Advanced Nanocomposite Research Articles

Vibration and nonlinear dynamic response of imperfect sandwich piezoelectric auxetic plate

In this article, the vibration and nonlinear dynamic response of imperfect advanced sandwich nanocomposite plate subjected to uniformly distributed pressure has been studied using fourth-order Runge–Kutta and Galerkin methods. The composites are assumed to be made of a gold layer, an auxetic layer, and a piezoelectric layer. Detailed parametric studies to evaluate the effects of the geometrical dimensions, the thickness of layers, imperfections and mechanical loads on the nonlinear dynamic response and natural frequency of advanced multilayer nanocomposite plates are discussed. The accuracy of the present results is validated by comparing with others from literature.

A gelatin-treated carbon nanofiber/epoxy nanocomposite with significantly improved multifunctional properties

Good dispersion of carbon nanofillers in a polymer is the prerequisite for the fabrication of advanced multifunctional polymeric nanocomposite. Herein, we report that gelatin, a cost-effective animal protein, is used as a highly efficient bio-surfactant to functionalize carbon nanofibers (CNFs), resulting in nanocomposite with impressively improved mechanical, electrical and processing properties. Excellent dispersion of CNFs in the epoxy resin and good interfacial adhesion between them are realized via gelatin modification, which can be validated from static suspension observation, quantitative macrodispersion analysis and SEM characterization. The electrical percolation threshold of the gelatin-CNFs/epoxy decreases notably from 0.33 wt% to 0.21 wt%. The flexural strength and modulus increase tremendously by 29.1 % and 27.1 % with 0.25 wt% nanofiller addition, which is further proved by nanoindentation test. The wettability of nanocomposite with gelatin treated CNFs is also improved with decreased contact angle. These promising results demonstrate a great potential of the proposed method to be applied in the fabrication of multifunctional polymeric matrix for fiber reinforced plastic composites.

Electropolymerization of chitosan in the presence of CuNPs on the surface of a copper electrode: an advanced nanocomposite for the determination of mefenamic acid and indomethacin in human plasma samples and prevention of drug poisoning

An innovative method was introduced for the electro-polymerization of chitosan on the surface of a copper electrode.

Hierarchical N‐Doped HMCN/CNT Hybrid Carbon Frameworks Assembling Cobalt Selenide Nanoparticles for Advanced Properties of Lithium/Sodium Storage

AbstractA hybrid nanostructure with Co0.85Se nanoparticles anchored in nitrogen‐doped hollow mesoporous carbon nanospheres/carbon nanotubes (Co0.85Se/N‐HMCNs/CNTs) is elaborately fabricated by a pyrolysis–reduction–selenization strategy derived from yolk–shell zeolitic imidazolate framework‐67 (ZIF‐67)@HMCNs, which are synthesized by the confined growth of ZIF‐67 inside HMCNs regarded as nanoreactors. Benefitting from the robust hollow carbon frameworks made of nitrogen‐doped hollow mesoporous carbon nanospheres, carbon nanotubes, and highly active Co0.85Se ultrafine nanoparticles, the as‐prepared nanocomposites show greatly enhanced lithium/sodium storage properties. When the Co0.85Se/N‐HMCNs/CNTs are applied to lithium‐ion batteries as anode materials, the advanced nanocomposite delivers excellent cycling stability (286 and 153 mA h g−1at 10 A g−1after 5000 and 10 000 cycles) and high rate performance (501 mA h g−1at 5 A g−1). When the Co0.85Se/N‐HMCNs/CNTs are applied to sodium‐ion batteries as anode materials, the material realizes better cycling performance (102 mA h g−1at 1 A g−1after 1000 cycles) and excellent rate performance (132 mA h g−1at 5 A g−1).

High-performance thin film nanocomposite membranes enabled by nanomaterials with different dimensions for nanofiltration

The incorporation of nanomaterials into a polyamide (PA) matrix has been demonstrated to be effective in the design of advanced thin film nanocomposite (TFN) membranes. In this study, a novel TFN membrane was developed by simultaneous introduction of two nanofillers with different dimensions. Graphitic carbon nitride (g-C3N4) and halloysite nanotubes (HNTs) were co-deposited onto a substrate surface with piperazine (PIP) monomers via vacuum filtration, followed by interfacial polymerization (IP) with trimesoyl chloride (TMC). A series of characterizations showed that the pre-loaded g-C3N4 was present as nanoaggregates wrapped by the formed PA film, while one-dimensional HNTs inclined to be horizontally aligned as a hydrophilic interlayer. This unique architecture led to a crumpled membrane surface with convex and ridged structures, and provided additional water transport channels. The surface roughness and hydrophilicity of the TFN membranes were also enhanced with the addition of nanomaterials. Although g-C3N4 and HNTs were able to elevate the water permeance, a superior separation performance could only be achieved by simultaneously incorporating these two nanofillers. The best performing TFN membrane containing 16.4 μg cm−2 g-C3N4 and 19.7 μg cm−2 HNTs exhibited a water permeance of 20.5 L m−2 h−1 bar−1, nearly twice as high as that of the thin film composite (TFC) membrane, while maintaining a comparably high Na2SO4 rejection of 94.5%. This demonstrated the effectiveness of g-C3N4 and HNTs in developing high-performance TFN membranes, which were ascribed to their respective advantages as well as the combined effect in the regulation of the PA layer microstructure.

Diamond nanothread reinforced polymer composites: Ultra-high glass transition temperature and low density

Diamond nanothread (DNT), a novel carbon-based nanomaterial exhibiting ultra-light density and outstanding mechanical properties, has attracted intensive attentions in polymer composites. This study investigates the influences of DNT on the glass transition temperature (Tg) of poly (methyl methacrylate) (PMMA) composites and reveals the glass-rubber transition mechanism through molecular dynamics simulation. We demonstrates that DNT exhibits better improvement than other carbon-based nanomaterials in enhancing the Tg of PMMA composite, suggesting that DNT is a promising reinforcement for polymer nanocomposite with higher service temperature and better mechanical performances. Significantly, we find that interfacial interactions including van der Waals interaction and mechanical interlocking play an important part in glass transition of PMMA composite. The transition from glassy state to rubbery is induced through the interfacial debonding brought by the enlargement of free volume at the interface. According to the interfacial degrading mechanism, cross links between DNT reinforcement and PMMA chains are introduced to provide bidirectional hindrance for free motions of polymer chains, resulting in a 70 K enhancement of Tg of PMMA composites. These findings not only shed light to the prospective application of DNT in advanced nanocomposite, but also provide important guidance to improve the reinforcing efficiency of nanomaterials in engineering application, such as building and aerospace industry.

Chemical grafting of nano-SiO2 onto graphene oxide via thiol-ene click chemistry and its effect on the interfacial and mechanical properties of GO/epoxy composites

A facile and rapid come close to the manufacture of advanced epoxy nanocomposites by grafting of nano-silicon dioxide (nano-SiO2) onto the graphene oxide (GO) through thiol-ene click reaction was reported. The correlations between surface modification, morphology, dispersion/exfoliation, interfacial interaction of sheets and the corresponding mechanical properties of the composites were methodically explored. It appeared that nano-SiO2 have been grafted onto GO via covalent bonding successfully, which effectively improved the interface compatibility and dispersion in epoxy matrix. The reinforcing mechanisms has been also elaborated. It is demonstrated that the tensile strength and elastic modulus for filler with 0.1 wt% GO-SiO2/epoxy composites increased by 32.18% and 22.86% compared to neat epoxy, respectively. It is believed that the simplistic and effectual method may provide a novel and promising strengthen design strategy for next‐generation advanced nanocomposite structures.

Nanocomposite of Nitrogen‐Doped Graphene/Polyaniline for Enhanced Ammonia Gas Detection

AbstractGraphene nanosheets are widely used for designing functional nanocomposite sensors that are highly sensitive. In this study, nitrogen‐doped reduced graphene oxide (N‐rGO) polyaniline (PANI) nanocomposites composed of localized heterojunctions are prepared for the detection of ammonia, dimethylamine, and trimethylamine gases with superior sensing performances. rGO nanosheets with electrical properties modified via N‐doping are strategically incorporated in p‐type PANI via in situ synthesis, with the nanosheets acting as templates for PANI growth. N‐rGO nanosheets featuring large specific area, high electrical conductivity, and n‐type semiconductive behavior combined with the attractive electrical p‐type characteristics of PANI are found to be highly beneficial for improving detection sensitivity toward ammonia, dimethylamine, and trimethylamine gases at 25 °C. Overall, the detection sensitivity of the advanced N‐rGO nanocomposites is more than two times higher than that of PANI alone. Moreover, the N‐rGO/PANI nanocomposites reach an estimated limit of detection for ammonia gas down to the sub‐ppm range. Improvement in sensing performance is also observed for rGO/PANI and GO/PANI nanocomposites; however, the level of the improvement is less than that of N‐rGO/PANI nanocomposites. This study demonstrates the excellent potential of designing advanced graphene nanocomposite gas sensors with superior performances by manipulating the electronic properties of the graphene nanosheets.

Design and Preparation of a New and Novel Nanocomposite with CNTs and Its Sensor Applications

Inorganic–organic nanocomposite poly(o-toluidine) Ce(III)tungstate@CNT was prepared by sol–gel intercalation insertion method, later on it was mixed with CNTs that leads to the formation of CNT intercalated inorganic–organic hybrid nanocomposite. The polymerization of monomer was achieved by ammonium persulphate (APS) chemical oxidation, inside the inorganic matrices that leads insertion of polymer. Characterization of POTCe(III)T@CNT nanocomposite by various physicochemical studies as FT-IR, X-ray, UV–vis spectrophotometry, TEM, SEM/EDX, TGA and four probe conductivity measuring technique was done. On the basis of physicochemical properties as cation-exchange capacity as well as electrical conductivity, the advanced nanocomposite was utilized for the sensor application for environmental remediation. It was used for the preparation of POTCe(III)T@CNT ion selective membrane electrode.

Fabrication of a versatile lignin-based nano-trap for heavy metal ion capture and bacterial inhibition

Diverse functional nanomaterial with minimal environmental impact and reduced production cost is currently great needed because of the growing environmental awareness and shortage of petroleum resources. Herein we reported the creation of a lignin-based nano-trap (LBNT) through functionalizing one of the most abundant biomass on Earth, lignin, with both soft and borderline bases facilitating the coordination of different types of heavy metal ions. The resultant LBNT exhibited remarkable removal efficiencies of >99% toward both soft (Ag(I), Hg(II), Cd(II)) and borderline (Pb(II), Cu(II), Zn(II)) ions, of which the residual concentrations were diminished from 5 mg/L to 3–9 μg/L that were below the permission values of drinking water regulated by the World Health Organization (WHO). Moreover, the produced nanomaterial could be adopted to load metal ions in atomic-level dispersion for preparing advanced nanocomposite. This was evidenced by the high bactericide rate of the silver-loaded nanocomposite (Ag@LBNT) as an antimicrobial toward Escherichia coli (99.68%) and Staphylococcus aureus (99.76%). This work may pave a way for the production of cost-effective and biomass-based nanomaterial that could be applied in the field of separation and antimicrobial.

Fabrication of floating CdS/EP photocatalyst by facile liquid phase deposition for highly efficient degradation of Rhodamine B (RhB) under visible light irradiation

The cadmium sulfide (CdS) faces photochemical corrosion, and hence, the photocatalytic efficacy decreases with the light-irradiation time. The deposition of suitable content of CdS on the expanded perlite (EP) may prevent the photochemical corrosion and aggregation of CdS nanoparticles. Hence, a series of solid nanocomposites containing CdS nanoparticles on the EP support with different CdS contents were synthesized. CdS/EP buoyant nanocomposites have been successfully prepared by deposition of CdS on the EP using a simple one-step facile liquid phase deposition route at ambient temperature. The as-prepared nanocomposites were characterized by scanning electron microscope (SEM), transmission and high-resolution transmission electron microscopy (TEM, HRTEM), UV–vis spectroscopy, X-ray diffraction, and FT-IR spectroscopy. The XRD and HRTEM results indicated the formation of CdS nanoparticles with the hexagonal cubic phase in the EP. The SEM, TEM and HRTEM results clearly show that CdS nanoparticles have homogenously embedded in the mesopores of EP supports. The photocatalytic activities of CdS/EP nanocomposites with varying CdS contents were examined for the degradation of Rhodamine B (RhB) dye under visible light irradiation. Hence, these results reveal that enhanced catalytic activity arises in novel CdS/EP nanocomposites and significantly, its photocatalytic activity is about two times higher than that of bare CdS. This advanced nanocomposite is expected to provide a new appreciation into the design of floating photocatalysts with excellent recyclability, high efficiency, and good stability.

Development and Physico-Chemical Characterization of Conducting Polymeric Zirconium Based Advanced Nanocomposite Ion-Exchangers for Environmental Remediation

Polyaniline-Zr(IV) tungstovanadate and Polyaniline-Zirconium oxide nanocomposite ion -exchangers were synthesized and physico-chemical characterization done by FT-IR-UV spectral studies, XRD, SEM and TGA. These composites are having high mechanical strength, good electrical conductivity and stability than their individual components. The organic polymeric component of the composites provides mechanical as well as chemical stability whereas the inorganic component supports the ion-exchange behavior and thermal stability. Both the inorganic and organic parts are jointly responsible for their improved electrical conductivity. They have more promising ion exchange capacity towards alkali metal halides and have selective adsorption towards Pb(II) ion and these can be used as powerful candidates for water softening

2D nanocomposite of hexagonal boron nitride nanoflakes and molybdenum disulfide quantum dots applied as the functional layer of all-printed flexible memory device

In this study, we have proposed a flexible, rewritable and nonvolatile memory device based on an advanced 2D nanocomposite of hexagonal boron nitride (hBN) flakes and molybdenum disulfide quantum dots (MoS2 QDs). Complete device fabrication was carried out by using extremely simple and highly controllable all printed technology. The electrical characteristics exhibited by the as developed memory devices included the switching ratio, electrical endurance and retention time of ∼103, 103 and 104 respectively. The device turned ON and OFF at the SET and RESET threshold voltages of +1.4 V and −1 V respectively. The obtained results of electrical and thermal characterizations exhibited that the switching ratio decreases via either increasing temperature (300 K–380 K) or device size (42 μm–100 μm) hence verifying the formation of conductive filament through the functional layer. Moreover, no major degradation in the switching characteristics was observed even after 1500 bending cycles.

Resistive switching effect in the planar structure of all-printed, flexible and rewritable memory device based on advanced 2D nanocomposite of graphene quantum dots and white graphene flakes

Pursuit of the most appropriate materials and fabrication methods is essential for developing a reliable, rewritable and flexible memory device. In this study, we have proposed an advanced 2D nanocomposite of white graphene (hBN) flakes embedded with graphene quantum dots (GQDs) as the functional layer of a flexible memory device owing to their unique electrical, chemical and mechanical properties. Unlike the typical sandwich type structure of a memory device, we developed a cost effective planar structure, to simplify device fabrication and prevent sneak current. The entire device fabrication was carried out using printing technology followed by encapsulation in an atomically thin layer of aluminum oxide (Al2O3) for protection against environmental humidity. The proposed memory device exhibited attractive bipolar switching characteristics of high switching ratio, large electrical endurance and enhanced lifetime, without any crosstalk between adjacent memory cells. The as-fabricated device showed excellent durability for several bending cycles at various bending diameters without any degradation in bistable resistive states. The memory mechanism was deduced to be conductive filamentary; this was validated by illustrating the temperature dependence of bistable resistive states. Our obtained results pave the way for the execution of promising 2D material based next generation flexible and non-volatile memory (NVM) applications.

Graphene Quantum Dots Functionalized by Chitosan and β-Cyclodextrin: An Advanced Nanocomposite for Sensing of Multi-Analytes at Physiological pH

This article describes a new alternative approach to the fabrication of electrochemical sensors based on the graphene quantum dots (GQDs) functionalized with chitosan and β-cyclodextrin. The graphene quantum dots functionalized with chitosan and β-cyclodextrin are shown to exhibit electrochemical performance that rivals that of GQDs modified glassy carbon electrode and display excellent properties against severe electrochemically sensors. The graphene quantum dots functionalized with chitosan and β-cyclodextrin electrodes is further extended to the demonstration of novel electrochemical sensors through the transfer of the electrode fabricated by GQDs. For comparison of the recognition efficiency, other electrodes including bare glassy carbone electrode (GCE), and GQDs modified glassy carbone electrode (GQDs-GCE) were used for the control experiments. The resulting sensors demonstrate a wide range of usability, from the detection of various physiological analytes, including uric acid, ascorbic acid, dopamine to the identification of some amino acids. Comparison of recorded cyclic voltamograms in the presence of L-cysteine, dopamine, uric acid, L-Tyrosine, L-Phenylalanine, and ascorbic acid using GQD-CS-GCE, -CD-GQDs-GCE shows ΔEp was decreased as β-CD-GQDs-GCE > CS-GQD-GCE > GQDs-GCE. The larger lowering of the overvoltage observed in the presence of β-CD-GQDs-GCE clearly indicates the essential role of β-CD in the observed electrocatalytical behaviour. In general, the attachment of chitosan and β-cyclodextrin to structure of GQDs provides new opportunities within the personal healthcare, fitness, forensics, homeland security, and environmental monitoring domains.

Selective laser melting of advanced Al-Al2O3 nanocomposites: Simulation, microstructure and mechanical properties

Aluminium-based metal matrix composites are widely used in the aerospace and automotive industries, but their manufacturability and mechanical properties are not well understood when these new materials are employed in additive manufacturing. This is an important consideration because, compared with traditional manufacturing technologies, additive manufacturing technologies such as selective laser melting (SLM) offer the ability to manufacture engineering parts with very complex geometries. This paper systematically studied the SLM of an advanced Al-Al2O3 nanocomposite that was synthesised using high-energy ball-milling. A finite element model was developed in the study to predict the thermal behaviour of the composite in order to narrow down the process parameters to be explored in the experiments; in particular, the SLM hatch spacing and scanning speed were found to be worth further experimental investigation for the composites. The experimental results demonstrated that the optimum laser-energy density and scanning speed in fabricating nearly fully dense composite parts were 317.5J/mm3 and 300mm/s, respectively. Furthermore, the as-fabricated composite parts were observed to exhibit a very fine granular-dendrite microstructure due to the rapid cooling, while the thermal gradient at the molten pool region along the building direction was found to facilitate the formation of columnar grains. Compared to pure Al, the addition of 4vol% Al2O3 nanoparticulates was found to contribute to a 36.3% and 17.5% increase in the yield strength and microhardness of the composite samples, respectively, because the reinforcement particulates improved the dislocation density by offering more grain boundaries. The paper also examines the influence of cold working on microstructural and mechanical properties. In comparison with the as-fabricated composite sample, the cold-worked composite sample was found to offer a 39% increase in microhardness; this is thought to have been caused by plastic deformation, which in turn resulted in grain deformation and elongation.

CVD nano-coating of carbon composites for space materials atomic oxygen shielding

Abstract: The present work analyzes the possibility to employ carbon nanostructures as a basic material to prevent the erosion effects of atomic oxygen suffered by the carbon fiber reinforced polymeric material used in low earth orbit space environment. The application of thin protecting coatings to base materials is a widely used method for preventing the atomic oxygen induced erosion, and thus degradation. The generic purpose is to integrate carbon nanostructures onto carbon composites surface in order to develop the basic substrate of advanced nanocomposite for atomic oxygen protection. The final goal is the characterization of carbon nanostructures-reinforced carbon composites by means of on-ground atomic oxygen simulation facility, with the future objective to assess and optimize the process of carbon-multiscale advanced composites production. With such an aim, a wide investigation on the methane chemical vapor deposition (CVD) over catalyzed carbon fiber-based substrates has been carried out. The as grown nanostructures have been analyzed in terms of morphology, as well as regarding the main features of the resulting growth (yield, purity, homogeneity, coating uniformity, etc.) and the influence of the deposition route operating parameters (catalyst typology, gas flowing rate, growth time/temperature, etc.). A high degree of reproducibility in terms of the relationship between the carbon deposit type/yield and the main process variables (catalyst and protocol) has been thus obtained. Finally, atomic oxygen ground tests have been conducted in order to evaluate the coating process effectiveness. The on-ground test in atomic oxygen environment, with respect to the performances of the reference carbon composites (in terms of total mass loss and atomic oxygen rate of erosion), showed a worsening for the disordered carbon deposit, while an intriguing improvement was achieved by the high-yield carbon nano-filaments deposition.

Understanding functionalized silica nanoparticles incorporation in thin film composite membranes: Interactions and desalination performance

Incorporation of functional nanoparticles in polymer membranes is a promising approach for the development of advanced thin film nanocomposite (TFN) membranes with improved desalination performance. This study was aimed to fabricate TFN membranes incorporated with functionalized silica nanoparticles (SNs), which were synthesized with different sizes (~50 and ~100nm) and surface functionalities (hydroxyl, epoxy and amine). Research focused on getting a better understanding of the interfacial interactions between SNs and polymer matrix and structure-property correlation of the TFN membranes. The physicochemical properties of the functionalized SNs and the TFN membranes were characterized using ATR-FTIR, TGA, DLS, SEM, TEM, XPS, tensiometer and streaming potential analysis. The results confirm successful incorporation of the surface functionalized SNs into the polymer membranes. The concentration, size and surface functionality of SNs were found to have strong impact on the surface hydrophilicity, morphology and chemistry of the TFN membranes. The SNs hybridized TFN members showed increased permeate flux and insignificant change in salt rejection. The surface functionalization of SNs with amine and epoxy moieties could facilitate the chemical interaction between SNs and polymer monomers, resulting in stabilizing the TFN membranes. Our research outcomes have provided new insight into the structure-performance correlation of TFN membranes and can be beneficial for fabrication of a wide range of nanoparticle incorporated membranes.

Advanced Nanocomposite Coatings of Fusion Bonded Epoxy Reinforced with Amino-Functionalized Nanoparticles for Applications in Underwater Oil Pipelines

The performance of fusion-bonded epoxy coatings can be improved through advanced composite coatings reinforced with nanomaterials. Hence, in this study a novel organic-inorganic nanocomposite finish was designed, synthesized, and characterized, achieved by adding γ-aminopropyltriethoxysilane modified silica nanoparticles produced via sol-gel process in epoxy-based powder. After the curing process of the coating reinforced with nanoparticles, the formation of a homogenous novel nanocomposite with the development of interfacial reactions between organic-inorganic and inorganic-inorganic components was observed. These hybrid nanostructures produced better integration between nanoparticles and epoxy matrix and improved mechanical properties that are expected to enhance the overall performance of the system against underwater corrosion.

Green synthesis of thermally stable Ag-rGO-CNT nano composite with high sensing activity

Advanced nano composite, containing Ag, was synthesized by coating on reduced graphene oxide (rGO)-carbon nanotube (CNT). Ag-rGO-CNT nanocomposite obtained by hydrothermal treatment of an aqueous dispersion of graphene oxide (GO) and CNTs. After the rGO-CNT composites have been dipped in silver salt solution, the spontaneous redox reaction between these two leads to the formation of nanohybrid materials consisting of rGO-CNT decorated with Ag NPs. Physicochemical characterization of Ag-rGO-CNT was carried out by scanning electron microscopy/energy-dispersive spectroscopy (SEM/EDS), fourier transform infrared spectroscopy (FT-IR) and TGA. Electrical resistivity measurements and thermal effect on resistivity of Ag-rGO-CNT was also studied after acid treatment. The dc conductivity was found within the range of 0.08–0.4 Ω cm for pure composite, measured by 4-in line–probe dc electrical conductivity measuring technique. Thermal conductivity is stable with all temperatures in isothermal studies showing excellent stability of Ag-rGO-CNT material. Graphene is attributed to its unique physical and chemical properties, e.g., subtle electronic characteristics, attractive π–π interaction, and strong adsorptive capability. This is used for in-vitro studies of dopamine on carbon fibre microelectrode that shows an excellent performance for dopamine with a detection limit of 0.033 μM and response time of 12s.