High-performance Nanocomposites Research Articles

Aliphatic Polyurethane Elastomers Quaternized with Silane-Functionalized TiO2 Nanoparticles with UV-Shielding Features.

The design of high-performance nanocomposites with improved mechanical, thermal or optical properties compared to starting polymers has generated special interest due to their use in a wide range of targeted applications. In the present work, polymer nanocomposites composed of polyurethane elastomers based on polycaprolactone or polycaprolactone/poly(ethylene glycol) soft segments and titanium dioxide (TiO2) nanoparticles as an inorganic filler were prepared and characterized. Initially, the surface of TiO2 nanoparticles was modified with (3-iodopropyl) trimethoxysilane as a coupling agent, and thereafter, the tertiary amine groups from polyurethane hard segments were quaternized with the silane-modified TiO2 nanoparticles in order to ensure covalent binding of the nanoparticles on the polymeric chains. In the preparation of polymer nanocomposites, two quaternization degrees were taken into account (1/1 and 1/0.5 molar ratios), and the resulting nanocomposite coatings were characterized by various methods (Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy, contact angle, thermogravimetric analysis, dynamic mechanical thermal analysis). The mechanical parameters of the samples evaluated by tensile testing confirm the elastomeric character of the polyurethanes and of the corresponding composites, indicating the obtaining of highly flexible materials. The absorbance/transmittance measurements of PU/TiO2 thin films in the wavelength range of 200–700 nm show that these partially block UV-A radiation and all UV-B radiation from sunlight and could possibly be used as UV-protective elastomeric coatings.

The Fabrication and Properties of a Bendable High-Temperature Resistance Conductive Pitch-Based Carbon/CNT Film Nanocomposite.

This paper fabricates a carbon nanotube (CNT ) film-reinforced mesophase pitch-based carbon (CNTF/MPC) nanocomposite by using a hot-pressing carbonization method. During the carbonization, the stacked aromatic layers tended to rearrange into amorphous carbon, and subsequently generated crystalline carbon in the matrix. The continuous entangled CNT networks were efficiently densified by the carbon matrix though optimized external pressure to obtain the high-performance nanocomposites. The CNTF/MPC@1300 displayed a stable electrical conductivity up to 841 S/cm at RT-150 °C. Its thermal conductivity in the thickness direction was 1.89 W/m∙K, an order of magnitude higher than that of CNT film. Moreover, CNTF/MPC@1300 showed a mass retention of 99.3% at 1000 °C. Its tensile strength was 2.6 times the CNT film and the tensile modulus was two orders of magnitude higher. Though the CNTF/MPC nanocomposites exhibited brittle tensile failure mode, they resisted cyclic bending without damage. The results demonstrate that the CNTF/MPC nanocomposite has potential application in multi-functional temperature resistance aerospace structures.

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.

Regulating dielectric performances of Poly(vinylidene fluoride) nanocomposites by individually controlling shell thickness of Core@Double‐Shells structured nanowires

The synthesis of core@double-shells structured TiO2@C@SiO2 nanowires (NWs) with variable thickness of carbon inner shell and SiO2 outer shell was achieved by individually controlling the chemical vapour deposition time and amount of silicon precursor added in the sol–gel synthesis. The resultant TiO2@C@SiO2 NWs filled nanocomposites exhibited an excellent dielectric performance with simultaneously improved dielectric constant and suppressed dielectric loss, which could be further regulated by individually controlling the carbon inner shell and SiO2 outer shell thickness. More importantly, the influences of the conductive carbon inner shell and insulated SiO2 outer shell thickness on the dielectric performance of nanocomposites were clearly revealed. The increase of the conductive carbon inner shell thickness would lead to an increase in dielectric constant and loss of nanocomposites, while the insulated SiO2 outer shell exhibited a totally opposite law that the dielectric constant and loss of nanocomposites decrease with increasing SiO2 outer shell thickness. Numerical simulations were also carried out to theoretically verify the relationship between the dielectric loss and SiO2 outer shell thickness. This promising controllable multi-shell structure could be extended to a variety of hybrids to develop high-performance dielectric nanocomposites.

Polyamide-MIL-101(Cr) Thin Films Synthesized on Either the Outer or Inner Surfaces of a Polysulfone Hollow Fiber for Water Nanofiltration.

High-performance thin film nanocomposite (TFN) hollow fiber (HF) membranes, with MIL-101(Cr) MOF nanoparticles (52 ± 13 nm) embedded, have been synthesized with the polyamide layer formed either on the outer or inner surface of a polysulfone HF (250 and 380 μm ID and OD, respectively). The TFN_out membrane was developed using the conventional interfacial polymerization method, typically applied to obtain TFN flat membranes (MOF particles added to the thin layer by deposition). This membrane gave a water permeance value of 1.0 ± 0.7 L·m–2·h–1·bar–1 and a rejection of 90.9 ± 1.2% of acridine orange (AO, 265 Da). In contrast, the TFN_in membrane was synthesized by microfluidic means and gave a significantly higher water permeance of 2.8 ± 0.2 L·m–2·h–1·bar–1 and a slightly lower rejection of 87.4 ± 2.5% of the same solute. This remarkable increase of flux obtained with small solute AO suggests that the HF membranes developed in this work would exhibit good performance with other typical solutes with higher molecular weight than AO. The differences between the performances of both TFN_in and TFN_out membranes lay on the distinct superficial physicochemical properties of the support, the synthesis method, and the different concentrations of MOF present in the polyamide films of both membranes. The TFN_in is more desirable due to its potential advantages, and more effortless scalability due to the microfluidic continuous synthesis. In addition, the TFN_in membrane needs much fewer quantities of reactants to be synthesized than the TFN_out or the flat membrane version.

MOF−Guest complex derived Cu/C nanocomposites with multiple heterogeneous interfaces for excellent electromagnetic waves absorption

Electrical conductivity and interfacial polarization are two crucial factors to design high-performance electromagnetic absorption (EMA) materials, but how to synergistically balance these factors still remains to be difficult. In this work, we report the synthesis of Cu/C nanocomposites via the controlled pyrolysis of a MOF-guest complex. The prepared Cu/C nanocomposites are made up of cross-linked carbon network and various irregular particles. The carbon network provides appropriate electrical conductivity to contribute to the conductance loss. Multiple heterogeneous interfaces, such as Mo2C/C, Mo2C/CuO, CuO/C, Mo2C/Cu, and Cu/C interfaces, have been determined in these Cu/C nanocomposites, resulting in obviously improved polarization loss. As a result, the Cu/C nanocomposite exhibits excellent EMA performance, where the efficient absorption bandwidth reaches 6.8 GHz, and the maximal absorption gets to −52 dB. This research provides new idea to design high-performance EMA nanocomposites by tuning the electrical conductivity and interfacial polarization.

Effect of graphene and carbon-nitride nanofillers on the thermal transport properties of polymer nanocomposites: A combined molecular dynamics and finite element study.

Low thermal conductivity of polymers, which is one of the considerable drawbacks of commonly used composite structures, has been the focus of many researchers aiming to achieve high-performance polymer-based nanocomposites through the inclusion of highly thermally conductive fillers inside the polymer matrices. Thus, in the present study, a multiscale scheme using nonequilibrium molecular dynamics and the finite element method is developed to explore the impact of different nanosized fillers (carbon-nitride and graphene) on the effective thermal conductivity of polyethylene-based nanocomposites. We show that the thermal conductivity of amorphous polyethylene at room temperature using the reactive bond order interatomic potential is nearly 0.36±0.05W/mK. Also, the atomistic results predict that, compared to the C_{3}N and graphene nanosheets, the C_{2}N nanofilm presents a much stronger interfacial thermal conductance with polyethylene. Furthermore, the results indicate that the effective thermal conductivity values of C_{2}N-polyethylene, C_{3}N-polyethylene, and graphene-polyethylene nanocomposite, at constant volume fractions of 1%, are about 0.47, 0.56, and 0.74W/mK, respectively. In other words, the results of our models reveal that the thermal conductivity of fillers is the dominant factor that defines the effective thermal conductivity of nanocomposites.

Effect of TiCnp on microstructure and mechanical behaviour of high-performance Al7150-TiC nanocomposites

This research deals with Al7150-TiC nanocomposites and its mechanical, microstructure and fracture surface studies. Two-step stir casting and vortex methods were employed to fabricate Al7150-TiC nanocomposites. TiC was selected as a ceramic reinforcement and added 0.5, 1.0, and 1.5 wt% to find the effect of reinforcement on hardness and strength of nanocomposites. Optical Microscope was used to analyse the grain boundaries, the average grain size of nanocomposites through “Linear Intercept Method” and compared with monolithic. SEM was used to study particle distribution and failure surface analysis. ImageJ-software” was used to analyse particle size distribution in the SEM images. EDS was performed to find the chemical compounds of the composite materials. Addition of 1.0 wt% of reinforcement showed better mechanical properties. Uniform dispersion and grain refinement were obtained and mechanical properties were enhanced by 33.3% in tensile strength and 14.7% in micro hardness at 1.0 wt% as compared to monolithic.

Correction: Semiconducting polymer contributes favorably to the Seebeck coefficient in multi-component, high-performance n-type thermoelectric nanocomposites

Correction for ‘Semiconducting polymer contributes favorably to the Seebeck coefficient in multi-component, high-performance n-type thermoelectric nanocomposites’ by Junhui Tang et al., J. Mater. Chem. A, 2020, 8, 9797–9805, DOI: 10.1039/d0ta02388d.

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.

The green one-step electrodeposition of oxygen-functionalized porous g-C3N4 decorated with Fe3O4 nanoparticles onto Ni-foam as a binder-free outstanding material for supercapacitors

In this study, the binder-free high-performance nanocomposite of Fe3O4/oxygen-functionalized g-C3N4 was fabricated through a one-pot electrophoretic-electrochemical (EP-EC) process.

Thermoplastic Polymer Compounding with ZnS Nanostructures: Innovations and Applications

This study investigates the compounding of thermoplastic polymers with ZnS nanostructures, focusing on innovative synthesis methods and applications. The principal objective was to enhance the mechanical, thermal, and electrical properties of thermoplastic polymers by incorporating well-characterized ZnS nanoparticles. Utilizing a chemical precipitation method, ZnS nanoparticles with controlled size and high purity were synthesized. Characterization techniques, including XRD, SEM, TEM, EDS, and FTIR, confirmed the crystalline structure and elemental composition of the nanoparticles. Three compounding techniques—melt blending, solution casting, and in-situ polymerization—were explored for integrating ZnS nanoparticles into thermoplastic matrices. Each method was optimized for uniform nanoparticle dispersion and strong interfacial bonding. The findings revealed that nanocomposites produced via these techniques exhibited significantly enhanced tensile strength, impact resistance, thermal stability, and electrical conductivity compared to pure thermoplastics. The study's implications extend to industrial applications in electronics, automotive components, aerospace parts, and advanced packaging materials. The environmental benefits, such as reduced material consumption and improved recyclability, along with potential economic savings, underscore the broader impact of these advanced materials. This research provides a solid foundation for future development of high-performance ZnS-thermoplastic nanocomposites, promoting innovation in material science and industrial applications.

Poly(acrylic acid) nanocomposites: Design of advanced materials

Poly(acrylic acid) is a synthetic polymer that is polymerized from acrylic acid monomers. Poly (acrylic acid) is a high molecular weight polymer having good water solubility. Poly(acrylic acid) also exists in the cross-linked forms. Poly(acrylic acid) is an important polymer for making polymeric blends and nanocomposites. This state-of-the-art review is an endeavour to define the unique capabilities of poly (acrylic acid) to form high performance nanocomposites. The nanofiller nanomaterials including carbon nanotube, graphene, nanodiamond, and inorganic nanoparticles are promising nanofillers for a poly(acrylic acid) matrix. Consequently, the article discusses the following categories: poly(acrylic acid)/carbon nanotube, poly(acrylic acid)/graphene, poly(acrylic acid)/nanodiamond, and poly(acrylic acid)/inorganic nanoparticle nanocomposites. The nanocomposite characteristics are significantly enhanced with the added nanoparticles. Especially, the nanoparticles influenced the electrical conductivity, thermal stability, strength, biocompatibility, adsorption, and anti-bacterial features of the poly(acrylic acid) nanocomposites. Their high performance was related to the interface interactions between the matrix and the nanofillers. The poly (acrylic acid) derived nanocomposites have been used to form advanced hybrid materials for batteries, sensors, antibacterial, and water filters.

Rapid Preparation of MWCNTs/Epoxy Resin Nanocomposites by Photoinduced Frontal Polymerization.

Due to their excellent mechanical and thermal properties and medium resistance, epoxy/carbon nanotubes and nanocomposites have been widely used in many fields. However, the conventional thermosetting process is not only time- and energy-consuming, but also causes the agglomeration of nanofillers, which leads to unsatisfactory properties of the obtained composites. In this study, multi-walled carbon nanotubes (MWCNTs)/epoxy nanocomposites were prepared using UV photoinduced frontal polymerization (PIFP) in a rapid fashion. The addition of MWCNTs modified by a surface carboxylation reaction was found to enhance the impact strength and heat resistance of the epoxy matrix effectively. The experimental results indicate that with 0.4 wt % loading of modified MWCNTs, increases of 462.23% in the impact strength and 57.3 °C in the glass transition temperature Tg were achieved. A high-performance nanocomposite was prepared in only a few minutes using the PIFP approach. Considering its fast, energy-saving, and environmentally friendly production, the PIFP approach displays considerable potential in the field of the fast preparation, repair, and deep curing of nanocomposites and coatings.

Constructing MoS2/Lignin-derived carbon nanocomposites for highly efficient removal of Cr(VI) from aqueous environment

Effective removal of Cr(VI) pollution from aquatic environment is in pressing need because of the detrimental effect of Cr(VI) to human health. Herein, we report a facile two-step approach to synthesis MoS2/Lignin-derived Carbon (MoS2@LDC) nanocomposites for highly efficient elimination of Cr(VI) from aqueous solutions. The MoS2@LDC exhibited outstanding removal efficient for Cr(VI) (198.70 mg/g at pH = 2.0, T = 298.15 K and CInitial = 20.0 mg/L). 99.35% of Cr(VI) can be removed by the composites in 30 min. Thermodynamic and kinetic studies suggest the removal of Cr(VI) is through both adsorption and reduction. The performance of MoS2@LDC can be further enhanced by hydrogen plasma treatments, which was attributed to the sulfur vacancies induced improvement in the reduction activity of MoS2 layer. The results of this work can guide the rational design of high-performance nanocomposite for efficient remediation of heavy metals in aquatic environment.

Excellent, Lightweight and Flexible Electromagnetic Interference Shielding Nanocomposites Based on Polypropylene with MnFe2O4 Spinel Ferrite Nanoparticles and Reduced Graphene Oxide.

In this work, various tunable sized spinel ferrite MnFe2O4 nanoparticles (namely MF20, MF40, MF60 and MF80) with reduced graphene oxide (RGO) were embedded in a polypropylene (PP) matrix. The particle size and structural feature of magnetic filler MnFe2O4 nanoparticles were controlled by sonochemical synthesis time 20 min, 40 min, 60 min and 80 min. As a result, the electromagnetic interference shielding characteristics of developed nanocomposites MF20-RGO-PP, MF40-RGO-PP, MF60-RGO-PP and MF80-RGO-PP were also controlled by tuning of magnetic/dielectric loss. The maximum value of total shielding effectiveness (SET) was 71.3 dB for the MF80-RGO-PP nanocomposite sample with a thickness of 0.5 mm in the frequency range (8.2–12.4 GHz). This lightweight, flexible and thin nanocomposite sheet based on the appropriate size of MnFe2O4 nanoparticles with reduced graphene oxide demonstrates a high-performance advanced nanocomposite for cutting-edge electromagnetic interference shielding application.

Photocatalytic degradation of patulin in apple juice based on nitrogen-doped chitosan-TiO2 nanocomposite prepared by a new approach

A high-performance nitrogen-doped chitosan-TiO2 nanocomposite to be used as a photocatalyst for patulin degradation in apple juice was successfully prepared by a simple precipitation method. The structure and properties were characterized by scanning electron microscopy (SEM), transmission electron microscope (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Brunauer-Emmett-Teller (BET), Fourier transform infrared spectroscopy (FT-IR), and UV–Vis diffuse reflectance spectrum. According to XPS and UV–Vis analyses, nitrogen had been successfully doped into the TiO2 nanoparticle crystals and reduced the band gap energy of TiO2 nanoparticles. The synthesized nanocomposite was able to photocatalytically degrade the patulin in apple juice under ultraviolet irradiation. The patulin (500 μg/kg) was completely degraded within 35 min, which exhibited significantly enhanced photocatalytic activities compared with TiO2 nanoparticles or chitosan-TiO2 nanocomposite. Moreover, the photocatalytic treatment significantly reduced the occurrence of juice browning, and had little effects on reducing sugar, pH, titratable acid and soluble solids of the apple juice. The nitrogen-doped chitosan-TiO2 nanocomposite would be an ideal photocatalyst for patulin degradation in apple juice due to its high photocatalytic activity and little effects on the quality of apple juice.

Electrical Conduction Behavior of High-Performance Microcellular Nanocomposites Made of Graphene Nanoplatelet-Filled Polysulfone.

Graphene nanoplatelet (GnP)-filled polysulfone (PSU) cellular nanocomposites, prepared by two different methods—namely, water vapor-induced phase separation (WVIPS) and supercritical CO2 dissolution (scCO2) foaming—were produced with a range of densities from 0.4 to 0.6 g/cm3 and characterized in terms of their structure and electrical conduction behavior. The GnP content was varied from 0 to 10 wt%. The electrical conductivity values were increased with the amount of GnP for the three different studied foam series. The highest values were found for the microcellular nanocomposites prepared by the WVIPS method, reaching as high as 8.17 × 10−2 S/m for 10 wt% GnP. The variation trend of the electrical conductivity for each series was analyzed by applying both the percolation and the tunneling models. Comparatively, the tunneling model showed a better fitting in the prediction of the electrical conductivity. The preparation technique of the cellular nanocomposite affected the resultant cellular structure of the nanocomposite and, as a result, the porosity or gas volume fraction (Vg). A higher porosity resulted in a higher electrical conductivity, with the lightest foams being prepared by the WVIPS method, showing electrical conductivities two orders of magnitude higher than the equivalent foams prepared by the scCO2 dissolution technique.

High-performance fluoroelastomer-graphene nanocomposites for advanced sealing applications

High-performance sealing materials that can guard key components against high pressure gases and liquid chemicals while withstanding mechanical deformation are of utmost importance in a number of industries. In this present work, graphene nanoplatelets (GNPs) were introduced into a fluoroelastomer (FKM) matrix to improve its mechanical and barrier properties and test its suitability for sealing applications. Nanocomposites filled with different loadings of GNPs were prepared and compared with their counterparts loaded with carbon black (CB). GNPs were dispersed homogeneously with a high degree of in-plane alignment. The tensile and barrier properties of the FKM were improved significantly by the addition of GNPs. Micromechanical modelling based on the shear-lag/rule-of-mixtures theory was used to analyse the reinforcing efficiency of the GNPs. Upon the addition of the GNPs, the elastomer was able to swell anisotropically in liquids, a fact that can be used to tune the swelling properties for sealing applications. In terms of gas permeability, a modification of the well-established Nielsen's theory was introduced to analyse the CO2 permeability for the bulk composite samples. The significantly improved mechanical, thermal and barrier properties at relatively low filler loadings, reveal that the FKM/GNP nanocomposites produced are very promising for use in advanced sealing applications.

High-Performance Nanosilver Thin Film Nanocomposite Membranes Prepared on Carbon Nanotube-Based Supports

Biofouling in membranes is a serious concern as it leads to a severe reduction in membrane performance by increasing the membranes’ resistance to permeate flow. This work describes a facile method for the production of high performance nanosilver polyamide thin-film nanocomposite (TFN) membranes on carbon nanotube-based supports for biofouling control. The TFN membranes were prepared by the interfacial polymerization of a thin polyamide layer over a polyethersulfone (PES) support layer. Nanosilver (nAg) particles were generated in-situ on the surface of the polyamide layer using a reduction reaction between a silver salt and sodium borohydride. The support layer of the TFN membrane contained nitrogen doped multi-walled carbon nanotubes (N-MWCNTs) at various dosages. The SEM/EDS microscopic analyses revealed that nAg particles were present on the polyamide layer and that they were evenly distributed throughout the TFN membrane. Furthermore, the TFN membrane showed an improved water permeability (from 16.74 L/m2.h to 22.86 L/m2.h at 150 Psi) without sever compromise in NaCl rejection (from 98.37% to 99.40%) compared to the bare TFC membrane. This was attributable to the combined hydrophilic effects imparted by the presence of nAg on the TFN polyamide layer and the oxidised CNTs in the support layer. Antibacterial tests conducted using Escherichia coli bacteria demonstrated that the TFN containing nAg particles membranes exude better antibacterial activity compared to the pristine TFC membrane as evidenced by a clear zone of inhibition, in the area surrounding the TFN membrane and the absence of bacterial colonies. The present study demonstrated that the presence of low dosages of CNTs in the support layer is essential in the improvement of mechanical strength and performance properties of the support layer, while nAg plays a crucial role in the enhancement of TFN membrane performance.