High-performance Polymer Nanocomposites Research Articles

Millefeuille-inspired highly conducting polymer nanocomposites based on controllable layer-by-layer assembly strategy for durable and stable electromagnetic interference shielding

High-performance conductive polymer nanocomposites containing two-dimensional (2D) MXene are garnering substantial interest for electromagnetic shielding interference (EMI) in flexible electronics. However, owing to the non-sticky nature and undesirable mechanical performances of freestanding MXene film, it remains a formidable challenge to make the trade-off between outstanding EMI shielding capability and high stability. In this study, inspired by the structure and manufacturing process of millefeuille cakes, we propose a controllably layer-by-layer assembling strategy for fabricating flexible multilayered EMI shielding composite films based on MXene and an inherently conductive polymer (ICP). The multilayer films bearing alternating aramid nanofibers/polypyrrole nanowires (AFPy) and Ti3C2Tx reinforced by waterborne polyurethane (Ti3C2Tx@WPU) layers are orderly constructed by a facile alternating vacuum filtration method. Benefiting from the special architectures, the AFPy-70/Ti3C2Tx@WPU-4 film exhibits a high electrical conductivity of 1.74 S cm−1 and superior EMI shielding effectiveness of 40.9 dB at lower Ti3C2Tx loading content (32 wt%). Moreover, synergistic integration of hydrogen bonding and π-π stacks in multilayered films is achieved, especially in tandem with controlled crack generation within the whole film. Excellent EMI shielding performance remains well maintained even after being suffered to back-and-forth bending test (over 10,000 cycles), ultrasonication, and cryogenic temperature, validating great potential as high-performance EMI shielding film resisting extreme conditions.

A Review on Synthesis, Functionalization, Processing and Applications of Graphene Based High Performance Polymer Nanocomposites

: Graphene as a nanofiller has gained tremendous importance in polymer nanocomposites for many applications. The attractive properties of graphene related to mechanical, electrical, and thermal domains pose a lucrative means of reinforcing the polymers to obtain the needed properties. The rise in the use of polymers supports this trend and urge researchers to excavate the hidden plethora of nanocomposite materials for multifunctional applications. In this review, an overview is provided on graphene-based materials which have been used extensively in various fields such as batteries, aerospace, automobile, and biomedical fields. With the increasing trend of graphene usage by many researchers as a nanofiller in polymer composites, its types, processing methods are highlighted with suitable applications to assimilate the updates in the development of graphene nanocomposites.

Liquid phase exfoliated nanosheets as multifunctional fillers to semicrystalline polymers

Two-dimensional (2 D) materials have emerged as important part of high-performance polymer nanocomposites, thanks to their immaculate and tunable properties. Layered double hydroxides (LDHs), in particular, have received much attention in the polymer industry as multifunctional fillers for polyolefins and vinyl polymers. Highly exfoliated boron nitride nanosheets (BNNSs) have been a reliable partner for polyesters and polyamides, especially as thermal conductivity fillers. In this article, we have critically reviewed the latest developments in the field of polymer nanocomposites based on 2 D materials, with special emphasis on liquid phase exfoliated LDHs and BNNSs. Liquid phase exfoliation delivers few-layered or even monolayered nanosheets, and further structural modifications or surface functionalizations of these nanosheets result in better compatibility with the polymer matrix. Trace amounts of the exfoliated 2 D nanofillers can significantly alter the crystallization kinetics, mechanical properties, thermal stability, thermal conductivity and flame-retardant properties of polymers. Through this review, we aim to track down some of the important contributions in this area along with our own works, and this article is expected to fertilize considerable progress in this field.

Designing high performance polymer nanocomposites by incorporating robustness-controlled polymeric nanoparticles: insights from molecular dynamics.

Introducing polymeric nanoparticles into polymer matrices is an interesting topic, and the robustness of the polymeric nanoparticles is crucial for the properties of the polymer nanocomposites (PNCs). In this study, by incorporating star-shaped polymeric nanoparticles (SSPNs) into the polymer, the effect of the sphericity (η) and arm length (L) of the SSPNs on the mechanical properties of PNCs is systematically investigated, using a coarse-grained molecular dynamics simulation. In addition, the linear and spherical nanoparticles (NPs) are compared with SSPNs by fixing the approximate diameter and mass fraction of the NPs. The radial distribution function, the second virial coefficient, mean-squared displacement, bond autocorrelation function, and primitive path analysis are employed to systematically characterize the structure and dynamics of these new PNCs. It is found that the dispersion of the NPs is enhanced with the increase of η, and the entanglement density reaches maximum, which both contribute to the greatest mechanical reinforcing effect. More significantly, it is found that the classical Payne effect, namely the storage as a function of the strain amplitude, decreases remarkably, and with a much smaller loss factor for these SSPN filled polymer nanocomposites, compared to conventional PNCs filled with rigid NPs. Furthermore, the change of the arm length of the SSPNs is found to exhibit the same effect on the mechanical and viscoelastic properties, as the variation of the number of the arms. In general, this work shows that these new SSPN filled polymer nanocomposites can exceed conventional PNCs, by manipulating the robustness of the SSPNs using, for example, the number and length of the arms. This research may provide guidelines for the investigation of the structure-property relationships of the topological structure of polymeric nanoparticles.

Effect of Length of Cellulose Nanofibers on Mechanical Reinforcement of Polyvinyl Alcohol.

Cellulose nanofibers (CNF), representing the nano-structured cellulose, have attained an extensive research attention due to their sustainability, biodegradability, nanoscale dimensions, large surface area, unique optical and mechanical performance, etc. Different lengths of CNF can lead to different extents of entanglements or network-like structures through van der Waals forces. In this study, a series of polyvinyl alcohol (PVA) composite films, reinforced with CNF of different lengths, were fabricated via conventional solvent casting technique. CNF were extracted from jute fibers by tuning the dosage of sodium hypochlorite during the TEMPO-mediated oxidation. The mechanical properties and thermal behavior were observed to be significantly improved, while the optical transparency decreased slightly (Tr. > 75%). Interestingly, the PVA/CNF20 nanocomposite films exhibited higher tensile strength of 34.22 MPa at 2 wt% filler loading than the PVA/CNF10 (32.55 MPa) while displayed higher elastic modulus of 482.75 MPa than the PVA/CNF20 films (405.80 MPa). Overall, the findings reported in this study provide a novel, simple and inexpensive approach for preparing the high-performance polymer nanocomposites with tunable mechanical properties, reinforced with an abundant and renewable material.

Distribution states of graphene in polymer nanocomposites: A review

Graphene has emerged as one of the promising nanoscale components of polymer nanocomposites owing to its exceptional properties. The 2D graphene material, when distributed appropriately in the host polymer can significantly alter the load, electron, and phonon transfer behavior of the nanocomposites. The in-plane strong covalent bonds in graphene are accountable for these unique properties, whereas the weak van der Waals forces existing between the adjacent monolayer graphene planes are responsible for the re-stacking or agglomeration of layers. Hence, the most critical challenge in translating these properties in high-performance graphene polymer nanocomposite is to alleviate the agglomeration of graphene. This can be achieved by improving the distribution states of graphene in the matrix by; (1) enhancing the dispersion and (2) controlling the relative lattice orientation of graphene in substrates to create an alignment or orientation. Mitigating the agglomerates during the composite fabrication will significantly extend the benefits of graphene's inherent properties to the nanocomposite. In this review article, various methods for improving dispersion and orientation of graphene in polymer nanocomposites is elucidated. A decision flowchart on the choice of dispersion or orientation based on the properties is considered and the techniques to quantify and verify the same is deliberated. Furthermore, composites' performance in terms of mechanical, electronic, and thermal enhancements due to the molecular level dispersion or anisotropic orientation of graphene is discussed. This review provides a constructive guidance in the composite processing methods and to correlate the enhancement of properties with the distribution state of graphene in composites. Predominantly epoxy and PDMS polymers are reinforced by 3D graphene as fillers due to their structural stability and wider applications. It is also witnessed that 3D graphene reinforced composites are mainly investigated for electrical and thermal properties followed by mechanical and acoustic properties.

Polymer Nanocomposites: Role of modified filler content and interfacial interaction on crystallization

The crystallization behavior of polymer nanocomposites is of great significance in scientific level and applications. In this work, the effects of modified filler contents and interfacial interactions on nucleation and crystallization were revealed by Monte Carlo simulation. The results show that the increase of filler content promotes the transformation of nucleation mode and significantly affects the crystallization rate of polymer nanocomposite system. When the modified filler contents in the system are too high, the chain mobility is greatly reduced due to the small spacing of fillers and the strong restriction of grafting points, which limits the diffusion and arrangement of segments to the nucleus and reduces the crystallization rate. By adjusting the interfacial strength between the matrix and modified fillers, it can be found that the nucleation rate of the system is determined by the changes of free energy barrier and diffusion activation energy under different interfacial interactions. In addition, for the polymer nanocomposite system with less fillers or strong interfacial interactions, it is more likely to form edge-on crystals. These results contribute to the design and preparation of high performance polymer nanocomposites.

Purification of commercial grade bentonite from LamDong, Vietnam for nano-size montmorillonite

The article will report the purification of Dilinh bentonite sample deposits of Lamdong province in Vietnam. The combination of sonication, sedimentation and dispersant (NaPO3)6 were applied to increase the montmorillonite (MMT) content. To evaluate the effect of (NaPO3)6 concentration, X-ray diffraction, Infra-red spectra, X-ray fluorescence spectra, dynamic light scatteringand scanning electron microscopy analyses were carried out. The results showed that, when (NaPO3)6content increased, the fraction of MMT increased and that of quartz decreased. The optimum (NaPO3)6 content was 5 wt%,to eliminate maximum of quartz and other non clay minerals, the recovery yield was 71.2%.This was a high quality MMT selection process; the purified MMT is suitable for application as nanofiller in high performance polymer nanocomposites.

A Review on the Synthesis, Properties, and Utilities of Functionalized Carbon Nanoparticles for Polymer Nanocomposites.

Carbon can form different allotropes due to its tetravalency. Different forms of carbon such as carbon nanotubes (CNTs), carbon nanofibers, graphene, fullerenes, and carbon black can be used as nanofillers in order to enhance the properties of polymer nanocomposites. These carbon nanomaterials are of interest in nanocomposites research and other applications due to their excellent properties, such as high Young’s Modulus, tensile strength, electrical conductivity, and specific surface area. However, there are some flaws that can be found in the carbon nanoparticles such as tendency to agglomerate, insoluble in aqueous or organic solvents or being unreactive with the polymer surface. In this study, the aim is to study functionalization in order to rectify some of these shortcomings by attaching different functional groups or particles to the surface of these carbon nanoparticles; this also enables the synthesis of high-performance polymer nanocomposites. The main findings include the effects of functionalization on carbon nanoparticles and the applications of polymer nanocomposites with carbon nanoparticles as nanofillers in the industry. Additionally, the different methods used to produce polymer composites such as in situ polymerization, solution mixing and melt blending are studied, as these methods involve the dispersion of carbon nanofillers within the polymer matrix.

Biaxial Stretching of Polymer Nanocomposites: A Mini-Review

Polymer nanocomposites with excellent physical and chemical properties and multifunctional performance have been widely used in various fields. Biaxial stretching is not only an advanced film manufacturing process, but also a deformation mode in other processing methods such as blow film extrusion and thermoforming. In recent research, high-performance polymer nanocomposites have been fabricated via sequential and simultaneous biaxial stretching. This fabrication method enhances the mechanical properties, optical performance, and thermal properties of polymer nanocomposites by changing the structure or orientation of materials during the process of stretching. Therefore, it is particularly suitable for use in optimizing material performance and preparing thin films with excellent properties in the packaging industry. With the emergence of new materials and technologies, polymer nanocomposites prepared by biaxial stretching have demonstrated multifunctional properties and their range of applications has further expanded. In this mini-review, the effect of biaxial stretching on the structure and properties of nanocomposites based on various nanofillers is discussed and applications are summarized. In addition, the challenges and future prospects of this technology are analyzed. The presented work will be beneficial for improving preparation processes and improving future research for the production of high-performance polymer nanocomposites.

Reinforcing natural rubber by amphiphilic graphene oxide for high-performance catheters

Graphene oxide (GO) has been considered as a promising nanofiller to reinforce water-borne polymer due to its exceptional mechanical properties and good dispersibility in an aqueous solution. However, the re-aggregation of hydrophilic GO sheets in a hydrophobic polymer matrix with the evaporation of water, resulting from remarkable discrepancy of the interfacial energy, remains a significant challenge to achieve the high-performance GO-based polymer nanocomposites. Herein, the amphiphilic graphene oxide (AGO) rather than the conventional GO is applied to enhance the mechanical properties of natural rubber latex (NRL) through simple solution blending. Our results show that the AGO demonstrates not only good dispersibility in the NRL aqueous solution but also strong hydrophobic interaction with the NRL particles. Benefiting from this amphiphilic character, the good dispersibility of AGO in the NRL matrix is realized after the oven-drying process, leading to a simultaneous enhancement in tensile strength (up to 35 MPa) and elongation at break (up to 1100%). In particular, it is found that the NRL tube, a kind of catheter, demonstrates a remarkable improvement in both blasting pressure, blasting volume with just a small amount addition of AGO (as less as 0.1%). This work provides a simple, green, and efficient route to fabricate high-performance polymer latex/graphene nanocomposites.

Outstanding in-situ CNTs on Fe-pillared nanoclay for high-performance polymer nanocomposites

The successful and novel synthesis of in-situ multi-walled carbon nanotubes (MWCNTs) on a pillared montmorillonite (Mt) nanoclay was achieved. These novel nanofillers were mixed with poly(methyl methacrylate) (PMMA) polymer to study electrical properties of these nanocomposites. The trinuclear Fe (III)-acetato complex, [Fe3(OOCCH3)7·OH·nH2O]+NO3−, was synthesized and analyzed by chemical analysis and FTIR spectroscopy, and was used as the precursor for the CNT synthesis. The complex proved to be an excellent precursor for the synthesis of CNTs. CNT-clay hybrid nanofillers with varying CNT contents and qualities were observed and investigated using XRD, TGA, XPS, Raman, SEM, and TEM. The ID/IG of CNTs decreased from 1.92 for 0.5 CEC of the iron complex to 0.72 for 6 CEC CNTs. The XRD indicated that Mt. layers were intercalated with iron species during the ion-exchange process, and further exfoliated due to the growth of CNTs. The synthesis yield increased at higher iron concentrations, i.e., 83.4% for 6 CEC CNTs. The 6, 7, and 8 CEC CNTs exhibited smaller diameter CNTs, 14.6 (±4.4), 18.2 (±4.4), and 16.5 (±6) nanometers, when compared to those of lower catalyst concentrations. The 8 CEC CNTs showed 3.5 S m−1 of conductivity, and ~ 90% of the sp2 structure. The electrical properties of PMMA nanocomposites showed these these CNT-clay hybrid fillers are effective for charge storage applications.

Effective Enhancement of a Carbon Nanothread on the Mechanical Properties of the Polyethylene Nanocomposite

The mechanical performance of nanomaterial-reinforced polymer nanocomposites is a prerequisite for their engineering implementations, which is largely determined by the interfacial load transfer efficiency. This work investigates the role of the nanofillers via molecular dynamics simulations under different deformation scenarios, mimicking a maximum and minimum load transfer scenario from the polymer matrix. On the basis of the polyethylene (PE) nanocomposite reinforced by a new nanofiller-carbon nanothread (NTH), we find that the loading conditions dominantly determine its enhancement effect on the mechanical properties of the PE nanocomposite. Under tensile deformation, the ultimate tensile strength of the PE nanocomposite receives around 61 to 211% increment when the filler deforms simultaneously with the PE matrix. However, such enhancement is largely suppressed when the NTH is deforming nonsimultaneously. Similar results are observed from the compressive deformation. Specifically, both morphology and functionalization are found to alter the enhancement effect from the NTH fillers, while also relying on the loading directions. Overall, this work provides an in-depth understanding of the role of the nanofiller. The observations signify the importance of establishing effective load transfer at the interface, which could benefit the design and fabrication of high-performance polymer nanocomposites.

Role of a nanoparticle network in polymer mechanical reinforcement: insights from molecular dynamics simulations.

Fully understanding the mechanism by which nanoparticles (NPs) strengthen polymer matrices is crucial for fabricating high-performance polymer nanocomposites (PNCs). Herein, coarse-grained molecular dynamics simulations were adopted to explicitly investigate the reinforcing effect of a NP network. Our results revealed that increasing the NP-NP interactions induced the self-assembly of NPs into a three-dimensional (3D) network that reinforced the polymer matrix. The reinforcing mechanism of NP-NP interactions was quite different from that of NP-polymer interactions. The latter promoted the orientation of polymer chains to transfer the external stress, while the former distributed the stress throughout the NP network. This work revealed the mechanism by which the NP network reinforced the polymer matrix at the molecular level and also provided guidelines for developing high performance PNCs via interfacial modification.

Elucidating the Role of Embedded Metal–Organic Frameworks in Water and Ion Transport Properties in Polymer Nanocomposite Membranes

Metal–organic frameworks (MOFs) have been extensively studied as promising nanofillers in developing high-performance polymer nanocomposite membranes (PNMs) for efficient water/ion separation appli...

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.

Polymer Nanocomposite-based Coatings for Corrosion Protection.

Corrosion of metals induces enormous loss of material performance and increase of cost, which has been a common and intractable issue that needs to be addressed urgently. Coating technology has been acknowledged to be the most economic and efficient approach to retard the metal corrosion. For several decades, polymers have been recognized as an effective anticorrosion coating material in both industries and scientific communities, as they demonstrate good barrier properties, ease of altering properties and massive production. Nanomaterials show distinctively different physical and chemical properties compared with their bulk counterparts, which have been considered as highly promising functional materials in various applications, impacting virtually all the fields of science and technologies. Recently, the introduction of nanomaterials with various properties into polymer matrix to form a polymer nanocomposite has been devoted to improve anticorrosive ability of polymer coatings. In this review article, we highlight the recent advances and synopsis of these high-performance polymer nanocomposites as anticorrosive coating materials. We expect that this work could be helpful for the researchers who are interested in the development of functional nanomaterials and advanced corrosion protection technology.

High performance epoxy nanocomposites based on dual epoxide modified α-Zirconium phosphate nanoplatelets

Epoxy nanocomposites with exfoliated α-zirconium phosphate (ZrP) using proton exchanged polyetheramines as surfactants have previously been demonstrated to show significant improvements anti-corrosion, barrier, and mechanical properties. However, these nanocomposites have a significant reduction in glass transition temperature (Tg). The low Tg of the nanocomposites is caused by detachment of the polyetheramine from ZrP which interferes with the epoxy curing process. Here, ZrP surfaces with covalently bound molecules containing epoxide functional groups were used to achieve ZrP exfoliation in epoxy without sacrificing Tg. By introducing dual epoxide functionalized ZrP, it is possible to achieve exfoliation and self-assembly of ZrP at high loadings in epoxy with greatly increased Young's modulus and significantly reduced thermal expansion coefficient, while maintaining a high Tg. Implication of the present study for preparation of high-performance polymer nanocomposites is discussed.

Engineering at the Nanoscale: A Strategy for Developing High-Performance Functional Polymer Nanocomposites

The talk will concentrate on various approaches being used to engineer materials at the nanoscale for various applications in future technologies. In particular, the case of clay, carbon nanostructures (e.g., nanotubes, graphene), metal oxides, bionanomaterials (cellulose, starch, and chitin) will be used to highlight the challenges and progress. Several bio-degradable polymer systems will be considered, such as rubbers, thermoplastics, thermosets, and their blends for the fabrication of functional polymer nanocomposites. The interfacial activity of nanomaterials in compatibilism binary polymer blends will also be discussed. Various self-assembled architectures of hybrid nanostructures can be made using relatively simple processes. Some of these structures offer an excellent opportunity to probe novel nanoscale behavior and can impart unusual macroscopic end properties. I will talk about various applications of these materials, taking into account their multifunctional properties. Some of the promising applications of clay, metal oxides, nano cellulose, chitin, carbon nanomaterials, and their hybrids will be reviewed.

Engineering MXene surface with POSS for reducing fire hazards of polystyrene with enhanced thermal stability

High-performance MXene-based polymer nanocomposites are highly desirable for diverse industry applications due to their exceptional mechanical, thermal and other properties. Nevertheless, it remains an intractable challenge to create flame retardant polymer/MXene nanocomposites due to the difficulty to achieve uniform dispersion of MXenes. Here, we reported a facile strategy for the surface manipulation of two-dimensional titanium carbide nanosheets (Ti3C2Tx) with 3-aminopropylheptaisobutyl-polyhedral oligomeric silsesquioxane (AP-POSS) (POSS-Ti3C2Tx) through electrostatic interactions. The POSS-Ti3C2Tx is steadily dispersed in many polar solvents. Upon incorporated into polystyrene (PS), the combined effect of AP-POSS and MXene makes the resultant PS nanocomposites exhibit significantly improved thermal and thermoxidative stability, e.g. 22 °C and 39 °C increases in the temperature at 5 wt% mass loss under nitrogen and air, respectively. Meanwhile, a 39.1 % reduction in the peak heat release rate, a respective 54.4 % and 35.6 % reduction in the peak CO production rate and the peak CO2 production rate was achieved, which are superior to those of its own and previous counterparts. This outstanding fire safety is attributed to the combination of adsorption, catalytic and barrier effects of POSS-Ti3C2Tx. Hence, as-designed functionalized MXenes can be effectively applied in PS to formulate multifunctional polymer nanocomposites attractive for wide potential applications.