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In recent years, additive manufacturing (AM) has seen extensive exploitation in the research areas for the processing of fiber-reinforced polymer composites (FRPCs). Existing reviews on AM have recommended either sustainable production methods or have introduced new processing methodologies. A relationship between materials used, manufacturing processes, process parameters, and their properties is essential in any manufacturing process. Accordingly, this review focuses on the manufacturing of FRPCs in relation to process parameters and properties of the polymer composites. Various studies dealt with the lightweight materials and parts that were manufactured through AM and which could retain the mechanical and other properties without compromising the strength and weight of the final product. The technologies involved in the major AM processes and the constituents used for the fabrication of FRPC parts, their advantages, and drawbacks are also deliberated. This review combines the material selection for AM technologies along with the choice of proper AM technique for printing FRPCs. This review further illustrates the recent research and technology that aims at embracing FRPCs into a circular economy. In summary, this review opens the door for new opportunities and for meeting challenges in the manufacturing of FRPCs by AM methodologies.

The global increase in polyethylene terephthalate (PET)-based waste fiber poses a persistent environmental risk. While efforts have been made to repurpose waste fibers into bags, clothing, and building materials, the depolymerization process to extract pure raw materials for recycling remains underdeveloped. This study investigates the impact of normal hexane treatment on the purity of terephthalic acid (TPA) recovered from wastewater containing sodium terephthalate, ethylene glycol, and impurities generated during polyester fabric weight reduction or waste fiber recycling processes. Nuclear magnetic resonance analysis of the recovered TPA (rTPA) revealed a maximum purity of 99.81%, suggesting the effective removal of diverse contaminants such as adhesives and surfactants present in waste fibers through normal hexane and activated carbon treatments. This research contributes to the development of efficient and sustainable PET waste fiber recycling processes, highlighting the potential of normal hexane treatment in enhancing the purity of rTPA.

The effect of long chain content (XL) on the static crystallization and tensile deformation mechanisms of bimodal HDPE/UHMWPE was investigated by molecular dynamics simulations. The crystallization of HDPE/ UHMWPE undergoes three stages: nucleation, rapid growth of lamellar crystals, and stabilization. The increase of XL leads to the formation of more nucleation sites, which promotes nucleation, but at the same time leads to an increase of entanglement sites, which is not conducive to the movement of the long chains to the growth front to fold and form lamellar crystals. Tensile deformation is performed on the crystallized models and the systems exhibit three stages: elastic deformation, plastic deformation and stress hardening. During deformation, the increase of XL improves the orientation nucleation and crystallinity (Xc), but when XL exceeds 4 wt.%, the entanglement effect becomes more pronounced, leading to a decrease in Xc. The effect of temperature is also taken into account: at low temperatures, a suitable range (2-4 wt.%) exists to optimize the mechanical properties of the material. At high temperatures, there is almost no stress-hardening phenomenon, but the addition of long chains has an impeding effect on the melting of the lamellar crystals, and when XL is greater than 8 wt.%, stress-induced melting is more likely to occur, accelerating the melting of the crystals.

The presence of ultrahigh molecular weight species in polymer melt facilitates the formation of highly-oriented crystalline structures and favors the improvement of mechanical properties. However, due to the random copolymer chain architecture, it is difficult to obtain high orientation of crystals for polypropylene random copolymers (PPR). In this work, two binary blends including polypropylene (PP)/ultrahigh molecular weight polyethylene (UHMWPE) and polypropylene random copolymer (PPR)/UHMWPE were fabricated via solution blending and subsequent melt shear through mini-injection molding. It was found that a highly-oriented crystalline structure forms under shear flow in both blend series. The tensile strength of PP blends increased from 38.3MPa to 43.8MPa while the PPR blends showed a more significant property enhancement and increased from 32.5MPa to 38.1MPa. Importantly, PPR showed an increased miscibility with UHMWPE in comparison with PP due to the existence of ethylene segments. The tensile toughness of PPR samples was greatly maintained especially for blends with small addition of UHMWPE, which may be ascribed to the crack-suppression effect originated from well dispersed UHMWPE domains (particle size < 0.50 μm) locked by the cocrystal structures between PPR segments and molecularly mixed PE chains.

This research aims to determine and quantify the radiation shielding characteristics of high-density polyethylene/ tungsten oxide (HDPE/WO3) nanocomposites including the linear attenuation coefficient (μ), mass attenuation coefficient (μ/ρ), half-value layer (HVL) and tenth-value layer (TVL) for photons at various energies using Geant4, XCOM, and experiment. Thus, HDPE was chosen as the polymer matrix. Then, the samples at various concentrations of WO3 nanoparticles (0, 1, 2, 3, 4, 5, 6, and 9.5 wt.%), different graphene oxide (GO) weight percentages (0, 0.25, 0.5, and 1 wt.%), and 10 and 20 wt.% linear low-density polyethylene (LLDPE) were fabricated. An NaI (Tl) scintillation detector was used to measure the shielding quantities using the 201Tl, and 99mTc sources at three energies of 135, 140, and 167 keV. The experimental results demonstrated that the addition of GO and LLDPE to the HDPE matrix resulted in a more uniform sample. Incorporating 20% LLDPE into the HDPE polymer matrix for the 99mTc resulted in an 18% rise in μ compared to pure HDPE. Finally, the experimental results revealed a comparatively good agreement with the Geant4 and XCOM simulations.

Polymers can be natural or synthetic and are largely used in several applications due to their versatile properties. Polymers can vary widely in their properties and applications, and they are a fundamental part of our everyday life. Polypropylene (PP) is a thermoplastic polymer from the polyolefin family. It is among the most widely used plastics in various automotive and packaging industries. Although PP is widely used in commodity range, still its applications are restricted in niche areas due to lack of toughness which can be improved by incorporation of rubbery materials or fillers. Graphene (G) is one of the nanomaterials used to strengthen polypropylene. Graphene is recognized for its outstanding thermo-mechanical properties, making it a highly desirable material in various fields of science and technology. Benefits gained by incorporation of graphene nanoparticles into polypropylene are studied by researchers. In this study, a finite element analysis is performed which shows the mechanical behaviour of PP and G using ANSYS, which is one of the most powerful finite element analysis (FEA) softwares that can help to perform such simulations to understand stress, strain, deformation of components before actual experimentation. The bending load of 100 N and 1400 N in vertical z-direction are applied for 100% PP model, 100% G model and 50% PP+50% G model and the linear part of stress-strain curve is captured in this analysis.

Describing the solidification process is very important in polymer processing. In polypropylene (PP), the increase of viscosity, named stiffening or hardening, is determined by a rise in crystallinity. When PP flows in a channel or is stretched on a chill roll, the stress induces an anticipated crystallization and thus can lead to an unexpected solidification. This study explores how flow fields influence the crystallization behavior of PP. A controlled-stress rheometer was used to investigate the effect of short shear stress steps on crystallization kinetics. The results revealed that applying a stress step significantly increased the rate of crystallization compared to a non-stressed sample. This acceleration is attributed to the stress-induced orientation of macromolecules, which promotes nucleation. Furthermore, longer durations of applied stress led to a faster increase in viscosity, indicating a higher nucleation density with increasing stress exposure. A mastercurve approach validated the consistency of the model describing the stress-crystallization relationship. The calculated parameter relating to nucleation density confirmed a linear increase with stress duration, allowing estimation of the nucleation rate during shear.

This research aims to determine and quantify the radiation shielding characteristics of high-density polyethylene/ tungsten oxide (HDPE/WO3) nanocomposites including the linear attenuation coefficient (μ), mass attenuation coefficient (μ/ρ), half-value layer (HVL) and tenth-value layer (TVL) for photons at various energies using Geant4, XCOM, and experiment. Thus, HDPE was chosen as the polymer matrix. Then, the samples at various concentrations of WO3 nanoparticles (0, 1, 2, 3, 4, 5, 6, and 9.5 wt.%), different graphene oxide (GO) weight percentages (0, 0.25, 0.5, and 1 wt.%), and 10 and 20 wt.% linear low-density polyethylene (LLDPE) were fabricated. An NaI (Tl) scintillation detector was used to measure the shielding quantities using the 201Tl, and 99mTc sources at three energies of 135, 140, and 167 keV. The experimental results demonstrated that the addition of GO and LLDPE to the HDPE matrix resulted in a more uniform sample. Incorporating 20% LLDPE into the HDPE polymer matrix for the 99mTc resulted in an 18% rise in μ compared to pure HDPE. Finally, the experimental results revealed a comparatively good agreement with the Geant4 and XCOM simulations.

Polyvinyl alcohol (PVA) is well-known for its excellent mechanical properties and eco-friendliness in food packaging. Recently, PVA has gained significant attention in research due to its potential as antibacterial substrates. However, because of its high hydrophilicity, practical application of pure PVA film has been limited by low water resistance and rapid bacterial growth in humid conditions. Diverse effective strategies have been developed to decrease hydrophilicity and endow films with antibacterial properties. This review provides an overview of universal antibacterial agents and their functions in PVA-based packaging films. It also introduces the changes in the mechanical and physical properties of PVA-based films after adding antibacterial agents. Additionally, the release behavior of antibacterial agents in PVA-based film materials and their practical applications in the food industry is discussed in fresh food packaging. Biodegradability of PVA-based films is also mentioned, with a promising future for more effective and eco-friendly food packaging materials.

Abstract Microplastics accumulate in the environment but methods to extract particles from sediment for quantification and identification often lack accuracy and reproducibility. Existing methods vary greatly and many do not achieve adequate microplastic separation. During method development for extraction procedures, spike-recovery experiments (positive controls) are essential to ensure accurate and reproducible results from each sample matrix. Furthermore, the large variability in grain size and organic matter can affect the extraction of microplastics from the matrix. Scientists have used density separation to separate microplastics from matrices for decades, but apparatuses are often made of plastic, need to be custom made, and require multiple sample transfers from one apparatus to another. This study presents an affordable, easily accessible, and simple to use Density Separation Device (DSD) to remove plastics from deep-sea sediments. Eight polymers were spiked into replicates of environmental sediment, including six fragments: high density polyethylene (HDPE), polypropylene (PP), polyvinyl chloride (PVC), polystyrene (PS), nylon (PA6), and crumb rubber (CR) and two fibers: cellulose acetate (CA) and polyester (PEST). Two size classes of polymers were used: 100 μm to 300 μm and > 300 μm. Using a sodium polytungstate solution at a density of 1.9 g/mL and reflectance FTIR microscopy for particle identification, mean recoveries of all fragments exceeded 78% (CR: 92.7% ± 30.8%, PP: 78.4% ± 34.0%, HDPE: 93.8% ± 13.5%, PS: 86.9% ± 25.7%, PA6: 98.4% ± 63.2%, PVC: 100.0% ± 12.4%). Fiber recovery was much lower (PEST: 28.1% ± 28.1% and CA: 25.9% ± 17.3%) because they aggregated, passed through sieves vertically, or were obscured under other particles. The fragment recovery success, accessibility (available online, all parts under $200) and ease of use of this DSD should facilitate widespread use, thus helping to standardize sample preparation methods for microplastic metrology.

Abstract Microplastics persist as a challenging pollutant in agroecosystems, posing potential risks to soil health and crop productivity. Root growth, elongation and expansion may significantly influence the vertical transport and infiltration of microplastics into the soil profile. Wheat plants (Triticum aestivum) grown in 70 cm deep rhizotrons were investigated for their influence on the vertical movement of two prevalent microplastic shapes, polyester fibres and polyvinyl chloride (PVC) fragments. Wheat was chosen for its dense and extensive fibrous and fine root system, which is a robust model for studying root-soil-microplastic interactions. Microplastics at a 0.24% w/w dry soil weight concentration were homogeneously distributed in the topsoil (0–20 cm). Infiltration of polyester fibres up to 50 cm into the soil profile was discerned as strong adherence to plant roots. PVC fragments exhibited greater mobility, reaching depths of 70 cm in the presence and absence of wheat plants. Plant growth response on exposure to microplastics appeared in the form of increased root branching and decreased shoot biomass, indicating a stress response in wheat plants. The results prove the vertical movement of microplastics, while the infiltration depth was influenced by microplastic shape. Movement was detected as either strong adherence of polyester fibres to plant roots or infiltration of PVC fragments. PVC fragments may have infiltrated through preferential flow paths in soil pores and the fissures created by root elongation and water movement.

Abstract The ongoing international negotiations on a global plastics treaty will have pivotal implications for future efforts to transform the plastic economy. This is essential since the current use of plastic in the economy impacts the environment beyond the planetary carrying capacity. To ensure that the forthcoming Treaty can provide the foundation for this transition, the best available science must be made available in the negotiations, but with no formal scientific mechanism to inform the negotiations process, this is not ensured. The Scientists’ Coalition for an Effective Plastic Treaty serves as an example of how the global scientific community has self-organized and come together to address this task, working with five different categories of science-policy communication. The Scientists’ Coalition’s work is made transparent here with the hope that it can inspire organization of scientific input into other future policy areas.

Abstract Banana fibers being highly strong and biodegradable, have always been an interesting aspect of polymer science. The research examines the pretreatment process to enhance the dyeability of banana fibers with synthetic dyes, followed by the preparation of polypropylene (PP) composites with dyed fibers to explore their mechanical properties. Raw banana fibers were extracted from the pseudo stems of banana plants for pretreating with sodium hydroxide and hydrogen peroxide and further dyed in the exhaust method using direct, basic, reactive, and vat dyes. Despite a decrease in fiber strength, the scoured‐bleached fibers appeared whiter and lustrous compared to untreated fibers. Direct dye exhibited a higher color strength (K/S) value of 20.7 and better wash fastness on average of 4‐3 rating compared to basic dye. Later polypropylene sheets were prepared using a Hot Plate Molding Machine, and composite specimens were fabricated by sandwiching the fibers between PP sheets and hot pressing. Fourier Transform Infrared Spectroscopy (FTIR) analysis revealed minor bond formations between the dyed fibers and polypropylene matrix in composites showing significant bonding at NH, CH, and OH regions. The composites containing dyed fibers showed slight improvements in tensile strength and modulus which is at best 2% than that of untreated fiber. Highlights Direct and basic dyes were determined as the most suitable synthetic dyes. FTIR analysis revealed minimal bond formation between the fiber and PP matrix. Composites having dyed banana fiber showed little better mechanical features.

Abstract As a consequence of their magnificent performance like mechanical, electrical and chemical properties, multiwalled carbon nanotubes (MWCNTs) are widely used as a secondary reinforcement in composite field. It has been developed by arc discharging process under atmospheric pressure. Subsequently, MWCNTs doped nano‐composite were developed through hand lay‐up and followed by vacuum bagging techniques. Quasi – isotropic symmetrical laminate of eight layers (0/90)/(±45)/(±45)/(0/90)//(0/90)/(±45)/(±45)/(0/90) were fabricated under room temperature. To fabricate the composite laminates, purified MWCNTs were homogeneously dispersed in glass fiber reinforced epoxy with 0.5%, 1.25%, and 2 wt% loading. Tensile strength, tensile modulus, strain to failure and fracture behavior of unfilled and MWCNTs doped composite laminates were evaluated. Field emission scanning electron microscope (FE‐SEM) was employed to evaluate the structural and morphological characteristics of advanced nano‐composites. Reinforcement effect is found to be more pronounced in 1.25% MWCNTs embedded glass fiber reinforced polymer. This reinforcement effect was corroborated by tensile fractography which depicted by hackle region. Results indicated that tensile strength of 1.25 wt% nano‐composite increased by 47.36% with respect to 0.5 wt% MWCNT doped composites. Highlights Development of multi‐walled carbon nanotubes (MWCNTs) by arcing process. Fabrication of MWCNTs doped glass fiber reinforced polymer (GFRP) composites. Mechanical characterization of nano‐composites. Modeling of nano‐composites by Halpin‐Tsai equation. Fractrography of nano‐composites in details.

Abstract New data analysis based on a spring‐dashpot model is developed to provide very close simulation of stress variation in polyethylene (PE) when subjected to a multi‐relaxation (MR) test. The model consists of a quasi‐static branch and two (long‐ and short‐term) viscous branches. The study shows that viscous stresses applied to the two dashpots and the model parameters can be quantified as functions of displacement (stroke) by simulating closely the stress variation in relaxation. Using these parameters, influences of stress triaxiality and material grade on PE's stress response at relaxation stages are examined, and along with experimental data at the loading stages, spring constants in the two viscous branches are determined. The results indicate that among three PE grades, spring constants and their trend of variation are similar in the long‐term viscous branch, but not in the short‐term counterpart. The results also show that by decreasing specimen gauge length 10 times to increase stress triaxiality, spring constants in the two viscous branches become closer to each other. The work concludes that the new data analysis can determine all parameters in the model, which can then be considered to quantify the role of the viscous stress response for PE's load‐carrying performance. Highlights Use a simple model to simulate complex, multiple relaxation behaviors of PE. Determine all model parameter values to characterize PE's relaxation behavior. Illustrate the effect of stress triaxiality on PE's viscous stress response. Show the similarity and difference of the viscous stress response among 3 PEs.

Abstract In the face of mounting environmental concerns, the textile industry is undergoing a pivotal transformation, with sustainability at the forefront of innovation. This review focuses on the exploration of natural compounds, renowned for their antimicrobial properties, as viable alternatives to conventional chemical agents that pose significant environmental challenges. It delves into a diverse array of natural sources, including plant extracts, essential oils, and microbial‐derived compounds, which have been identified for their potent antimicrobial efficacy. These natural agents not only demonstrate a broad spectrum of activity against pathogenic microorganisms but also represent a stride towards eco‐friendly textile processing by offering a sustainable substitute for synthetic antimicrobials. The integration of these green antimicrobial agents into textiles is scrutinized, with a particular emphasis on their impact on enhancing fabric functionalities. This includes improvements in durability, wash resistance, and the sustained antimicrobial effectiveness of treated fabrics, without sacrificing environmental integrity. Moreover, the study underscores the potential health benefits of these natural agents, such as a decrease in allergic reactions and skin irritations commonly associated with traditional antimicrobial treatments. The review culminates by highlighting the significant role these eco‐conscious solutions play in revolutionizing antimicrobial textiles, promoting industry‐wide sustainable practices, and catering to the escalating consumer demand for environmentally responsible products. Highlights Provides eco‐friendly and sustainable alternatives in textile processing, offering a greener choice over synthetic options. Enhances fabric functionality while preserving environmental integrity, addressing sustainability concerns throughout production. Improves fabric durability, wash resistance, and long‐lasting efficacy, thereby contributing to superior product performance. Reduces allergic reactions and skin irritations, underscoring the health benefits of eco‐friendly antimicrobial treatments. Promotes sustainable practices, shaping the future of antimicrobial textiles and catering to the growing demand for environmentally conscious consumer choices in the industry.

Abstract The expanded graphite (EG) was used as a filler in EG/polyurethane (PU) composite foams for electromagnetic interference shielding (EMI). The EG/PU composite foams were characterized by Fourier transform infrared spectroscopy (FTIR) and SEM. The shielding effectiveness (SE) of the EG/PU composite form containing 5 wt% EG was −24 dB at 5 wt% in the 8–12 GHz range. The optimal EG loading was 3 wt% and the corresponding EG/PU composite foam had a total SE of −18.9 dB and fairly good mechanical characteristics (compressive strength: 13.43 MPa and compressive modulus: 4.95 MPa). These attributes position the EG/PU composite foam as a promising candidate for diverse EMI SE applications. Highlights Synthesis by thermal exfoliation and characterization by x‐ray diffraction, Raman and SEM of EG. Preparation of EG/PU foams for enhanced EMI SE. Optimization of the EG loading with regard to SE and mechanical properties of the EG/PU foams.

Abstract E‐glass fibers are widely preferred due to ease of processing and its low cost, which has substantial scope in the fields of electronics and electrical insulation applications. Because of its low strength and corrosion resistance, use of E‐glass fibers is limited in aerospace and automotive applications. There is a need for enhancing the properties of the composite to overcome such limitations. Therefore, an attempt is made to introduce multi‐walled carbon nanotubes (MWCNT) as fillers into E‐glass fibers to meet the industry needs. In the current study, woven glass fiber of 5 layers and multi‐walled nano carbon fillers of 2, 4 and 6 by wt%, LY556 epoxy resin, and HY951 hardener were used to prepare 4 different type of composites along with the neat epoxy glass fiber reinforced polymer composites (GFRP). The hand‐layup route was used in the composite preparation due to its low cost, technological feasibility, and simple process setup. The developed samples were characterized for mechanical properties via tensile, flexural and impact tests. Tribological characteristics were performed by air jet erosion test. Chauvenet's criterion is applied for identifying the outliers (if any) from the data of repeated test properties. Taguchi's L9OA (orthogonal array) is selected for obtaining optimal hybrid composite, which yield better mechanical properties. Empirical relations are developed for the material properties in terms of process variables. The sample (4 wt% MWCNT) exhibited enhancement of 17.27% in tensile strength, 6% of impact strength and 7.3% of flexural strength when compared with neat epoxy GFRP. This hybrid composite is considered for thermal aging and observed at 60°C, 8% increase in tensile, 7% increase of impact and 15% in flexural strength due to the precipitation on carbon nano tubes along the gain boundaries. The present study recommends 4% MWCNT fillers in developing hybrid glass epoxy polymer composites for use in aerospace, automotive and civil construction industries due to economic and technological feasibility. Highlights Utilize low‐cost E‐glass fibers in electronics and electrical insulation applications. Improve composite properties for aerospace and automotive industries. Develop hybrid glass epoxy composites with 2 to 6 wt% MWCNT fillers. Examine wear characteristics under air jet erosion and study the impact of thermal aging on mechanical properties. Apply Chauvenet's criterion for outlier identification in measured properties datasets.

Abstract Jarosite, an industrial waste, has the potential to be used as an alternative filler in biocomposites used as packaging material and can replace nondegradable thermoplastic. Such a novel approach of waste management strategy has not been studied till date. In this research work, different weight percentages of jarosite were mixed with poly(vinyl alcohol) (PVA) to fabricate polymer composites with better physico‐chemical, thermal, tensile, and biodegradation properties. The data indicate that a low concentration of jarosite (3 wt.%) improved the tensile strength by 198.7% and the composite showed higher thermal stability by 6.3% than that of the neat PVA. X‐ray diffractogram and transmission electron microscopic analysis revealed a strong interaction between PVA and jarosite. Interestingly, the addition of jarosite reduced the water absorption capacity and thickness swelling of the PVA composite by 58% and 54.7%, respectively. Jarosite‐incorporated composites showed lesser degradation potential (64%) than the control composites (84%) after 60 days under soil burial conditions, indicating that PVA‐jarosite composites have a higher shelf‐life, which is needed for packaging materials. These composites can also be good alternant for thermoplastic used in preparation of cuboid, sealing, and decorative materials. Also, this would be a novel sustainable approach for managing/reducing jarosite waste. Highlights Jarosite was reinforced with PVA to fabricate biocomposites. The maximum tensile strength of the composite was achieved as 45.4 MPa. The thermal stability of mechanically optimized composite is found at 320°C. After 60 days under soil burial, the composite lost 64.8% of its original weight. Developed composites can be good alternant for nondegradable thermoplastic.

Abstract Natural fiber‐reinforced polymer composites (NFRCs) are increasingly favored over synthetic fiber‐reinforced alternatives due to their beneficial properties and environmental sustainability. Mechanical properties of composites are critical to ensure optimized utilization of NFRCs. Here, this research explores the effects of different fiber parameters on the tensile strength of high‐density polymer composites reinforced with banana fiber and utilizes the Taguchi method for both experimental and statistical analysis of the outcomes. Three different parameters are considered here: weight fractions, fiber orientation angle, and plasma treatment to fabricate the composites using the compression molding process. Taguchi analysis revealed that fiber orientation angle has the greatest influence among the three variables, with plasma treatment and weight fraction following in impact on tensile strength. The composite that exhibited the highest tensile strength was determined to have a weight fraction of 10%, a fiber orientation angle of 90°, and a plasma treatment period of 5 min. This combination yielded a strength of 30.351 MPa. The analysis of the interaction between any two factors was done using contour plots. In order to compare the experimental tensile strength values with the anticipated values derived from the regression equation, regression analysis was carried out. Highlights Composites were made up of recycled HDPE (rHDPE) from plastic bottles using a compression molding technique. The Taguchi method is applied to achieve an experimental design employing an L4 orthogonal array. Contour plot analysis is conducted to identify points of minimum and maximum responses, as anticipated from the results. Tensile strength was optimized to a maximum of 30.351 MPa.

Abstract Previous studies have shown that gel‐spun‐ultra‐high‐molecular‐weight polyethylene (UHMWPE) produces thin fibril products that exhibit high tensile moduli (35–200 GPa). The elaborate gel‐spinning process involves complex drawing stages with solvent incorporation. In this study, a previously proposed two‐stage, environmentally friendly solventless methodology was optimized. The two‐stage process included cross‐rolling (Stage 1) and orientation (Stage 2) to obtain oriented HDPE thin rods with an impressively high modulus using conventional HDPE. The optimization of the process was successfully achieved by thoroughly investigating the voiding mechanism. In addition, rapid relaxation during orientation supports the cavitation mechanism. Owing to this optimization, a modulus of 75 GPa was readily attained. The significant enhancement in the mechanical properties was a direct result of the optimization of our processing methodology to achieve a high degree of orientation. Notably, the fabricated oriented HDPE thin rods showed moduli comparable to those of the gel‐spun UHMWPE fibers but were at least 40 times thicker. Our comprehensive characterization of the voiding process and stress relaxation during our two‐stage process indicated the formation of a highly taut network structure and craze‐like configuration with controlled delamination. Thus, our proposed hierarchical model was refined to elucidate the process‐structure‐property relationships in greater detail. Highlights An optimized two‐stage environmentally friendly solventless process has been developed to create oriented polyethylene thin rods with impressively high modulus (75 GPa). The optimization was achieved by thoroughly investigating the voiding effect during cross‐rolling and crystalline relaxation during orientation. Comparison of the modulus from our process are similar to various commercial, gel‐spun fibers. Our thin rod products are at least 40 times thicker than commercial gel‐spun fibers. The thin rod product has impressively high modulus‐to‐weight and strength‐to‐weight ratios for future study in composite systems.

Abstract This study aims to investigate the flame retardancy and mechanical properties of polypropylene (PP)‐based intumescent flame retardants (IFRs) consisting of melamine phosphate (MP) and pentaerythritol (PER), and different additives; boron phosphate (BP), antimony oxide (AO), and preceramic polymers, namely poly(dimethylsilane) (PDMS) and poly(methylsilsesquioxane) (PMSQ). The composites were produced by twin‐screw extrusion, and then molded by injection molding. Their characterizations were performed with limiting oxygen index (LOI), horizontal burning tests, thermogravimetric analysis (TGA), tensile and impact tests. The total amount of IFRs and the additives in polypropylene was kept constant at 20 wt%. The additive concentration was varied as 1, 3, and 5 wt% in the composites. The highest LOI value of 29% was obtained for PP/MP/PER composite with MP/PER ratio of 3/1. PP/IFR‐based composites with 1 wt% additive exhibited higher LOI and horizontal burning performance than the other composites with 3 and 5 wt% additives. It is revealed that tensile modulus and impact strength of neat PP were improved with the addition of IFRs, and for each type and amount of the additives used in the study. Highlights Usage of IFRs, preceramic polymers, BP and AO in PP improved flame retardancy. Lower amount of additives (1%) in PP/IFR composites led to higher LOI values. Additive incorporation enhanced tensile modulus and impact strength of neat PP.

Abstract The recycled nylon (RN)‐based biocomposites were fabricated by adding 25% lignin biocarbon. Lignin was pyrolyzed at 300, 600, and 900°C to produce Lig300, Lig600, and Lig900 biocarbon (BioC) samples, respectively. Higher functionality of Lig600 (unlike Lig900) allowed for improved interfacial interaction with the polar nylon matrix. Mechanical properties were further enhanced for RN_Lig600 composite with enhanced flexural and tensile strength by 18% and 8%, respectively, compared to neat polymer (RN). RN_Lig900 composite showed enhancement in tensile and flexural modulus by 32.6% and 51.1%, respectively, compared to RN. Incorporation of Lig900 in RN matrix resulted in 77.9% reduction in burning rate compared to RN. These results show the potential of lignin BioC as a filler in RN composites for flame retardant applications and mechanical enhancement, such as in the automotive industry. Highlights Effect of pyrolysis temperatures (300, 600, and 900°C) on lignin biomass. Composites prepared from recycled polyamide 6 from carpet waste and biocarbon. Improved interfacial adhesion of 600°C biocarbon with recycled nylon matrix. Enhanced thermal, mechanical properties, reduced flammability of biocomposites. Sustainable biocomposites with 900°C biocarbon reduced burning rate by 78%.

Abstract Textile coloration is a complex process involving the interaction of dye molecules with fibers in a dye bath. Synthetic dyes pose environmental hazards, leading to increased interest in natural dyes sourced from plants, animals, and minerals. However, natural dyes often require mordants for application to textiles. Despite their eco‐friendliness, natural dyes can exhibit poor wash fastness on fabrics, necessitating further research to enhance their performance. This study investigates the use of mahogany sawdust extract as a natural dye for cotton coloration, focusing on the enhancement of fastness properties through metallic mordants and associated environmental risks. Mahogany sawdust, rich in flavonoids and tannins, shows promise as a sustainable alternative to synthetic dyes. The dyeing process involves the extraction of natural dyes from sawmill bio‐waste and subsequent application onto cotton fabrics using various metallic mordants. Evaluation of colorfastness properties, color strength, color coordinates, tensile strength, FTIR, and SEM analysis provides insights into the dye‐fiber interactions and fabric properties. Environmental risk assessment considers metal exhaustion onto fabric surfaces, residual metal concentrations in mordant baths, and metal content in dyeing wastewater. Overall, this study contributes to the development of sustainable dyeing processes and highlights the importance of environmental considerations in textile coloration. Highlights Mahogany sawdust extract: potential natural dye for sustainable cotton coloration. Metallic mordants enhance colorfastness and fabric durability in dyeing processes. Comprehensive analysis reveals the intricate dynamics of dye‐fiber interactions. Environmental risk evaluation guides sustainable textile manufacturing practices. Research paves the way for greener, more sustainable textile industry practices globally.

Abstract The textile industries are looking forward to sustainable textile products. The bio‐based products are very important for protecting the environment, reducing carbon emissions, eliminating chemical pollution, and preserving the resources. These products provide economic advantages and strengthen communities with customer expectations for environmentally friendly items. In addition, sustainable practices encourage innovation and contribute to a healthier and adaptable environment, making them an essential textile product. Here the natural flax fiber plays a vital role due to its eco‐friendly behavior. Cotton‐flax blended yarns are manufacturing for perfect use of natural fibers and getting the better quality yarn than single product yarn. Here in this work it was trying to find out the perfect blending ratio by using Design‐Expert software. Because different blended ratio contain different characteristics. So it was trying to find out a perfect blending solution from the thirteen different ratios by using Design‐Expert software. This software analyses the blended ratios through statistical analysis. This study focuses on the unevenness (U%), imperfection index (IPI), hairiness (H%), tenacity (cN/tex) and elongation at break of the blended yarn. During the analysis the actual and predicted values were checked and it shows good significance, the correlation and regression analysis highlight the results of the samples summary. The findings of the study have great impact on the quality of cotton‐flax blended yarn, which impact on the quality of textile products. This work not only helps to understand cotton‐flax blending using Design‐Expert software, but it also highlights the possibility of using the perfect blended ratio by giving a solution. Highlights To identify the perfect blended ratio of flax and cotton fiber for producing blended yarn. Design‐Expert software has been used to find out the perfect response through yarn properties surface methodology. Thirteen experimental runs were trailed to find the perfect result.

Abstract The local interaction within poly(vinylidene fluoride)/poly(3,4‐ethyelenedioxythiophene):poly(styrelenesulfonate) (PVDF/PEDOT:PSS) composite films has been explored in this study. Vibrational and impedance spectroscopy were used extensively to investigate the potential interactions within the moieties of PVDF and PEDOT:PSS in the composite. The increased concentration of PEDOT:PSS used as additives enhanced the dielectric constant of the composite films significantly. Both the AC conductivity and the estimated mobility also increased in the composite films with increasing additives. X‐ray absorption spectroscopy gave an insight into the local chain interactions within the polymer composite films. A shift in the C K‐edge toward higher energy confirmed the local interaction of the polymer moieties, suggesting a change in the polymer chain structure due to the possible association of moieties.

Polyester-cotton fabrics (PTCO) have excellent properties and are ubiquitous in daily life, but their serious flammability brings great safety hazards to people's lives. This study used phenylphosphonic acid (PPOA) and urea as raw materials to prepare a flame retardant named POU. PTCO/POU was prepared by the pad-dry-cure technique, and the performance was compared with that of PTCO/PPOA, revealing many interesting phenomena. Based on the gas phase and condensed phase flame-retardant mechanism brought by P/N synergy, PTCO/POU had better flame retardancy than PTCO/PPOA did. The damaged length was 6.7 cm, and the limiting oxygen index (LOI) value was 30.1%. The char residues after burning were complete and denser with a higher degree of graphitization. Thermogravimetric analysis showed that POU can significantly reduce the Rmax of PTCO, and improve its thermal stability in high temperature zones. The CCT results showed that PTCO/POU had the longest time to ignition and the smallest fire growth index, which was of great significance for reducing fire risk. The TG-FTIR results showed that the volatile products of PTCO/POU were greatly reduced, and during the burning process, NH3 was produced to dilute the concentration of combustible gases. In addition, PTCO/POU also had better whiteness performance than PTCO/PPOA did. This work greatly improved the flame retardancy of PTCO in a simple way and expanded its application prospects.

The substitutional structure of cyclotriphosphazene derivatives significantly influences their flame-retardant effectiveness. A cyclotriphosphazene derivative with triazole group, referred to as hexa(1,2,4-triazol-3-ylamine) cyclotriphosphazene (HATA), was utilized to improve the flame retardancy of epoxy resin (EP). Differential scanning calorimetry, thermogravimetric analysis, and dynamic mechanical analysis were employed to characterize the thermal properties of EP/HATA thermosets. HATA facilitated the curing of EP due to its triazole and secondary amine structure. EP/HATA thermosets exhibited improved char-forming ability and storage modulus, attributed to the rigid cyclophosphonitrile structure of HATA. As a result of incorporating 5% HATA with 0.73 wt% phosphorus, EP passed UL-94 V-0 level. Subsequent analysis using a cone calorimeter revealed obvious reductions in the peak heat release rate, fire growth rate, and total smoke production of EP with the addition of HATA. Simultaneously, there was a significant enhancement in the char yield of EP during combustion, indicating notable improvements in fire safety. Additional investigations, including X-ray photoelectron spectroscopy, scanning electron microscopy, TG-FTIR, and pyrolysis gas chromatography/mass spectrometry, were employed to analyze the char residue and gaseous volatiles. HATA promoted the formation of a dense, continuous, and intumescent char layer containing cyclophosphonitrile structure in EP. Moreover, the decomposition of HATA released a notable quantity of nitrogen-containing volatiles, effectively mitigating flammable gases originating from the EP matrix in gaseous phase. A biphasic flame-retardant mode of action was proposed, underscoring cooperative flame-retardant effects arising from the interaction between triazole substituents and cyclophosphonitrile structure in HATA molecular for EP.

Polylactic acid/Polycarbonate (PLA/PC) blend was prepared via twin screw extruder by taking the bio-based content as much as possible and the better mechanical, thermal, and impact properties into consideration. Flame retardant (FR) performance of the PLA/PC blend was improved by using the mixture of ammonium polyphosphate, triphenyl phosphate, and zinc borate. FR properties of PLA/PC blend was evaluated according to the UL 94 test standard. The variations in tensile and flexural strength, and Izod-notched impact strength values were determined. In order to reduce the total amount of flame retardant additive, instead of using a mixture of TPP and APP (weight ratio of 2/1) at 21 wt% weight fraction, 1 wt% Zinc borate together with 18 wt% TPP-APP mixture was used and obtained V0 rating for the thickness of 1.5 mm. It was reported that weight fraction of flame retardant additives (APP and TPP) was successfully reduced by using a mixture of APP, TPP and ZnB without degrading the mechanical properties such as tensile and flexural strengths. Using less total FR additive weight (19 wt%) led to 15 and 24% higher tensile and flexural strength values, respectively, compared to higher FR additive weight (21 wt%).

Rapid development of energy, electrical and electronic technologies has put forward higher requirements for the thermal conductivities of epoxy resins and their composites. However, the thermal conductivity of conventional epoxy resins is relatively low, which could cause major heat dissipation issues. Therefore, the thermal conductivity enhancement of epoxy resins has long been a hot research topic in both academia and industry. In recent years, many promising advances have been made at the technical and mechanistic levels. This review includes the different approaches, the thermal conduction mechanisms implied, and the main research progresses. The research and academic achievements are mainly focused on the development of intrinsically liquid crystal epoxy resins and their composites, and the addition of fillers on amorphous epoxy resins. Finally, the challenges and prospects for thermal conductive epoxy resins are provided. Notably, this review can provide a more comprehensive understanding of thermally conductive epoxy resins and a guideline for the cutting-edge development direction of thermally conductive epoxy resins.

Asphalt pavement is widely applied to the surface in high-grade highway tunnels due to its prominent preponderance in road performance. However, asphalt is flammable as the binder material to adhere the aggregates and other additives, resulting that a fire in the semi-closed space of the tunnel can ignite and burn asphalt pavement to generate a large amount of heat and smoke. Therefore, further promoting the advance of flame-retardant asphalt pavement is essential to ensure security in tunnels. We gathered the relevant standards or regulations of diverse nations and test methods concerning flame retardancy of asphalt. Then we reviewed the research status of flame-retardant asphalt mixture, including thermal characteristics of the asphalt and four fractions, the flame retardants applicable to asphalt, and effects on other components. This review demonstrated that establishing universal standards and test methods is a research basis specifically for flame-retardant asphalt pavement. To optimize the flame retardancy of asphalt pavement, it should focus on the synergy with diversified aspects such as asphalt binders, multiple flame retardants, aggregates, mineral powders, fibers, and other additives.

Polyethylene Glycol (PEG)-based flexible phase change materials have broad and practical application value in thermal management of flexible electronic devices. Considering the typical application cases and safety of phase change materials (PCMs), in this work, we grafted molecular nanoparticles, POSS, with both hydrophobic and flame retardant functions to the surface of PLR sheets through amidation reaction. The successful grafting of POSS has been fully verified by Fourier-transform infrared spectroscopy, energy dispersive spectroscopy and surface contact angle. The formation of the cross-linked structure and the introduction of POSS make the phase change latent heat of the phase change material slightly decrease from 102.4 J g−1 to 94.4 J g−1, but there is still a high retention rate. It is worth pointing out that the PCMs have excellent shape stability and leakage resistance, cycle stability, and shape memory performance (Rf-99%, Rr-99%). The introduce of cross-linked structure and POSS significantly enhanced the Young’s modulus and tensile strength of the PCM. The surface POSS functionalization endowed the PCM with significantly enhanced hydrophobicity. Specifically, the contact angle of the material was significantly increased from 71° for PLR to 123° for POSS-PLR, and it also had enhanced fire safety with pHRR reduction by 18.4% and THR reduction by 19.1%.

The fire performance durability of products containing flame retardants may be significantly affected after aging and mechanical recycling. Publications of the last ten years show that even under severe conditions simulating outdoor applications, progress has been made in using halogenated and halogenfree flame retardants with high temperature stability, stabilizers acting as flame retardants, improved coating formulations for wood and steel less sensible to hydrolysis by using topcoats and layer by layer approaches. Mechanical recycling is possible for halogenated and non-halogenated flame retardant systems, but has only been studied for virgin thermoplastics which may be available from post-industrial waste. Post-consumer waste is still unsuitable due to its mixed contents. Examples from practice show that the lifetime of products containing flame retardants may be durable for decades in indoor and probably for a much shorter time in outdoor applications.

To address the shortcomings of traditional intumescent flame retardants (IFRs), a novel four-in-one IFR (M [APP/NiCo2O4]) was constructed for the first time. It integrates acid source, gas source, carbon source (crosslinking β-CD), and synergistic agent (NiCo2O4 nanoparticles) into a single entity by a co-encapsulation technology. Under the loading of 20 wt%, its flame retardant performance was significantly better than that of simple mixed flame retardants, and it could increase the limiting oxygen index of polypropylene (PP) from 18 to 30.2 and pass the UL-94 V-0 rating. At the same time, it could reduce the peak of heat release rate, total heat release, and peak of CO production of PP by 77%, 22%, and 80%, respectively, showing excellent flame retardant performance. The excellent flame retardant performance is mainly because the synergist NiCo2O4 nanoparticles in the four-in-one flame retardant can easily combine and efficiently interact with the acid source, carbon source, and gas source in the intumescent flame retardant to form a more stable protective char residue. In addition, the crosslinking β-CD shell enhances both the water resistance and initial thermal decomposition temperature of PP containing the four-in-one IFR compared to PP with simple mixed control samples. After 72 h of water resistance test, it can still maintain the UL-94 V-0 rating. The presence of the crosslinking β-CD shell also improves the compatibility of the four-in-one flame retardant in PP, and its adverse effects on the mechanical properties of PP are also significantly smaller than those of the mixed control sample.

Abstract Micro- and nanoplastics (MNPs) are ubiquitous environmental pollutants representing a concern for human health. MNPs have been detected in human placentas, indicating that during pregnancy maternal exposure may lead to placental transfer and foetal exposure, with potential for adverse effects on early-life development. However, a comprehensive risk assessment (RA) framework, specific to early-life is lacking. Here, we propose a novel roadmap to assist the development of an early-life health RA of MNPs. This roadmap is designed based on established chemical, mixture, particle, and MNP assessment strategies aligned with standard RA components (problem formulation, hazard identification, hazard characterisation, exposure assessment, risk characterisation). We systematically work through these stages to identify what is needed to progress a RA for the early-life impacts of MNPs, including what information is missing, and what may be used in the interim. While challenges such as complex physicochemical properties of MNPs, limited toxicity data at relevant exposure levels, and uncertainties related to characterising complex exposures have been described elsewhere, our work discusses how these challenges specifically impact early-life stages such as the significance of MNP presence in biological samples and factors influencing bioaccumulation and placental transfer. Additionally, we introduce the development of new technology readiness levels for methods used in the detection of MNPs in complex matrices. Importantly, this review integrates a broad scope of relevant information into one comprehensive document, providing a unified resource. We highlight specific requirements and areas for targeted research, including the development of dose-response relationships specific to early-life stages and novel strategies for assessing bioaccumulation and placental transfer of MNPs. By addressing these gaps, our roadmap aims to advance the development of a robust framework, ultimately enhancing the understanding and mitigation of risks associated with early-life exposure to MNPs.

This study aims to develop a thin-film nanofibrous composite (TFNC) membrane for removing fermentation inhibitors from a hydrolysate solution. Such membrane was fabricated via interfacial polymerization of a polyamide thin-film layer on top of a solution blow-spun polyacrylonitrile nanofiber scaffold. The effects of pH (3.29, 4.29, 8.26) and pressure (4, 6.67, 9.33, 12 bar) on the membrane’s performance were investigated. The TFNC membrane had a high pure water permeability of 21.06 L/m2-h-bar and was able to deliver satisfactory rejection coefficients at pH 3.29 and pressure of 4 bar (glucose − 91.84%, xylose − 86.06%, hydroxymethylfurfural − 20.52%, furfural − 21.32%). Different pH settings resulted in similar permeate fluxes, but increasing the pH from acidic to basic reduced the rejection coefficients due to electrostatic repulsion. Increasing the pressure increased the permeate flux but decreased the rejection coefficients. The developed membrane showed remarkable permeability and effectively removed inhibitors, useful in biorefineries.

Hybrid composites comprising conducting nanowires (NWs) and insulating particulate fillers exhibit varying trends in their electrical conductivity based on the conditions of the constituent fillers. This study presents a quantitative model that comprehensively describes these changes, encompassing both increasing and decreasing trends. The model is formulated as an equation with two parameters quantifying the excluded volume effect and the NW bending effect, which are considered the primary factors determining NW network morphology in the composites. The influence of the parameters on the electrical conductivity of hybrid composites is analyzed with respect to the size and content of the constituent fillers using Monte Carlo-based simulations and statistical regression techniques. Numerical investigations reveal that distinct conductivity patterns under various particulate filler dimensions result from the interplay of these effects. The proposed model, validated through 2-D and 3-D simulations, effectively captures these complex interactions across diverse configurations of the constituent fillers.

Herein, poly(pentanediamine terephthalamide) (PA5T) homopolymer was synthesized via a salt-forming reaction+solid state polycondensation method using bio-based 1,5-pentanediamine and terephthalic acid as the primary raw materials. To address the issue of its narrower processing window, poly(hexamethylene terephthalamide)(PA6T), which also cannot be melt processed due to the processing window is negative, was introduced into its molecular chain to synthesize poly (pentanediamine/hexanediamine terephthaloyl) (PA5T-co-6T) copolymers. The structures were investigated by Fourier transform infrared spectroscopy (FTIR) and nuclear magnetic resonance carbon spectroscopy (13C-NMR). Furthermore, the melting temperature, crystallization temperature, thermal stability, and crystal growth mode of the polymer were tested and analyzed using differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and wide-angle x-ray diffraction (WAXD), respectively. The results demonstrate that the crystal growth mode gradually changes from three-dimensional spherical growth to two-dimensional disk-like or three-dimensional spherical growth with the increase of 6T chain segment content. Simultaneously, the crystallization temperature, melting temperature, and crystallization rate of the polymer all showed a trend of decreasing first and then increasing, which was due to the combined effects of the increase in the content of 6T chain segments on the molecular-chain structure and crystal structure of the polymer. Bio-based PA5T-co-6T has excellent heat resistance and a wider processing window than PA5T and PA6T, which possesses great application prospects in the fields of automotive, electronic appliances, and LED optics.

Hyperbranched polyphosphate polyesters (HPPs) as a special class of hyperbranched polymers have attracted increased interest and have been intensively studied, because of peculiar structures, excellent biocompatibility, flexibility in physicochemical properties, biodegradability, water soluble, thermal stability, and mechanical properties. HPPs can be divided into phosphates as monomers and phosphates as end groups. In this article, the classification, general synthesis, modifications, and applications of HPP are reviewed. In addition, recent developments in the application of HPP are described, such as modified or functionalized by end capping and hypergrafting to improve the performances in polymer blends, coatings, flame retardant, leather. Furthermore, the modifications and application of HPPs in biomedical materials, such as drug delivery and bone regeneration were discussed. In summary, the hyperbranched polymer enlarges its application range and improves its application performance compared with conventional polymer. In the future, more new HPPs composite materials will be developed through hyperbranched technique. This review of HPPs will provide useful theoretical basis and technical support for the development of new hyperbranched polymer material.

Although traditional dental-implant approaches have served as primary solutions, they are limited by infection risks, complications, and prolonged failures. Hybrid electrospun nanofiber matrices based on biomaterials have emerged as compelling alternatives for dental-tissue regeneration, offering direct cell-matrix contact and facile modification to incorporate anti-inflammatory, angiogenic, antimicrobial, and osteogenic properties. In this review, we discuss the advancements in hybrid nanofiber matrix-based approaches in dental-tissue engineering over the past five years (2019–2023). Beginning with an exploration of dental tissues and tooth structures, we discuss the innovative strategies in each study, including fabrication methods, physicochemical and biological properties, and osteogenic potential. We anticipate that ongoing research will enable the widespread application of innovative biomaterials and nanofiber matrices in future dental therapies.

To explore the effect of polycarboxylate superplasticizers on the strength and hydration performance of alkali slag building materials, this study prepared cross-linked polycarboxylate superplasticizers with different ratios of hydrogen peroxide, methyl allyl alcohol polyoxyethylene ether, acrylic acid, polyethylene glycol diacrylate, monomer aqueous solution, reducing agent, chain transfer agent, etc. according to certain ratios, and tested their effects on the hydration performance and strength of alkali slag building materials. Through experimental analysis, it was found that the higher the proportion of cross-linked polycarboxylate based high-efficiency water-reducing agents, the lower the initial flowability of building material slurry; The addition of cross-linked polycarboxylate water-reducing agent will prolong the initial and final setting time of alkali slag building materials, delaying the hydration time of building materials; Cross linked polycarboxylate superplasticizers can reduce the electrical conductivity of alkali slag building material slurry, delaying its hydration rate; Different ratios of water-reducing agents have a significant impact on the water reduction rate of alkali slag building materials, with V2 water-reducing agent having the highest water-reduction rate of 28.6%; Cross linked polycarboxylate superplasticizers can increase the flexural and compressive strength of alkali slag building materials. Therefore, cross-linked polycarboxylate water-reducing agents have shown great potential in regulating the properties of alkali slag building materials.

This paper may be the first meta-analysis that presents a comprehensive synthesis of scientific works spanning the last five years, focusing on methodologies and results related to the analysis of nanocomposite using nanoparticles. The primary objective is to identify the optimal algorithm using software information and leading to better classification methodology. Specifically, this study comes up with the advantages and the drawbacks of the most used algorithms and proposes an enhancement and performance of Recurrent Neural Networks based on Long Short Term Memory (LSTM) neurons. Besides, a comparison of Deep Learning methods for the classification of polymeric nanoparticles, with polypropylene serving as a case study will be implemented. Experiment comparisons are conducted to assess with one physical property, later expanded to four properties and finally to eight properties. Neural networks, including Artificial Neural Networks (ANN), Recurrent Neural Networks (RNN), and Recurrent Neural Networks-Monte Carlo, are employed for simulations. The evaluation criteria encompass accuracy, calculation time, mean square error (MSE) and other metrics. The findings contribute to the selection of an optimal algorithm for the analysis of polymeric nanoparticles, emphasizing the potential of Deep Learning methodologies, particularly Recurrent Neural Networks Monte Carlo, in advancing classification accuracy and efficiency.

This work reports a green synthesis of CuO/NiO nanocomposite with different CuO/NiO ratios. The X-ray diffraction (XRD) confirmed the existence of both CuO and NiO. This was also confirmed by energy dispersive X-ray (EDX). Scanning electron microscopy (SEM) reveals that changing the compositions of the nanocomposites resulted in different surface morphologies with different particle shapes, sizes, and levels of aggregation. Nitrogen adsorption-desorption analysis showed microporous structures with pore size in the range of 1.66-1.75 nm and surface area in the range of 82-513 m2g−1. The supercapacitive activity was examined by cyclic voltammetry (CV) and galvanostatic charge-discharge (GCD). The results display that the 1C3N exhibited the highest capacitive performance of 1072 Fg−1 compared to 760, 716, and 260 Fg−1 for 3C1N, 4 N, and 4 C, respectively. Furthermore, the 1C3N electrode shows a cyclic stability of 72% after 4000 cycles, which makes it a promising candidate for supercapacitive applications.

The C3-symmetry ionic polymer PPyTri has been designed with multi-walled carbon nanotubes (MWCNTs) or graphene nanoplatelets (GNPs) and studied as an ultrasensitive electrochemical sensor for trace Hg(II) detection. The synthesis approach incorporated attaching three pyridinium cationic components with chloride anions to the triazine core. The precursors, BPy, were synthesized using a condensation process involving 4-pyridine carboxaldehyde and focused nicotinic hydrazide. The polymer PPyTri was further modified with either MWCNTs or GNPs. The resulting ionic polymer PPyTri and its fabricated nanocomposites were characterized using infrared (IR), nuclear magnetic resonance (NMR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and powder X-ray diffraction (XRD). The analysis revealed that both the polymer and its nanocomposites have semi-crystalline structures. The electroactivity of the designed nanocomposites toward Hg + 2 ions revealed that among the nanocomposites and bare copolymer, the glassy carbon electrode (GCE) adapted with the PPyTri GNPs-5% exhibited the greatest current response over a wide range of Hg + 2 concentrations. The nanocomposite-modified electrode presented an excellent sensitivity of 83.33 µAµM − 1 cm − 2, a low detection limit of 0.033 nM, and a linear dynamic range of 0.1 nM to 0.01 mM (R2 = 0.9945).

In the present study, MnO2 nanoparticles were synthesized using Citrus limetta peels extract and functionalized by chitosan polymer. Surface morphology analysis of chitosan functionalized MnO2 nanoparticles was carried out using a scanning electron microscope (SEM) and transmission electron microscope (TEM), which revealed that the synthesized nanoparticles were spherical, with a size range of 14–24 nm. Energy dispersive X-ray analysis and elemental mapping were used to observe Mn, O, C, H, and N. Fourier-transform infrared spectroscopy confirmed the presence of hydroxyl, carboxyl, and amino groups on the surface of the nanoparticles. The kinetics and isotherms were compared and it was found that the pseudo-second-order and Langmuir isotherm were the best fit, with R2 values of 0.99. The thermodynamic study demonstrated that the adsorption was endothermic and spontaneous. These findings indicate that chitosan functionalized nanoparticles have a better Pb(II) removal efficiency (94.40%), making them an eco-friendly and cost-effective alternative for wastewater treatment. HighlightsChitosan functionalized nanoadsorbent was synthesized through green route.Sorption mechanism explored through isotherm, kinetics, and thermodynamic models.Synthesized adsorbent showed high Pb(II) removal capacity.

Nanocomposites represent one of the most useful strategies for resolving the pharmaceutical challenge about the dissolution and delivery of poorly water-soluble drugs. Besides the compatibility between the drug and polymeric carriers, the physical shapes of materials also play their important roles on the release behaviors of a guest poorly water-soluble drug from the host polymeric matrices. In this study, three kinds of nanocomposites in the forms of homogeneous nanofibers (E1), spindles-on-a-string (E2), and beads-on-a-string (E3) were prepared using electrospinning with ketoprofen (KET) as the model drug and a mixture of ethylcellulose (EC) and polyvinylpyrrolidone (PVP) as the polymeric matrices. Controllable preparation mechanisms of these morphologies are disclosed based on the results of SEM, TEM, and processes observations. XRD and FTIR data demonstrated that KET was compatible with PVP and EC. In vitro dissolution tests verified that all the three nanocomposites were able to provide the typical bi-stage fast-sustained release profiles of KET. Whereas, the beads-on-a-string E3 had a better functional performance than the spindles-on-a-string E2, and the homogeneous nanofibers E1 in terms of the KET sustained release profiles in the second stage. The protocols reported here pioneered a new way for developing novel functional nanocomposites based on the process-shape-performance relationship.

In this paper, a novel mono-methacrylated β-cyclodextrin (β-CD) monomer mediated by disulfide bond was synthesized, and then thermal copolymerized with HEMA monomer in the presence of a little crosslinker to prepare redox-responsive hydrogel for regulated drug delivery. The structure of the monomer was confirmed by FTIR, 1H NMR, 13C NMR spectroscopy. The substitution degree of polymerizable methacrylated group grafted onto β-CD was about 1 by calculating by1H NMR (0.987) and element analysis (0.937). The mono-methacrylated β-CD monomer can well copolymerize with 2-hydroxyethyl methacrylate (HEMA) monomer with gel fraction over 80%. The hydrogel shows low cytotoxicity, and copolymerization of the mono-methacrylated β-CD monomer in the hydrogels increases its equilibrium swelling degree (ESD) and tensile strength, while its transmittance slightly decreases. Drug loading and release rate are dependent on the β-CD content. The hydrogel with high β-CD content of 13.83 wt% shows 1.8 and 8.5 folds puerarin (PUE) and curcumin (CUR) loading than pure pHEMA hydrogel, respectively. The incorporation of β-CD sustained drug release, especially CUR release was prolonged more than 24 h from 5 h of pure pHEMA hydrogel (80% release). The hydrogels are highly sensitive to reduced glutathione (GSH), and low concentration of GSH of 3 mM can significantly accelerate drug release rate. The higher of β-CD content, the more sensitive the hydrogels to GSH, resulting in rapider drug release rate.

A new class of biologically active polyazomethine/pyrazole and their related nanocomposites, polyazomethine/pyrazole/zinc oxide nanoparticles, have been successfully synthesized through the polycondensation technique in the form of polyazomethine pyrazole (PAZm/Py4–6) and polyazomethine/pyrazole/zinc oxide nanoparticles (PAZm/Py/ZnOa-c). The polymeric nanocomposites were prepared with a 5% loading of zinc oxide nanofiller using the same preparation technique, in addition to the help of ultrasonic radiation. The characteristics of the new polymers, such as solubility, viscometry, and molecular weight, were examined. All the polymers were completely soluble in the following solvents: concentrated sulfuric acid, formic acid, dimethylformamide, dimethyl sulfoxide, and tetrahydrofuran. Furthermore, the weight loss of the polyazomethine pyrazole (4, 5, and 6) at 800 °C was 67%, 95%, and 86%, respectively, which indicates the thermal stability of these polymers. At 800 °C, the polyazomethine/pyrazole/zinc oxide nanoparticles (a, b, and c) lost 74%, 68%, and 75% of their weight, respectively. This shows that adding zinc oxide nanoparticles made these compounds more stable at high temperatures. The X-Ray diffraction pattern of the polyazomethine pyrazole (PAZm/Py4–6) shows a number of sharp peaks with varying intensities. The polymers that were studied had straight crystal structures. Furthermore, the measurements of polyazomethine/pyrazole/zinc oxide nanoparticles (PAZm/Py/ZnOa-c) indicate a good merging of zinc oxide nanoparticles into the matrix of polymers. The antimicrobial activity of polymers and polymer nanocomposites was tested against some selected bacteria and fungi. The synthesized polymer (c) shows the highest activity against the two types of gram-negative bacteria selected. Most tested compounds were found to be effective against gram-positive bacteria except polyazomethine pyrazole (PAZm/Py5) and polyazomethine pyrazole (PAZm/Py6), which do not exhibit any activity. The synthesized polymers and their related nanocomposites were tested for their ability to kill the chosen fungi. All of them were effective against Aspergillus flavus, but only polyazomethine pyrazole (PAZm/Py4) and polyazomethine/pyrazole/zinc oxide (PAZm/Py/ZnOc) were effective against Candida albicans.

AbstractNanoclays (layered silicates) have been applied as effective reinforcements for range of natural and synthetic polymeric matrices. Recent research has turned toward design and exploration of green nanocomposites using green polymers and nanoclay nanofillers. This state-of-the-art comprehensive overview debates design and performance prospects of green nanoclay nanocomposites. In this regard, numerous green polymers like poly(lactic acid), poly(vinyl alcohol), natural rubber, cellulose, starch, etc. have been considered. The effectiveness of green nanoclay nanocomposites has been analyzed through microscopic, electrical, mechanical, thermal, adsorption, and biomedical properties and wide span of applications such as packaging, dye removal, and biomedical sectors. Packaging based on cellulose/montmorillonite had very low water vapor transmission rate of 43 g/m2.day, whereas poly(lactic acid)/cellulose/montmorillonite packaging performed better with high water vapor transmission rate of 512–1861 g/m2.day. Poly(vinyl alcohol)/Cloisite Na possess optimum water vapor transmission rate of 533 g/m2.day. Nanocellulose/nanoclay packagings have also been found ideal due to low water vapor permeability (6.3–13.3 g.μm/m2.day.kPa) and oxygen permeability (0.07 cm3μm/m2.day.kPa) values. In dye removal applications, poly(ethylene glycol)/montmorillonite revealed optimum dye adsorption capacities of 190–237 mg/g, where chitosan/montmorillonite had high dye adsorption capacity of 446.43 mg/g. Poly(lactic acid)/modified Cloisite 20 A systems also own high dye adsorption efficiency of 97%. Poly(ɛ-caprolactone) and poly(vinyl alcohol) systems with montmorillonite nanoclay have effective drug delivery, tissue engineering, and wound healing applications. Furthermore, dielectric, mechanical, non-flammability, and self-extinguishing features of cellulose/montmorillonite nanocomposite systems have been reported. Future of these nanomaterials definitely relies on innovative design, facile fabrication strategies, and overcoming related challenges.