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Different chemical treatment methods were employed to modify the surface of cotton stalk fibers, which were then utilized as fillers in composite materials. These treated fibers were incorporated into polylactic acid/polypropylene melt blends using the melt blending technique. Results indicated that increasing the surface roughness of cotton stalk fibers could enhance the overall mechanical properties of the composite materials, albeit potentially leading to poor fiber–matrix compatibility. Conversely, a smooth fiber surface was found to improve compatibility with polylactic acid, while Si-O-C silane coating increased fiber regularity and interfacial interaction with the matrix, thereby enhancing heat resistance. The mechanical properties and thermal stability of the composite materials made from alkali/silane-treated fibers exhibited the most significant improvement. Furthermore, better dispersion of fibers in the matrix and more regular fiber orientation were conducive to increasing the overall crystallinity of the composite materials. However, such fiber distribution was not favorable for enhancing impact resistance, although this drawback could be mitigated by increasing the surface roughness of the reinforcing fibers. [ABSTRACT FROM AUTHOR]

As one of the emerging nanomaterials, boron nitride nanotubes (BNNTs) provide promising opportunities for diverse applications due to their unique properties, such as high thermal conductivity, immense inertness, and high-temperature durability, while the instability of BNNTs due to their high surface induces agglomerates susceptible to the loss of their advantages. Therefore, the proper functionalization of BNNTs is crucial to highlight their fundamental characteristics. Herein, a simplistic low-cost approach of BNNT surface modification through catechol-polyamine (CAPA) interfacial polymerization is postulated to improve its dispersibility on the polymeric matrix. The modified BNNT was assimilated as a filler additive with AlN/Al2O3 filling materials in a PDMS polymeric matrix to prepare a thermal interface material (TIM). The resulting composite exhibits a heightened isotropic thermal conductivity of 8.10 W/mK, which is a ~47.27% increase compared to pristine composite 5.50 W/mK, and this can be ascribed to the improved BNNT dispersion forming interconnected phonon pathways and the thermal interface resistance reduction due to its augmented compatibility with the polymeric matrix. Moreover, the fabricated composite manifests a fire resistance improvement of ~10% in LOI relative to the neat composite sample, which can be correlated to the thermal stability shift in the TGA and DTA data. An enhancement in thermal permanence is stipulated due to a melting point (Tm) shift of ∼38.5 °C upon the integration of BNNT-CAPA. This improvement can be associated with the good distribution and adhesion of BNNT-CAPA in the polymeric matrix, integrated with its inherent thermal stability, good charring capability, and free radical scavenging effect due to the presence of CAPA on its surface. This study offers new insights into BNNT utilization and its corresponding incorporation into the polymeric matrix, which provides a prospective direction in the preparation of multifunctional materials for electric devices. [ABSTRACT FROM AUTHOR]

The high specific stiffness materials are used to design the space payload components. These components should sustain the extreme environmental condition throughout their life cycle without failure. The prerequisites of future space missions need lightweight materials which must be mechanically strong and high thermal and electrically conductive. The Carbon Nanotubes (CNTs) are efficient filler material in composite or metal matrix to enhance greater electrical and thermal conductivity. The quality of the CNT nano composite relies upon several parameters like the types of CNTs, its purity, aspect ratio, amount of loading, alignment, and interfacial adhesion between the nanotube and polymer. The performance of the CNT-CFRP composite depends on the successful execution of the processing technique. This review paper intends to highlight the enhancement of the mechanical, thermal, electrical properties of the composite, and the challenges to achieving it. This review paper helps to optimise the process parameters to fabricate Space Payload Components, required to replace existing high-density Space Qualified Materials. This review paper should help optimize the process parameters to fabricate Space Payload Components, which can be excellent alternatives to the existing high-density Space Qualified Materials without making any compromise on the performance index. [ABSTRACT FROM AUTHOR]

A novel UV-light-curable poly(ethylene glycol) diacrylate matrix composite material with unmodified and methacryloxyl-grafted TiO2 and TiO2-ZrO2 systems was developed and tested as a potential coating material for medical components. The main goal of the research was to evaluate how the addition of (un)modified inorganic oxide fillers affects the properties of the composition (viscosity, UV/Vis spectra), the kinetics of photocuring (photo-DSC), and the morphological (SEM), physicochemical, and thermal properties (DSC, TGA) of the resulting composites. The applied filler functionalization process decreased their polarity and changed their size, BET surface area, and pore volume, which influenced the viscosity and kinetics of the photocurable system. In addition, the addition of synthesized fillers reduced the polymer's glass transition temperature and increased its thermal stability. It was also observed that additional UV irradiation of the tested composite changed its surface, resulting in hydrophobic properties (with the addition of 7 wt.% filler, an increase in the contact angle by more than 45% was observed). [ABSTRACT FROM AUTHOR]

Polymer nanocomposites have recently been introduced as lead-free shielding materials for use in medical and industrial applications. In this work, novel shielding materials were developed using low-density polyethylene (LDPE) mixed with four different filler materials. These four materials are cement, cement with iron oxide, cement with aluminum oxide, and cement with bismuth oxide. Different weight percentages were used including 5%, 15%, and 50% of the cement filler with LDPE. Furthermore, different weight percentages of different combinations of the filler materials were used including 2.5%, 7.5%, and 25% (i.e., cement and iron oxide, cement and aluminum oxide, cement and bismuth oxide) with LDPE. Bismuth oxide was a nanocomposite, and the remaining oxides were micro-composites. Characterization included structural properties, physical features, mechanical and thermal properties, and radiation shielding efficiency for the prepared composites. The results show that a clear improvement in the shielding efficiency was observed when the filler materials were added to the LDPE. The best result out of all these composites was obtained for the composites of bismuth oxide (25 wt.%) cement (25 wt.%) and LDPE (50 wt.%) which have the lowest measured mean free path (MFP) compared with pure LDPE. The comparison shows that the average MFP obtained from the experiments for all the eight energies used in this work was six times lower than the one for pure LDPE, reaching up to twelve times lower for 60 keV energy. The best result among all developed composites was observed for the ones with bismuth oxide at the highest weight percent 25%, which can block up to 78% of an X-ray. [ABSTRACT FROM AUTHOR]

• Exclusive comparison on multiple thermal properties of PEG-based nanocomposites. • Effect of interfacial resistance subjected to nanofiller aspect ratio and morphology. • Use of Raman mapping to quantify the agglomeration effect in carbon-based nanomaterials. • Different compatibility between PEG and nanofillers lead to varying heat mechanisms. New implementation of phase change materials (PCMs), such as Polyethylene Glycols (PEGs), can alleviate the overconsumption of natural resources and can also be applied in solar-thermal energy conversion applications due to their distinctive semi-crystalline structure. To further enhance the thermal properties of PCMs, carbon-based nanomaterials such as graphene nanoplatelets (GNPs) and milled carbon fibre (MCF) can be incorporated to fabricate PEG-based composites due to their high thermal conductivity. One of the possible drawbacks of the addition of carbon-based fillers is their aggregation at high loadings, leading to a possible reduction in the latent heat of PCM composites. Hence, this study explored the most appropriate loading level (5 wt.%) of carbon-based fillers with pristine PEGs to achieve optimal thermal performance. Specifically, PEG-based composites were synthesised with three fillers (GNPs, graphite and MCF) via a temperature-assisted ultrasonication method and rapid solidification. Then, Raman Spectroscopy was used to quantify the dispersion of fillers among the PEG matrices. The results showed that despite a 32.6 % reduction in enthalpy of fusion to 155.5 J g–1, the addition of 15 wt.% of MCF increased the thermal conductivity up to 0.67 W m–1 K–1, which was approximately 2.5 times higher than that of pristine PEG. Moreover, explanations were provided on the possible heat transfer mechanisms in different types of carbon-based fillers. PEG/MCF PCMs displayed good properties on latent heat, thermal conductivity, aggregation prohibition, volumetric heat capacity, phase change temperature and thermal stability, while PEG/graphite composites exhibited excellent performance on thermal diffusivity, phase change (melting) temperature, specific heat capacity and cyclability. [ABSTRACT FROM AUTHOR]

Polymeric positive temperature coefficient (PTC) materials with low switching temperature points are crucial for numerous electronic devices, which typically function within the room temperature range (0–40 °C). Ideal polymeric PTC materials for flexible electronic thermal control should possess a room-temperature switching temperature, low room-temperature resistivity, exceptional mechanical flexibility, and adaptive thermal control properties. In this study, a novel PTC material with a room-temperature switching temperature and superb mechanical properties has been designed. A blend of a semi-crystalline polymer EVA with a low melting temperature (Tm) and an amorphous polymer (PVAc) with a low glass transition temperature (Tg) was prepared. Low-cost graphite was chosen as the conductive filler, while CNF was incorporated as a hybrid filler to enhance the material's heating stability. PVAc0.4/EVA0.6/GP-3wt.% CNF exhibited the lowest room temperature resistivity, and its PTC strength (1.1) was comparable to that without CNF addition, with a Curie temperature of 29.4 °C. Room temperature Joule heating tests revealed that PVAc0.4/EVA0.6/GP-3wt.% CNF achieved an equilibrium temperature of approximately 42 °C at 25 V, with a heating power of 3.04 W and a power density of 3.04 W/cm2. The Young's modulus of PVAc0.4/EVA0.6/GP-3wt.% CNF was 9.24 MPa, and the toughness value was 1.68 MJ/m3, indicating that the elasticity and toughness of the composites were enhanced after mixing the fillers, and the mechanical properties of the composites were improved by blending graphite with CNF. [ABSTRACT FROM AUTHOR]

This article presents the results of research on the development of chemically resistant polymer–mineral casting composites based on industrial waste. The aim of this work is to develop a technological basis for obtaining effective inorganic fillers and highly filled composites for use in chlorine-containing environments. On the basis of theoretical data, mineral fillers and a polymer binder for filling composites were selected, optimal quantities of input hardeners and an appropriate thermal curing mode were determined, and the influence of the filling degree on the properties of composites was studied. The influence of various factors on the properties of the obtained composites was also studied, and the possibility of using local raw materials to obtain special-purpose composites was investigated. Ash from a thermal power plant (TPP) was used as an acid-resistant filler in composites. Two components were chosen as binders: phenol formaldehyde resin and mineral filler (TPP ash). As the third component, hydrolytically active fillers—anhydrite, phosphogypsum and phosphate slag—were used. The degree of filling has a significant influence on the properties of composites, including the compressive strength, chemical resistance and degree of curing, the values of which were elucidated across a wide range of composite variations based on the degree of filling. The conducted research allowed us to establish the limit of admissible anhydrite content, which should not exceed 15 mas.%. To optimize the chemical resistance and durability of the composites of the investigated substances, the method of mathematical planning was used. According to the results of this study, the optimal compositions of composites, in terms of anhydrite, phosphogypsum and phosphorus slag contents, were selected. At the maximum possible degree of filling, these composites exhibit high target characteristics. [ABSTRACT FROM AUTHOR]

There is always a vital need for more robust, affordable, and multifunctional materials to satisfy the demands of industrial consumers. Therefore, polymer matrix composites (dual and hybrid matrix) have become popular with multiple fillers to meet these needs. Graphene nano-platelet (GNP) and Carbon fibre (CF) are popular among those fillers due to their superior properties, such as good mechanical, thermal, and electrical properties. Low density polyethylene (LDPE), Polystyrene (PS), GNP, and CF are popular and heavily used in the packaging, automotive, and aerospace industries. However, it would be good to look at how these areas have evolved over the last few decades. Hence, this review focuses on a comparison of LDPE and PS as a matrix and GNP and CF as a filler, considering the content that determines the overall performance of blends and composites. The literature was screened for the last few decades. The blends and/or composites produced by a twin-screw extruder were included. A total of 1628 relevant papers were retrieved from all databases. Based on the review, it was deduced that more research should be needed in areas such as the aerospace industry to identify optimum content. Most of the analysis showed that factors such as filler surface area, dispersion, and content affect overall blends and composites' performance in terms of mechanical properties, especially elastic modulus and tensile strength, and other properties. Based on the review, it was realised that using 20 and 30 wt%, 2 and 30 wt%, 2 and 4 wt%, and 20 and 30 wt% filler was the most common combination giving the optimum content for LDPE, PS, GNP, and CF, respectively. EMS and TSH changes of the composites were calculated according to their optimum content. Overall, LDPE and PS are good in packaging areas, but their mechanical properties still need to be improved for use in industries such as automotive, aerospace etc. Due to the advantages of GNP and CF, they are used in different applications, such as electrical devices, medical tools, and automobile vehicles. However, these properties are affected easily by interfacial adhesion, dispersion, and aggregation. Many researchers have searched these parameters and analysed how to prevent the negative effects of these parameters. In conclusion, this review will be helpful for researchers and industrial people to be aware of the state-of-theart of carbon-based composites and the evolution of LDPE, PS, GNP, and CF. [ABSTRACT FROM AUTHOR]

This document is a compilation of research articles and reviews on the mechanical behavior and applications of natural fiber-reinforced polymer composites. The articles cover various topics, including the effect of fillers on mechanical properties, the use of natural and industrial wastes as fillers, and the characterization of different types of fiber-reinforced composites. The studies explore the potential of using natural fibers and fillers to improve the mechanical properties of composites and discuss the use of seashell waste and other unconventional fillers in composite materials. The document provides valuable insights into the field of natural fiber-reinforced polymer composites and highlights recent developments and challenges in this area. [Extracted from the article]

In this paper, metal matrix composites of Al6061 strengthened with 6 wt. % SiC were produced by stir casting and further subjected to the Tungsten Inert Gas (TIG) welding fabrication process using ER5356 as the filler material. The effect of TIG welding on hardness and wear resistance was studied by varying current at 150, 170, and 200 A. Samples of cast composite as per ASTM standards were prepared. Hardness tests on TIG-welded composite were carried out on the base, heat-affected, and weld zones. The test results showed higher hardness with an increase in welding current. Sliding wear properties were explored using the pin-on-disc machine. The wear rate and weight loss decreased as the welding current increased. The surface morphological images obtained through SEM indicated that the wear in the non-welded specimen was due to abrasion and delamination, whereas that of the welded specimen showed a reduced delamination and lower wear rate. [ABSTRACT FROM AUTHOR]

The filling efficiency during the hot embossing process at micro scale is essential for micro-component replication. The presence of the unfilled area is often due to the inadequate behavior law applied to the embossed materials. This research consists of the identification of viscoplastic law (two-layer viscoplastic model) of polymers and the optimization of processing parameters. Mechanical tests have been performed for two polymers at 20 °C and 30 °C above their glass transition temperature. The viscoplastic parameters are characterized based on stress–strain curves from the compression tests. The influences of imposed displacement, temperature, and friction on mold filling are investigated. The processing parameters are optimized to achieving the complete filling of micro cavities. The replication of a micro-structured cavity has been effectuated using this process and the experimental observations validate the results in the simulation, which confirms the efficiency of the proposed numerical approach. [ABSTRACT FROM AUTHOR]

Glass was introduced as an additive to filaments used for the manufacturing of composite materials, employed by Additive Manufacturing applications. Glass accounts for a large waste electric and electronic equipment (WEEE) percentage, and its recovery and recycling can lead to the production of sustainable composite materials. In this work, poly(lactic acid) (PLA)/commercially available silicon oxide composite filaments were manufactured and their structural, thermal, rheological, and mechanical properties were assessed. Scanning Electron Microscopy confirmed the 1:2 ratio of silicon: oxygen, along with the relatively low adhesion between the filler and the matrix. Differential Scanning Calorimetry presented steady glass transition and melting temperatures of composites, whereas a crystallization temperature of 10% wt. and a crystallinity of 15% wt. composite slightly increased. Rheological analysis showcased that the viscosity of the composite filaments decreased compared to PLA (10–100 compared to 300–400 Pa·s), with a more shear-thinning behavior. Dynamic mechanical analysis exhibited increased elastic, flexural moduli, and flexural strength of composites (up to 16, 23, and 11%, respectively), whereas tensile strength and elongation decreased. The affordability of raw materials (with the future introduction of recycled ones) and the minimal processing steps can lead to the potential scaling up of the study. [ABSTRACT FROM AUTHOR]

Introducing fillers into polymeric materials is one of the methods of modifying the properties or reducing the costs of polymeric materials. Thanks to their use, it is possible to obtain new materials with interesting mechanical and chemical properties. Some features are often improved among the new materials obtained, while others deteriorate. In this work, an attempt was made to obtain a polymer composite based on PLA filled with cork flour in amounts of 5%, 10%, 15%, 20% and 30% by weight. The processing and sample preparation process using injection molding technology was assessed and the basic mechanical properties were assessed. The research shows that it is possible to obtain PLA products with a cork filler without the mixing process on an extruder, but only by using an injection molding machine and appropriately selecting the parameters of the technological process. Tests of mechanical properties showed deterioration of parameters, but not to such an extent that the obtained composites were disqualified from use in products that are not subject to heavy mechanical loads. The undoubted advantage of the obtained materials is maintaining their so-called "green" character and thus the ability to biodegrade. [ABSTRACT FROM AUTHOR]

Composites based on polysulfone materials filled with various types of graphite and carbon black were studied and a solution technique was used to create composite materials with filling degrees ranging from 30 to 70% by weight. High filling levels with graphite fillers enabled thermal conductivity of 17.4 W/m·K to be achieved. The addition of carbon black as a filler to the composite helped to improve its mechanical characteristics, and its influence on electrical and thermal conductivity has also been explored. Natural graphite provides the best effect on composite thermal and electrical properties, whereas using artificial graphite allows to improve the mechanical behavior of composites. The relationship between sample density, porosity, and composition, as well as the effect of these factors on composite conductivity, has been studied and addressed. [ABSTRACT FROM AUTHOR]

In the present contribution, we report the results from a study on the ancient technology used to create decorative color plasters in the Thracian tomb near the village of Alexandrovo, Bulgaria. A series of fragments of red, black, grey, white and brown colored lime plasters from the dromos and funeral chamber were investigated by laser-induced breakdown spectroscopy, X-ray diffraction analysis, infrared spectroscopy, paramagnetic electron resonance spectroscopy and differential scanning calorimetry. Based on the combined analytical data, it was possible to identify the pigments, fillers and other materials in the composition of the decorative plasters in the interior, as well as to clarify the technological features related to the plaster creation. The results demonstrated that the murals were implemented on two layers in the case of white, black, grey and brown decoration—first coarse mortar, followed by a white, fine mortar, which usually was made of calcite. In the case of red decoration, a pigment was added to the fine mortar to achieve a colored surface. The pigments were identified as mostly traditional mineral pigments—calcite, kaolinite, red natural ochres (colored earth), brown colored earth and black pigment (amorphous C). The use of the fresco technique is implied by the major participation of calcite and the absence of organic binder in all of the painting layers. [ABSTRACT FROM AUTHOR]

Three-dimensional concrete printing (3DCP) is of great interest to scientists and the construction industry to bring automation to structural engineering applications. However, studies on the thermal performance of three-dimensional printed concrete (3DPC) building envelopes are limited, despite their potential to provide a long-term solution to modern construction challenges. This work is a numerical study to examine the impact of infill geometry on 3DPC lattice envelope thermal performance. Three different lattice structures were modeled to have the same thickness and nearly equal contour lengths, voids, and insulation percentages. Additionally, the effects of filament width and the application of granular insulating materials (expanded polystyrene beads and loose-fill perlite) were also studied. Finally, the efficacy of insulation was established. Results show that void area affects the thermal performance of 3DPC envelopes under stagnant air conditions, while web length, filament width, and contact (intersection) area between the webs and face shells affect the thermal behavior when cavities are filled with insulating materials due to thermal bridging. The thermal efficiency of insulation, which shows the effective use of insulation, varies between 26 and 44%, due to thermal bridges. [ABSTRACT FROM AUTHOR]

The problem of the growing amount of waste polymer materials currently affects virtually every area of the global economy. New actions taken by the E.U. and member states could lead to a reduction in the burden on the natural environment, as well as the reuse of thermoplastic waste. The aim of this study was to analyze the possibility of reusing post-industrial waste (recycled polypropylene—rPP) in order to produce mixtures with original polypropylene (PP) and glass fibers. The research undertaken is characterized by a high level of innovation and was carried out on an industrial scale from industrial waste. The primary goal of the analyses was to determine changes in the properties of the polymer mixtures depending on the amount of recycled polymers. For this purpose, four types of mixtures were prepared, characterized by different degrees of filling with recycled material obtained from big-bag packaging (the filling levels were 0 wt.%, 20 wt.%, 30 wt.%, and 70 wt.%). A detailed analysis of the physical properties of the obtained mixtures was carried out to determine changes in the densities depending on the amount of rPP material. In addition, changes in the MFIs (melt flow indexes), characterizing viscosity changes, were analyzed depending on the amount of secondary raw material used. An analysis of the mechanical properties was also carried out based on static tensile testing, the impact strength (the Charpy method), and the Rockwell hardness test (the M method). The analysis of the thermal changes was performed using the DSC method. The results showed that the composites made of virgin polypropylene (PP GF30) and those made from re-granulates and glass fibers (rPP GF30) are characterized by similar mechanical properties and significantly different processing properties, determined by MFI. This means that the addition of re-granulates significantly affects the processability of the obtained materials, while the addition of glass fibers maintains the basic mechanical properties. [ABSTRACT FROM AUTHOR]

Vertebral compression fractures (VCFs) are common in osteoporotic patients, with a frequency projected to increase alongside a growing geriatric population. VCFs often result in debilitating back pain and decreased mobility. Cement augmentation, a minimally invasive surgical technique, is widely used to stabilize fractures and restore vertebral height. Acrylic-based cements and calcium phosphate cements are currently the two primary fill materials utilized for these procedures. Despite their effectiveness, acrylic bone cements and calcium phosphate cements have been associated with various intraoperative and postoperative incidents impacting VCF treatment. Over the past decade, discoveries in the field of biomedical engineering and material science have shown advancements toward addressing these limitations. This narrative review aims to assess the potential pitfalls and barriers of the various types of bone cements. [ABSTRACT FROM AUTHOR]

The current practice of reconstruction of oxidized turbine parts (due to hot corrosion) using arc welding methods facilitates restoration of the nominal shapes and dimensions, as well as other attributes and features. Intense development of 3D additive methods and techniques contributes to the repair/modification of different parts including gas turbine (GT) hardware. The article proves the viability of the concept of using a robotized additive arc welding metal active gas (MAG) process to repair and modify gas turbine diaphragms using different filler materials from the substrate. The industrialized robotic additive process (hybrid repair) shows that very good results were achieved if the diaphragm is cast of nickel-iron and the filler material for welding the passes is austenitic stainless steel (for instance 308 LSi). This is one of the novelties introduced to the repair process that was granted a patent (US11148235B2) and is already implemented in General Electric Service Centers. [ABSTRACT FROM AUTHOR]

Defining an accurate friction model without having the mesh distortion in an optimized computational time has always been a significant challenge for modelling solid-state natural processes. The presented paper proposes an Eulerian frictional-based solid static model for the accurate modeling of sliding and sticking conditions for the friction stir additive manufacturing process (FSAM). For the frictional behavior, a modified friction model is proposed to investigate the sliding and sticking conditions during the process. The magnesium alloy is selected as the workpiece material and AZ31B-F is employed as the filler material. Two different subroutines, Dflux and Sfilm, are used in order to simulate the heat flux during the process. The convection and emission during the process are determined using the Goldak double ellipsoidal model. DC3D8 and C3D8R elements are employed as the thermal and mechanical models, respectively. The results indicated that the temperature sharply increased up to 870 °C in the first and the second layers. After that, the increasing rate becomes slower with a maxim temperature of 1310 °C. A linear cooling behavior is obtained at the cooling step. The stress results indicated that the tool and the filler material pressure play a significant role in increasing the stress at the center of the workpiece. On the sides of the workpiece, a peak stress is also obtained due to the clamping force. At the cooling phase for the center of the workpiece, the longitudinal residual stress of 5 MP and transverse residual stress of 7 MPa (compression) are achieved. The distortion of the workpiece is also investigated and a maximum value of 0.13 mm is obtained. To wrap up, it should be noted that by implementing an accurate sliding/sticking condition in a frictional based model, a more comprehensive investigation about frictional interactions and their influence on thermal and mechanical behavior can be carried out. [ABSTRACT FROM AUTHOR]

Grouting is a method or technique that is carried out to improve underground conditions by injecting material that is still in a liquid state, through pressure (it can inject semi-viscous materials) so that the material will fill in all the existing cracks and holes. The main purpose of grouting in this study is to strengthen the soil and increase soil strength. The injection material will enter the soil pores, react with the soil, and harden to form a strong and sturdy bond. The grouting material in this study was applied to filling boreholes in pile foundations when a load is applied, will be held by the frictional resistance between the piles, cement, epoxy paste, and soil. The filling materials for this grouting are soil paste, cement, and epoxy resin which were observed in a laboratory with a tensile test system to see the behavior of increasing soil strength at 7 days, 14 days, and 28 days. Based on the results of laboratory tests carried out, the use of epoxy resin, cement, soil, and water as grouting materials for foundations increases the soil stiffness value expressed in the modulus of elasticity value and increases the soil shear parameter values, namely the values c and f. The increase in value occurs at the ratio ER/W = 80/180 where with a longer curing time, namely 28 days, the value of shear stress, c and f and the modulus of elasticity are each 2.3kg/cm2; 39,520; 12.08 MPa. [ABSTRACT FROM AUTHOR]

Nowadays, many researchers aim to fill polymer materials with inorganic nanoparticles to enhance the polymer properties and gain the merits of the polymeric host matrix. Sol–gel synthesized Co3O4 nanoparticles are subjected to different doses of electron beam (10, 20, and 30 kGy) to study their physiochemical properties and choose the optimized nanoparticles to fill our polymeric matrix. Crosslinked polyethylene (XLPE) has been filled with 5 wt % of un-irradiated cobalt oxide nanoparticles using the melt extruder method. The structural, optical, magnetic, and electrical properties of the XLPE/Co3O4 nanocomposite before and after exposure to different doses of electron beam radiation have been characterized. The crystallite size of face-centered cubic spinel Co3O4 nanoparticles has been confirmed by XRD whereas and their unique truncated octahedral shape obviously appears in SEM micrographs. The crystallite size of Co3O4 nanoparticles has decreased from 47.5 to 31.5 nm upon irradiation at a dose of 30 kGy, and significantly decreased to 18.5 nm upon filling inside XLPE matrix. Related to the oxidation effect of the electron beam, the Co2+/Co3+ ratio on the surface of Co3O4 nanoparticles has decreased upon irradiation as verified by XPS technique. This consequently caused the partial elimination of oxygen vacancies, mainly responsible for the weak ferromagnetic behavior of Co3O4 in its nanoscale. This appears as decreased saturation magnetization as depicted by VSM. The XLPE/Co3O4 nanocomposite has also shown weak ferromagnetic behavior but the coercive field (Hc) has increased from 112.57 to 175.72 G upon filling inside XLPE matrix and decreased to 135.18 G after irradiating the nanocomposite at a dose of 30 kGy. The ionic conductivity of XLPE has increased from 0.133 × 10–7 to 2.198 × 10–3 S/cm upon filling with Co3O4 nanoparticles while a slight increase is observed upon irradiation. [ABSTRACT FROM AUTHOR]

Owing to its abundant supply from renewable resources, lignin has emerged as a promising functional filler for the development of sustainable composite materials. However, achieving good interfacial compatibility between lignin and synthetic polymers, particularly poly (lactic acid) (PLA), remains a fundamental challenge. To advance the development of high-performance bio-based composites incorporating lignin and PLA, our study has scrutinized to unravel the nuances of interfacial binding interactions with the lignin and PLA composite system. Molecular level and experimental examinations were employed to decipher fundamental mechanisms governing and demonstrating the interfacial adhesion. We synthesized casted films of lignin/PLA and acetylated lignin/PLA at varying weight percentages of lignin (5%, 10%, and 20%) and comprehensively investigated their physicochemical and mechanical properties. The inclusion of acetylated lignin in the composites resulted in improved mechanical strength and Young's modulus, while the glass transition temperature and melting point were reduced compared to neat PLA. Systematic variations in these properties revealed distinct compatibility behaviors between unmodified lignin and acetylated lignin when incorporated into PLA. Molecular dynamics (MD) simulation results elucidated that the observed changes in material properties were primarily attributed to the acetylation of lignin. Acetylated lignin exhibited lower Coulombic interaction energy and higher van der Waals forces, indicating a stronger affinity to PLA and a reduced propensity for intermolecular aggregation compared to unmodified lignin. Our findings highlight the critical role of controlling intermolecular interactions and lignin aggregation to develop PLA composites with predictable performance for new applications, such as functional packaging materials. [ABSTRACT FROM AUTHOR]

This study examined the shrinkage rate and mechanical properties of cob samples. Cob is a natural building material composed of clay, water, and varying amounts of plant fibres. The red and beige cob materials in this study containing 3% and 6% wheat fibres were manufactured by hand with clay, bulk fibres (short and long fibres), and a 25% water ratio (water/clay) in order to make their manufacture and use on construction sites feasible and simple. The reference samples were mixed with clay, 25% water, and 0% wheat fibre. The mechanical properties were assessed through compression and flexural tests after 28 and 120 days. The results showed that the fibre addition decreased the bulk density of the composites from 1902 kg/m3 to 1264 kg/m3. The compressive strength increased from 1.8 MPa to 4.57 MPa for the red clay samples and from 1.65 MPa to 4.61 MPa for the beige clay samples at 28 days. The compressive strength of each mixture decreased slightly with age for the red and beige clay samples, respectively. Conversely, the flexural strength increased with age for the samples reinforced with 3% and 6% fibres. The results also showed that the cob samples can deform without breaking. Increasing the fibre content in the mix resulted in a significant reduction in the shrinkage rate and an increase in the mass loss rate during thermogravimetric analysis. This analysis showed a total mass loss of approximately 5.64%, 6.12%, and 44.87% for the red clay, beige clay, and fibres, respectively. An average volume shrinkage of 1% was observed for the samples with 6% fibre content. The cob discussed in this article can be used as a filling material. In large quantities, it can be made by hand, with feet protected by boots, or with the use of a mixer. The environmental benefits are considerable, as the raw materials are renewable, and the manufacturing process is less energy-intensive. [ABSTRACT FROM AUTHOR]

Waste tempura flakes collected from local restaurants were upcycled to be utilized as a polymer filler material. The oil fraction in collected waste tempura flakes were extracted two times via centrifugal solid-liquid separation and organic solvent extraction. Then, oil-extracted residual starch was freeze-milled to produce fine powders. Waste tempura flakederived starch powder was substituted with 1%, 3%, and 5% (wt%) of virgin starch powder to produce thermoplastic starch. Composition, X-ray diffraction, and Fourier transform infrared analyses showed that the mixture was successfully thermally plasticized. Substitution of waste tempura flake-derived starch decreased tensile strength while increasing elongation at break of some samples. Produced thermoplastic starch samples again were compounded with polylactic acid (PLA) and polybutylene adipate-co-terephthalate (PBAT) following a mixing ratio of 3:5:2. The analyses indicated that thermoplastic starch, PLA, and PBAT were successfully compounded. The compound containing 1 wt% substituted thermoplastic starch showed the minimal mechanical strength decrease. This study revealed the possibility of upcycling waste fried food into a valuable bioplastic material. Waste tempura flakes can be utilized as both bio-jet fuel and bioplastic filler material. [ABSTRACT FROM AUTHOR]

Hollow microspheres as the filler material of syntactic foams have been adopted in extensive practical applications, where the physical parameters and their homogeneity have been proven to be critical factors during the design process, especially for high-specification scenarios. Based on double-emulsion droplet templates, hollow microspheres derived from microfluidics-enabled soft manufacturing have been validated to possess well-controlled morphology and composition with a much narrower size distribution and fewer defects compared to traditional production methods. However, for more stringent requirements, the innate density difference between the core–shell solution of the double-emulsion droplet template shall result in the wall thickness heterogeneity of the hollow microsphere, which will lead to unfavorable mechanical performance deviations. To clarify the specific mechanical response of microfluidics-derived hollow silica microspheres with varying eccentricities, a hybrid method combining experimental nanoindentation and a finite element method (FEM) simulation was proposed. The difference in eccentricity can determine the specific mechanical response of hollow microspheres during nanoindentation, including crack initiation and the evolution process, detailed fracture modes, load-bearing capacity, and energy dissipation capability, which should shed light on the necessity of optimizing the concentricity of double-emulsion droplets to improve the wall thickness homogeneity of hollow microspheres for better mechanical performance. [ABSTRACT FROM AUTHOR]