of an interfacial polymer layer on the surface of nanoparticles. The results show that whereas the calorimetric glass transition temperature varies only weakly with nanoparticle loading, the segmental mobility of the polymer interfacial layer is slower than the bulk polymer by 2 orders of magnitude. Detailed analysis of BDS and SAXS data reveal that the interfacial layer has a thickness of 4–6 nm irrespective of the nanoparticle concentration. These results demonstrate that in contrast to some recent articles on polymer nanocomposites, the interfacial polymer layer is by no means a “dead layer”. However, its existence might provide some explanation for controversies surrounding the dynamics of poly...
TL;DR: Recent theory and simulation studies on polymer nanocomposites with bare or un-functionalized nanoparticles as additives are reviewed, presenting briefly the methodological developments underlying PRISM theories, density functional theory, self-consistent field theory approaches, and atomistic and coarse-grained molecular simulations.
Abstract: Polymer nanocomposites are a class of materials that consist of a polymer matrix filled with inorganic/organic nanoscale additives that enhance the inherent macroscopic (mechanical, optical and electronic) properties of the polymer matrix. Over the past few decades such materials have received tremendous attention from experimentalists, theoreticians, and computational scientists. These studies have revealed that the macroscopic properties of polymer nanocomposites depend strongly on the (microscopic) morphology of the constituent nanoscale additives in the polymer matrix. As a consequence, intense research efforts have been directed to understand the relationships between interactions, morphology, and the phase behavior of polymer nanocomposites. Theory and simulations have proven to be useful tools in this regard due to their ability to link molecular level features of the polymer and nanoparticle additives to the resulting morphology within the composite. In this article we review recent theory and simulation studies, presenting briefly the methodological developments underlying PRISM theories, density functional theory, self-consistent field theory approaches, and atomistic and coarse-grained molecular simulations. We first discuss the studies on polymer nanocomposites with bare or un-functionalized nanoparticles as additives, followed by a review of recent work on composites containing polymer grafted or functionalized nanoparticles as additives. We conclude each section with a brief outlook on some potential future directions.
TL;DR: In this article, a facile approach to the fabrication of advanced polymeric nanocomposites of epoxy by the incorporation of polyetheramine-functionalized graphene oxide (PEA-f-GO) was reported.
Abstract: Interface design plays a crucial role in developing superior mechanical performance of graphene/polymer nanocomposites. Herein, we report a facile approach to the fabrication of advanced polymeric nanocomposites of epoxy by the incorporation of polyetheramine-functionalized graphene oxide (PEA-f-GO). Two types of PEA molecules with different molecular lengths were used to synthesize the PEA-f-GO sheets. The chemical bonds formed between the amine functional groups on the GO surface and the epoxy resin during curing provided strong sheet/matrix interfacial adhesion. The addition of PEA-f-GO was found to produce significant enhancements in the mechanical properties of epoxy, including elastic modulus, tensile strength, elongation at break and toughness. In particular, the PEA-f-GO sheets containing shorter PEA molecules produced higher improvement in strength but smaller increases in both ductility and toughness than those containing longer PEA molecules. For example, at 0.50 wt% filler loading, two nanocomposites showed increases of 63% and 51% in tensile strength and 90% and 119% in toughness as compared to the unfilled epoxy. Our results suggest that the interphases between the GO and the polymer matrix can be tuned by varying the molecular lengths of grafted modifiers, thereby providing a new route for the rational designing and development of the GO-based composite materials.
TL;DR: In this article, the potential for carbon nanotube polymer nanocomposites to release nanoparticles into the environment as the polymer matrix degrades or is mechanically stressed is discussed.
TL;DR: The magnetic polymer nanocomposites are of particular interest because of the combination of excellent magnetic properties, stability, and good biocompatibility as discussed by the authors, and they have been exploited for in vivo imaging, as superparamagnetic or negative contrast agents, drug carriers, heavy metal adsorbents and magnetically recoverable photocatalysts for degradation of organic pollutants.
Abstract: Hybrid nanomaterials have received voluminous interest due to the combination of unique properties of organic and inorganic component in one material. In this class, magnetic polymer nanocomposites are of particular interest because of the combination of excellent magnetic properties, stability, and good biocompatibility. Organic–inorganic magnetic nanocomposites can be prepared by in situ, ex situ, microwave reflux, co-precipitation, melt blending, and ceramic–glass processing and plasma polymerization techniques. These nanocomposites have been exploited for in vivo imaging, as superparamagnetic or negative contrast agents, drug carriers, heavy metal adsorbents, and magnetically recoverable photocatalysts for degradation of organic pollutants. This review article is mainly focused on fabrication of magnetic polymer nanocomposites and their applications. Different types of magnetic nanoparticles, methods of their synthesis, properties, and applications have also been reviewed briefly. The review also provides detailed insight into various types of magnetic nanocomposites and their synthesis. Diverse applications of magnetic nanocomposites including environmental and biomedical uses have been discussed.
TL;DR: The architecture of the nanofiller phase in polymer nanocomposites matters!
Abstract: The architecture of the nanofiller phase in polymer nanocomposites matters! Polymer hydrogels that can combine stimuli-responsiveness with excellent electrically conductivity and mechanical strength can be fabricated by incorporation of the polymer into an ultralight and superelastic graphene aerogel to form a binary network.
TL;DR: By the combination of reversible addition-fragmentation chain transfer (RAFT) polymerization and thiol-ene click reaction, two types of core-shell structured polymer@BaTiO3 (polymer@BT) nanocomposites with high dielectrics constant and low dielectric loss were successfully prepared via a "grafting to" method.
Abstract: Nanodielectric materials with high dielectric constant, low dielectric loss, and high energy storage capability are highly desirable in modern electric and electronics industries. It has been proved that the preparation of core–shell structured dielectric polymer nanocomposites via “grafting from” method is an effective approach to these materials. However, by using this approach, the deep understanding of the structure–dielectric property relationship of the core–shell structured nanodielectrics has been limited because of the lack of detailed information (e.g., molecular weight, grafting density) about the macromolecules grafted onto the nanoparticle surfaces. In this work, by the combination of reversible addition–fragmentation chain transfer (RAFT) polymerization and thiol–ene click reaction, two types of core–shell structured polymer@BaTiO3 (polymer@BT) nanocomposites with high dielectric constant and low dielectric loss were successfully prepared via a “grafting to” method. Compared with the “grafti...
TL;DR: In this article, a method for the preparation of PLA bio-nanocomposites containing cellulose nanocrystals (CNCs) is reported, which enhances interfacial adhesion and dispersion of CNCs into PLA matrix.
TL;DR: A facile, plasma-assisted, biomimetic, environmentally friendly method was developed to enhance the interfacial interactions in polymer nanocomposites by modifying the surface of polypropylene, indicating that polydopamine-functionalized polypropane is a promising material for various high-performance applications.
Abstract: Polypropylene is one of the most widely used commercial commodity polymers; among many other applications, it is used for electronic and structural applications. Despite its commercial importance, the hydrophobic nature of polypropylene limits its successful application in some fields, in particular for the preparation of polymer nanocomposites. Here, a facile, plasma-assisted, biomimetic, environmentally friendly method was developed to enhance the interfacial interactions in polymer nanocomposites by modifying the surface of polypropylene. Plasma treated polypropylene was surface-modified with polydopamine (PDA) in an aqueous medium without employing other chemicals. The surface modification strategy used here was based on the easy self-polymerization and strong adhesion characteristics of dopamine (DA) under ambient laboratory conditions. The changes in surface characteristics of polypropylene were investigated using FTIR, TGA, and Raman spectroscopy. Subsequently, the surface modified polypropylene wa...
TL;DR: In this article, a solution casting method was used to synthesize poly vinyl alcohol (PVA) and zinc oxide (ZnO) nanocomposite, and the optical absorption spectrum of nano ZnO showed blue shift in the optical band gap energy.
TL;DR: In this article, a review of the current literature on the issues relevant to low-dimensional carbonaceous nanofillers-induced polymer crystallization is presented, where the origins of LDCN-induced polymeric crystallization are discussed in depth based on molecular simulation and experimental studies.
TL;DR: This study exfoliated bulk molybdenum disulfide into nanoplatelets, which were then dispersed in epoxy polymers at loading fractions of up to 1% by weight, and characterized the tensile and fracture properties of the composite.
Abstract: Emerging two-dimensional (2D) materials such as transition metal dichalcogenides offer unique and hitherto unavailable opportunities to tailor the mechanical, thermal, electronic, and optical properties of polymer nanocomposites. In this study, we exfoliated bulk molybdenum disulfide (MoS2) into nanoplatelets, which were then dispersed in epoxy polymers at loading fractions of up to 1% by weight. We characterized the tensile and fracture properties of the composite and show that MoS2 nanoplatelets are highly effective at enhancing the mechanical properties of the epoxy at very low nanofiller loading fractions (below 0.2% by weight). Our results show the potential of 2D sheets of transition metal dichalcogenides as reinforcing additives in polymeric composites. Unlike graphene, transition metal dichalcogenides such as MoS2 are high band gap semiconductors and do not impart significant electrical conductivity to the epoxy matrix. For many applications, it is essential to enhance mechanical properties while ...
TL;DR: These results are in essentially quantitative agreement with a force-level generalized Langevin equation theory for all the NP sizes and chain lengths explored, and imply that for these lightly entangled systems, activated NP hopping is not important.
Abstract: Large-scale molecular dynamics simulations show that nanoparticle (NP) diffusivity in weakly interacting mixtures of NPs and polymer melts has two very different classes of behavior depending on their size. NP relaxation times and their diffusivities are completely described by the local, Rouse dynamics of the polymer chains for NPs smaller than the polymer entanglement mesh size. The motion of larger NPs, which are comparable to the entanglement mesh size, is significantly slowed by chain entanglements, and is not describable by the Stokes-Einstein relationship. Our results are in essentially quantitative agreement with a force-level generalized Langevin equation theory for all the NP sizes and chain lengths explored, and imply that for these lightly entangled systems, activated NP hopping is not important.
TL;DR: The results show that, to achieve nanocomposites with high discharged energy density, the core-shell nanoparticle filler should simultaneously have high dielectric constant and low electrical conductivity.
Abstract: The interfacial region plays a critical role in determining the electrical properties and energy storage density of dielectric polymer nanocomposites. However, we still know a little about the effects of electrical properties of the interfacial regions on the electrical properties and energy storage of dielectric polymer nanocomposites. In this work, three types of core–shell structured polymer@BaTiO3 nanoparticles with polymer shells having different electrical properties were used as fillers to prepare ferroelectric polymer nanocomposites. All the polymer@BaTiO3 nanoparticles were prepared by surface-initiated reversible-addition–fragmentation chain transfer (RAFT) polymerization, and the polymer shells were controlled to have the same thickness. The morphology, crystal structure, frequency-dependent dielectric properties, breakdown strength, leakage currents, energy storage capability, and energy storage efficiency of the polymer nanocomposites were investigated. On the other hand, the pure polymers ha...
TL;DR: In this article, the polymer nanocomposites reinforced with exfoliated graphene layers were manufactured by melt blending and shown to have superior tensile strength and stiffness compared to pristine polyethylene terephthalate.
TL;DR: In this article, microwave exfoliated reduced graphene oxide (MERGO) was prepared from natural graphite for subsequent fabrication of epoxy nanocomposites using triethylenetetramine (TETA) as a curing agent via in-situ polymerization.
TL;DR: In this article, the authors reported the preparation and characterization of PVDF/reduced graphene oxide (RGO)-ZnO nanocomposite films via synthesis of reduced graphene oxide and ZnO by solution casting method and found that an intimate relation exists between the size of the interface region and the piezoelectric β-phase formation.
TL;DR: It is shown that the method of preparation influenced the swelling behavior and kinetics of modulus switching, consistent with different arrangements of the CNCs, which serve as channels for water absorption and transport within the hydrophobic SBR matrix.
Abstract: Biomimetic, stimuli-responsive polymer nanocomposites based on a hydrophobic styrene–butadiene rubber (SBR) matrix and rigid, rod-like cellulose nanocrystals (CNCs) isolated from cotton were prepared by three different approaches, and their properties were studied and related to the composition, processing history, and exposure to water as a stimulus. The first processing approach involved mixing an aqueous SBR latex with aqueous CNC dispersions, and films were subsequently formed by solution-casting. The second method utilized the first protocol, but films were additionally compression-molded. The third method involved the formation of a CNC organogel via a solvent exchange with acetone, followed by infusing this gel, in which the CNCs form a percolating network with solutions of SBR in tetrahydrofuran. The thermomechanical properties of the materials were established by dynamic mechanical thermal analysis (DMTA). In the dry state, all nanocomposites show much higher tensile storage moduli, E′, than the ...
TL;DR: In this article, a solution-casting method was used to investigate the electroactive β-phase formation mechanism and the dielectric properties of the clay polymer nanocomposite (CPN) films.
TL;DR: In this paper, high aspect ratio of graphene platelets, filler-polymer interactions at the interface, as well as uniform dispersion of the platelets in the polymer matrices have been attributed to high aspect ratios of platelets.
Abstract: Polymer/graphene based nanomaterials have attracted significant scientific interest in the recent years due to marked enhancement in the polymer properties at low filler fractions. The property enhancements are attributed commonly to high aspect ratio of graphene platelets, filler–polymer interactions at the interface, as well as uniform dispersion of the platelets in the polymer matrices. Graphene also provides opportunities to tune its surface in order to achieve compatibility with the polymer matrices. Occasionally, chemical binding of the polymer matrix to the graphene surface has also been achieved.