Advanced Polymer Nanocomposites Research Articles

Recent Advances in Polymer Nanocomposites: Unveiling the Frontier of Shape Memory and Self-Healing Properties-A Comprehensive Review.

Shape memory and self-healing polymer nanocomposites have attracted considerable attention due to their modifiable properties and promising applications. The incorporation of nanomaterials (polypyrrole, carboxyl methyl cellulose, carbon nanotubes, titania nanotubes, graphene, graphene oxide, mesoporous silica) into these polymers has significantly enhanced their performance, opening up new avenues for diverse applications. The self-healing capability in polymer nanocomposites depends on several factors, including heat, quadruple hydrogen bonding, π-π stacking, Diels-Alder reactions, and metal-ligand coordination, which collectively govern the interactions within the composite materials. Among possible interactions, only quadruple hydrogen bonding between composite constituents has been shown to be effective in facilitating self-healing at approximately room temperature. Conversely, thermo-responsive self-healing and shape memory polymer nanocomposites require elevated temperatures to initiate the healing and recovery processes. Thermo-responsive (TRSMPs), light-actuated, magnetically actuated, and Electrically actuated Shape Memory Polymer Nanocomposite are discussed. This paper provides a comprehensive overview of the different types of interactions involved in SMP and SHP nanocomposites and examines their behavior at both room temperature and elevated temperature conditions, along with their biomedical applications. Among many applications of SMPs, special attention has been given to biomedical (drug delivery, orthodontics, tissue engineering, orthopedics, endovascular surgery), aerospace (hinges, space deployable structures, morphing aircrafts), textile (breathable fabrics, reinforced fabrics, self-healing electromagnetic interference shielding fabrics), sensor, electrical (triboelectric nanogenerators, information energy storage devices), electronic, paint and self-healing coating, and construction material (polymer cement composites) applications.

Advancing elastomer performance with dynamic bond networks in polymer-grafted single-chain nanoparticles: a molecular dynamics exploration.

This research introduces a method to enhance the mechanical properties of elastomers by grafting polymer chains onto single-chain flexible nanoparticles (SCNPs) and incorporating dynamic functional groups. Drawing on developments in grafting polymers onto hard nanoparticle fillers, this method employs the distinct flexibility of SCNPs to diminish heterogeneity and enhance core size control. We use molecular dynamics (MD) simulations for a mesoscale analysis of structural properties, particularly the effects of dynamic functional group quantities and their distribution. The findings demonstrate that increased quantities of functional groups are correlated with enhanced mechanical strength and toughness, showing improved stress-strain responses and energy dissipation capabilities. Moreover, the uniformity in the distribution of these functional groups is crucial, promoting a more cohesive and stable dynamic bonding network. The insights gained from MD simulations not only advance our understanding of the microstructural control necessary for optimizing macroscopic properties, but also provide valuable guidance for the design and engineering of advanced polymer nanocomposites, thereby enhancing the material performance through strategic molecular design.

Recent Developments in Polymer Nanocomposites for Bone Regeneration.

Most people who suffer acute injuries in accidents have fractured bones. Many of the basic processes that take place during embryonic skeletal development are replicated throughout the regeneration process that occurs during this time. Bruises and bone fractures, for example, serve as excellent examples. It almost always results in a successful recovery and restoration of the structural integrity and strength of the broken bone. After a fracture, the body begins to regenerate bone. Bone formation is a complex physiological process that requires meticulous planning and execution. A normal healing procedure for a fracture might reveal how the bone is constantly rebuilding as an adult. Bone regeneration is becoming more dependent on polymer nanocomposites, which are composites made up of a polymer matrix and a nanomaterial. This study will review polymer nanocomposites that are employed in bone regeneration to stimulate bone regeneration. As a result, we will introduce the role of bone regeneration nanocomposite scaffolds, and the nanocomposite ceramics and biomaterials that play a role in bone regeneration. Aside from that, recent advances in polymer nanocomposites might be used in a variety of industrial processes to help people with bone defects overcome their challenges will be discussed.

Recent Advances in the Synthesis of Polymer-Grafted Low-K and High-K Nanoparticles for Dielectric and Electronic Applications.

The synthesis of polymer-grafted nanoparticles (PGNPs) or hairy nanoparticles (HNPs) by tethering of polymer chains to the surface of nanoparticles is an important technique to obtain nanostructured hybrid materials that have been widely used in the formulation of advanced polymer nanocomposites. Ceramic-based polymer nanocomposites integrate key attributes of polymer and ceramic nanomaterial to improve the dielectric properties such as breakdown strength, energy density and dielectric loss. This review describes the “grafting from” and “grafting to” approaches commonly adopted to graft polymer chains on NPs pertaining to nano-dielectrics. The article also covers various surface initiated controlled radical polymerization techniques, along with templated approaches for grafting of polymer chains onto SiO2, TiO2, BaTiO3, and Al2O3 nanomaterials. As a look towards applications, an outlook on high-performance polymer nanocomposite capacitors for the design of high energy density pulsed power thin-film capacitors is also presented.

Study on Structure, Thermal Behavior and Viscoelastic Properties of Nanodiamond-Reinforced Poly (vinyl alcohol) Nanocomposites.

In this work, advanced polymer nanocomposites comprising of polyvinyl alcohol (PVA) and nanodiamonds (NDs) were developed using a single-step solution-casting method. The properties of the prepared PVA/NDs nanocomposites were investigated using Raman spectroscopy, small- and wide-angle X-ray scattering (SAXS/WAXS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and dynamic mechanical analysis (DMA). It was revealed that the tensile strength improved dramatically with increasing ND content in the PVA matrix, suggesting a strong interaction between the NDs and the PVA. SEM, TEM, and SAXS showed that NDs were present in the form of agglomerates with an average size of ~60 nm with primary particles of diameter ~5 nm. These results showed that NDs could act as a good nanofiller for PVA in terms of improving its stability and mechanical properties.

Effect of Dispersion and Improper Bonding of Nanofiller Polymer Composites

Nanofiller is used to enhance the properties in composite materials, with at least one phase of nanomaterials that can be referred as nanocomposites. The nanomaterial due to uniform dispersion recently used in advanced polymer nanocomposites, to mix effectively in the polymer matrix. The production of polymer composites with nanofiller is limited due to the unresolved issues such as agglomeration during processing, high production cost and limited availability of good quality. Graphene filled nanocomposites is a novel material and considered in different applications. The properties of the nanocomposites mainly depend on the arrangement of graphene layers with the polymer matrix and interfacial bonding between them. Here an attempt is made to develop polymer composites using graphene as reinforcements and epoxy as matrix materials. Sonication is a process of applying ultrasound energy to disperse nanoparticles in epoxy. The sound waves that are created in sonication are generally large ultrasound waves and during this process, considerable heat is produced. If the sonication treatment is too long, nanoparticles were seriously damaged, particularly when a probe sonicator is used. The localized damage causes nanoparticles to deteriorate the mechanical properties of the polymer composites. The study from XRD and SEM showed that the use of graphene at higher weight % resulted in a decrease in strength of the composites. Hence, it is not a better choice to produce nanocomposites at increased addition of nanofiller.

Recent Advances in Polymer Nanocomposites Based on Polyethylene and Polyvinylchloride for Power Cables.

Polymer nanocomposites used in underground cables have been of great interest to researchers over the past 10 years. Their preparation and the dispersion of the nanoparticles through the polymer host matrix are the key factors leading to their enhanced dielectric properties. Their important dielectric properties are breakdown strength, permittivity, conductivity, dielectric loss, space charge accumulation, tracking, and erosion, and partial discharge. An overview of recent advances in polymer nanocomposites based on LDPE, HDPE, XLPE, and PVC is presented, focusing on their preparation and electrical properties.

Multifunctional graphene-based nano-additives toward high-performance polymer nanocomposites with enhanced mechanical, thermal, flame retardancy and smoke suppressive properties

Despite many important industrial applications, the acrylonitrile–butadienestyrene copolymer (ABS) suffers from an inherent flammability, extremely hampering its practical use. Current flame retardants can effectively reduce the flammability issue but give rise to degraded mechanical and thermal properties of ABS. To address this intractable challenge, a graphene-derived flame retardant (Mo5/PN-rGO) was designed by introducing the functional elements (phosphorus, nitrogen and molybdate) onto the graphene oxides nanosheets. The resultant ABS nanocomposite containing 1.0 wt% of Mo5/PN-rGO exhibits a 28% increase in the tensile strength and a 58% enhancement in the Young’s modulus as compared to the ABS host. Furthermore, the glass transition temperature (Tg) increases by ca. 12 °C while the onset thermal decomposition temperature is significantly delayed by ca. 21 °C. In addition, the final ABS nanomaterial shows a 20% reduction in the total heat release and a 45% decrease in the total smoke production in comparison to the ABS bulk. This work paves a new way for the creation of high-performance flame retardants towards advanced flame-retardant polymer nanocomposites with expandable industrial applications.

High-performance graphene reinforced epoxy nanocomposites using benzyl glycidyl ether as a dispersant and surface modifier

The special structure and excellent properties make graphene a great potential in developing advanced polymer nanocomposites; however, its dispersion in molecular-level as well as reinforcement in high efficiency in matrixes has been a challenge. Herein, we report a facile and effective strategy to disperse graphene in epoxy resin by using benzyl glycidyl ether (BGE) as a dispersant and surface modifier through π-π interaction between BGE and graphene. The measurements of UV–vis spectroscopy and Raman spectrum confirm π-π interaction of BGE and graphene, and the remarkably improvement in properties of graphene reinforced epoxy resin are achieved. For 5 mg/mL graphene dispersion, tensile strength increases by 15%, Young's modulus increases by 32.8%, storage modulus at 30 °C increases by 37%, and thermal conductivity increases by 95.7%. This method opens up a feasible approach to make high performance graphene nanocomposites for engineering and high-tech applications.

Influence of OMMT on Surface Breakdown of Epoxy Resin in Liquid Nitrogen

Epoxy resin is employed as the main insulation materials or support components in the high-temperature superconducting (HTS) system. But surface breakdown of epoxy resin threatens the safe operation of the HTS system. Introducing organic montmorillonite (OMMT) into epoxy resin is an effective way to improve the resistance of surface breakdown. The OMMT with fraction of 0, 1, 3, 5, and 7 wt% is filled into the epoxy resin to investigate the conductivity properties, partial discharge, and trap distribution characteristics. The results shows that the conductivity of epoxy resin is reduced by incorporating OMMT into the matrix, and the smallest value is obtained with the filler content of 5 wt%. The modified partial discharge (PD) properties are related to trap distribution of epoxy resin/OMMT composites, which is with larger trap energy level and trap density than the pure epoxy resin one in liquid nitrogen. However, the PD resistance is decreased with filler content increasing from 5 wt% to 7 wt%, which is associated with the reducing trap energy level and trap density induced by the overlapping of OMMT. The research establishes the foundation for design and development of advanced polymer nanocomposites for HTS system.

Highly Thermally Conductive Yet Electrically Insulating Polymer/Boron Nitride Nanosheets Nanocomposite Films for Improved Thermal Management Capability.

Thermally conductive yet electrically insulating polymer composites are urgently required for thermal management applications of modern electrical systems and electronic devices because of their multifunctionality and ease of processing. However, the thermal conductivity enhancement of polymer composites is usually at the price of the loss of lightweight, the deterioration of flexibility, and electrical insulation. Here we report advanced polymer nanocomposites containing orientated boron nitride nanosheets (BNNSs), which simultaneously exhibit high thermal conductivity enhancement, excellent electrical insulation, and outstanding flexibility. These nanocomposite films can be easily constructed by electrospinning polymer/BNNSs nanocomposite fibers, vertically folding the electrospun nanocomposite fibers and the subsequent pressing. The nanocomposite films exhibit thickness-dependent in-plane thermal conductivity, which can reach 16.3 W/(m·K) in the 18 μm thick nanocomposite film with 33 wt % BNNSs. In addition, the nanocomposite films have superior electrically insulating properties compared with the pristine polymer, such as reduced dielectric loss, increased electrical resistivity, and enhanced breakdown strength. The strong thermal management capability of the nanocomposite film was demonstrated in switching power supply, which showed the importance of high in-plane thermal conductivity in thermal management of high-power density electronic devices.

Polylactic acid nanocomposites toughened with nanofibrillated cellulose: microstructure, thermal, and mechanical properties

Structure–property interdependency is of vital importance in developing advanced polymer nanocomposites as well as enhancing their ultimate properties. In this research study, toughening of polylactic acid (PLA) with nanofibrillated cellulose (NFC) was studied and comparison was made between the thermal and mechanical properties of systems containing pristine and modified NFC. NFC was modified through two different methods: acetylation of hydroxyl groups and grafting of poly(ethylene glycol) (PEG) onto cellulose chains. Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and differential scanning calorimetry were employed to probe into the surface characteristics, thermal properties, and crystallinity of NFC/modified NFC, respectively; moreover, SEM imaging was utilized for surface morphology of the samples. Subsequently, PLA with modified and unmodified NFC was prepared to evaluate the filler addition effect on toughness. Acetylated NFC has changed the PLA crystallinity degree and rate, which affected the modulus of PLA, as signaled by the changed NFC surface. Particularly, mechanical and toughening behaviors of the prepared nanocomposites were analyzed based on tensile measurements which showed an eightfold rise in toughening along with 18% decrease in modulus of the samples comprising 1 wt% of acetylated NFC compared to a blank PLA. However, a sevenfold increase in toughening was observed upon introduction of both modified NFC to the PLA matrix. SEM observations divulged proper dispersion of NFC-g-AC in the PLA matrix which reduced stress concentration, but enhanced toughness in comparison with NFC-g-PEG with agglomeration that caused stress concentration leading to brittle behavior. In the light of the obtained results, it can be inferred that brittle PLA can be toughened by the surface-modified NFC. This research study can illuminate the way for future works on the modifications of nano-scale fillers/additives to achieve improved mechanical and thermal properties of PLA.

The Optimisation of Processing Condition for Injected Mould Polypropylene-Nanoclay-Gigantochloa Scortechinii based on Melt Flow Index

The fundamental knowledge of flow behaviour is essential in producing various plastic parts injection moulding process. Moreover, the adaptation of advanced polymer-nanocomposites such as polypropylene-nanoclay with natural fibres, for instance Gigantochloa Scortechinii may boost up the mechanical properties of the parts. Therefore, this project was proposed with the objective to optimise the processing condition of injected mould polypropylene-nanoclay-Gigantochloa Scortechini fibres based on the flow behaviour, which was melt flow index. At first, Gigantochloa Scortechinii fibres have to be preheated at temperature 120°C and then mixed with polypropylene, maleic anhydride modified polypropylene oligomers (PPgMA) and nanoclay by using Brabender Plastograph machine. Next, forms of pellets were produced from the samples by using Granulator machine for use in the injection moulding process. The design of experiments that was used in the injection moulding process was Taguchi Method Orthogonal Array -L934. Melt Flow Index (MF) was selected as the response. Based on the results, the value of MFI increased when the fiber content increase from 0% to 3%, which was 17.78 g/10min to 22.07 g/10min and decreased from 3% to 6%, which was 22.07 g/10min to 20.05 g/10min and 3%, which gives the highest value of MFI. Based on the signal to ratio analysis, the most influential parameter that affects the value of MFI was the melt temperature. The optimum parameter for 3% were 170°C melt temperature, 35% packing pressure, 30% screw speed and 3 second filling time.

Recent Developments in the Fabrication, Characterization, and Properties Enhancement of Polymer Nanocomposites: A Critical Review

During the last few decades, significant progress in developing polymer nano-composites and their wide scope in extensive engineering applications such as packaging, sports equipment, automobile sector and bio-medical, has been the result of continuous developments in polymer science and nanotechnology. Moreover, the polymer nano-composites can be tailored to meet the widespread engineering accomplishments due to unique combination of mechanical properties, electrical properties, corrosion resistance, thermal stability and high reliability in rigorous environments. The present research study significantly reviews the various theories and models used to fabricate the polymer nano-composites. Furthermore, the paper also emphasizes the impact of nanofillers dispersion on morphology, thermal, water barrier, flame retardant and mechanical properties of nanocomposites. Earlier research unveils that addition of different nano-particle, for instance, carbon nanotubes, nanofibers, layered silicate clays and metallic nanoparticles into thermosetting or thermoplastic polymers acquire high surface area to volume ratio of the spherical nanofiller and high aspect ratio which results in properties enrichment. Therefore, this analysis would discover several key research gaps and to discuss the future scope for the synthesis of advanced polymer nanocomposites with tunable mechanical, thermal and electrical properties.

Size-controlled self-assembly of anisotropic sepiolite fibers in rubber nanocomposites

The development of advanced polymer nanocomposites requires a strong filler-polymer interfacial interaction and an optimal filler nanodispersion. The incorporation of the clays into a polymer matrix frequently does not improve the composite mechanical properties, owing to both poor dispersion and macroscopic particle dimensions. In this work, pristine and organically-modified sepiolites (Sep) were structurally modified by an acid treatment, which provides nano-sized sepiolite (NS-Sep) fibers with reduced particle size and increased silanol groups on the surface layer. NS-Sep fibers were used to prepare styrene-butadiene rubber nanocomposites with enhanced mechanical properties.Dynamic-mechanical analysis of clay polymer nanocomposites demonstrated that the NS-Sep fibers provided an excellent balance between reinforcing and hysteretic behavior, compared to the large-sized pristine Sep and isotropic silica. This was related to the enhanced interfacial chemical interaction between NS-Sep and rubber, as well as to the size and self-assembly of anisotropic nanofibers to form filler network structures, as supported by transmission electron microscopy analysis.The preparation of nanocomposites, based on Sep nanofibers obtained by a simple and versatile acid treatment, can thus be considered an alternative approach for the designing of advanced clay polymer nanocomposites.

ANALYSIS OF WEAR BEHAVIOR OF GRAPHENE OXIDE — POLYAMIDE GEARS FOR ENGINEERING APPLICATIONS

Recent advances in polymer nanocomposites open a wide range of applications in various industrial sectors. Due to their high potential properties, these materials are replacing the usage of metals for many heavier components in automobile industries. In this experimental work, the tribological performance of Graphene oxide (GO) — Polyamide is investigated against pristine polyamide by fabricating gears for the usage in engineering applications. A gear test rig was developed in-house for analysis to study the specific wear rate and temperature gradient at different conditions of load and speeds. The wear resistance of the polyamide gears with the addition of 0.03[Formula: see text]wt.% of graphene oxide is better than the pristine polyamide gears and the specific wear rate is reduced significantly. The reduced specific wear rate of these polymer nanocomposite gears is attributed to the superior properties of graphene oxide such as High specific surface area, good adhesion properties and enhanced glass transition temperatures. The GO nanocomposite gear seems to be a potential alternative against conventional gears for engineering applications. Finally, the wear mechanisms and the potential of GO-based polyamide nanocomposite gears were proposed tentatively in the development of transmission gears for engineering applications.

Optimisation of Injection Moulding Parameter towards Shrinkage and Warpage for Polypropylene-Nanoclay-Gigantochloa Scortechinii Nanocomposites

The setting of suitable parameter's level and values were very crucial in determining the quality characteristic of the injection moulding's product, especially made from advanced polymer nanocomposites. Therefore, this research was proposed to optimise the injection moulding parameters towards the quality characteristics of samples made from polypropylene-nanoclay-Gigantochloa Scortechinii fibers. The quality characteristics that need to be controlled were shrinkage and warpage, and the selected parameters were packing pressure, barrel temperature, screw speed and filling time. The Gigantochloa Scortechinii fibers need to be preheated at 1200C first, and then mixed with polypropylene, polypropylene grafted maleic anhydride and nanoclay through the compounding process by using Brabender Plastograph. The injection moulding process was performed based on the orthogonal array from Taguchi Optimisation Method. According to the results, the value of warpage was reduced when the fiber content was increased from 1wt. % to 3wt. %. The warpage value changed from 0.025mm to 0.009mm. The optimum parameter for warpage were 175°C barrel temperature, 40% packing pressure, 35% screw speed and 2seconds filling time for both 1wt. % and 3% of GS fiber. However, in terms of shrinkage, the increment of fiber content doesn’t have much impact towards the response. The value of shrinkage was reduced but not significantly from 0.0136mm to 0.0134mm when the percentage of fiber was added. The optimum parameter for 1wt. % fiber to control shrinkage are 170°C melt temperature, 35% packing pressure, 30% screw speed and 2seconds of filling time. The findings of this research will be valuable for quality control and references for products made from polypropylene-nanoclay-Gigantochloa Scortechinii fibers.

Core–shell structured BaTiO3@Al2O3 nanoparticles in polymer composites for dielectric loss suppression and breakdown strength enhancement

Design of core–shell nanoarchitectures is powerful approach to obtain advanced high-k polymer nanocomposites. Core–shell nanoparticles with uniform amorphous Al2O3 shell layer encapsulating BaTiO3 (BT) particles were fabricated through an effective, facile and low-cost heterogeneous nucleation method. The dielectric behaviors of the polyvinylidene fluoride (PVDF) nanocomposite films were adjusted by varying BT@Al2O3 nanoparticles loadings. The effects of Al2O3 shell and the arising interfaces on the dielectric and electric properties in comparison with bare BT nanoparticles were studied. Due to the highly insulating Al2O3 shell with proper dielectric constant, the local electric field distribution around interfaces between polar BT nanoparticles and PVDF were greatly modified leading to obvious dielectric loss suppression yet maintaining high dielectric constant. The study provides a solution for obtaining high-k dielectric composite with low loss and high breakdown strength, which is highly desired in high power systems.

Nanoparticle chemically end-linking elastomer network with super-low hysteresis loss for fuel-saving automobile

Achieving energy sustainability has imposed a great challenge to improve fuel efficient vehicles. Tires, to overcome the rolling resistance, are responsible for a rather large fraction of energy consumed by vehicles, and a 10% reduction in the rolling resistance corresponds to a 2% decline in the fuel consumption, which, for instance, would save 1–2 billion gallon of fuel per year consumed by the entire passenger vehicle fleet in the United States. From the materials’ perspective, the key bottleneck to lower the rolling resistance of tires lies in designing a novel kind of advanced elastomeric polymer nanocomposites tailored for tire tread, with remarkably low dynamic hysteresis loss (DHL). Here we show that, a nanoparticle chemically end-linking elastomer network, with nanoparticles (NPs) acting as netpoints to chemically connect the dual end-groups of each polymer chain to form a network, exhibits excellent static and dynamic mechanical properties of super-low DHL. The DHL is reduced for ~50% compared to silica NPs filled elastomer that is conventionally used for tire tread. By taking advantage of a library of other nanomaterials such as functionalized carbon nanotube and graphene, our approach provides a versatile framework to fabricate the fuel-saving tires, opening up valuable opportunities for large-scale industrial applications of these nanomaterials in the tire industry.

Molecular structures of (3-aminopropyl)trialkoxysilane on hydroxylated barium titanate nanoparticle surfaces induced by different solvents and their effect on electrical properties of barium titanate based polymer nanocomposites

Surface modification of nanoparticles by grafting silane coupling agents has proven to be a significant approach to improve the interfacial compatibility between inorganic filler and polymer matrix. However, the impact of grafted silane molecular structure after the nanoparticle surface modification, induced by the utilized solvents and the silane alkoxy groups, on the electrical properties of the corresponding nanocomposites, has been seldom investigated. Herein, the silanization on the surface of hydroxylated barium titanate (BT-OH) nanoparticles was introduced by using two kinds of trialkoxysilane, 3-aminopropyltriethoxysilane (AMEO) and 3-aminopropyltrimethoxysilane (AMMO), with different solvents (toluene and ethanol), respectively. Solid-state 13C, 29Si nuclear magnetic resonance (NMR) spectroscopy and high-resolution X-ray photoelectron spectroscopy (XPS) were employed to validate the structure differences of alkoxysilane attachment to the nanoparticles. The effect of alkoxysilane structure attached to the nanoparticle surface on the dielectric properties of the BT based poly(vinylidene fluoride) (PVDF) nanocomposites were investigated. The results reveal that the solvents used for BT nanoparticle surface modification exhibit a significant effect on the breakdown strength of the nanocomposites. Nevertheless, the alkoxy groups of silane show a marginal influence on the dielectric properties of the nanocomposites. These research results provide important insights into the fabrication of advanced polymer nanocomposites for dielectric applications.