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This study offers a detailed examination of vinyl ester composites strengthened with nettle fibres and annealed biosilica from foxtail millet husk biomass waste. The primary objective is to investigate how the different dwell time processed heat treated biosilica particles perform under repeated and prolonged loading applications in natural fibre-reinforced polymer composite materials. The biosilica particles were annealed at 1200 °C and dwelled for 2 h and 4 h. The results highlight VNS32 (resin with nettle fibre of 30 vol.% and biosilica of 2 vol.%) as the superior composite, exhibiting higher fatigue counts of 29,108, 27,898, and 26,247 for 25%, 50%, and 75% of the ultimate tensile strength (UTS). Similarly, VNS32 demonstrates superior values in creep and dynamic mechanical analysis (DMA). In creep testing, VNS32 shows creep strain values of 0.0015, 0.0019, and 0.0035 for 5000 s, 10,000 s, and 15,000 s, while in DMA, it achieves a storage modulus of 5.6 GPa at 107 °C and a loss factor of 0.42. These findings suggest that the utilization of prolonged annealed biosilica contributes to enhanced structural integrity and uniform load transfer, both in normal and cyclic loading conditions at specific temperatures. Moreover, these composites could be used in automotives, lightweight building material applications, drones, defence and food packaging where lightweight and high strength is required. [ABSTRACT FROM AUTHOR]

Flexible electronics have revolutionized various industries by offering lightweight and conformable solutions for diverse applications. However, their vulnerability to environmental factors, particularly moisture, remains a critical challenge. Polymer composite coatings enriched with superhydrophobic properties have gained considerable attention as a promising solution to safeguard flexible electronics. The present research report is a comprehensive review of the recent advancements in the development and application of superhydrophobic polymer composite coatings in flexible electronics, highlighting its potential applications in sensors and EMI shielding. The improvement in superhydrophobic characteristics hinges upon the choice of materials, fabrication techniques, surface morphology, and topographical features. This review article elaborates on the selection criteria for various organic and inorganic fillers suitable for polymers possessing innate hydrophobic or conducting properties. The different materials used as fillers in polymer matrix for fabricating superhydrophobic coating, the factors affecting the superhydrophobic properties of surfaces, and the superhydrophobic properties of fabricated surfaces using different materials have been reported. [ABSTRACT FROM AUTHOR]

Highlights Polypropylene composites with different contents of zinc‐ammonium salts (3, 5 and 7 wt%) and nanocellulose (1 wt%) after enzymatic bioconversion were characterized by structural, dispersion‐morphological, thermal, antimicrobial and mechanical analysis. It was shown that the use of a newly synthesized salt significantly affected the formation of the supermolecular structure of the polymer matrix and increased the nucleation activity, thermostability and flexibility of the composite materials. Moreover, the addition of the inorganic filler allowed to obtain composites with very good antimicrobial properties against Staphylococcus aureus, Escherichia coli and Candida albicans. An interesting relationship between the degree of filler dispersion in the polymer matrix and the formation of polymorphic varieties was elucidated in the study, which contributes to the improvement of final performance characteristics of composite materials. It is noteworthy that a hybrid filler in the form of nanometric cellulose and a biocidal additive containing zinc‐ammonium complex salt was used for the first time. Research has shown that such polymer composites can find application during the manufacture of smart packaging materials with enhanced barrier properties against oxygen and water vapor as well as improved biocidal characteristics, which will notably extend food storage time. At the same time, the presented process of obtaining the innovative composite materials is an excellent example of sustainable technologies for the design of antimicrobial treatments, while guaranteeing the possibility of further processing of these composite materials through material recycling. Zinc‐ammonium complex with antimicrobial properties was obtained The strength properties and thermal stability of the composites were improved Degree of filler dispersion in polymer affects formation of polymorphic varieties The composites can be applied in the production of smart packaging materials [ABSTRACT FROM AUTHOR]

Highlights With the emergence of two‐dimensional (2D) materials analogous to graphene, transition metal carbides and carbonitrides with unique desirable characteristics known as MXenes have turned out to be a hot research topic. Recent studies increasingly focus on the structure–property relationships of MXenes and their hybrid formations with other materials. The exfoliation and delamination of MXenes using various agents is gaining attention, while their application in functional composites presents another exciting research direction. However, the exfoliation of multi‐layered MXene into few‐layered nanosheets using bio‐based agents remains underexplored. In this study, tannic acid (TA) is employed as a bio‐exfoliating agent to delaminate Ti3C2Tx MXene, while optimizing the ratio of TA to achieve efficient exfoliation and dye adsorption. The MXene/TA composites demonstrated a maximum adsorption capacity of 187.264 mg/g and a removal efficiency of 93.69% for methylene blue (MB) in water, in accordance with the Langmuir isotherm model. Furthermore, MB adsorption caused MXene to coagulate into floccules, enabling easy removal via filtration. The study highlights the trifold role of tannic acid in MXene as a delaminating, antimicrobial, and adsorption‐enhancing agent, creating a multifunctional MXene‐tannic acid system. It introduces a new class of hybrid materials with effective applications in water purification. Additionally, incorporating this hybrid material into polymers can fine‐tune their properties, leveraging the synergistic effects of the trio to develop high‐performance smart polymer composites for diverse applications. Synthesis of MXene from Ti3C2Tx Optimization of the delamination efficiency of the biomolecule tannic acid Characterization of tannic acid‐MXene delaminated composites Analysis of the antibacterial efficiency of tannic acid delaminated MXene Investigation of water purification efficiency of delaminated MXene [ABSTRACT FROM AUTHOR]

Highlights Investigating the macro‐mechanical properties of polymer composites at the nanoscale is a challenging topic. Here we report the compressive performances of carbon fiber‐reinforced epoxy composites using molecular dynamics (MD) simulations. The evolution of microstructure and microscopic energy, including free volume, radius of gyration, dihedral angle, potential energy, and interaction energy, has been investigated to characterize compressive behaviors at the nanoscale. Molecular chains gradually bend, and the movement space of the molecular chains decreases during compression loading. The radius of gyration and dihedral angle are deformed into a state of irreversible plasticity to accommodate the microstructural transformation. The interaction energy increases and subsequently declines as the carbon fiber/epoxy interface gets closer, reflecting the transition of the internal structure. The inhomogeneity and interfacial concentration distribution of stress, and local molecular stiffness under various strains have been obtained to reveal the nanoscopic mechanism of epoxy failure and interface delamination during compression. This study reveals the compression behaviors and deformation mechanism of carbon fiber‐reinforced epoxy composites at the molecular level, providing directions and possibilities for molecular design and structural optimization of composites. The nanoscopic compression deformation of CFRP composites is studied. Microstructural evolution and conformation transformation are revealed. The evolution and transition of microscopic energy are analyzed. Micro‐mechanism of epoxy deformation and interface delamination is elucidated. [ABSTRACT FROM AUTHOR]

Great challenges exist in producing reliable welding between metals and polymer composites. In this study, self‐riveting welding (SRW) is employed to obtain metal–polymer hybrid joints with high load‐bearing capability. In this investigation, it is shown that the SRW joints with a prefabricated hole of 5.8 mm in diameter are characterized by fewer void defects with sufficient polymer filling, a tightly bonded joint interface, and a relatively uniform stress distribution along the joint interface during the tensile test, leading to the high load‐bearing capability of the SRW joints. The maximum average tensile force is 1.5 kN. The fracture occurs across the polymer composite rather than along the joint interface. In the results, it is shown that SRW has the potential to be developed into a method for fabricating reliable hybrid joints for the aerospace and automotive industries. [ABSTRACT FROM AUTHOR]

In this research study, a non-deformable, stiff electromagnetic interference (EMI) shielding material was prepared and characterized. The composites were prepared using industrial waste silver slag fine particles; woven abaca fiber and silk fabric with two different stacking order designated as ASSA and SAAS. The composites were created utilizing a hand layup technique and the American society for testing of materials (ASTM) standards were used to assess their performance. The findings showed that the abaca/silk/silk/abaca sequence of fibers had greater dielectric values. The ASSA2 composite designation was observed to have a maximum dielectric constant of 4.81. Similar to this, the ASSA2 configuration produced a total EMI shielding effectiveness of 56.85 dB at 20 GHz. Moreover, the ASSA2 composite configuration resulted in enhanced mechanical and hardness qualities. These mechanically hardened epoxy-based composites with increased EMI shielding could be employed in applications for radar, radomes, and the telecommunications industry. [ABSTRACT FROM AUTHOR]

The industrial waste known as cenosphere is rich in ceramic and is created when coal is burned in thermal power plants. The purpose of this study is to examine how cenosphere, a particulate filler, affects the mechanical behavior of woven Sisal/CFRP-Rubber-Sisal/CFRP sandwich composite. Composite specimens are made using the traditional hand lay-up method. The hybrid composite also included cenosphere with varied proportions (5, 10, 15, and 20 wt%). To determine the impact of filler content, the samples underwent tensile, flexural and impact testing following ASTM standards. It is shown that adding discarded cenosphere equivalent to about 15% by weight significantly changes the mechanical properties and enhances the tensile, flexural, inter-laminar shear strength (ILSS), and impact strength as opposed to unfilled sandwich composites. Morphologies of the composites examined show excellent cenosphere dispersion in the matrix, which enhances the strengths noticeably. [ABSTRACT FROM AUTHOR]

Compared to single natural fibre composites, hybridising natural fibres with filler particles presents a promising avenue for enhancing composites physical, mechanical, and damping properties. This study delves into incorporating clamshell powder, a filler derived from clams' hard protective outer shells, into polymer composites. The focus is on investigating the potential of clamshell powder as a filler material to augment the mechanical and damping properties of epoxy-bamboo mat composites. The weight ratio of clamshell fillers varied from 0% to 9%, and the compression moulding method was used to fabricate the composites. As per ASTM standards, mechanical properties were evaluated by conducting tensile and flexural tests. Free vibration tests by impact hammer technique were employed to evaluate the natural frequency, damping ratio, and mode shapes of developed composites to measure damping properties. Results revealed that adding clamshell filler significantly improved composites tensile strength, flexural strength, and damping properties. The addition of clamshell elevated the tensile strength by 18.5%, and flexural strength by 24.2% for composite with 6 wt% filler, which can be attributed to the efficiency of load transfer and the interfacial bonding between fillers and epoxy matrix. SEM analysis supported the experimental results obtained. The highest damping value is received for 9 wt% filler, showing 30% enhancement compared to composites without clamshell filler. Modal analyses using ANSYS software further validated the positive impact of clamshell filler. This study underscores the potential of clamshell filler in enhancing the mechanical and damping properties of epoxy-bamboo composites, broadening their applicability in various fields. [ABSTRACT FROM AUTHOR]

\nHIGHLIGHTSThe advancement of carbon nanotube (CNT) polymer composites has significantly revolutionized material science by offering exceptional mechanical, electrical, and thermal properties. However, the practical application of these composites is often hindered by the poor dispersion and compatibility of CNTs within polymer matrices. This paper explores advanced functionalization techniques to address these challenges, aiming to achieve superior dispersion and compatibility. Through a comprehensive review of chemical, physical, and hybrid functionalization methods, this study evaluates their effectiveness in enhancing CNT-polymer composite properties. Additionally, key characterization techniques, including spectroscopic and microscopy methods, are utilized to assess the quality of dispersion, interfacial bonding, and the presence of functional groups. Detailed case studies showcase the successful application of these advanced functionalization techniques, with significant improvements in mechanical properties such as tensile strength, modulus, and fracture toughness, resulting in composites with enhanced performance. This research advances the understanding of functionalization strategies and provides a robust framework for future studies and industrial applications, paving the way for the commercialization of high-performance CNT-polymer composites.Tailored functionalization optimizes electrical and mechanical performance.Hybrid functionalization enhances CNT dispersion in polymer matrices.Covalent and noncovalent methods combine for superior composite properties.Improved interfacial bonding boosts tensile strength and thermal stability.Enhanced CNTpolymer compatibility leads to advanced industrial applications.Tailored functionalization optimizes electrical and mechanical performance.Hybrid functionalization enhances CNT dispersion in polymer matrices.Covalent and noncovalent methods combine for superior composite properties.Improved interfacial bonding boosts tensile strength and thermal stability.Enhanced CNTpolymer compatibility leads to advanced industrial applications. [ABSTRACT FROM AUTHOR]

This study investigates the gamma-ray attenuation capabilities of ABS polymer reinforced with nano-sized yttrium particles. The analysis focuses on three key parameters: mass attenuation coefficient, half-value layer, and radiation protection efficiency. Utilizing a sol–gel process for polymer molding, various test samples were prepared and subjected to scanning electron microscopy (SEM) for surface structure examination. Then, experimental, theoretical, and simulation approaches are used to obtain gamma-ray shielding parameters. The base and additive materials are chosen as ABS polymer and yttrium nanoparticles, respectively, and the results revealed a consistent enhancement in gamma-ray attenuation characteristics with the incorporation of yttrium nanoparticles. These findings offer valuable perspectives for advancing the development of sophisticated radiation shielding materials, presenting potential applications across diverse fields including medical imaging, industrial processes, and nuclear technologies. [ABSTRACT FROM AUTHOR]

Bi-continuous phase polymer composite materials have garnered significant attention in the realm of advanced functional composites owing to their unique dual continuous structure and multifunctional properties. They served as a versatile platform for the incorporation of functional fillers, enabling the enhancement of polymer composite materials in terms of both performance and multifunctionality through diverse filler distributions. This article provides a succinct overview of the construction of bi-continuous structure. Next, the factors influencing filler selective distribution in bi-continuous phase polymer composites were discussed, covering polymer matrices, fillers, and fabrication methods. It further explores the classification of various filler distribution types. Following that, we present typical application scenarios across diverse fields, including electrical and thermal conductivity, flame retardancy, and energy storage. Finally, we discuss current challenges and outline prospective development opportunities. [ABSTRACT FROM AUTHOR]

Three-dimensional (3D) fillers are a new hotspot in the development of polymer composites. The 3D microstructure is capable of effectively solving the agglomeration problem of low dimensional microstructure and forming 3D network in the polymer matrix at a very low percolation threshold. This could assist to transfer the charge carrier and heat as well as disperse the stress, further greatly improving the electrical conductivity, thermal conductivity, and mechanical properties of polymer composites. Starting from the different types of fillers, this review discusses the various methods including vapor deposition technology, template method, directional freezing method, and 3D printing technology for preparation of 3D carbon-based fillers, 3D inorganic fillers, and 3D organic-inorganic hybrid fillers in recent years, which will facilitate researchers to inspire the preparation of 3D fillers/polymer composites. Besides, this article also reviews the applications of 3D fillers/polymer composites in the fields of electronics and energy storage such as electromagnetic interference (EMI) shielding materials, thermally conductive materials, organic phase change materials, shape-memory materials, piezoresistive materials, and batteries as well as capacitors in detail. The relevant knowledge can boost researchers to fabricate the diverse 3D fillers/polymer composites and promote the development of related research on the 3D fillers/polymer composites. [ABSTRACT FROM AUTHOR]

This research investigates the manufacturing and characterisation of polyester-based composites reinforced with jute fibres and red mud particulates. The motivation stems from the need for sustainable, high-performance materials for applications in industries, like aerospace and automotive, where resistance to erosion is critical. Jute, a renewable fibre, combined with red mud, an industrial byproduct, offers an eco-friendly alternative to conventional composites. The composites were fabricated using compression moulding with varying red mud contents (10, 20, and 30 wt.%) and a fixed 40 wt.% of jute fibre. Fibre treatments included sodium hydroxide (NaOH) and silane treatments to improve bonding and performance. Erosion tests were performed using an air-jet erosion tester, examining the effects of the red mud content, fibre treatment, and impact angles. Scanning Electron Microscope (SEM) analysis provided insights into the erosion mechanisms. A distinctive reduction in erosion rates at higher impact angles (30°–60°) was observed, attributed to the semi-ductile nature of the composites. The addition of red mud enhanced erosion resistance, although an excess of 30 wt.% reduced resistance due to poor surface bonding. Silane-treated composites showed the lowest erosion rates. This study provides new insights into the interplay among material composition, fibre treatment, and erosion dynamics, contributing to the development of optimised, eco-friendly composite materials. [ABSTRACT FROM AUTHOR]

The paper presents an analysis of the filler's effect on the machining process and on changes in the thermomechanical properties of polymer composites based on aluminum chips. Composite research samples with a polymer matrix in the form of polyamide 6 were made by the pressing method. Comparative studies were carried out on the changes in thermomechanical properties and structure of the obtained molders with different filler contents and different fractions after the machining process. In order to determine the changes in thermal and mechanical properties, analysis was carried out using the differential scanning calorimetry (DSC) method, thermal analysis of dynamic mechanical properties (DMTA) and a detailed stereometric analysis of the surface. After mechanical processing, roughness amplitude parameters and volumetric functional parameters were determined. In order to analyze the structure, tomographic examinations of the manufactured composite were conducted. In relation to the polymer matrix, a significant increase in the storage modulus of the composites was noted in the entire temperature range of the study. An increase in the enthalpy of melting of the matrix was noted in composites with a lower filler content and a shift in the melting range of the crystalline phase. Significant differences were noted in the study of the composite surfaces in the case of using fillers obtained after machining with different fractions. The dependencies of the functional and amplitude parameters of the surfaces after machining of composite samples prove the change in the functional properties of the surface. The use of aluminum chips in the composite significantly changed the surface geometry. [ABSTRACT FROM AUTHOR]

The current research work involves the fabrication and tribological properties analysis of constant basalt filler reinforced (30 wt %) bio-based polypropylene (PP) and high density polyethylene (HDPE) thermoplastic composites. Compression molding technique is used after an internal mixing process in order to produce composite samples. The physical and hardness properties have been evaluated for both neat polymers and composite samples. In order to study the coefficient of friction (COF) and specific wear rate (SWR) of PP and HDPE composite samples, the Taguchi and Analysis of Variance (ANOVA) methodologies were applied. For PP samples, the optimum parameters in response to COF are found to be 0 wt% basalt (rank 3), 9 N load (rank 1), 200 r/min speed (rank 4), and 100 m distance (rank 2); for the SWR output, the optimum parameters are 30 wt% basalt (rank 1), 6 N load (rank 4), 100 r/min speed (rank 2), and 200 m distance (rank 3). For HDPE samples, the optimum parameters in response to COF are 0 wt% basalt (rank 1), 6 N load (rank 3), 100 r/min speed (rank 4), and 100 m distance (rank 2); for the SWR output, the optimum parameters are 30 wt% basalt (rank 1), 6 N load (rank 3), 100 r/min speed (rank 4), and 150 m distance (rank 2). Consistently, it has been shown that incorporating basalt fillers to PP and HDPE composites has more dramatically decreased SWR than COF. The depth of wear constantly rises according to increasing load, irrespective of the processing variables, as shown in 2D depth profiles. It is discovered that the confirmation tests carried out for the optimum parameters are within statistically acceptable bounds. The depth profile plots revealed that the worn track edges are found with polymer bumps because of deep grooves and softened polymer debris, which commonly observed more with HDPE samples due to low softening temperature. Moreover, the worn surfaces of the composites have plowed lines and cracks that are brought about by the micro-cutting and micro-plowing activity of the erosive asperities counterface. In addition to surface characteristics, the transfer films created during sliding also significantly influenced the mode of sample wear. [ABSTRACT FROM AUTHOR]

This study presents a focused investigation into development of high-performance self-healing graphene polymer composites targeted for critical applications in aerospace, automotive, and electronics sectors. The research emphasizes strategic integration of bioinspired approaches and multi-material systems to enhance autonomous repair capabilities of these composites. Specifically, bioinspired strategies are employed to mimic natural healing processes, while multi-material systems combine graphene with tailored polymers and nanoparticles to achieve superior mechanical strength and facilitate the incorporation of customized functionalities within the composite. The incorporation of stimuli-responsive agents within the graphene composite matrix enables rapid and efficient self-healing upon damage. Advanced characterization techniques, including in-situ microscopy and spectroscopy, are employed to gain a deeper understanding of underlying self-healing mechanisms, guiding development of significantly more resilient graphene composites. Additionally, the study addresses critical challenges associated with scalability, durability, and cost-effectiveness, paving way for wider industrial adoption. Real-world applications, such as self-repairing aircraft components and self-healing electronic circuits, are presented to demonstrate substantial market potential and societal benefits of these advanced materials. By leveraging bioinspired design principles and integrating multi-material systems, this research offers a significant contribution to advancement of self-healing graphene polymer composites, promising smarter, more robust, and ultimately more reliable materials for various high-performance applications. HIGHLIGHTS: Enhanced self-healing in graphene composites for aerospace, automotive, and electronics. Stimuli-responsive agents enable rapid healing, nanoscale structuring boosts strength. In-situ microscopy unveils healing mechanisms; improves composite reliability. Improved properties: mechanical, electrical, thermal, in graphene-based materials. Focus on scalability, durability, cost for broader industrial use; real-world applications showcase potential. [ABSTRACT FROM AUTHOR]

Our study aimed to evaluate the efficiency of solar power systems by developing dye-sensitized solar cells (DSSCs) with an electrolyte of carbon nanotubes (CNTs) dispersed in poly (methyl methacrylate) (PMMA). Photovoltaic and impedance spectral studies showed that a polymer electrolyte with 3% carbon nanotubes resulted in an efficiency of solar power conversion of 7.40% and a photovoltaic current per unit cross-sectional area of 17.13 mA/cm2 in DSSCs. The optimal distribution of CNT fillers decreased the charge recombination of the titanium dioxide-dye-CNT-PMMA electrolyte surface. The X-ray diffraction spectrum showed characteristic peaks of PMMA and CNT at 28.6° and 63.0°, respectively, obtained in pure form and composites with dispersed carbon nanotubes. The peak intensity increased with the addition of CNTs in the polymer. A Fourier transform infrared spectroscopy investigation revealed the bonding within the CO and CH of PMMA and CNT to the polymer composite. The dielectric constant increased from 2.9 to 4.4, and the dielectric loss increased from 0.10 to 0.90 at 1 MHz for the dispersion of 6% CNT in PMMA. Scanning electron microscopy analysis showed that the internal particle structure and porosity had changed due to the presence of the CNTs in the PMMA. The dispersion of CNTs into the PMMA increased the maximum voltage of the polymer electrolytes. A breakdown voltage of 7.4 kV was attained with 6% CNTs in the polymer. [ABSTRACT FROM AUTHOR]

This study investigates the development and characterization of a novel composite hydrogel composed of polyacrylamide (PAAm), starch, and gelatin for use as an amoxicillin delivery system. The optical properties, swelling behavior, and drug release profile of the composite hydrogel's were studied to evaluate its efficacy and potential applications. UV-visible spectroscopy was employed to determine the optical properties, revealing significant transparency in the visible range, which is essential for biomedical applications. The incorporation of starch and gelatin into the polyacrylamide matrix significantly enhanced the hydrogel's swelling capacity and biocompatibility. Studies on drug delivery demonstrated a sustained release profile of amoxicillin in simulated gastrointestinal fluids, which is essential for maintaining therapeutic levels for a prolonged amount of time. The results indicate that the composite hydrogel of PAAm/starch/gelatin has good swelling behavior, appealing optical characteristics, and a promising controlled drug release mechanism. These results point to this hydrogel's considerable potential as a drug delivery method, providing a viable path toward enhancing the medicinal effectiveness of amoxicillin and maybe other medications. [ABSTRACT FROM AUTHOR]

The primary objective of the present study was to transform discarded agricultural remnants and poultry waste into value-added materials. Rice straw and chicken feathers are disposed of after their primary consumption into landfills or are incinerated, causing pollution and environmental threats. In this study, epoxy composites were fabricated using different volume proportions (5–45%) of these raw and alkali-treated remnants, and their mechanical strength was tested. The flexural strength of the rice straw composites and chicken feather composites initially decreased with the addition of fibers from 5 to 35 vol% and then the values increased when the fiber content was more than 35 vol%. The chicken feather composites showed increased impact strength with fiber addition. Alkali treatment of the rice straw resulted in improved flexural and impact strengths of the composites due to the removal of the waxy layer on the fiber surface, which was observed in the FTIR studies. Alkali treatment of the chicken feathers did not produce any significant change in the flexural strength of the composites, but their impact strength increased with fiber addition. Hybrid composites fabricated using rice straw and chicken feathers exhibited enhanced flexural and impact strength properties both with and without the alkali treatment, corroborating the synergistic effect of these fibers. SEM analysis of the fractured samples showed noteworthy interfacial adhesion between the fibers and matrix. This study presents a better method for converting these disposable materials into value-added usable materials and increasing their life cycle in the circular economy. [ABSTRACT FROM AUTHOR]

The aim of this project was to assess the thermal conductivity of polyethylene (PE) filled with carbon black (CB), specifically for geothermal pipes. The project explored the potential modification of PE's thermal conductivity by incorporating recycled textile fibers. Different types of shredded recycled fibers were tested, including two types of polyamide fibers with varying contaminations and one type of polyester fiber. Following several preparation steps, various composite materials were manufactured and compared to bulk PE using various testing methods: Differential Scanning Calorimetry analysis (DSC), mechanical testing (flexural and tensile), and laser flash analysis (LFA). The results revealed alterations in the mechanical properties of the composite materials in comparison to PE filled with CB. The LFA tests demonstrated the effectiveness in reducing polymer thermal diffusivity at higher temperatures, particularly when the material was loaded with recycled polyester fillers. [ABSTRACT FROM AUTHOR]

A novel modeling approach is developed for investigating the effectiveness of buckypaper (BP), a porous membrane made of a highly cross-linked network of carbon nanotubes, in improving the electromagnetic interference (EMI) shielding properties of carbon fiber-reinforced polymer (CFRP) composites. The methodology uses quantum tunneling-based equivalent electrical circuits and Monte Carlo simulations to predict the frequency-dependent electrical conductivity and EMI shielding effectiveness (SE) of the hybrid BP/CFRP composites. The study examines a signal frequency range of 50 MHz to 12 GHz that includes the very high and X-band. The results show that at a frequency of 12 GHz, the transverse conductivity increases to approximately 12.67 S/m, while the longitudinal conductivity decreases to about 3300 S/m from an initial value of 40,000 S/m. These results are then integrated into the ANSYS High-Frequency Structure Simulator to predict SE by simulating the propagation of electromagnetic waves through a semi-infinite composite shield element. The numerical simulations illustrate that incorporating BP significantly improves the SE of CFRP composites beyond 2 GHz owing to its high conductivity in that frequency range. For instance, at 12 GHz signal frequency, adding a single BP interleaf enhances the SE of a [90, 0] laminate by up to ~64%. [ABSTRACT FROM AUTHOR]

This study is on the mechanical properties of bronze infill poly lactic acid composites fabricated by fused deposition modelling. By changing the nozzle temperature, printing speed, layer thickness and infill density the mechanical properties of the composites were studied. Tensile, flexural and impact strength tests were conducted on the composite specimen. Mathematical models were developed using response surface methodology and the significance of the models was tested using analysis of variance. Increase in infill density and nozzle temperature increased the strengths of the composites. Increase in layer thickness and printing speed decreased the strengths of the composite specimen. Tensile strength is primarily influenced by infill density (38.82%), flexural strength is primarily influenced by Nozzle Temperature contributes (44.02%) while Infill density (58.12%) plays the major role in contributing the impact strength followed by other parameters. The highest tensile strength, flexural strength, impact strength values obtained in this study are 19.3 (N/mm2), 36.08 (N/mm2) and 0.26 (kJ/m2) respectively. The mechanism of the fractured specimen was investigated using scanning electron microscopy. Fracture mechanisms such as cracks, infill gaps, voids, interface, delamination, hillocks, particle pull out, delamination had an effect on the fracture of composite specimens. [ABSTRACT FROM AUTHOR]

This study investigates the mechanical, thermal, and morphological properties of abaca-polyester composites made using lignin from fluorescent perianths of jack fruit. The primary scope of this research is to study the viability of producing lignin from waste jack fruit fluorescent perianths and how it influence the mechanical, wear, creep and flammability properties of abaca-polyester composite. The lignin biopolymer was extracted via thermo-chemical method and composites were prepared using hand layup method. The produced composites were evaluated based on American society of testing and materials (ASTM) standards and the results revealed significant improvements in tensile and flexural strength. The addition of abaca fiber and 3.0 vol% of lignin in PA2 composite shows the highest tensile strength, while the PA3 at 5.0 vol% of lignin shows slight shortfall due to clustering of particle. However the PA3 outperform in impact strength, hardness, and wear resistance. The Flammability test reveals effective self-extinguishing properties for PA3 exhibiting superior performance due to lignin's char-forming capabilities. Moreover, creep and TGA analysis demonstrated that the incorporation of abaca fiber and lignin of 5 vol% contributed to reduced creep strain and mass loss at initial, middle and final stages. SEM analysis confirms the effective interaction of lignin particle with resin matrix and ensured effective toughening. The study concludes the optimization potential of abaca-polyester composites, with 3.0% lignin identified as an optimal concentration for balanced improvements across various properties, providing valuable insights for composite material design and applications. [ABSTRACT FROM AUTHOR]

This study investigates the practical applications of biochar as an innovative and sustainable conductive filler in composite materials. Utilizing the conventional melt-blending method, we prepared conductive pinewood biochar-filled poly(lactic acid)/poly(butylene adipate-co-terephthalate) (PLA/PBAT) composites and systematically examined their electrical, mechanical, rheological and thermal properties. Our results reveal a significant enhancement of electrical and mechanical properties upon the inclusion of conductive pinewood biochar in the PLA/PBAT matrix. With the addition of 10 wt% of conductive pinewood biochar, the average surface resistivity of the composites decreased by three orders of magnitude, measuring $4.86 \times {10^{10}}{\rm{\Omega }}/{\rm{sq}}$4.86×1010Ω/sq, which meets the antistatic requirements for polymer composites. Additionally, the average tensile strength of the biochar filler composites improved by 53% with an addition of just 1 wt% of biochar. [ABSTRACT FROM AUTHOR]

AbstractQuantum dots (QDs) have emerged as transformative nanomaterials in drug delivery due to their unique optical and electronic properties, such as tunable fluorescence, high surface area and size-dependent emission in pharmaceutical origin. When integrated with polymers, this hybrid system offers enhanced functionality for targeted, controlled and stimuli-responsive drug delivery. This review focuses on the synthesis and application of quantum dot-polymer composites in drug delivery, emphasizing their ability to improve drug targeting, sustained release and real-time imaging in therapeutic applications. The multifunctionality of these systems enables personalized medicine approaches, particularly in cancer therapy and neurological disorders. Despite their promising potential, concerns related to toxicity and scalability pose significant challenges for their widespread clinical use. Ongoing research efforts are focused on developing more biocompatible QDs, optimizing the design of polymer-QD hybrids and addressing regulatory hurdles. This review, we believe, provides a comprehensive analysis of current advancements in quantum dot-based drug delivery systems and outlines future directions to overcome the existing limitations and enhance clinical applicability. The integration of quantum dots with polymers represents a significant leap forward in the field of nanomedicine, offering the potential for highly efficient, precise and safe drug delivery platforms. [ABSTRACT FROM AUTHOR]

Polytetrafluoroethylene (PTFE) based microwave dielectric composite has been widely used because of its adjustable dielectric constant and low dielectric loss, but its low thermal conductivity can not meet the heat dissipation requirements of high-power microwave devices. Therefore, it is of great significance to develop microwave dielectric composites with high thermal conductivity and low loss. In order to obtain microwave composite materials with high thermal conductivity and low losses, schistose Al 2 O 3 /PTFE (S-A/PTFE) composites and globular Al 2 O 3 /PTFE (G-A/PTFE) composites were successfully prepared. It is compared whether S-A can combine with PTFE more fully than G-A, which can promote the dielectric properties and thermal conductivity of Al 2 O 3 /PTFE composites. Surprisingly, the S-A/PTFE composites demonstrate higher thermal conductivity, lower thermal expansion and hygroscopic properties. The S-A/PTFE composites can deliver a high thermal conductivity of 0.986 W/m K. Composite substrates with 53 wt% S-A filler exhibits excellent performance, which specifically show credible dielectric constant (ε r = 4.01) and admissible dielectric loss (tanδ = 0.0014 at 10 GHz). Furthermore, the composite substrate shows a similar thermal expansion coefficient to copper, and lower water absorption rate (0.05 %). The relationship between dielectric constant of composite and filler was predicted by different theoretical modeling methods. [ABSTRACT FROM AUTHOR]

Silver nanowires (AgNWs) have excellent electrical conductivity and nano-sized effects and have been widely used as a high-performance electromagnetic shielding material. However, silver nanowires have poor mechanical properties and are prone to fracture during the preparation of composite materials. In this study, PVDF/rGO/AgNW composites with a segregated structure were prepared using low-pressure compression molding and the AgNW-backfilling process. The low-pressure compression of the composite significantly improves its electromagnetic shielding performance because the low-pressure process can maintain the AgNWs' integrity. The backfilled AgNWs played a vital role in increasing the path of electromagnetic wave propagation and the absorption of electromagnetic waves. The backfilled amount of AgNWs was only 1 wt%, which increased the composite material's conductivity by one order of magnitude. The total electromagnetic interference shielding (SET) of the composite materials increased by 23.3% from 24.88 dB to 30.67 dB. The absorption contribution (SEA/SET) increased from 84.2% to 92.8%, significantly improving the electromagnetic interference shielding and the absorption contribution of the AgNWs in the composites. This was attributed to the backfilling of the porous structure by the AgNWs, which promoted multiple reflections and enhanced the absorption contribution. [ABSTRACT FROM AUTHOR]

To improve the reinforcement effect between a binder and high solid filler in a propellant formula, grafting the bonding group into the binder to form a neutral polymeric is a practically novel approach to improving the interface properties of the propellant. In this work, a glycidyl azide polyol energetic thermoplastic elastomer binder with a –CN bonding group (GAP–ETPE) was synthesized, and the mechanical and thermal decomposition mechanism of GAP–ETPE with Hexogeon (RDX) model propellants were studied. The stress–strain results indicated that the tensile strength and strain of GAP–ETPE/RDX model propellants were 6.43 MPa and 32.1%, respectively. DMA data showed that the storage modulus (E') of the GAP–ETPE/RDX model propellants could increase the glass transition temperature (Tg) values, those were shifted to higher temperature with the increase in filler RDX percentages. TG/DTG showed the four decomposition stages of the decomposition process of the GAP–ETPE/RDX model propellants, and the thermal decomposition equation was constructed. These efforts provide a novel method to improve GAP–ETPE/RDX propellants mechanical property, and the thermal decomposition behavior of GAP–ETPE/RDX propellants also provided technical support for the study of propellant combustion characteristics. [ABSTRACT FROM AUTHOR]

Exposure to high levels of radiation can cause acute, long-term health effects, such as acute radiation syndrome, cancer, and cardiovascular disease. This is an important occupational hazard in different fields, such as the aerospace and healthcare industry, as well as a crucial burden to overcome to boost space applications and exploration. Protective bulky equipment made of heavy metals is not suitable for many advanced purporses, such as mobile devices, wearable shields, and manned spacecrafts. In the latter case, the in-space manufacturing of protective shields is highly desirable and remains an unmet need. Composites made of polymers and high atomic number fillers are potential means for radiation protection due to their low weight, good flexibility, and good processability. In the present work, we developed electrospun composites based on polycaprolactone (polymer matrix) and tungsten powder for application as shielding materials. Electrospinning is a versatile technology that is easily scalable at an industrial level and allows obtaining very lightweight, flexible sheet materials for wearables. By controlling tungsten powder size, we engineered homogeneous, stable and processable suspensions to fabricate radiation composite shielding sheets. The shielding capability was assessed by an in vivo model on prototype composite sheets containing 80 w% of W filler in a polycaprolactone (PCL) fibrous matrix by means of irradiation tests (X-rays) on mice. The obtained results are promising; as expected, the shielding effectivity of the developed composite material increases with the thickness/number of stacked layers. It is worth noting that a thin barrier consisting of 24 layers of the innovative shielding material reduces the extent of apoptosis by 1.5 times compared to the non-shielded mice. [ABSTRACT FROM AUTHOR]

Highlights Artificial intelligence (AI) techniques are increasingly used for structural health monitoring (SHM) of polymer composite structures. However, to be confident in the trustworthiness of AI models, the models must be reliable, interpretable, and explainable. The use of explainable artificial intelligence (XAI) is critical to ensure that the AI model is transparent in the decision‐making process and that the predictions it provides can be trusted and understood by users. However, existing SHM methods for polymer composite structures lack explainability and transparency, and therefore reliable damage detection. Therefore, an interpretable deep learning model based on an explainable vision transformer (X‐ViT) is proposed for the SHM of composites, leading to improved repair planning, maintenance, and performance. The proposed approach has been validated on carbon fiber reinforced polymers (CFRP) composites with multiple health states. The X‐ViT model exhibited better damage detection performance compared to existing popular methods. Moreover, the X‐ViT approach effectively highlighted the area of interest related to the prediction of each health condition in composites through the patch attention aggregation process, emphasizing their influence on the decision‐making process. Consequently, integrating the ViT‐based explainable deep‐learning model into the SHM of polymer composites provided improved diagnostics along with increased transparency and reliability. Autonomous damage detection of polymer composites using vision transformer based deep learning model. Explainable artificial intelligence by highlighting region of interest using patch attention. Comparison with the existing state of the art structural health monitoring methods. [ABSTRACT FROM AUTHOR]

Phase change materials (PCM) have greatly contributed to optics with applications ranging from rewritable memories to smart windows. This is possible thanks to the variation in optical properties that PCMs undergo upon thermally‐induced phase change. However, this behavior is accompanied by a loss of optical transparency in one (or more) of their phases, posing a major limitation for transmission‐based functionalities. Here this challenge is addressed by producing PCM‐based composites that remain transparent in the visible spectrum during their phase transition. The cornerstone of this innovative material is the use of 30 nm‐in‐size nanoparticles of paraffin as PCMs, which minimizes the scattering within the polymer host matrix regardless of the paraffin's phase. To demonstrate the potential of this approach, it is shown that thin composite layers can modulate the phase of the incident visible light using temperature, achieving uniform phase profiles with maximum phase shifts up to π radians. Notably, the composites studied exhibit up to threefold larger phase changes for the same input power over reference thermo‐optical materials like polydimethylsiloxane. These findings position paraffin‐based composites as promising materials for various thermo‐optical applications, including wavefront shaping and aberration correction, with the potential to significantly impact a variety of optical technologies. [ABSTRACT FROM AUTHOR]

Polycyclic aromatic hydrocarbons (PAHs) are omnipresent toxic pollutants found in numerous ecosystems, including soil, water, and living organisms. Due to their hydrophobic nature, PAHs tend to accumulate in aquatic environments, leading to high concentrations in aquatic sediments and subsequent bioaccumulation in organisms. This accumulation poses substantial risks to humans and aquatic life. Recent advances in photocatalytic methods, particularly those using nanocomposite materials, have shown promising outcomes in the degradation of PAHs. Photocatalysis, a process that uses UV and visible light to accelerate a chemical reaction, is effectively breaking these harmful compounds. This review focuses on the recent advances in the degradation of PAHs, the toxicological effects of PAHs on living organisms, and the mechanisms underlying nanocomposite‐based photocatalysis. The utilization of nanocomposite for photocatalysis is an eco‐friendly substitute to traditional methods for remediating PAH pollution in the ecosystem. This green approach using nanocomposite‐based photocatalysis offers a sustainable and effective approach for the degradation of PAHs. [ABSTRACT FROM AUTHOR]

Highlights This research focuses on understanding of polymer composites' ability to absorb Radio frequency waves for stealth application, specifically for evading radar detection. The composites were developed using a Carbon‐Graphite base plate layered with carbon fiber mat on both sides reinforced in a polyaniline (PANI) and Graphene oxide (GO) mixed Epoxy matrix with added triethylamine (TEA). Four samples with different volume percentage were fabricated, having same Epoxy of 52%, Hardener of 26% and PANI of 10%, but different volume percentages of GO and TEA. The fabricated composites are named as EPCG‐1 (4% GO and 8% TEA), EPCG‐2 (5% GO and 7% TEA, no Carbon fiber), EPCG‐3 (5% GO and 7% TEA) and EPCG‐4 (7% GO and 5% TEA). The developed composites were characterized by subjecting to tensile testing, Scanning Electron Microscopy analysis, Ultraviolet–visible spectroscopy, Fourier Transform Infrared spectroscopy, Impedance spectroscopy and Directional Coupler test. The EPCG‐4 composites achieve a highest tensile strength of 45.61 N/mm2 and highest absorbance of 1.574 AU corresponding to a wavelength of 875.00 nanometers. The microwave absorbing capacity was evaluated in terms of absorption, reflection and transmission, where the highest shielding efficiency of 32.76 is observed in EPCG‐4 composite when tested in X‐band frequency range (8–12 GHz). Infrared indicated the stretching of bonds like CN and CH due to addition of graphene oxide. The permittivity of the composite is higher for EPCG‐4 composite. Compared to all the tested composites, EPCG‐4 exhibits better mechanical and stealth properties. Development of electromagnetic absorbing composites material for stealth application. Conductive composites of Graphite‐Carbon plate, layered with Carbon fiber mat bonded by PANI and GO mixed Epoxy matrix are prepared. Analyzing radio‐frequency absorption, reflection and transmission of the composites using wave guide method. UV–vis spectroscopy analysis the wave absorbing capacity of stealth composites. Microscopic analysis on stealth composite to understand the conducting fillers distribution. [ABSTRACT FROM AUTHOR]

Highlights The utilization of continuous fiber‐reinforced thermoplastic composites (CFRTP) in additive manufacturing technology (AM) is envisioned to enable the production of high‐performance parts with enhanced mechanical properties. In the production of CFRTP filaments, ensuring proper impregnation plays a crucial role in improving the characteristics of the produced filament. Carbon fiber (CF) reinforced polyphenylene sulfide (PPS) composites find applications in secondary aerospace parts, automotive structural parts, and chemical process applications. Continuous CF‐reinforced PPS filaments enable the production of lightweight, high‐performance parts with mechanical strength, heat, and chemical resistance in AM. In the present study, continuous CF‐reinforced PPS filaments were produced using the melt impregnation method for use in fused deposition modeling technology. Filament diameter, geometrical evenness, and effective fiber impregnation are important criteria in filament production. An impregnation mold was designed and manufactured to provide impregnation. The influence of three different pin angles (56°, 70°, and 82°) on impregnation and mechanical properties has been investigated by developing an impregnation die for CFRTP filament production. Tensile testing, fiber content analysis, optical microscopy, and scanning electron microscope analysis were performed on the produced filaments. Furthermore, increasing the pin angle leads to an increase in both the spreading and impregnation of fibers. Impregnation die for effective wetting of fibers with polymer. Significance of pin angle in fiber spreading and wetting with polymer. Application of test standards for fiber content. [ABSTRACT FROM AUTHOR]

The development of triboelectric nanogenerators (TENGs) using sustainable materials addresses the global electronic waste issue. This research focuses on fabricating a TENG device with biodegradable polylactic acid (PLA) as the tribopositive material and polytetrafluoroethylene (PTFE) as the tribonegative material. ZnFe2O4 nanoparticles are incorporated into the PLA matrix to enhance surface charge density and synthesised via a simple combustion method. PLA-ZnFe2O4 composite films were prepared by solvent casting with varying nanofiller content (0.25, 0.45, 0.65, and 0.85 g). Prepared composites were characterised by Powder X-ray Diffraction (PXRD) for crystalline nature and phase purity, Fourier Transform Infrared Spectroscopy (FTIR) for vibrational analysis, and Scanning Electron Microscopy (SEM) for surface morphology. The inclusion of ZnFe2O4 nanoparticles improves TENG output performance, with a maximum output voltage of 18.4 V and a current of 1.57 µA observed for a PLA (poly(lactic acid)) composite with 39.39% nanoparticle content. Electrical studies on the optimised device show successful charging of various capacitors and powering 20 LEDs and a calculator. Body movements like walking and jumping were also tested to measure voltage and current outputs. These findings highlight new possibilities for developing smart, self-powered electronic devices. [ABSTRACT FROM AUTHOR]

Highlights In a time when global initiatives to lower CO2 emissions are accelerating the shift towards bio‐based products, various efforts are being made to develop wood plastic composites (WPCs) and similar bio‐composites using a variety of raw materials. This paper first showcases benchmark material properties serving as standards and models the composition, for polypropylene‐based WPCs integrating wood flour and maleic anhydride‐modified polypropylene. Subsequently, by applying statistical modeling techniques, we demonstrate an adaptive experimental design that efficiently and rapidly adjusts formulations. Beginning with an empirical dataset (24 samples), we established high‐performing models that articulate the individual contributions of the constituents on ten vital properties of WPCs. Our adaptive experimental design, leveraging nonlinear partial least squares regression and the Bayesian optimization, successfully refined formulations to enhance bending and impact strengths. Notably, we proposed optimal conditions starting from just eight samples with minimal iterations. This study shows that statistical techniques can quickly optimize WPC formulations, making the overall development process faster. By addressing the multiple conflicting properties, these techniques can greatly reduce the time and effort needed for development. Applied several regression methods to analyze ten properties of PP‐based WPCs. Showcased distinct impacts of the formulations of WF and MAPP on WPCs. Implemented the adaptive experimental design for formulation optimization. Enhanced bending and impact strengths in the formulations of WPCs. Advanced sustainable material development with data‐driven approach. [ABSTRACT FROM AUTHOR]

The development of high‐strength and multiple self‐healing polymer materials remains a major challenge. In this study, a hybrid self‐healable polymer using the combination of intrinsic and extrinsic self‐healing is demonstrated. The epoxy resin microcapsules with dynamic disulfide bonded shells are successfully prepared through an interfacial polymerization method, which are then added into the intrinsically self‐healable epoxy resin substrate also containing disulfide bonds. The unique combination structure enables the polymer composites to exhibit high mechanical strength and excellent multiple self‐healing efficiency. On the one hand, the Young's modulus and tensile strength of the material are enhanced due to the reinforcement effect of the fillers. On the other hand, the extrinsic self‐healing strategy of the microcapsules, which released repair agents, can support the intrinsic repairing substrate to improve the self‐healing ability of the material. More interestingly, the design of the disulfide bond structure of the microcapsule shell contributes to the high self‐healing capability of the material during multiple self‐healing processes. [ABSTRACT FROM AUTHOR]

The emergence of additive manufacturing has enabled scientists to efficiently construct complex geometries, facilitating the development of novel, high-impact energy-absorbing structures suitable for a wide range of industrial applications. The present study conducted flexural and impact test to quantitatively assess the energy absorption capabilities of polymer composites fabricated through fused filament fabrication. Specifically, the polymer composites investigated were multi-walled carbon nanotubes reinforced poly-lactic acid, carbon fibre reinforced poly-ethylene terephthalate glycol, and carbon fibre reinforced poly-lactic acid. The investigation also examined the influence of different infill patterns and nozzle hole diameters on the polymer composites. The investigation depicts that by altering the process parameters, the flexural strength is improved from 21.079 MPa to 70.653 MPa by 235.18%. The experimental study of impact specimens utilising the Izod impact test demonstrates that the rectilinear infill pattern and a nozzle hole diameter of 0.6 mm result in the highest energy absorption of 37.76 kJ/m2 for carbon fibre reinforced poly-lactic acid. The study revealed that the energy absorption of the specimens was significantly influenced by both the independent and interaction effects of process variables. The application of the fused filament fabrication demonstrates an improved energy absorption, making it suitable for manufacturing of vehicle and aircraft components. [ABSTRACT FROM AUTHOR]

The antibacterial activity of biomedical polymer materials is an important basis for their resistance to biofilm contamination as implantable medical devices. However, developing durable and stable antibacterial composites through a universal manufacturing method remains a challenge. Herein, based on an organic–inorganic synergistic antibacterial strategy, functional nanoparticles with high antibacterial performance and better polymer compatibility were prepared by combining zinc oxide nanoparticles (ZnO NPs) with quaternary ammonium compound 3-(trimethoxysilyl)-propyldimethyloctadecyl ammonium chloride (QAS), which containing siloxane group. The ZnO-QAS nanoparticles were then introduced to low-density polyethylene (LDPE) by simple melt blending to manufacture synergistic antibacterial composites. The organic–inorganic hybrid strategy significantly improved the antibacterial activity of the composites, the PE/ZnO-QAS composites possess satisfactory antibacterial efficiency of 99.9% and 99.75% against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus), respectively, and it could effectively inhibit biofilms. In addition, the functionalization of organic compound QAS provides excellent polymer compatibility for ZnO NPs, which is conducive to their uniform dispersion in LDPE, and comprehensively improves the thermal stability, mechanical properties, and crystallinity of the composites. This provides potential application value for the preparation of long-term stable antibacterial biomedical materials. [ABSTRACT FROM AUTHOR]

The continuous raise of environmental issues by the polymer products has led to the use of eco-friendly basalt as a reinforcement for the composites fabrication. Basalt reinforcement has attractive qualities such as non-toxicity, ease of processing steps, economical, less harmful, and excellent thermal, and mechanical properties. Basalt loading into different polymer matrices is indeed a comparably novel concept that may offer some very intriguing views, which have not yet been fully explored. The ability of mineral fillers such as basalt powder to reduce the polymer portion in polymer goods by retaining their original characteristics hand out to the establishment of a pollution-free ecosystem and the stabilizing of ecological issues. In this context, the current research aims to manufacture and characterize thermoset (i.e., synthetic epoxy, bio-epoxy, unsaturated polyester, and vinyl ester) and thermoplastic (i.e., polylactic acid, bio-based polypropylene, and bio-based high density polyethylene) composites reinforced with the same weight content (i.e., 30%) of basalt powder. These composites were employed for physical, mechanical, wettability (contact angle analysis), morphological, and water absorption investigations. Moreover, basalt powder was subjected to elemental analysis (Energy dispersive X-ray), particle dimensional analysis, and morphological (Scanning Electron Microscopy) observations. The experimental results revealed that the tensile, flexural, and impact strength characteristics of composites were slightly reduced in comparison to neat polymers because of higher reinforcement. Besides, the tensile modulus, flexural modulus, and hardness values were gradually improved due to the filler effect. The increased water absorption is mainly caused by the voids inside of the composites, which create the quintessential environment for moisture to seep into the interface. Differential scanning calorimetry analysis reveals that the filler has successfully maintained the chain relaxation with the reduction of molecular movement and achieved stability as equivalent to a 100% polymer system, despite the incorporation of basalt by reducing the 30 wt% polymers. Except for synthetic epoxy composite, the remaining polymer composites have shown enhanced thermal conductivity values than neat polymers. However, the obtained findings can be considered satisfactory for prospective applications concerning lightness and environmental friendliness. [ABSTRACT FROM AUTHOR]

The aim of this work is to investigate new, relatively cheap and effective catalyst, which could be used as PP fillers in the primary production of polymer matrix composites with improved mechanical properties and, at the same time, characterized with high catalytic activity in the process of the PP-based composites recycling by the thermo-catalytic cracking. Two kinds of the protonated potassium polytitanate (PPT), having platy shape of particles and characterized with low friction coefficient and high reflectance of UV radiation, but different Ti4+/Ti3+ molar ratio, are investigated as such functional fillers. It is shown that the admixture of the PPT fillers (10 wt.%) allows obtaining the PP-matrix composites characterized with increased values of Young modulus and, especially, wear resistance, in comparison with the materials filled with talc. It is shown that the PP matrix composites containing the PPT fillers can be directly used for pyrolytic processing due to high catalytic activity in the cracking processes taking place at moderate temperatures (~ 450 °C). The chemical composition of gaseous and liquid products, obtained as a result of this processing, is investigated. Some differences in the chemical composition of the products are considered taking into account chemical and structural features of the PPT and zeolite catalysts. [ABSTRACT FROM AUTHOR]

The progress in polymer science and nanotechnology yields new colloidal and macromolecular objects and their combinations, which can be defined as complex polymer materials. The complexity may include a complicated composition and architecture of macromolecular chains, specific intermolecular interactions, an unusual phase behavior, and a structure of a multi-component polymer-containing material. Determination of a relation between the structure of a complex material, the structure and properties of its constituent elements, and the rheological properties of the material as a whole is the subject of structural rheology—a valuable tool for the development and study of novel materials. This work summarizes the author's structural–rheological studies of complex polymer materials for determining the conditions and rheo-manifestations of their micro- and nanostructuring. The complicated chemical composition of macromolecular chains and its role in polymer structuring via block segregation and cooperative hydrogen bonds in melt and solutions is considered using tri- and multiblock styrene/isoprene and vinyl acetate/vinyl alcohol copolymers. Specific molecular interactions are analyzed in solutions of cellulose; its acetate butyrate; a gelatin/carrageenan combination; and different acrylonitrile, oxadiazole, and benzimidazole copolymers. A homogeneous structuring may result from a conformational transition, a mesophase formation, or a macromolecular association caused by a complex chain composition or specific inter- and supramolecular interactions, which, however, may be masked by macromolecular entanglements when determining a rheological behavior. A heterogeneous structure formation implies a microscopic phase separation upon non-solvent addition, temperature change, or intense shear up to a macroscopic decomposition. Specific polymer/particle interactions have been examined using polyethylene oxide solutions, polyisobutylene melts, and cellulose gels containing solid particles of different nature, demonstrating the competition of macromolecular entanglements, interparticle interactions, and adsorption polymer/particle bonds in governing the rheological properties. Complex chain architecture has been considered using long-chain branched polybutylene-adipate-terephthalate and polyethylene melts, cross-linked sodium hyaluronate hydrogels, asphaltene solutions, and linear/highly-branched polydimethylsiloxane blends, showing that branching raises the viscosity and elasticity and can result in limited miscibility with linear isomonomer chains. Finally, some examples of composite adhesives, membranes, and greases as structured polymeric functional materials have been presented with the demonstration of the relation between their rheological and performance properties. [ABSTRACT FROM AUTHOR]

The structural, optical and acoustical properties of a polymer composite of sodium sulfate (Na2SO4) doped polyvinyl pyrrolidone (PVP) were studied. The simple chemical route method was utilized for the preparation of the polymer composite by varying the concentration of Na ions in the PVP. The pure 3% PVP solution was mixed with five different concentrations of Na2SO4 solutions in the ratio of 80:20. X-ray diffraction (XRD) spectra of PVP/Na2SO4 (1.0% of Na2SO4 in 3.0% of PVP) confirmed the crystalline nature of the PVP/Na2SO4 polymer composite. The identification of several chemical functional groups contained in the PVP/Na2SO4 was demonstrated by Fourier transform infrared (FTIR) spectroscopy. The FTIR showed the excellent interaction between the polymer (PVP) and the dopant Na2SO4. Optical studies were performed by utilizing a UV-visible absorbance spectrophotometer. The UV-VIS spectroscopy results indicated that absorption increased in an asymmetric manner and the absorption peak showed a red shift with increasing Na ions concentration in the host PVP. The optical band gaps (direct and indirect) were found to decrease with increase in Na ions concentration in the polymer due to increase in the density of localized states in the band-gap. The activation and Urbach energies were evaluated from the conductivity measurements and the absorption coefficient, respectively. Several acoustical parameters, viz. ultrasonic velocity, density, viscosity, adiabatic compressibility, intermolecular free length, acoustic impedance, and surface tension, were also computed. The ultrasonic velocity, acoustic impedance, density, viscosity, and surface tension of the polymer solutions were found to increase while the adiabatic compressibility and intermolecular free length decreased with the addition of increasing amounts of Na ions in PVP. [ABSTRACT FROM AUTHOR]

In this work, we studied the preparation of graphene dispersions by liquid-phase ultrasound exfoliation in aqueous solutions, using amphiphilic stabilizers, such as Pluronic F108 (Plu) and polyvinylpyrrolidone (PVP), as well as in N-MP. The resulting dispersions were characterized by TEM, dynamic light scattering, UV spectroscopy. Optimal conditions for ultrasonic treatment of few-layer graphene dispersions were established, which make it possible to obtain stable concentrated graphene dispersions (1–4 layers) with lateral dimensions of 50–2000 nm. Based on the developed graphene dispersions, composite films with various polymer matrices (polylactide, collagen, chitosan), using graphene as nano-filler, were obtained. The presence of the latter provided electrical conductivity up to 0.9 S cm−1, a change in electrical resistance during deformation with a strain sensitivity coefficient of 1.3–5.7, as well as an increase in breaking stress up to 97.1 ± 1.6 MPa and in elastic modulus up to 3.99 GPa. The designed films possess a wide variety of properties and are promising for use as flexible biosensors for biomechanical studies and electrically conductive matrices for tissue engineering. [ABSTRACT FROM AUTHOR]

Porphyrin–polymer systems are promising materials for their use in biotechnology, biochemistry, and medicine. The creation of composite materials from porphyrins expands the possibilities of using both high molecular weight compounds and porphyrins. Polylactide–porphyrin film samples obtained by solution watering method are studied in this work. It was found that the density of the film compositions decreases with an increase in an amount of porphyrin in the polymer matrix. A Soret peak of porphyrin immobilized into the polylactide matrix splits (425 and 447 nm) and shifts bathochromically. The addition of 5,10,15,20-tetrakis(4-n-hexyloxyphenyl)porphyrin changes the elastic behavior and strength properties. Shear modulus, elastic modulus, and tensile strength decrease with an increase in an amount of porphyrin in the polylactide matrix. Relative elongation at break increases slightly, and the Poisson's ratio is almost unchanged compared to those of starting polylactide. [ABSTRACT FROM AUTHOR]

Abstract Natural fibres are abundant, renewable, and biodegradable, which has inspired numerous academics worldwide to investigate their possible applications in various industrial fields. The food packaging sector is seeking bio-based and biodegradable substitutes to increase sustainability. In this study, new composites were prepared from natural rubber (NR) and sugarcane bagasse fibres (SCB) with different concentrations of SCB (0, 2.5, 5, 10 &20 phr). The effect of SCB on the properties of natural rubber was studied before and after the alkaline treatment of the fibres. The biocomposites are characterized using Fourier transmission infrared spectroscopy, thermogravimetric analysis, scanning electron microscope, transmission electron microscope, and dielectric measurements in addition to rheological and mechanical analysis. The overall migration test for biocomposites loaded with 20phr SCB was performed to assess the biocomposite’s safety as food contact materials. The study’s results indicated that, adding SCB improved the conductivity, tensile strength, and elongation at break of natural rubber. Alkaline treatment strengthened the bonding between the filler and matrix and improved biocomposites’ thermal dielectric and mechanical properties. The overall migration test indicated that the alkaline treatment increased the overall migration to simulants. Accordingly, alkaline-treated NR-SCB biocomposites are effective eco-friendly food packaging candidates for certain types of food such as aqueous non-acidic products.

This study investigates the practical applications of biochar as an innovative and sustainable conductive filler in composite materials. Utilizing the conventional melt-blending method, we prepared conductive pinewood biochar-filled poly(lactic acid)/poly(butylene adipate-co-terephthalate) (PLA/PBAT) composites and systematically examined their electrical, mechanical, rheological and thermal properties. Our results reveal a significant enhancement of electrical and mechanical properties upon the inclusion of conductive pinewood biochar in the PLA/PBAT matrix. With the addition of 10 wt% of conductive pinewood biochar, the average surface resistivity of the composites decreased by three orders of magnitude, measuring [Formula: see text], which meets the antistatic requirements for polymer composites. Additionally, the average tensile strength of the biochar filler composites improved by 53% with an addition of just 1 wt% of biochar.

New applications and modern methods are described for manufacturing gears made of polymer composites using additive (3D printing) and microelectronics technologies (burning and rapid prototyping from photopolymers). The methods of calculation of the load-bearing capacity, wear and durability of polymer and metal-polymer gears (straight and helical spur, bevel) are considered which are based on methodology of composite mechanics and phenomenological model of fatigue wear during sliding friction. The application of analytical solutions for fast parametric analysis of the stress-strain state of gears is shown, as well as the use of their spatial discretization by finite and boundary elements, taking into account the real geometry of engagement. The use of gears in drives of microelectromechanical systems and the specifics of calculations due to the strengthening of adhesive interaction in tooth contact of miniature gears are considered. The features of the deformation of polymer composites, as structurally inhomogeneous and physically nonlinear materials are noted, which should be taken into account when determining the kinematic accuracy of gears. In this regard, the possibilities of a three-level method are discussed for designing gears made of dispersion-filled polymer composites according to the criteria of strength, deformability and wear resistance. The proposed method provides an iterative procedure for optimizing the material composition and gear parameters, each stage of which includes analytical modeling of the dispersion-reinforced composites used (microlevel), computational and experimental verification of micromechanical models on test samples (mesolevel) and numerical analysis of the stress-strain state of gears by finite element method (macrolevel).

This study explores the transformative potential of calcium lignosulfonate (CaL) as a sustainable additive in rubber composites based on nitrile rubber (NBR) and styrene-butadiene rubber (SBR). Through comprehensive mechanical testing, fatigue crack growth (FCG) analysis, and scanning electron microscopy (SEM), we evaluated the tensile strength, elongation at break, surface morphology, and crack growth behavior of these innovative composites. By incorporating CaL into carbon black-reinforced rubber compounds (RUB/CB) based on nitrile rubber and styrene-butadiene rubber, we achieved good dispersion of both components as well as satisfactory morphology, resulting in tensile strengths of 16.3 and 12.7 MPa, respectively. While the CB/CaL hybrid did not significantly influence the intrinsic strength of the rubber samples, the ultimate strength of these compounds increased drastically – over five-fold compared to RUB/CB – indicating great potential for real-life applications. This study underscores the promise of lignin-based additives in the development of eco-friendly, high performance rubber materials. [ABSTRACT FROM AUTHOR]