Reinforcement Of Nanocomposites Research Articles

A complex impedance spectroscopy study on PVDF/PANI/CoFe2O4 composites

Abstract The synthesis of polymer composites consisting of conducting polyaniline (PANI), cobalt ferrite (CoFe2O4), and poly(vinylidene fluoride) (PVDF) is achieved by the polymerization technique. A nanocomposite consisting of polyaniline (PANI) and CoFe2O4 is prepared using the interfacial chemical oxidation polymerization technique, resulting in a composition containing 50 wt.% of CoFe2O4. Nanoparticles of cobalt ferrite (CoFe2O4) were synthesized by using the sol–gel auto-combustion process. The PANI/CoFe2O4 (1:1) nanocomposites with weight percentages of 5, 10, 15, and 20 are incorporated into the PVDF matrix as fillers in order to alter the morphology and AC electrical conductivity of the PVDF/PANI/CoFe2O4 composite materials. The structural and morphological properties were studied using characterization techniques such as X-ray diffraction, Fourier transform infrared spectroscopy, and field emission scanning electron microscopy. At room temperature, impedance spectroscopy, dielectric measurements, and AC electrical conductivity were carried out in the frequency range of 40 Hz to 5 MHz. The dielectric permittivity has been shown to decline exponentially in low-frequency zones before remaining almost constant up to 5 MHz. When the frequency is increased up to 1 MHz, the AC conductivity of all composites remains constant; after that, it increases as the frequency increases. It was found that PANI-CoFe2O4 nanocomposites modified the overall charge transport mechanism by modulating the core grain and grain boundary. The experimental Nyquist plot for different composite samples was fitted by an appropriate RC electrical model to evaluate relaxation time. The relaxation time τ 1 (R 1 C 1) and τ 2 (R 2 C 2) were both reduced after the reinforcement of PANI-CoFe2O4 nanocomposites.

Biobased solvent-free fluids based on spherical cellulose nanocrystals for epoxy nanocomposite adhesive reinforcement

Biobased solvent-free fluids based on spherical cellulose nanocrystals for epoxy nanocomposite adhesive reinforcement

Enhanced mechanical and thermal properties of epoxy vinyl ester nanocomposites through hybridization with functionalized graphene oxide and nanoglass flakes

This study presents the preparation of epoxy vinyl ester nanocomposites based on hybrid nanofillers, namely functionalized graphene oxide and nanoglass flakes, for outstanding mechanical, thermal, and water resistance properties. Significantly, these hybrid nanocomposites exhibited considerable improvement in tensile strength and modulus, about 39 % and 52 % greater than neat resin, respectively. DSC analysis has shown that Tg increased from 108 °C for the neat resin to 130.9 °C for the FGO/FNGF hybrid nanocomposite, which confirmed an improvement in thermal stability. Water absorption tests have shown a remarkable reduction of moisture intake. Saturation moisture content decreased from 1.35 % for the neat resin to 0.53 % for the hybrid nanocomposite due to the tortuous pathways created by the hybrid fillers. The rheological studies confirmed that better filler dispersion and interfacial bonding are achieved, which is a 34 % increase in the storage modulus with respect to neat resin. SEM studies showed homogeneous distribution of fillers with good filler-matrix adhesion in the case of the hybrid system. The studies thus confirm FGO and FNGF synergies in reinforcement of epoxy vinyl ester nanocomposites for high-performance applications in hostile environments.

Quantitative Study on Reinforcing Mechanism of Nanofiller Network in Silicone Elastomer Based on Fluorescence Labeling Technology

Although there have been many theoretical studies on the enhancement effect of nanofiller networks and their interaction with elastomer molecular chains on the mechanical properties of elastomers, its mechanism description is still not completely clear. One of the main obstacles is the lack of quantitative characterization techniques and corresponding theoretical models for the three-dimensional morphology of complex nanofiller networks. In this paper, the precipitated silica-filled silicone rubber was studied by fluorescence labeling combined with laser scanning confocal microscopy, and the real three-dimensional images of dispersion and aggregation structure of filled rubber systems were obtained. The microstructure evolution of nano-particle aggregates caused by the increase in the filler volume fraction was quantitatively described, and the reinforcement mechanism of elastomers with a distribution of aggregates and filler networks composed of nanoparticles was studied. Furthermore, a nano-composite reinforcement model based on volume fraction, particle shape, interaction, and filler dispersion has been proposed.

Central Role of Filler–Polymer Interplay in Nonlinear Reinforcement of Elastomeric Nanocomposites

Central Role of Filler–Polymer Interplay in Nonlinear Reinforcement of Elastomeric Nanocomposites

Synchrotron scanning transmission x-ray spectro-microscopy (STXM) characterisation of β-SiC nanowhisker AZ91 magnesium alloy nanocomposites

β-SiC nanoparticles are one of the most common reinforcements in Mg-Al alloy matrix nanocomposites (MgMNCs). The interfacial interactions between β-SiC and the alloy matrix are complex due to the occurrence of new phases and the fine scale of the 3D architecture. This study aims to explore the feasibility of using synchrotron Scanning Transmission X-ray spectro-Microscopy (STXM) to investigate such interfacial interactions and acquire reference X-ray Absorption Spectroscopy (XAS) data for some common interphase crystals present within the composites, which are not readily available. Throughout this study, a reliable procedure for collecting STXM data on samples derived from MgMNCs was developed, and reference XAS spectra for α-Mg, β-Mg17Al12, T2-Al2MgC2, Mg2Si and MgO present in MgMNCs were collected. The accessibility of STXM and spatially resolved XAS spectrum is not only useful for nanocomposite alloy research but applicable widely across the magnesium alloy research community when identifying and quantifying the phases with complex crystal structures and oxide states.

Preparation and properties of multiphase composite enhanced functional organosilicon nano-coatings

BackgroundTo improve the inherent stability and environmental compatibility of traditional organosilicon coatings, nano-reinforced composite materials were innovatively designed and synthesized to improve the performance of organosilicon coatings. MethodologyThe silicon dioxide (SiO2) clusters on the surface of graphene oxide (GO) incorporated with calcium carbonate (CaCO3) and dicyclohexylamine nitrite (Dn) nanocomposites (GO@SiO2/CaCO3/Dn) were prepared successfully. Then nanocomposites were integrated into the coating matrix to comprehensively assess their effects on morphology, mechanics, corrosion resistance, and anti-fouling properties. Significant findingsScanning Electron Microscopy (SEM) observations revealed that 4.0 wt.% of the nanocomposite reinforcement led to stratification within the organosilicon coating. The mechanical properties test shows that the hardness, bonding strength, and maximum impact resistance of SiNC2.0 coating is 10.3 HV, 2.8 MPa, and 75 kg·cm, respectively. Electrochemical assessments confirmed that SiNC2.0 displayed superior corrosion resistance, with a corrosion potential (Ecorr) of 0.199 V and a corrosion current density (Icorr) of 7.308 × 10–6 A/cm2. Furthermore, the surface free energy of the nano-coatings is calculated in the range of 20–30 mN/m by contact angle measurement, indicating the anti-fouling and self-cleaning of the organosilicon nano-coatings. Long-term immersion in natural lake water further confirms the stability and durability of the SiNC2.0 coating in real environments.

Investigation of thermal conductivity and mechanical properties in multi-layer of graphene and graphene oxide: a molecular dynamics study

ABSTRACT Multi-layered graphene and graphene oxide have been used as reinforcements in nanodevices and nanocomposites due to their extraordinary mechanical and thermal properties. However, compared to graphene, graphene oxide has a lower Young’s modulus and lower thermal conductivity. Nanodevices and nanocomposites based on multi-layered graphene and graphene oxide require different mechanical properties and thermal conductivity. This study employed molecular dynamics simulation to investigate 10 models of multi-layered graphene and graphene oxide (in the form of different layer arrangements) in single, double, and triple layers. The results showed that an increase in the number of graphene oxide layers leads to irregularities in the nanosheets, resulting in decreased thermal conductivity (by 64.4%) of the nanosheets decreases. Furthermore, the greater number of graphene layers in multi-layer nanosheets resulted in an increase in Young’s modulus (by 79.3%) and tensile strength (by 73.7%). Moreover, the arrangement of graphene and graphene oxide is a crucial factor that can significantly impact the mechanical properties and thermal conductivity of the models. Moreover, an increase in temperature can lead to a decrease in Young’s modulus of multilayered nanosheets. Increasing the number and size of graphene layers enhances both the ultimate tensile strength and the critical energy release rate.

Enhancement in mechanical properties of GFRP‐coal‐derived graphene oxide composites by addition of multiwalled carbon nanotubes and halloysite nanotubes: A comparative study

AbstractIn this study, we compare synergistic performance of two different nanofillers, namely halloysite nanotubes (HNT) clay and multiwalled carbon nanotubes (MWCNT), in conjunction with a fixed concentration (0.125 phr) of semi‐anthracite coal‐derived graphene oxide (AC‐GO) on mechanical properties improvement of EGFPs (E‐glass fiber‐based epoxy resin composites). The dispersion of AC‐GO with HNT clay (GO‐H) and AC‐GO with MWCNT (GO‐C) within epoxy matrix was achieved using sonication and homogenization. Further mixture was incorporated into mats of E‐glass fiber employing “vacuum‐assisted resin infusion molding” (VARIM). Significant enhancements (18.3% flexural strength, 14.6% tensile strength, and a slight increase of impact strength (1.8%)) were observed in EGFPs reinforced with GO‐H at 0.50 phr loading of HNT, with an AC‐GO concentration maintained at 0.125 phr. Correspondingly, optimal values for GO‐C reinforced EGFPs at 0.25 phr were 40.3%, 18.7%, and a 10.5% decrease in impact strength, respectively. Analytical techniques such as XRD, FESEM, EDX mapping, and FTIR reveal presence of relatively abundant functionalities and strong interfacial adhesion in GO‐H as well as GO‐C. The cost of HNT clay is approximately 15 times cheaper than industrial‐grade MWCNTs, therefore, these results underscore potential of GO‐H as a very economical nano‐reinforcement alternative to GO‐C for polymer nanocomposites.Highlights 0.50 phr HAGRP improves 18.3% flexural, 14.6% tensile, 1.8% impact strengths. Beyond 0.50 phr HAGRP and 0.25 phr CAGRP, mechanical properties decreased. 0.25 phr CAGRP improves 40.3% flexural, and18.7% tensile strengths. FESEM, FTIR reveal strong interfacial adhesion between nanofillers and epoxy. GO‐H has proven to be an inexpensive reinforcement for polymer nanocomposites.

Role of Al2O3 reinforcements in polymer-based nanocomposites for enhanced nanomechanical properties: Time-dependent modeling of creep and stress relaxation

Alumina (Al2O3) based nanocomposites mark a paradigm shift in materials science, offering unprecedented opportunities for multifunctional applications. This study meticulously examines the mechanical properties of polymer nanocomposites (PNCs), with a specific focus on the impact of varying sizes and concentrations of Al2O3 nanoparticles. By investigating these parameters, the research enables the tailoring of mechanical properties to meet specific requirements. The study reveals remarkable enhancements in the reduced modulus (Er), reaching up to 350%, 175%, and 100% under load and displacement control modes for 25 nm, 80 nm, and 200 nm average particle sizes, respectively. Beyond mechanical strength, the research delves into the nanocomposites resistance to long-term deformation (creep) and their ability to maintain consistent performance under load (stress relaxation). Additionally, the tribological performance lays the groundwork for the development of high-performance materials. The insights gained from this study represent more than an incremental improvement; they signify a transformative leap forward in addressing the multifaceted challenges of advanced material technology, with the potential to revolutionize various industries.

Thermal buckling of the concrete structures reinforced by nanocomposites: Introducing advanced deep neural networks for thermal buckling problem

The thermal buckling behavior of concrete annular sector plates reinforced with nanocomposites is investigated in this work. The thermal buckling issue is stated using mathematical modeling, taking into account the geometric linearity and material heterogeneity caused by the nanocomposite reinforcement. The governing differential equations that are obtained from the theoretical model are solved using the discrete singular convolution (DSC) technique. To generate accurate buckling load predictions, the DSC method’s great accuracy in handling complicated boundary conditions and discontinuities is used. Furthermore, using mathematical modeling to create extensive datasets, the research aims to train deep neural networks (DNNs) to anticipate thermal buckling reactions. These datasets provide a strong basis for DNN training as they include a wide range of factors, such as geometric configurations, loading situations, and material properties. By combining DNN predictions with DSC solutions, this unique technique for solving this difficult issue seeks to improve the accuracy and efficiency of thermal buckling analysis. The findings show how well sophisticated mathematical methods and machine learning models work together, opening the door to creative solutions for the design and analysis of concrete structures reinforced with nanocomposite under complicated stress.

Introducing innovative deep neural networks to predict natural frequency of the nanocomposites reinforced concrete structures under external loading

The dynamic response of concrete structures reinforced with nanocomposites to supersonic airflow represents a critical aspect in aerospace and defense applications, necessitating accurate predictive models for enhanced structural integrity and performance. In this study, we introduce innovative deep neural networks (DNNs) as a novel approach to predict the dynamic behavior of such structures under supersonic airflow conditions. Traditional modeling techniques often face challenges in capturing the intricate interactions between material properties, structural geometry, and airflow dynamics, particularly in the presence of nanocomposite reinforcements. DNNs offer a promising solution by leveraging their ability to learn complex patterns and nonlinear relationships from extensive datasets. This paper presents a comprehensive framework for developing and deploying DNN-based models for dynamic prediction, encompassing network architecture design, training strategies, and data preprocessing techniques tailored to the unique characteristics of nanocomposite-reinforced concrete structures. Through a series of case studies and comparative analyses, we demonstrate the effectiveness and accuracy of DNNs in capturing the dynamic response of such structures to supersonic airflow, including phenomena such as vibration, flutter, and aerodynamic instability. Furthermore, we discuss the potential advantages and challenges associated with the adoption of DNNs in aerospace and defense applications, including model interpretability, computational efficiency, and data requirements. Finally, we outline future research directions and opportunities for further advancing the application of DNNs in addressing dynamic challenges in aerospace engineering and beyond.

Polyimide nanocomposites for high‐temperature capacitive energy storage applications by incorporating functional graphene oxide nanosheets: Design, preparation, and mechanism

AbstractHerein, graphene oxide (GO) and its derivative, reduced GO (rGO) and p‐phenylenediamine (PPD) functionalized GO (GO‐g‐PPD) were first synthesized and selected as dielectric fillers, and then GO/polyimide (PI), rGO/PI, and GO‐g‐PPD/PI dielectric nanocomposites were fabricated through in situ polymerization‐composition strategy. Fourier transform infrared, Ram, and x‐ray diffraction analysis confirmed the success synthesis of rGO and GO‐g‐PPD dielectric fillers. The mechanical properties showed that GO‐g‐PPD/PI nanocomposites exhibited the highest tensile strength and elasticity modulus. TGA analysis revealed that the enhancement of thermal stability by addition of dielectric fillers. The dielectric constant of 2.5 wt.% GO‐g‐PPD/PI nanocomposites reached 25.05, which was 8.55 times that of pure PI (2.93). Energy storage performance tests showed that the energy storage density of GO‐g‐PPD/PI containing 2 wt.% filler reached 0.77 J/cm3, which was 71% higher than pure PI. These findings underscore the potential of GO derivative as a cost‐effective reinforcement for PI dielectric nanocomposites for high‐temperature capacitive energy storage applications.

Comparative study of tensile behavior in micro/nanofiber-enhanced epoxy nanocomposites featuring different textile structures

Recent advancements in nanofiber production technology have opened up exciting possibilities for highly sophisticated applications in nanofiber-based structures, particularly in the realm of nanofiber yarns. These yarns serve as fundamental components in various fabric designs, encompassing woven, knitted, braided, and nonwoven patterns. Additionally, these fabrics can serve as reinforcement in nanocomposites with a polymeric matrix. This study aims to investigate the reinforcing effect of micro/nanofibers in various fabric structures, such as nonwoven, woven, and knitted fabrics. Apart from depositing micro/nanofibers, we successfully manufactured a micro/nanofiber yarn made of polyamide-6. This was achieved by employing two nozzles equipped with opposite charges and flat-tipped needles. Furthermore, we created both woven and weft-knitted fabrics using this micro/nanofiber yarn. Subsequently, we utilized nonwoven, woven, and weft-knitted fabrics to reinforce epoxy resin. The results indicated that the nanocomposite reinforced with woven fabric in the warp direction, featuring a volume fraction of 12%, exhibited the highest Young’s modulus (7500 MPa, 5.47 times more compared to epoxy) and ultimate strength (112 MPa, 5.09 times more compared to epoxy). This study represents a pioneering step towards the development of nanofiber-based reinforcements with promising potential applications.

Fabrication of electrospun ultrafine fibreous membrane and their application in paraben adsorption

Electrospinning provides a simple and versatile method for generating ultrafine fibers from a rich variety of materials that include polymers, composites, and ceramics. Find applications in various fields, including tissue engineering, filter media, reinforcement in nanocomposites, and micro/nano-electro-mechanical systems. In this study the polystyrene fibers in 10%, 20% and 30% (w/v) in THF: DMF solvents were characterized by ATR-FTIR, AFM and SEM. The obtained fibers exhibited a smooth surface with fine structures, emphasizing a ribbon-like morphology with bead-like features within the range of 3 µm to 5 µm in diameter. The aim of this study was to extract the parabens at optimized conditions such as pH, adsorbent dose, contact time and the elution of solvent. To examine the mechanism of adsorption kinetics, the two most commonly used kinetics models (pseudo-first order and pseudo-second order) were employed to test experimental data along with the Morris-Weber diffusion model. The obtained data showed that the maximum sorption efficiency obtained at pH 3.0, adsorbent dose optimized as 10 mg of fiber with time of 24 hours, the methanol was sufficient to elute paraben from fibers met. The experimental data of the adsorption followed by first-order reaction with a mass transfer-controlled diffusion mechanism

Role of the Carbon Nanotube Junction in the Mechanical Performance of Carbon Nanotube/Polyethylene Nanocomposites: A Molecular Dynamics Study.

Carbon nanotube (CNT)-based networks are promising reinforcements for polymer nanocomposites without the issue of CNT agglomeration. In this study, the CNT junction, a vital and representative structure of CNT-based networks, was applied as the reinforcement of the polyethylene (PE) matrix. The tensile properties of the CNT-junction/PE nanocomposite were investigated via molecular dynamics (MD) simulations and compared with those of pure PE matrix and conventional CNT/PE nanocomposites. The CNT junction was found to significantly increase the mechanical properties of the PE matrix. The Young's modulus, yield strength, and toughness rose by 500%, 100%, and 200%, respectively. This mechanism is related to the enhanced interfacial energy, which makes the polymer matrix denser and stimulates the bond and angle deformations of the polymer chains. Furthermore, the CNT junction demonstrated a more profitable reinforcement efficiency compared to conventional straight CNTs in the PE matrix. Compared to the ordinary CNT/PE model, the improvements in the Young's modulus and toughness induced by the CNT junction were up to 60% and 25%. This is attributed to the reduced mobility induced by the geometry of the CNT junction and stronger interfacial interactions provided by the Stone-Wales defects of the CNT junction, slowing down the void propagation of the nanocomposite. With the understanding of the beneficial reinforcing effect of the CNT junction, this study provides valuable insights for the design and application of CNT-based networks in polymer nanocomposites.

Multi-walled carbon nanotube reinforcement in polypropylene nanocomposites: comprehensive analysis of thermal behavior, mechanical properties, and dispersion characteristics

Multi-walled carbon nanotube reinforcement in polypropylene nanocomposites: comprehensive analysis of thermal behavior, mechanical properties, and dispersion characteristics

SiO2‑g‑Polyisoprene Particle Brush Reinforced Advanced Elastomer Nanocomposites Prepared via ARGET ATRP

AbstractNanoparticle reinforcement is a general approach toward the strengthening of elastomer nanocomposite in large‐scale applications. Extensive studies and efforts have been contributed to demonstrating the property reinforcement of polymer nanocomposites in relation to matrix‐filler and filler‐filler interaction. Here, a facile synthetic method is creatively reported to synthesize SiO2,15/120‐g‐polyisoprene (SiO2‐g‐PI) particle brushes using atom transfer radical polymerization (ATRP). The dispersion and microstructures of the nanoparticles in the nanocomposites are investigated by morphological characterizations, whereas the reinforcing mechanism is studied through mechanical measurements as well as computational simulation. Remarkably, compared with the cured bulk elastomers and matrix(M)/SiO2 blends, M/particle brushes (PB) exhibit significant improvement in mechanical properties, including tensile strength, elongation at break, modules, and rolling resistance. This elastomer nanocomposites afford a novel prospect for the practical application of next‐generation automobile tires with enhanced performance.

Reinforcement of Cement Nanocomposites through Optimization of Mixing Ratio between Carbon Nanotube and Polymer Dispersing Agent.

Carbon nanotubes (CNTs), known for their exceptional mechanical, thermal, and electrical properties, are being explored as cement nanofillers in the construction field. However, due to the limited water dispersion of CNTs, polymer dispersing agents like polycarboxylate ether (PCE) and sulfonated naphthalene formaldehyde (SNF) are essential for uniform dispersion. In a previous study, PCE and SNF, common cement superplasticizers, effectively dispersed CNTs in cement nanocomposites. However, uncertainties remained regarding the extent to which all dispersing agents interacted efficiently with CNTs. Therefore, this research quantitatively assessed CNT interaction with dispersing agents through dispersion and centrifugation. Approximately 37% of PCE and 50% of SNF persisted compared to CNT after centrifugation. The resulting cement nanocomposites, with optimized mixing ratios, exhibited enhanced compressive strength of about 14% for CNT/PCE (78.13 MPa) and 12.3% for CNT/SNF (76.97 MPa) compared to plain cement (68.52 MPa). XRD results linked strength reinforcement to increased cement hydrate from optimized CNT dispersion. FE-SEM analysis revealed that CNTs were positioned within the pores of the cement. These optimized cement nanocomposites hold promise for improved safety in the construction industry.

Pengembangan Acetylated Cellulose Nanofibers dari Microcrystalline Cellulose: Studi Perubahan Gugus Fungsi dan Indeks Kristalinitas melalui Asetilasi dan Nanofibrilasi

Cellulose nanofiber (CNF) has promising potential as a reinforcement in polymer matrix nanocomposites. CNF is polar or hydrophilic due to having many hydroxyl groups. When CNF particles are combined with a non-polar polymer matrix, the CNF is difficult to distribute evenly and tends to agglomerate due to differences in polarity so that the strengthening effect of CNF is limited. To overcome this problem, it is necessary to chemically modify the CNF surface. Acetylation is one of the most widely used CNF surface modification methods to increase the compatibility between a non-polar polymer matrix and CNF. Through the acetylation process, some of the hydroxyl groups of CNF are replaced with acetyl groups which are hydrophobic. Furthermore, the CNF resulting from the acetylation process is known as acetylated CNF (acetylated cellulose nanofibers or ACNF). The acetylation process is carried out by first mixing microcrystalline cellulose (MCC) particles into 75 mL of acetic anhydride solution. Next, the mixture was stirred using a high-speed blender for 30 minutes for the MCC nanofibrillation process to occur. In this research, the influence of acetylation and nanofibrillation processes on the characteristics of ACNF was studied through studying chemical structure changes using ATR-FTIR and crystallinity index using XRD. The results of the ATR-FTIR analysis show that there are 3 new peaks in the ACNF spectrum, namely at 1720, 1369 and 1203 cm-1, which proves that there is a change in the structure of cellulose after being given acetylation treatment. The results of XRD show that surface treatment of acetylation and nanofibrillation with a high-speed blender increases the ACNF crystallinity index value by 82.53%. Overall, the resulting ACNF has great potential as a reinforcement for polymer matrix nanocomposites.