Properties Of Nanocomposites Research Articles

Dielectric properties of chitosan-based ZnO nanocomposites for high-frequency electronic devices

Dielectric properties of chitosan-based ZnO nanocomposites for high-frequency electronic devices

Investigation of the Effect of Reprocessing on Thermal and Mechanical Properties of Polymers and Polymer Nanocomposites

This study explored the impact of multiple reprocessing cycles on the thermomechanical properties of polystyrene (PS) and low‐density polyethylene (LDPE), simulated through reprocessing with a twin‐screw extruder. Additionally, it compared the thermal and mechanical properties of graphene nanoplatelets (1% w/w) reinforced polypropylene (PP‐GNP) nanocomposites with PP. The materials undergo seven consecutive extrusion cycles at varying screw speeds (100 and 150 rpm) and temperatures (180 and 200 °C). Increasing the screw speed from 100 to 150 rpm raised LDPE's screw torque by about 40% at the first reprocessing cycle. Processing PS at 200 °C reduced screw torque by ≈20% compared to 180 °C at 1–5 reprocessing cycles. Both torque and power decrease for PP and PP‐GNP with each reprocessing cycle. LDPE's tensile modulus decreases with more cycles at 200 °C, while PS shows no consistent variation. PP's tensile modulus and ultimate tensile strength drop by 24% and 12%, respectively, from the first to the fifth cycle, while PP‐GNP exhibits no consistent variation. Differential scanning calorimetry shows no clear change in LDPE's melting point, but an increase in PP and PP‐GNP's melting points up to the fifth cycle. This research provides crucial insights to advance the recycling of polymers reducing environmental impact.

Electronic Properties of Polyaniline-Graphene Nanocomposites Synthesized via Solution Mixing Method.

A key advantage of combining the exceptional properties of graphene with conducting polymers, lies in their remarkable property tunability through filler additions into polymer matrices, with synthesis routes playing a crucial role in shaping their characteristics. In this work, we examine the electronic properties of polyaniline(PANI) and graphene nanocomposites synthesized via a simple solution mixing method, which offers advantages such as ease of use and efficiency. Increasing graphene content enhances nanocomposite conductivity, and a percolation effect is observed. The percolation threshold is high and is consistent with a strong role played by voids in the structure. Temperature-dependent conductivity measurements highlight three distinct conduction regimes: insulating, critical, and metallic. These findings underscore the significant influence of synthesis method and structural disorder on shaping electronic properties, paving the way for engineering multifunctional nanocomposites with exceptional versatility and performance.

Experimental Investigation on Climate-Control Nano-Composite Polycarbonate Sheets Enhanced with TiO2, ZnO, and Zeolite Nanoparticles for Polyhouse Use

Abstract Optimal food production is achieved when crops receive the necessary nutrients, and the desired levels of temperature, humidity, solar radiation, and sufficient water. Climate Control Agriculture, or Controlled Environment Agriculture, utilizes a technology-based approach to grow plants in a controlled environment. This study focuses on the experimental investigation of polycarbonate sheets doped with TiO2, ZnO, and zeolite nanoparticles for potential use in polyhouse applications. The thermal performance of these synthesized sheets and standard polycarbonate sheets was tested in a laboratory setting. A specialized experimental setup, consisting of two cabinets, was designed and fabricated for this purpose. Ten synthesized sheets each with thicknesses of 50 µm and 70 µm, and two commercial sheets of 70 µm thickness were tested experimentally in the laboratory for their thermal performance. Results indicated that the doping concentration of 0.3% was the most effective, while 0.1% was the least effective. Among the three doping materials, TiO2-doped sheets demonstrated superior ultra-violate light absorption capacity due to their high refractive index and band gap energy, which enhances their ability to absorb and scatter ultra-violate light. . ZnO offered stronger UV protection than the remaining three materials. However, it has a lower refractive index than TiO2. Its overall thermal performance was lower than TiO2. The desired properties of nanocomposites for use in polyhouse applications such as thermal performance in the laboratory, UV protection, mechanical strength and durability, transparency, photostability, and safety were compared based on the experimental results and the data available in the literature and was concluded that polycarbonate doped with ZnO and TiO₂ nanoparticles were the most suitable.

Utilizing Binary Phase Segregation and Extrusion to Enhance the Electronic Properties of Graphene Nanocomposites.

Our goal in this study is to incorporate graphene nanoplatelets (GNPs) in a polymer blend of poly(lactic acid) (PLA) and isotactic polypropylene (iPP) to facilitate the dispersion of GNPs and use the morphology of phase segregation to create a pathway for concentrating GNPs to achieve percolation with lower GNP concentration. Investigating the interfacial properties between PLA/GNPs and iPP/GNPs, we noticed that iPP has a lower contact angle on GNPs compared to PLA on GNPs. This showed a great potential that the GNP are easily confined in iPP rather than in PLA domains or at the PLA/PP interfaces. Utilizing this property, as the PLA content increases, the iPP content decreases, resulting in a reduction of the available space for GNPs. This decrease in space leads to a higher chance for GNPs to accumulate together. Furthermore, through careful control of the concentration in the immiscible blend of PLA/PP, it is possible to achieve a bicontinuous structure. This structure facilitates the creation of a pathway for the fillers, allowing for the use of minimal GNPs while achieving optimal electrical conductivity properties. The PLA/PP/GNPs can be oriented by the shear forces coming from the nozzle that produce a higher performance.

Surface enhanced Raman scattering-based sensing and ultrafast nonlinear optical properties of silver-hexagonal boron nitride nanocomposites achieved by femtosecond laser ablation

This study investigated the surface-enhanced Raman spectroscopy (SERS) properties and nonlinear optical (NLO) behavior of silver nanoparticles (Ag NPs) decorated hexagonal boron nitride (hBN) nanocomposites. Although Ag NPs are known for their excellent plasmonic properties, their susceptibility to oxidation in ambient conditions significantly reduces SERS activity. To overcome this, a femtosecond laser-assisted single-step novel approach is developed for synthesizing hybrid Ag-hBN nanocomposites via ablating Ag target in a solution of exfoliated hBN nanosheets, forming uniformly embedded Ag NPs on hBN nanosheets. The morphological characteristics and elemental compositions were validated by field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), and energy dispersive X-ray spectroscopy (EDS). TEM analysis revealed that Ag NPs averaged 15 nm in size, while hBN nanosheets had lateral dimensions of approximately 250 nm. The SERS activity of the prepared nanocomposites was investigated using dye and explosive molecules, achieving detection sensitivities of 1 μM and 100 μM, respectively, with high reproducibility. These detection sensitivities are significant as they demonstrate the potential of the Ag-hBN nanocomposites for sensitive and reliable detection of trace amounts of analytes. Notably, the Ag-hBN nanocomposites showed enhanced SERS activity compared to pure Ag NPs, with a 2.5-fold improvement for Nile blue, 3.6-fold for methylene blue, and 2.4-fold for RDX. The current study also demonstrates that hBN prevents Ag NPs’ oxidation and preserves the SERS functionality even at elevated temperatures. Furthermore, the NLO properties of the nanocomposites were investigated using the standard Z-scan technique, revealing two-photon and three-photon absorption coefficients of 3 × 10−4 cm/GW and 6.5 × 10−5 cm3/GW2, respectively. The findings highlight the potential of Ag-hBN nanocomposites to enhance SERS and NLO devices, enabling future applications in sensing and photonics.

Toward 3D printability prediction for thermoplastic polymer nanocomposites: Insights from extrusion printing of PLA-based systems

The development of new thermoplastic-based nanocomposites for, as well as using, 3D printing requires extensive experimental testing. One typically goes through many failed, or otherwise sub-optimal, iterations before finding acceptable solutions (e.g. compositions, 3D printing parameters). It is desirable to reduce the number of such iterations as well as exclude failed experiments that often require laborious disassembly and cleaning of the 3D printer. This issue could be addressed if we were able to understand, and ultimately predict ahead of experiments if a given material can be 3D printed successfully. Herein, we report on our investigations into forecasting the printing and resultant properties of polymer nanocomposites while encompassing both material properties and printing parameters, enabling the model to generalize across various thermoplastics and additives. To do so, nanocomposites of two different commercially available bio-based PLAs with varying concentrations of nanoclay (NC) and graphene nanoplatelets (GNP) were prepared using a twin-screw extruder. The thermal and rheological properties of the nanocomposites were analyzed. These materials were printed at varying temperature and flow using a pellet printer. The quality of the printing was evaluated by measuring weight fluctuation, internal diameter of cylindrical specimen, and surface uniformity. The interactions between material properties and printing parameters are complex but captured effectively by a machine learning model, specifically we demonstrate such a predictive model to forecast printability and, printing quality utilizing a Random Forest algorithm. Printability was predicted by developing a classification model with constraints based on the weight fluctuation (ΔW) of the printed sample w.r.t. the optimal print; defining “not printable” for −1.0≤ΔW<−0.8 and “printable” for ΔW≥−0.8. The classification model for predicting printability, performed well with an accuracy of 92.8% and identified flow index and complex viscosity, contributing 52% to the model’s importance. Another model to predict ΔW of the only on successful prints also showed strong performance, emphasizing the importance of viscoelastic properties, thermal stability, and printing temperature. For diameter change (ΔDi), the Random Forest model identified flow consistency index, complex viscosity, and thermal stability as influential parameters, with crystallization enthalpy gaining increased importance, reflecting its role in crystallization and shrinkage. In contrast, the surface roughness average (RA) model had lower performance, yet revealed remarkable insights regarding the feature importance with crystallization enthalpy and complex viscosity being most significant.

Polyvinyl alcohol and alginate bio-composite film containing titanium dioxide nanotubes for skin injury repair

This study explores the potential of polyvinyl alcohol (PVA) and alginate (SA) blend polymer films with embedded titanium dioxide nanotubes (TiO2NT) for wound healing applications. The nanocomposite film (PVA+SA@TiO2NT) was fabricated via a simple solvent casting process. The synergistic interaction between PVA and alginate significantly enhanced the film's stability in aqueous environments without compromising its weight. After 24 hours of immersion, the film exhibited a substantial swelling capacity (836±6%) and good WVTR ((282±4%). Scanning electron microscopy (SEM) revealed the formation of a smooth and random pore structure within the film. Fourier-transform infrared spectroscopy (FTIR) confirmed the successful formation of hydrogen bonds between PVA and alginate, along with the presence of Ti-O bonds, indicating successful incorporation of TiO2NT into the PVA+SA matrix. X-ray diffraction (XRD) analysis further corroborated the presence of TiO2NT. In vitro biocompatibility studies demonstrated the non-cytotoxic nature of the PVA+SA@TiO2NT bio-composite film. Additionally, in vitro wound healing studies suggest its potential as a promising biomaterial for wound dressing applications. These findings warrant further investigation to elucidate the complete mechanisms of action and optimize the nanocomposite's properties for clinical translation.

A Comprehensive Study on Thermal/Electrical Conduction, Mechanical and Curing Properties of Silicone Rubber Nanocomposites Contained Exfoliated-Surface Modified h-BNs

A Comprehensive Study on Thermal/Electrical Conduction, Mechanical and Curing Properties of Silicone Rubber Nanocomposites Contained Exfoliated-Surface Modified h-BNs

The role of synthesizing time on the optoelectronic properties of TiO2-ZnO nanocomposite on PTFE substrate fabricated by the chemical bath deposition method

ZnO-based ultraviolet photodetectors have been employed in advanced applications, including environmental monitoring, space exploration, and secured optical communication. In this work, TiO2-ZnO nanocomposite that included Ti-doped ZnO nanorods was synthesized using chemical bath deposition method at 96 °C on PTFE substrates for ultraviolet photodetectors. ZnO nanorods grew for 3 hours, followed immediately by the synthesis of TiO2 for 2 hours. The characterizations revealed several distinguished structural, optical, and electrical properties compared with reference ZnO-only samples deposited for 3 h and 5 h respectively. The indirect band gap of the produced nanocomposite was 3.09 eV. The fabricated ultraviolet photodetector revealed outstanding results: a responsivity of 673.667 mA/W, a detectivity of 5.121×108 Jones, and an external quantum efficiency of 229.44%. The results showed the potential of the nanocomposite for photodetector applications on flexible substrate.

Tailored dielectric properties of polypropylene nanocomposites through laboratory synthesized titania

Tailored dielectric properties of polypropylene nanocomposites through laboratory synthesized titania

Processing and properties of graphene-reinforced polylactic acid nanocomposites for bioelectronic and tissue regenerative functions

An in-situ polymer-solution-processing approach enables the efficient production of uniform graphene-reinforced polylactic acid (G-PLA) nanocomposites with notable physical and biomedical properties. The approach effectively enhances the interfacial bonding between graphene and PLA by creating graphene dangling bonds and defects during exfoliation. As a result, an 182 % increase in Young's modulus and an 85 % increase in tensile strength can be achieved in G-PLA. Only 0.5 wt% graphene addition can reduce the contact angle of the composite from 75.3 to 70.4 and reduce its oxygen permeability by 23 %. The improved hydrophilicity, hermeticity, and mechanical properties make G-PLA an excellent encapsulation material for implantable bioelectronics. Moreover, the composite surface attributes and cell behaviors at the material-tissue interface are investigated histologically through the culture of stem cells on as-synthesized G-PLA. G-PLA composites can significantly boost cell proliferation and regulate cell differentiation towards vascular endothelium, offering tissue regeneration at the surface of implants to recover the injured tissues. The degradation rate of G-PLA nanocomposite can also be regulated since the graphene slows down the autocatalytic chain splitting induced by the terminal carboxylic acid groups of PLA. Therefore, such G-PLA nanocomposites with physical and biomedical properties regulated by graphene loading enable the development of next-generation implantable electronic systems providing both sensing and tissue engineering functions for complicated applications such as implanted sensors monitoring the healing of fractured bones or intracranial pressure.

Recent Advancements in Mechanical Properties of Graphene-Enhanced Polymer Nanocomposites: Progress, Challenges, and Pathways Forward

Recent Advancements in Mechanical Properties of Graphene-Enhanced Polymer Nanocomposites: Progress, Challenges, and Pathways Forward

Third-order nonlinear optical properties of metal oxide nanoparticles and nanocomposites: A review

This paper reviews the vibrant field of nonlinear optical (NLO) properties of metal oxide nanoparticles and nanocomposites. It includes a historic introduction which discusses the birth and successive developments of NLO. An attempt is made to give a summary in a nutshell about the basic concepts of nonlinear optics and different NLO phenomena with special attention to third-order phenomenon and [Formula: see text]-scan technique. The review also touches on the topic of science and technology of metal oxide nanoparticles and nanocomposites, various synthesis processes that include co-precipitation, micro-emulsion, sol–gel route, etc. have been discussed. Metal oxide nanoparticles and nanocomposites are introduced with a deep focus on the origin of various physical mechanisms and optical properties. The origin of NLO properties from these important structures has also been discussed. Some recently studied metal oxide nanocomposites along with their NLO coefficients are also given.

Processing and Properties of Polyhydroxyalkanoate/ZnO Nanocomposites: A Review of Their Potential as Sustainable Packaging Materials.

The escalating environmental concerns associated with conventional plastic packaging have accelerated the development of sustainable alternatives, making food packaging a focus area for innovation. Bioplastics, particularly polyhydroxyalkanoates (PHAs), have emerged as potential candidates due to their biobased origin, biodegradability, and biocompatibility. PHAs stand out for their good mechanical and medium gas permeability properties, making them promising materials for food packaging applications. In parallel, zinc oxide (ZnO) nanoparticles (NPs) have gained attention for their antimicrobial properties and ability to enhance the mechanical and barrier properties of (bio)polymers. This review aims to provide a comprehensive introduction to the research on PHA/ZnO nanocomposites. It starts with the importance and current challenges of food packaging, followed by a discussion on the opportunities of bioplastics and PHAs. Next, the synthesis, properties, and application areas of ZnO NPs are discussed to introduce their potential use in (bio)plastic food packaging. Early research on PHA/ZnO nanocomposites has focused on solvent-assisted production methods, whereas novel technologies can offer additional possibilities with regard to industrial upscaling, safer or cheaper processing, or more specific incorporation of ZnO NPs in the matrix or on the surface of PHA films or fibers. Here, the use of solvent casting, melt processing, electrospinning, centrifugal fiber spinning, miniemulsion encapsulation, and ultrasonic spray coating to produce PHA/ZnO nanocomposites is explained. Finally, an overview is given of the reported effects of ZnO NP incorporation on thermal, mechanical, gas barrier, UV barrier, and antimicrobial properties in ZnO nanocomposites based on poly(3-hydroxybutyrate), poly(3-hydroxybutyrate-co-3-hydroxyvalerate), and poly(3-hydroxybutyrate-co-3-hydroxyhexanoate). We conclude that the functionality of PHA materials can be improved by optimizing the ZnO incorporation process and the complex interplay between intrinsic ZnO NP properties, dispersion quality, matrix-filler interactions, and crystallinity. Further research regarding the antimicrobial efficiency and potential migration of ZnO NPs in food (simulants) and the End-of-Life will determine the market potential of PHA/ZnO nanocomposites as active packaging material.

Temperature-dependent variation in ammonia sensing properties of ZnO-GO nanocomposites

Industrialization has caused significant environmental and health risks due to the emission of hazardous gases like ammonia. This study investigates the temperature-dependent gas sensing properties of a ZnO-GO nanocomposite synthesized via microwave-assisted combustion. The ammonia sensor, tested from 25 °C (room temperature) to 200 °C, showed its highest sensitivity (72 %) at 100°C for 100 ppm ammonia. It achieved a response time of 94 seconds and a recovery time of 58 seconds. These results demonstrate the potential of ZnO-GO nanocomposite sensors in reducing ammonia-related risks in industrial environments.

Physical properties of hydrogel nanocomposite of ZnFe2O4/PVA:GA:AC spinel ferrite as solar energy evaporator materials for distillation water processing

Physical properties of hydrogel nanocomposite of ZnFe2O4/PVA:GA:AC spinel ferrite as solar energy evaporator materials for distillation water processing

Hierarchical Nano/Micro-Array Structured CuMgAl-LDH/rGO Hybrids for Remarkably Improved Flame Retardancy and Smoke Suppression Performance of Flexible Polyvinyl Chloride.

In this study, we explored the rational integration of layered double hydroxides (LDHs) with reduced graphene oxide (rGO) to create a hierarchical nano/microarray structured CuMgAl-LDH/rGO hybrid aimed at enhancing the flame retardancy and smoke suppression properties of polymer nanocomposites. The results indicated that the limiting oxygen index (LOI) value of the G-CuMgAl/polyvinyl chloride (PVC) composite reached 35.8%, reflecting a 6.4% increase compared to pristine PVC (29.4%), and achieved a UL-94 V-0 rating. Furthermore, in comparison to pristine PVC, the peak heat release rate (PHRR) of the G-CuMgAl/PVC composite was significantly reduced by 40.2%; the total heat release rate (THR) decreased by 24.3%; the maximum average heat release rate (MARHE) diminished by 41.6%; the peak smoke production (PSPR) decreased by 37.8%; the total smoke production (TSP) was reduced by 31.3%; and the average effective heat of combustion (av-EHC) decreased by 15.2%. The enhanced flame retardancy and reduced smoke production can primarily be attributed to the multiple synergistic interactions among the highly dispersed constituents and the nano/microstructures, which effectively impede the transfer of heat, mass, and O2 from various directions while preventing further combustion of the underlying matrix by creating a tortuous path in the condensed phase. Additionally, this study provides a novel perspective on the design and synthesis of structured LDHs/rGO hybrids, with the potential to enhance flame retardancy and smoke suppression properties across a broad spectrum of polymer materials.

Deep learning-assisted morphological segmentation for effective particle area estimation and prediction of interfacial properties in polymer composites.

The link between the macroscopic properties of polymer nanocomposites and the underlying microstructural features necessitates an understanding of nanoparticle dispersion. The dispersion of nanoparticles introduces variability, potentially leading to clustering and localized accumulation of nanoparticles. This non-uniform dispersion impacts the accuracy of predictive models. In response to this challenge, this study developed an automated and precise technique for particle recognition and detailed mapping of particle positions in scanning electron microscopy (SEM) micrographs. This was achieved by integrating deep convolutional neural networks with advanced image processing techniques. Following particle detection, two dispersion factors were introduced, namely size uniformity and supercritical clustering, to quantify the impact of particle dispersion on properties. These factors, estimated using the computer vision technique, were subsequently used to calculate the effective load-bearing area influenced by the particles. An adapted micromechanical model was then employed to quantify the interfacial strength and thickness of the nanocomposites. This approach enabled the establishment of a correlation between dispersion characteristics and interfacial properties by integrating experimental data, relevant micromechanical models, and quantified dispersion factors. The proposed systematic procedure demonstrates considerable promise in utilizing deep learning to capture and quantify particle dispersion characteristics for structure-property analyses in polymer nanocomposites.

Preparation and Electrical Properties of Nanocomposite Based on Epoxy Resin and Core-Shell Polyaniline/Multi-Walled Carbon Nanotubes

Nanocomposites of epoxy resin containing various concentrations of carboxylated multiwalled carbon nanotubes (C-MWCNTs) and surface modified C-MWCNTs various concentration of both C-MWCNTs and core-shell nanoparticles were prepared. The physical, mechanical and electrical properties of prepared epoxy nanocomposites were investigated using experimental evaluations such as dynamic mechanical thermal analysis (DMTA), differential scanning calorimeter (DSC), and tensile strength measurements. The results of DSC tests revealed that the introduction of nanoparticles into the epoxy resin did not have much effect on the curing system, and by adding these nanoparticles to the epoxy resin, there is no need to change the curing system. However, the released energy during of epoxy curing show a 24% increase with the introduction of nanofiller into the epoxy matrix. The results of electrical conductivity measurements indicated a higher elastic dielectric constant for nanocomposites up to 200% incomparison with neat epoxy resin. The use of these epoxy nanocomposites in modern electrical and electro-optical industries is of great practical importance.