Nanocomposite Materials Research Articles

Batch and column studies for the removal of basic red-46 dye and textile by using magnesium oxide (MgO), strontium titanium trioxide (SrTiO3), cobalt- and iron-doped lanthanum chromium trioxide (Co.Fe.LaCrO3), and cadmium sulfide (CdS)-doped graphene oxide nanocomposites.

Despite efforts to reduce the risk of toxic chemicals, colors, and dyes being released into the environment from urban and industrial areas, there is still cause for concern. Colored water must be filtered and sterilized before it can be used for irrigation. The utilization of metal oxide and nanocomposite materials in wastewater treatment procedures appears to be a viable option for the future. Therefore, different compounds were doped with graphene oxide to identify the best material for dye removal by the adsorption process. According to recent studies, the ideal conditions for graphene oxide-doped magnesium oxide (GO/MgO) are as follows: pH 10 showed the highest adsorption capacity (qe) at 49.4mg/g; an adsorbent dosage of 0.01g/50mL showed 48.3mg/g qe; a shaking time of 30min resulted in 44.2mg/g qe; an initial dye concentration of 100mg/L yielded 53.6mg/g qe; and a temperature of 35°C gave 49.5mg/g qe. For graphene oxide-doped strontium titanate (GO/SrTiO3), the optimum conditions were as follows: pH 10 with 45.8mg/g qe; an adsorbent dose of 0.01g/50mL with 40.5mg/g qe; a shaking time of 30min with 75mg/g qe; and a temperature of 35°C with 44.7mg/g qe. Graphene oxide-doped cobalt and iron-doped lanthanum chromium titanate (GO/Co.Fe.LaCrO3) showed optimum conditions of pH 9 with 34.2mg/g qe; an adsorbent dose of 0.01g/50mL with 27.5mg/g qe; a shaking time of 45min with 33.2mg/g qe; an initial dye concentration of 100mg/L with 37.6mg/g qe; and a temperature of 35°C with 42.5mg/g qe. Graphene oxide-doped cadmium sulfide (GO/CdS) showed the following optimum conditions: pH 8 with 23.1mg/g qe; an adsorbent dose of 0.01g/50mL with 25.5mg/g qe; an initial dye concentration of 75mg/L with 28.3mg/g qe; and a temperature of 35°C with 33.5mg/g qe. The pseudo-first-order model was the best fit only for graphene oxide-doped magnesium oxide (GO/MgO) with an R2 value of 0.966, while the pseudo-second-order adsorption isotherm was the best fit for all four products, with R2 values ranging from 0.991 to 0.998. Additionally, the Langmuir adsorption isotherms provided good results for all four products, with R2 values ranging from 0.957 to 0.985. The Freundlich adsorption kinetics showed satisfactory fit only for graphene oxide-doped magnesium oxide (GO/MgO) and graphene oxide-doped cadmium sulfide (GO/CdS), with R2 values of 0.951 and 0.982, respectively. To examine the characteristics and practicality of the adsorption process, certain thermodynamic variables were calculated. The adsorption capability of the most efficient nanocomposites for the degradation of basic red-46 was significantly affected by various concentrations of heavy metal ions and electrolytes. In dye solutions containing surfactants/detergents, the adsorption efficiency of several effective photocatalysts for basic dyes was significantly reduced. A 0.5M HCl solution was found to be the most effective for desorption. In column investigations, the optimal bed height, flow velocity, and dye intake levels were determined to be 3cm, 1.8mL/min, and 70mg/L, respectively, for maximal adsorption of basic red-46. The adsorption investigation of genuine textile waste products has also been carried out to facilitate the practical deployment of this approach. The methods used in this study were cost-effective, easy to handle, and eco-friendly and involved no hazardous materials in the synthesis, making the resulting materials non-hazardous. All these methods were part of green chemistry.

Fabrication and Tribological Properties of Epoxy Nanocomposites Reinforced by MoS2 Nanosheets and Aligned MWCNTs.

The epoxy nanocomposites reinforced by MoS2 nanosheets and aligned multi-walled carbon nanotubes (MWCNTs) were fabricated by DC electric field inducement. The epoxy nanocomposites achieved improvement in the tribological properties with the addition of randomly dispersed MoS2 and MWCNTs compared to the pure epoxy. Furthermore, the epoxy nanocomposites exhibit anisotropic tribological and mechanical properties when the MWCNTs are aligned in the composites. The tribological properties of epoxy nanocomposites containing 1 wt% MoS2 and aligned 1.2 wt% MWCNTs achieved the maximum improvement when the sliding direction is perpendicular to the axial direction of MWCNTs. Compared to random MoS2 nanosheets and random MWCNTs reinforced epoxy nanocomposites, the friction coefficient and wear rate of random MoS2 and aligned MWCNTs reinforced epoxy nanocomposites decreased by 11.3 and 66.7% under a load of 5 N, respectively. The increased thermal conductivity and mechanical properties, higher surface content of nanoparticles, as well as unique alignment mode of MWCNTs are considered to be the main reasons for the improvement of tribological properties of epoxy nanocomposites.

Poly(methyl methacrylate) functionalized graphene oxide/CuO as nanocomposite for efficient removal of dye pollutants

In this research, the use of a three-component nanocomposite of graphene oxide-methyl methacrylate and copper(II) oxide (PMMA-GO-CuO) was investigated. The aim of synthesizing this nanocomposite is to removal dye pollutants, specifically methylene blue (MB) and methyl orange (MO), which are commonly used in dyeing industries, through adsorption. The study focuses on creating GO-CuO and PMMA-GO-CuO nanocomposites as effective adsorbents. A simple and quick method led to the development of the PMMA-GO-CuO nanocomposite, which shows enhanced physical and chemical properties. Key materials include graphene oxide, methyl methacrylate, and copper(II) oxide nanoparticles. Characterization techniques such as FT-IR, XRD, SEM, and TGA were used to analyze the nanocomposite. Results indicate that dye adsorption is more effective at lower pH levels, suggesting that the PMMA-GO-CuO nanocomposite can efficiently remove dyes from industrial wastewater. The experimental data showed that the Langmuir isotherm model accurately represented the equilibrium adsorption, with maximum capacities of 285.71 mg g−1 for methylene blue and 256.41 mg g−1 for methyl orange, indicating a single layer of adsorption. The kinetics followed a pseudo-second order model, suggesting that the adsorption process involves chemical bonding. Additionally, thermodynamic parameters (ΔG°, ΔH°, and ΔS°) indicated that the adsorption is spontaneous. The adsorption mechanism involves hydrogen bonding, π-π interactions, and electrostatic interactions. This study investigates how factors like pH, temperature, contact time, and dye concentration affect the adsorption of methyl orange and methylene blue dyes. A PMMA-GO-CuO nanocomposite was used, achieving 84% removal of MB and 35% removal of MO from industrial wastewater. This study highlights the promising potential of PMMA-GO-CuO nanocomposite as an effective material for the removal of dye pollutants from industrial wastewater. The results showed that the graphene oxide in the composite is effective for removing cationic dyes due to its negative charge. Further research will focus on the optimization of the synthesis process with the aim of achieving competitive performance of this nanocomposite on a large scale. These findings not only advance the field of nanocomposite materials but also provide a practical solution to an important environmental issue, demonstrating the innovation of the present study in the literature.

GSH responsive AuNRs@TFF nanotheranostic for NIR-II photoacoustic imaging-guided CDT/PTT synergistic cancer therapy

Gold nanorods (AuNRs) are important photothermal therapeutic agents; however, a single therapy does not achieve satisfactory outcomes, and the synthesis process often leads to the adsorption of cetyltrimethylammonium bromide on the surface of AuNRs, which reduces its biocompatibility. Natural polyphenols are abundant in natural plants and have good biocompatibility. The metal-polyphenol network is formed by the coordination of metal ions and polyphenols, which has good drug loading, surface adhesion, and biocompatibility. In this study, the metal-polyphenol network structure formed by a transition metal (iron) and natural polyphenol tannic acid was used to modify the surface of gold nanorods (AuNRs@TF). Additionally, the surfaces of AuNRs were modified using the targeted functional molecule mercapto folic acid (AuNRs@TFF). The constructed composite nanomaterials AuNRs@TFF has good biocompatibility and tumor targeting ability. Tannic acid‑iron degrades in the tumor microenvironment and releases iron ions that catalyze the Fenton reaction, thereby facilitating chemodynamic therapy. The good photo-thermal ability of AuNRs generate good photoacoustic signals to facilitate photoacoustic imaging mediation and enhances photothermal and chemodynamic therapy performance. This study expands on the application of AuNRs in the field of nanomedicine. The simple and effective design of AuNRs@TFF provides a strategy for the development of synergistic therapeutic agents for photothermal therapy and chemodynamic therapy.

Genetic algorithm optimization of langevin thermostat and thermal properties of graphene-aluminum nanocomposites: a molecular dynamics

Abstract The thermal properties of a laminated structure of graphene-coated aluminum composite nanomaterial were investigated through non-equilibrium molecular dynamics (NEMD) simulations to address the problem of temperature deviation in the thermostat volume applied. This paper presents a new insight into the best values of timestep and Langevin thermostat damping parameters for each atom in the nanomaterial with different size configurations using the genetic algorithm (GA) method by considering the timestep and thermostat damping parameters for each atom type, as well as the thickness of the nanomaterial, the thermostat, buffer, and heat flow lengths. The initial population results indicate that the thermostat temperature deviation increases with higher thermostat damping coefficients and timestep. However, the deviation decreases significantly with increased heat flow and thermostat lengths. Variations in buffer length and aluminum thickness do not have a significant effect on temperature. The application of a GA for optimization leads to a decrease in thermostat temperature deviation. The optimized parameters resulted in better thermostat temperature deviations when analyzing the temperature, aluminum thickness, and both buffer and thermostat lengths. Additionally, the thermal conductivity of aluminum-graphene nanomaterial decreases with increasing temperature, buffer length, and aluminum thickness, but increases by up to 9.85% with increasing thermostat length.

Flexible intelligent fabric composed of pinecone-like microstructure Co-cMOFs/CoZnAl-LDH composite nanomaterial for various types of sensor signals to guide personalized health activities

Multifunctional interfacing is a key aspect of flexible sensor development that facilitates enhanced interaction with the natural environment. However, challenges faced by contemporary multifunctional flexible sensors are structural complexity and high cost. Herein, inspired by the specific structure of pinecone in nature and the microstructured neural networks randomly distributed within human skin, we fabricated Co-cMOFs/CoZnAl-LDH composite nanomaterials with pinecone-like microstructure. Through the mutual verification of finite element simulation and experimental data, the mechanism of high sensitivity of the sensor is dynamically revealed from the structural point of view. The prepared pressure sensors exhibit a detection range (0–120 kPa), high sensitivity (2.35 × 109 kPa−1) and fast response. The photoelectric sensor shows enhanced photoelectric energy conversion, which shows great potential in the detection of sunlight intensity (20–100 mW cm−2). Simultaneously, building a hybrid pressure, acoustic and optical sensing platform and validating its superior performance in human movement and health monitoring applications. Furthermore, a strategy of light intensity feedback system to guide personalized health activities is put forward, so that doctors can guide patients/elderly health activities remotely.

Photocatalytic applications of metal oxide-based nanocomposites for sustainable environmental remediation

Change in human lifestyle and excessive use of commercial products have caused an ecological deterioration. A major contribution towards this comes from the mixing of toxins and persistent organic pollutants into water bodies, which poses a serious risk to the ecosystem. In the above context, materials scientists are involved in the search for sustainable solutions to address the above environmental challenges by the development of advanced materials. In this study, we prepared nanocomposite materials such as; ZnO-SnO2 and ZnO-MoS2 by wet-chemical approach to degrade dye pollutants like Rhodamine B (RhB) and Congo red (CR) towards achieving environmental remediation. Powder X-ray diffraction (PXRD) measurement was done for structural characterization of the samples and the formation of the nanocomposite phase was validated by the above study. The goal of the field emission scanning electron microscopy (FESEM) study was to examine the morphology of the composites which was accompanied by the energy dispersive analysis of x-rays (EDAX) and electron mapping experiments which verified the presence of Zn, Sn, O, Mo, S elements in the respective samples. Fourier transformed infrared spectroscopy (FTIR) meas urement was conducted to investigate the vibrational properties of the samples. Photocatalytic measurement showed improved degradation efficiency of the composites as compared to the pristine samples. The degradation efficiency was found to increase with irradiation time and attained saturation after 180 min. ZnO-SnO2 nanocomposite show 91.23 % and 88.11 % of degradation for RhB and CR dyes respectively whereas 89.29 % and 83.25 % degradation have been obtained for ZnO-MoS2 for the same dyes. Several aspects of the experiment were varied, including the amount of catalyst employed, the initial dye concentration, and the pH levels, in order to assess the efficacy of the photocatalysts. Both the photocatalysts degraded CR dye most effectively at acidic pH, although RhB dye gets degraded more at neutral and alkaline pH. ZnO-SnO2 was found to be an effective photocatalyst for degrading RhB dye at neutral pH and CR dye at acidic pH. After multiple iterations of experimentation, the photocatalytic mechanism has been extensively described, and the stability and reusability of the photocatalysts have been ensured for effective environmental cleanup.

3D framework MXene Ti3C2/g-C3N4/Fe3Si magneto-dielectric foam unveiling superior microwave absorption and thermal management performance

In conjunction with the swift advancement of detection technologies, the challenge persists in developing advanced stealth materials. The focus of this work is on the straightforward synthesis of a hybrid magneto-dielectric nanocomposite material composed of MXene Ti3C2/Fe3Si/g-C3N4 within a three-dimensional melamine foam framework, designed to deliver effective stealth capabilities. The high electrical conductivity and considerable permittivity of Ti3C2 have imposed limitations on its effectiveness in electromagnetic wave absorbers. In this context, the utilization of this compound in combination with substances like g-C3N4 and Fe3Si to fine-tune impedance matching and fully exploit the intrinsic properties is suggested. Furthermore, the distinctive 3D porous frameworks of the melamine foam, combined with the accordion-like structure of the MXene compound, extend and elongate paths for wave propagation to enhance energy dissipation. Through the activation of various loss mechanisms, it was possible to achieve a minimum reflection loss of −44.3 dB using a 1.5 mm thickness with an effective absorption bandwidth of 1.9 GHz. The enhancement of stealth performance was achieved through the combination of heterojunction interfaces among hybrid components and a 3D interconnected continuous path within the structure.

Self-Assembly of Soft and Conformable Broadband Absorbing Nanocellulose-Gold Nanoparticle Composites.

Broadband light-absorbing materials are of large interest for numerous applications ranging from solar harvesting and photocatalysis to low reflection coatings. Fabrication of these materials is often complex and typically utilizes coating techniques optimized for flat and hard materials. Here, we show a self-assembly based strategy for generating robust but mechanically flexible broadband light-absorbing soft materials that can conform to curved surfaces and surface irregularities. The materials were fabricated by adsorbing large quantities of gold nanoparticles (AuNPs) on the nanofibrils of hydrated bacterial cellulose (BC) membranes by tailoring the interaction potential between the cellulose nanofibrils and the AuNPs. The highly efficient self-assembly process resulted in very dense multilayers of AuNPs on the nanofibrils, causing extensive broadening of the localized surface plasmon resonance band and a striking black appearance of the BC membranes. The nanocomposite materials showed an absorptance >96% in both the visible and the near-infrared wavelength range. The AuNP-functionalized BC membranes demonstrated excellent conformability to curved and structured surfaces and could adopt the shape of highly irregular surface structures without any obvious changes in their optical properties. The proposed self-assembly based strategy enables the fabrication of soft and conformable broadband light-absorbing nanocomposites with unique optical and mechanical properties using sustainable cellulose-based materials.

Preparation and Characterization of Black Phosphene/Titanium Dioxide Composite Nanomaterials by Liquid-Stripping and Solution Mixing Method

In this study, black phosphorus (BP) was prepared via the high-energy ball milling method, and two-dimensional (2D) BP was further fabricated using the liquid-phase stripping approach. Nano TiO2 was synthesized via the sol-gel method, and it was combined with black phosphene through N, N-dimethylformamide (DMF) medium by a straightforward solution mixing process to produce BP/ TiO2 composite photocatalyst. Subsequently, spectrophotometric analysis, X-ray diffraction (XRD), and high-resolution transmission electron microscopy (HRTEM) were conducted. The band gap of BP was calculated using the Tauc plot method. The results revealed that the values are 1.06 eV and 1.23 eV, corresponding to the band gap emissions of four-and three-layer BP band gap emission, indicating the successful preparation of few layers of black phosphorus. The HRTEM analysis demonstrated that the BP/ TiO2 composite photocatalyst formed a relatively stable crystalline state.

Synthesis and functional mechanism evaluation of novel polymer-graphene oxide-biochar nanocomposite for efficient removal of diethyl phthalate

Phthalates, categorized as a main constituent of endocrine-disrupting chemicals (EDCs), are present in polymeric products. These substances can enter the environment through several pathways, including improper handling, which leads to their presence in toilet water, floor washings, surface runoff, and landfill leachate. This study focuses on the performance analysis of nanocomposite materials made of polymer (polypyrrole), quasi-metal (graphene oxide), and biochar (from palmyra seed) for the elimination of diethyl phthalates (DEP) from aqueous environments. Scanning electron microscope (SEM), X-ray diffraction (XRD), and Fourier-transform infrared spectroscopy (FTIR) were used to describe the nanocomposite characteristics. The experimental results supported a chemisorption process by agreeing well with the pseudo-second order. The Langmuir isotherm explained the DEP sorption data, which aligned to monolayer DEP adsorption on the nanocomposite surface. With a binding affinity of −13.36 (kcal/mol) and the highest docking score, Diethyl phthalates and graphene oxide interaction is validated. The produced nanocomposite is suggested as a possible alternative for the sorption of DEP. Future applications could benefit from the higher adsorption capacity, and environmental friendliness of nanocomposites.

Photocatalytic degradation of naphthalene, using various nanocomposite materials mostly based on metal oxides

Photocatalytic degradation of naphthalene, using various nanocomposite materials mostly based on metal oxides

Activated carbon-supported LaNiO3 perovskite nanocomposite supercapacitor electrode material exhibiting superior power density and life cycle

Activated carbon-supported LaNiO3 perovskite nanocomposite supercapacitor electrode material exhibiting superior power density and life cycle

Dual-mode detection of α-fetoprotein using the photothermal effect and peroxidase-like activity of Au@Cu/Cu2O-rGO

α-Fetoprotein (AFP) is widely recognized as an important marker for monitoring hepatocellular carcinoma (HCC), and its monitoring using two different transduction mechanisms is an effective way to avoid the risk of false positives or false negatives. In this paper, Au@Cu/Cu2O-rGO was used as a photothermal converter as well as an actuator to promote the decomposition of hydrogen peroxide (H2O2), which was further designed as a probe for dual-mode detection to quantitatively assess AFP. The composite nanomaterials possessed photothermal conversion efficiencies (η) of up to 54.9 % and catalytically generated signals up to 1.6 times greater, relative to a single material. Based on the generated temperature and current signals, AFP has been sensitively detected in the range of 0.01–100 ng/mL, with limits of detection (LOD) of 5.62 pg/mL and 1.23 pg/mL, respectively. The dual-mode assay combines portability with high accuracy for the detection of human health systems.

Heat transfer analysis and melting behavior of nano composite phase change materials (NCPCMs) in a reverse flow solar air heater

This paper presents a CFD investigation on heat transfer analysis and melting behavior of Nanocomposite Phase Change Materials (NCPCMs) in a Reverse Flow Solar Air Heater (RFSAH). Semicircular tubes filled with PCM are embedded on the top surface of the absorber plate. The study was conducted with three different nanoparticles (CuO, Al2O3, Fe3O4) based NCPCMs at three concentrations of 0.1, 0.2, and 0.3 % by weight. The constant geometrical parameters such as pitch ratio (P/e = 6), height ratio (e/Dh=0.1571), and Reynolds number (Re = 5000) is considered for this study. A 2-D transient numerical analysis using the RNG k-ε turbulence model is performed for the melting behavior of NCPCMs inside the semicylindrical tubes. The incorporation of nanoparticles into the base PCM enhances thermal conductivity but reduces the latent heat of NCPCMs. Thus, it is observed that NCPCMs have a faster melting rate. The CuO based NCPCM shows a more quick and uniform phase transition compared to the Fe3O4, and Al2O3 based NCPCMs and reached their peak value at a higher mass fraction of 0.3. Furthermore, the heat transfer and melting fraction improves with increasing in mass fraction of nanoparticles. The phase transition process of CuO based NCPCM is approximately 1.9 times, and 1.01 times, 1.03 times faster as compared to the base PCM, and Fe3O4, Al2O3 based NCPCMs respectively.

Synthesis and application of SBA-15 adsorbent for the removal of organic and inorganic substances.

This study investigates the adsorption of pollutants with different chemical structures; organic Naphtol Green B (NGB) dye and copper on a nanocomposite material with a hexagonal structure of the SBA-15 type. This research is divided into two main parts: the first carries out the synthesis of SBA-15 (Santa Barbra Amourphous) and its derivatives phases functionalized by 3-aminopropyl-triethoxylane (APTES) and calcined at 823K. The second part presents the influence of the adsorption conditions on the adsorption efficiency of NGB dye and copper. High-resolution X-ray diffractogram (XRD) showed three distinct peaks characteristic of highly ordered mesoporous material. Nitrogen adsorption-desorption isotherm of SBA-15 at 77K° is type IV typical of mesoporous materials. In addition, Fourier transform infrared spectroscopy (FT-IR) was also used in the characterization before and after the adsorption of the selected pollutants. At optimal conditions of pH 5.2, initial concentration of 50mg/L, adsorbent dosage of 20mg, and at adsorption time of 90min the maximum removal of pollutants reached 76% and the adsorption capacity was 227.25mg/g for NGB dye and 221.006mg/g for copper. Furthermore, the adsorption kinetics followed the pseudo-second-order model, indicating that chemisorption was the dominant mechanism and the Sips isotherm model best described the adsorption data. Our research demonstrates that the SBA-15 material after modification is an effective adsorbent for removing effluents regardless of their different chemical structure (organic and inorganic).

FeSnO3/rGO nanocomposite electrode development for supercapacitor application

The manufacturing of electrode materials that are both highly efficient and cost-effective is crucial for energy storage systems. Because of their remarkable performance, nanocomposite materials are a good choice for creating energy storage systems. And the present study contains the fabrication of FeSnO3 and FeSnO3/rGO nanocomposite by hydrothermal approach. To assess electrochemical behavior of FeSnO3 and FeSnO3/rGO nanocomposite number of analytical tools such as galvanostatic charge-discharge (GCD), electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV) and chronoamperometry (CA) were employed. FeSnO3/rGO nanocomposite demonstrate specific capacitance (Csp) 1342.02 F/g and energy density (Ed) was 88.74 Wh/kg at a power density (Pd) of 345 W/kg at a current density of 1.0 A/g. The charge transfer resistance (Rct) of FeSnO3/rGO nanocomposite was found to be Rct = 0.43 Ω which was determined from Nyquist plot as well as showed cycling stability even after remains 5000th cycles. The addition of rGO increased the specific capacitance as well as surface area rise total number of active sites which allows electrolyte and electrode surface to make ideal connection for quick electrolyte ion diffusion. In accordance with the obtained findings, the FeSnO3/rGO nanocomposite is convincing capacitive electrode material for energy storage devices the future.

Nanocomposite formulations of titanium dioxide and algal biomass: A rheological characterization for topical cosmetics and dermal applications

This study investigates rheological properties of novel, algae-based nanocomposites developed for potential use in dermal applications. The purpose of this investigation is to develop a highly tunable, biocompatible cosmetic base formulation and demonstrate how rheology relates to spreadability in its application. It was hypothesized that Spirulina biomass could be used in conjunction with titania (TiO2) nanoparticles and crosslinking and binding agents of calcium and/or citric acid to form nanocomposite materials with highly tunable rheological characteristics in absence of chemical surfactants. In this study, Arthrospira platensis (Spirulina) biomass, titanium (IV) dioxide, calcium chloride, and citric acid are used to develop a formulation that is then tested for a wide range of rheological characteristics and sensory-related properties. The rheological tests include amplitude sweep, frequency sweep, viscosity flow curve, 3-interval strain oscillatory thixotropy, and creep – recovery. Additionally, yield stress, complex viscosity, zero-shear viscosity, and power law indices were determined. The sensory-related properties that are discussed include formulation pH, static load spreadability, and dynamic shearing spreadability. After completing the investigation, it was concluded that the surfactant-free formulations were highly tunable, in terms of viscosity, rigidity, and thixotropy.

Harnessing potential of microwave-assisted ultrafast synthesis of reduced graphene oxide/Mn3O4 bioactive nanocomposite hydrogel for bone tissue engineering

The development of functional materials with the potential for bone tissue regeneration along with rapid synthesis and cost-effective approach has been challenging. In this regard, hydrogels have been explored as a potent candidate to behave as a 3D scaffold for bone repair. However, poor mechanical attributes impeded their clinical translation. Enthralling demonstration of the potential of carbon-based nanocomposites in bone tissue engineering has been constantly encouraging the fabrication of advanced nanocomposites. Here, we investigated the fabrication of reduced graphene/manganese (II, III) oxide (RGO/Mn3O4) nanocomposites by taking advantage of the microwave-assisted synthesis approach for cost effective, and ultrafast synthesis. Mn3O4 nanoparticles with uniform distribution in RGO sheets and ∼ 1.7 nm size was fabricated using the approach. Further, fine-tuning of the structural interaction and mechanical behavior of the GelMA-based hydrogels upon reinforcement with RGO/Mn3O4 nanocomposites was investigated as a function of different concentrations of the nanocomposites where upto 50 % increment in the compressive stress was observed compared to native GelMA hydrogel. The ability of these hydrogels was further investigated for their osteogenic behaviour on MC3T3-E1 preosteoblast cells where constant cell proliferation for up to 10 days was witnessed for the hybrid hydrogel with the highest concentration of the nanofillers.

Probing the Linear-to-Plastic Transition in Polymer Nanocomposites via Atomistic Simulations: The Role of Interphases.

Polymer nanocomposites have found ubiquitous use across diverse industries, attributable to their distinctive properties and enhanced mechanical performance compared to conventional materials. Elucidating the elastic-to-plastic transition in polymer nanocomposites under diverse mechanical loads is paramount for the bespoke design of materials with desired mechanical attributes. In the current work, the elastic-to-plastic transition is probed in model systems of polyethylene oxide (PEO) and silica, SiO2, nanoparticles, through detailed atomistic molecular dynamics simulations. This comprehensive, multi-scale analysis unveils pivotal markers of the elastic-to-plastic transition, highlighting the quintessential role of microstructural and regional heterogeneities in density, strain, and stress fields, featuring the polymer-nanoparticle interphase region. At the atomic level, the behavior of polymer chains interacting with nanoparticle surfaces is traced, differentiating between free and adsorbed chains, and identifying the microscopic origins of the linear-to-plastic transition. The mechanical behavior of subregions are characterized within the PEO/SiO2 nanocomposites, focusing on the interphase and bulk-like polymer areas, probing stress heterogeneities and their decomposition into various force contributions. At the inception of plasticity, a disruption is discerned in isotropy of the polymeric density field, the emergence of low-density regions, and microscopic voids/cavities within the polymer matrix concomitant with a transition of adsorbed chains to free. The yield strain also emerges as an inflection point in the local versus global strain diagram, demarcating the elastic limit, and the plastic regime shows pronounced strain heterogeneities. The decomposition of the atomic Virial stress into bonded and non-bonded interactions indicates that the rigidity of the material is primarily governed by non-bonded interactions, significantly influenced by the volume fraction of the nanoparticle. These findings emphasize the importance of the microstructural and micromechanical environment at the polymer-nanoparticle interface on the linear-to-plastic transition, which is of great importance in the design of nanocomposite materials with advanced mechanical properties.