Inclusion Of Filler Research Articles

Investigation of 3D Printed Self-Sensing UHPC Composites Using Graphite and Hybrid Carbon Microfibers

This paper explores the development of 3D-printed self-sensing Ultra-High Performance Concrete (UHPC) by incorporating graphite (G) powder, milled carbon microfiber (MCMF), and chopped carbon microfiber (CCMF) as additives into the UHPC matrix to enhance piezoresistive properties while maintaining workability for 3D printing. Percolation curves were established to identify optimal filler inclusion levels, and a series of compressive tests, including quasi-static cyclic, dynamic cyclic, and monotonic compressive loading, were conducted to evaluate the piezoresistive and mechanical performance of 29 different mix designs. It was found that incorporating G powder improved the conductivity of the UHPC but decreased compressive strength for both mold-cast and 3D-printed specimens. However, incorporating either MCMF or CCMF into the UHPC resulted in the maximum 9.8% and 19.2% increase in compressive strength and Young’s modulus, respectively, compared to the plain UHPC. The hybrid combination of MCMF and CCMF showed particularly effective in enhancing sensing performance, achieving strain linearity over 600 με. The best-preforming specimens (3G250M250CCMF) were fabricated using 3 wt% of G, 0.25 wt% of MCMF, and 0.25 wt% of CCMF, yielding a maximum strain gauge factor of 540, a resolution of 68 με, and an accuracy of 4.5 με under axial compression. The 3D-printed version of the best-performing specimens exhibited slightly diminished piezoresistive and mechanical behaviors compared to their mold-cast counterparts, yielding a maximum strain gauge factor of 410, a resolution of 99 με, and an accuracy of 8.6 με.

Inter-crosslinked spirocyclic mixed matrix membranes exhibiting enhanced gas permeability, selectivity, and plasticization resistance

Poor interfacial compatibility is the most common issue inhibiting performance enhancement in mixed matrix membranes (MMM) for gas and liquid separations. To address this issue, we fabricated highly selective and permeable inter-crosslinked mixed matrix membranes (IcMMMs) based on carboxylic-acid functionalized polymer of intrinsic microporosity-1 (CPIM) containing up to 30 wt % triptycene-isatin polymer porous network (PPN) particles. Polymer-filler inter-crosslinking is accomplished via thermal decarboxylation at 200 °C, which is the lowest temperature this reaction has been found to occur in the literature. This low temperature circumvents potential issues with degradation of porous supports or gutter layer materials, and thus enables these materials to be integrated into traditional membrane processes. The resulting IcMMMs exhibit gel fractions above 90 %. Beyond IcMMMs, membranes based on neat CPIM, thermally crosslinked CPIM, as well as non-crosslinked CPIM-PPN mixed matrix membranes were fabricated to elucidate the individual and synergistic effects of filler inclusion and thermal treatment. In addition to showing upper bound permeability-selectivity performance, IcMMMs also exhibit an almost unprecedented stability against plasticization upon extended exposure to CO2 up to 50 atm or above. This study shows that crosslinking across the polymer-filler interface is the key feature to achieve simultaneous enhancement in permeability, selectivity, and stability. To elucidate the molecular mechanism of these enhancements in the IcMMMs with respect to the baseline materials, permeability was broken into its sorption and diffusion contributions and an energetic analysis of sorption was performed. The low cost of PPNs coupled with the mild crosslinking temperature make this approach highly scalable, resulting in materials exhibiting high rigidity and structural stability with the potential to excel in aggressive separations, such as organic solvent separations or high-CO2 content, high-pressure natural gas sweetening.

Effects of locally-gradient Co-doping on the electron properties of Bi2Te2.1Se0.9+0.33wt.% Co composite

Interconnected effects of the locally-gradient Co-doping and electron scattering by filler inclusions has been for the first time observed in thermoelectric Bi2Te2.1Se0.9 + 0.33 wt.% Co composite, prepared via spark plasma sintering (SPS) of matrix and filler powders at temperatures TS=573, 598, 623, 648, 673 and 698 K and at the same time t = 2.5 min. During SPS-process, initial Co inclusions, randomly distributed inside the Bi2Te2.1Se0.9 matrix, act as electron doping sources. High-temperature diffusion embedding of Co atoms in the Bi2Te2.9Se0.1 structure results in increasing electron concentration. This diffusion process corresponds to diffusion from limited doping sources, which are spatially separated inside the Bi2Te2.9Se0.1 matrix. Separate filler inclusion is each such source. Concentration profiles of Co distribution were applied to extract a diffusion coefficient, DCo, of Co atoms inside Bi2Te2.9Se0.1. The DCo increases with TS in accordance with Arrhenius law. Owing to locally-gradient distribution of doping Co atoms, the Co-doping is locally-gradient doping. Initial inclusions, consisting of only Co atoms, are gradually transforming into the “core Co@shell CoTe2” inclusions. This transformation is related to diffusion of Co atoms that is accompanied by subsequent solid-state Co+2Te→CoTe2 reaction. Room-temperature weighted mobility of electrons increases with growing TS. This behavior of mobility can be originated from electron scattering by magnetic moments of the Co cores.

Mechanical investigation for enhancing jute fibre vinyl ester composite performance through garnet waste utilization

This study explores the potential utilization of garnet waste, a byproduct of the Abrasive Water Jet Machining process, as a promising filler material in composite manufacturing. The disposal of garnet waste presents significant environmental and economic challenges, underscoring the need for sustainable waste management strategies. To tackle these challenges, this research investigates the incorporation of garnet waste into composites to create value-added materials. Consequently, the study focused on developing garnet-filled jute fibre-reinforced vinyl ester composites using the hand layup method. Various mechanical properties including flexural strength, tensile strength, hardness, and impact strength were assessed. The findings demonstrate that the inclusion of garnet filler enhances the mechanical strength of the composites. Particularly, composites containing 10 wt% garnet exhibit notable improvements in tensile, flexural, impact, and hardness strengths, with increases of 40%, 124%, 26%, and 15%, respectively. This research has the potential to advance the development of advanced materials across diverse industries, marking a significant stride towards sustainable and value-driven composite manufacturing practices.

Effect of alumina fillers on physical and mechanical properties of luffa/groundnut shell natural fiber reinforced polymer composites

AbstractThis study aims to investigate the physical and mechanical properties of epoxy composites reinforced with hybrid luffa waste and groundnut shell waste natural fibers and to evaluate the effect of different filler loadings of alumina on the mechanical behavior of the hybrid composites. The luffa fibers were made to undergo mercerization in 10% NaOH solution. All the treated fibers and the alumina fillers were characterized using X‐ray diffraction analysis (XRD). The study used three different filler loadings of alumina (Al2O3) (5%, 10%, and 15% by volume) and three different fractions of treated luffa‐waste groundnut shell hybrid fibers (10%, 30%, and 50% by volume). The composites were fabricated using the hand layup technique, and the prepared test specimens were subjected to mechanical and physical properties testing as per ASTM standards. The experimental findings indicated that the inclusion of Al2O3 filler improved the physical and mechanical characteristics of the natural fiber‐reinforced hybrid composites. The results showed that the composites with 30 vol. % fibers (1:1 luffa fiber: groundnut shell fiber) and 10 vol. % Al2O3 content showed enhanced tensile, flexural, shear, and impact strength and hardness. Besides, a good synergy between the alumina fillers, natural fibers, and the polymer matrix was observed in the surface morphology of the composite specimen. The developed composites can be used in low and medium‐load‐bearing structural and non‐structural applications.Highlights Development of hybrid polymer composites with luffa and novel groundnut shell fibers Hybridization of alumina ceramic particles with natural fiber hybrid composites Assessment of physical and mechanical properties of the polymer composites

Experimental Investigations on Physical and Mechanical Properties of Hybrid Bamboo Composites

The present study aims to develop a novel hybrid composite by incorporating clamshell as a secondary reinforcing filler into a bamboo-epoxy composite. The primary objective of this hybridization is to optimize the synergistic benefits of each component, harnessing the strength of bamboo fibres, the durability of epoxy, and the cost-effective repurposing of the waste clamshell. Compression moulding was employed to develop composites with varying filler content (0- 9 wt%). The effect of filler on the physical and mechanical properties of bamboo-epoxy composites was evaluated by conducting tests as per ASTM standards. Experimental results show that the addition of clamshell filler significantly improved composites' properties, but there was a limitation to the addition. Hardness, tensile, and flexural properties were increased, whereas impact strength was reduced. Composites with 6 wt% clamshell exhibited optimum properties, enhancing tensile strength by 20.5% and flexural strength by 24.4 % compared to composites without filler. SEM analysis of fractured tensile and bending specimens revealed an enhanced fibre-matrix bonding with the inclusion of filler and supported the experimental results obtained. The outcome of this study contributes to sustainable development by using natural resources like bamboo fibre and repurposing seashell waste to create cost-effective composite material with enhanced properties.

Extrusion and characterization of eggshell-based composite filaments for sustainable development in additive manufacturing

Additive manufacturing (AM) is an extending manufacturing method which has many advantages such as minimalistic material wastage, less fabrication time and so on, over other manufacturing technologies such as subtractive, moulding, casting, etc. Strength enhancement of additively fabricated structures is an active area of study and much research was evolved in terms of developing innovative feedstock for AM. Polymers and their composites gain great attention in the research community. Even though many composites available commercially were observed with enhanced properties, most of them are not sustainable and recyclable in nature. Eggshell is a naturally available calcium carbonate, which gets wasted in a huge amount. Such eggshells were synthesized and transformed into nanosized for inclusion of filler in polylactic acid (PLA) matrix. PLA is a bio-degradable polymer with numerous applications and is one of the popular feedstocks for fused deposition modelling. This study explains the proper procedure to extrude commercial-grade eggshell-based composite filaments and qualities of such composites would be elaborately discussed with the help of single fibre tensile test, scanning electron microscopy and X-ray diffraction. Totally five filaments such as PLA, 5, 10, 15 and 20 wt % of eggshell in composites were extruded by following proper sonication and suitable filament extrusion process. 15 wt % composite seems to be the best among all filaments and possesses better characteristics than all other filaments.

Utilization of wollastonite, jarosite, and their blends for the sustainable development of concrete paver block mixes containing reclaimed asphalt pavement aggregates.

While several research studies considered the utilization of reclaimed asphalt pavement (RAP) aggregates for asphalt and concrete pavements, very few attempted its possible utilization for precast concrete applications like concrete paver blocks (CPBs). Moreover, few attempts made in the recent past to improve the strength properties of RAP inclusive concrete mixes by incorporating certain supplementary cementitious materials (SCMs) have reported an insignificant or marginal effect. The present study attempts to comprehensively investigate the utilization potential of some locally and abundantly available materials having suitable physicochemical properties to improve the performance of a zero-slump CPB mix containing 50% RAP aggregates. The studied filler materials, namely, wollastonite (naturally occurring calcium metasilicate mineral) and jarosite (hazardous zinc industry waste), were used to replace 5-15% and 10-20% by volume of Portland cement in the 50% RAP CPB mix. Apart from their individual effects, the efficacy of wollastonite-jarosite blends was also investigated. Considering the lack of indoor storage facilities and economic aspects of CPBs, the influence of water spray curing regime on the performance of the RAP CPB mixes was studied and compared to that of continuous water curing regime. Inclusion of the considered fillers was found to statistically and significantly enhance the flexural strength, tensile splitting strength, and abrasion resistance of the 50% RAP CPB mix; however, the compressive strength (in most cases), permeable voids, water absorption, and water permeability properties showed an insignificant improvement. Results of thermogravimetric analysis confirmed the occurrence of pozzolanic reactivity, and microstructure analysis revealed improvements in packing of concrete matrix and ITZ with filler inclusion qualitatively substantiating the improvements in strength and durability characteristics. The toxicity characteristics of heavy metals that may leach from the hazardous jarosite-based RAP CPB mixes were found to be within permissible limits. Based on the performance requirements specified by IS, IRC, and ASTM standards, all the RAP CPB mixes with filler inclusions fulfilled the acceptance criteria for heavy traffic applications, and water spray curing can enact as an alternate method for curing these mixes. However, to avail maximum performance benefits, it is recommended to use 5% wollastonite, 15% jarosite, and a combination of 10% wollastonite and 10% jarosite as a Portland cement substitute to produce sustainable eco-friendly RAP CPB mixes.

Impact of filler and gelling catalyst/agent on properties of flexible polyurethane foam

AbstractIn this study, the physiomechanical properties of carboxymethylcellulose sodium salt (Na‐CMC salt) filler‐loaded foam and its impact on the wicking capacity of the foam were investigated in juxtaposition with the increasing tin concentration. According to the study's findings, standard unfilled foam demonstrated no wicking at all, while flexible PU foam filled with Na‐CMC salt, even with low porosity and subpar mechanical traits, displayed wicking heights of 4 mm, 3.4 mm, and 2.8 mm in test specimens of thicknesses of 6 mm, 8 mm, and 10 mm. Moreover, filled foam with a higher porosity level exhibited significantly better wicking heights of 11.4 mm, 10.8 mm, and 8.2 mm. The inclusion of CMC filler in the PU foam matrix is the reason for enhanced wicking property in foam. The sample thickness and wicking height trends are consistent among all foams; as foam sample thickness increases, wicking height progressively falls. The correlation between the foam's porosity value and the number of closed cell windows is confirmed by stereomicroscopy and the porosity values. According to this study, the infused filler's characteristics have a greater influence on the foam's wicking capacity than the foam's porosity. This study contributes significant insights into ongoing initiatives to enhance user experience, well‐being, and hygiene through innovative and meticulously designed new developed mattress foam using Na‐CMC as a filler.Highlights Co‐relation between concentration of tin and infused filler on wicking property. Standard unfilled foam demonstrated no wicking at all. Na‐CMC salt filled foam displayed wicking heights. After 15% increase in tin level, mechanical properties of foam degrade. Wicking depends on nature of infused filler and the foam's porosity.

Sliding wear behaviour of micro-sized Kota stone dust reinforced epoxy composites using Taguchi method and Grey Wolf optimisation algorithm

Kota stone dust (KSD) is an unwanted material engendered throughout the process of manufacturing Kota stone. The present work comprises the appropriate consumption of KSD for evolving a composite system with epoxy as the base matrix material. The samples are developed by the hand lay-up technique. The micrographs clearly show that KSD is uniformly distributed within the epoxy matrix and establishes good adhesion with it. With the inclusion of filler, density unwillingly increases by 21.86%, but voids generated are limited to only 4.98% for a maximum filler content of 40 wt. %. A very low water absorption rate of 0.81% for maximum filler loading is observed. The compressive strength and micro-hardness increased by 31.8% and 26.25% respectively. Tensile strength, as well as flexural strength, improves for low filler loading of 20 wt. % and decreases thereafter. The sliding wear tests of the fabricated composites are studied in this research employing fairly advanced nature-inspired Grey wolf optimisation (GWO). The wear tests are based on a real-world issue that is framed in Taguchi L25 OA. A simple linear regression equation demonstrates adequate agreement between predicted and experimental values. The inclusion of KSD decreases the wear rate. Further, it is found that the KSD loading is the utmost significant factor, whereas normal load is the least significant factor that administrates the sliding wear rate of the composite system. Using the grey wolf optimiser, the optimal settings are 2500 m sliding distance, 40 wt.% KSD content, 52 cm/s sliding velocity, and 10 N normal load. The validation test results suggest that GWO is superior to the classical Taguchi approach. The wear loss mechanism is examined under the scanning electron microscope.

Study on the Crystallization Behavior of Neodymium Rare-Earth Butadiene Rubber Blends and Its Effect on Dynamic Mechanical Properties.

Utilizing neodymium-based butadiene rubber as a baseline, this study examines the effect of eco-friendly aromatic TDAE oil, fillers, and crosslinking reactions on neodymium-based rare-earth butadiene rubber (Nd-BR) crystallization behavior. The findings suggest that TDAE oil hinders crystallization, resulting in decreased crystallization temperatures and heightened activation energies (Ea). The crystallization activation energies for 20 parts per hundreds of rubber (PHR) and 37.5 PHR oil stand at -116.8 kJ/mol and -48.1 kJ/mol, respectively, surpassing the -264.3 kJ/mol of the unadulterated rubber. Fillers act as nucleating agents, hastening crystallization, which in turn elevates crystallization temperatures and diminishes Ea. In samples containing 20 PHR and 37.5 PHR oil, the incorporation of carbon black and silica brought the Ea down to -224.9 kJ/mol and -239.1 kJ/mol, respectively. Crosslinking considerably restricts molecular motion and crystallization potential. In the examined conditions, butadiene rubber containing 37.5 PHR oil displayed no crystallization following crosslinking, albeit crystallization was discernible with filler inclusion. Simultaneously, the crystallinity level sharply declined, manifesting cold crystallization behavior. The crosslinking process elevates Ea, while the equilibrium melting point (Tm0) noticeably diminishes. For instance, the Tm0 of pure Nd-BR is approximately -0.135 °C. When blended with carbon black and silica, the Tm0 values are -3.13 °C and -5.23 °C, respectively. After vulcanization, these values decrease to -21.6 °C and -10.16 °C. Evaluating the isothermal crystallization kinetics of diverse materials via the Avrami equation revealed that both the oil and crosslinking process can bring about a decrease in n values, with the Avrami index n for various samples oscillating between 1.5 and 2.5. Assessing the dynamic mechanical attributes of different specimens reveals that Nd-BR crystallization notably curtails its glass transition, marked by a modulus shift in the transition domain and a decrement in loss factor. The modulus in the rubbery state also witnesses a substantial augmentation.

Physical and mechanical characterization of glass fiber‐grewia optiva fiber reinforced hybrid polymer composite fabricated by vacuum assisted resin transfer moulding

AbstractThe natural and synthetic fibers are combined in a single composite to achieve a balance between the desired strength and cost considerations. In this study, the vacuum resin transfer moulding process was used to prepare an epoxy‐based composite. The composite consisted of grewia optiva as the natural fiber and glass fiber as the synthetic fiber, both with a fixed weightage of 10 %. Dolomite was used as a filler with varying content (0 %, 5 %, 10 %, and 15 weight %). The physical, mechanical, erosion wear and morphological behavior of the epoxy‐based composite were investigated. The inclusion of dolomite filler significantly increased the composite hardness and impact strength but reduced its tensile and flexural strength. At a dolomite filler content of 10 weight %, the erosive wear was reduced, while it increased at higher dolomite filler contents. The composite was examined using the L16 array, and the minimum wear rate was observed at an impingement angle of 30°, a velocity of 10 m/s, and an erodent size of 150 μm. Morphological studies were conducted to explore the possible mechanism for the variation in erosive wear at different dolomite contents in the hybrid composites.

Exploring the mechanical, tribological, and morphological characteristics of areca fiber epoxy composites reinforced with various fillers for multifaceted applications

This investigation is primarily concerned with the effect of fly ash, basalt powder, and tungsten carbide (WC) on the mechanical, microstructural, and tribological behaviour of areca fiber-reinforced composites. The fillers (5–10 wt. %) were included with the areca fiber epoxy reinforced composites. In comparison to areca fiber composites without fillers, the inclusion of fly ash, basalt powder, and WC increased the tensile strength by 33–48.2 MPa. The tensile strength of an A2 composite containing areca fiber (20 wt. %), epoxy (70 wt. %) and basalt powder (10 wt. %) was measured to be 48.2 MPa. Similarly, filler incorporation enhanced flexural, impact, and Shore D hardness properties by up to 21.25%, 13.18%, and 15.66%, respectively. Furthermore, the hybridization of fillers enhanced the mechanical properties and abrasion resistance of areca fiber reinforced composites. The inclusion of filler increases the load-carrying capability and adhesion, as determined by SEM. The river-like pattern demonstrates that ductile failure was dominated in the A5 [areca fiber (20 wt. %), epoxy (70 wt. %), fly ash (5 wt. %) and basalt powder (5 wt. %)] composites. A4 [areca fiber (20 wt. %), epoxy (70 wt. %), fly ash (5 wt. %) and tungsten carbide (5 wt. %)] composite has a lower wear resistance than all other composites. The hybrid filler-reinforced composite exhibits increased wear resistance as a result of the absence of wear detritus and textured surfaces.

Thermo physical and mechanical properties plaster of Paris ceilings modified with oil palm mesocarp fiber for application in buildings

The essence of this study is to assess the feasibility of improving the properties of the plaster of Paris (POP) ceiling by modifying it with oil palm mesocarp fibre (OPMF) in order to solve the disposal problem of the latter. Various weight proportions of the OPMF were used to replace the POP during the fabrication of the samples. All the samples were dried completely and then tested. The results showed that as the filler (OPMF) inclusion in the POP matrix increased from 0% to 40%, the change in mean values of water absorption, bulk density, thermal conductivity, specific heat capacity, thermal diffusivity, heat flow time, flakiness, and flexural strength (12.22 – 25.75) %, (1.768 – 1.407) 103 kgm-3, (0.2245 – 0.1465) Wm-1K-1, (1.498 – 1.825) 103 Jkg-1K-1, (8.477 – 5.705) 10-8 m2s-1, (9.64 – 14.37) mins., (0.65 – 2.08) %, and (3.02 – 1.38 ) N/mm2 respectively. It was found generally that the inclusion of the OPMF into the POP matrix could yield composite ceilings with enhanced/better thermal insulation capability for use in buildings. This, if implemented, could help to solve the disposal problem associated with waste while ensuring sustainable construction of thermally-safe and inexpensive buildings.

Modified reduced graphene oxide-LDH/WPU nanohybrid coated nylon 6 fabrics for durable photothermal conversion performance

The demand for photothermal fabrics requires more efficient photothermal nanoparticles and more stable interface binding fastness. Nanohybrid coating is considered as used as an efficient method to reach the goal. In this study, a nanohybrid of reduced graphene oxide-zinc-aluminum layered double metal hydroxide (RGO-LDH) was filled to WPU coating to prepare the photothermal textiles. RGO-LDH nanohybrid was surface modified by polydopamine (PDA) to improve the dispersion in WPU. In comparison to the pure WPU film, the WPU nanocomposite film exhibited enhanced water resistance, mechanical properties, and scratch resistance with the inclusion of nanohybrid filler at a 1 wt% concentration. Furthermore, the nanohybrid/WPU coated fabric showed excellent anti-ultraviolet (anti-UV) and photothermal conversion performance. The surface temperature of the nanohybrid/WPU coated fabric rose to 64 °C when exposed to a xenon lamp. After undergoing various durability tests including wearing, washing, folding, and bending, it was confirmed that the modified fabric had outstanding photothermal stability. This work provides a new strategy to fabricate the photothermal textile with excellent warming effect and weather resistance.

Impact of Hybrid Fillers on the Properties of High Density Polyethylene Based Composites.

The main objective of this work is to develop a variety of hybrid high-density polyethylene (HDPE) micro- and nanocomposites and to investigate their thermal, mechanical, and morphological characteristics as a function of number of fillers and their contents percentage. In this study, 21 formulations of the composites were prepared using fillers with different sizes including micro fillers such as talc, calcium carbonate (CaCO3), as well as nano-filler (fumed silica (FS)) though the melt blending technique. The morphological, mechanical, and thermal properties of the composite samples were evaluated. The morphological study revealed negligible filler agglomerates, good matrix–filler interfacial bonding in case of combined both CaCO3 and FS into the composites. Sequentially, improvements in tensile, flexural and Izod impact strengths as a function of fillers loading in the HDPE matrix have been reported. The maximum enhancement (%) of tensile, flexural and impact strengths were 127%, 86% and 16.6%, respectively, for composites containing 25% CaCO3 and 1% FS without any inclusion of talc filler; this indicates that the types/nature, size, quantity and dispersion status of fillers are playing a major role in the mechanical properties of the prepared composites more than the number of the used fillers.

Amelioration of ionic conductivity (303 K) with the supplement of MnO2 filler in the chitosan biopolymer electrolyte for magnesium batteries

In the present work, the significance of adding MnO2 filler towards the development of biopolymer electrolyte and chitosan with enhanced ionic conductivity has been reported. The complexation that has been taken place with the inclusion of MgNO3.6H2O salt and MnO2 filler in the chitosan matrix has been investigated through the Fourier transform infrared (FTIR) spectra analysis. Further, the transport parameter values such as number of charge carrier densities (n), mobility (μ) and diffusion coefficient (D) have been calculated from the deconvoluted FTIR spectra. X-Ray diffraction (XRD) and differential scanning calorimetric (DSC) examination revealed that the inclusion of filler significantly reduced the degree of crystallinity and the glass transition Tg values, respectively. These findings show that the inclusion of filler increases the segmental mobility of the polymer chains, allowing for faster ion transport. The conduction properties of the prepared electrolytes have been determined using alternating current (AC) impedance analysis, with the electrolyte containing 60 wt% magnesium salt (2.6 ± 0.08) × 10−4 S cm−1 achieving the maximum ionic conductivity value at room temperature (303 K). This value is further increased by one order of magnitude with the addition of MnO2 filler into the polymer matrix (1.25 ± 0.09) × 10−3 S cm−1. To elucidate the individual contributions of ions and electrons in the conduction process, the direct current (DC) polarization method has been used to determine the transference number (tion) of the produced electrolytes. The filler-added chitosan polymer exhibits an extended electrochemical stability window, 1.7 V, as determined by linear sweep voltammetry (LSV).

Influence of Supplementary Cementitious Materials on Fresh Properties of 3D Printable Materials

The development of printers and materials for 3D Printing Construction during the last two decades has allowed the construction of increasingly complex projects. Some of them have broken construction speed records due to the simplification of the construction process, particularly in non-standard geometries. However, for performance and security reasons the materials used had considerable amounts of Portland cement (PC), a constituent that increases the cost and environmental impact of 3D Printable Materials (3DPM). Supplementary Cement Materials (SCM), such as fly ash, silica fume and metakaolin, have been considered a good solution to partially replace PC. This work aims to study the inclusion of limestone filler, fly ash and metakaolin as SCM in 3DPM. Firstly, a brief literature review was made to understand how these SCM can improve the materials’ 3DP capacity, and which methods are used to evaluate them. Based on the literature review, a laboratory methodology is proposed to assess 3DP properties, where tests such as slump and flow table are suggested. The influence of each SCM is evaluated by performing all tests on mortars with different dosages of each SCM. Finally, a mechanical extruder is used to extrude the developed mortars, which allowed us to compare the results of slump and flow table tests with the quality of extruded samples.

Investigation on the Electrical and Rheological Properties of AlN-Based Synthetic Ester Nanofluids

The present study deals with the characterization of electrical and rheological behaviour of the Synthetic ester fluid incorporated with various concentration of Aluminium nitride (AlN) nanoparticles. Zeta potential measurement has shown an excellent stability of the ester fluid mixed with the nanoparticle. Corona inception voltage (CIV) measured using ultra-high frequency (UHF) technique and the results confirmed higher discharge resistance for nanofluid dispersed with 0.005% of AlN. Phase resolved partial discharge (PRPD) analysis with higher harmonic voltages has shown increase in pulse magnitude and number of discharges. Dielectric constant and tan <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\delta $ </tex-math></inline-formula> measurements have revealed a slight marginal increase in its value with the inclusion of filler. Streaming current magnitude was found to increase with the disc rotational speed, concentration of nanoparticle and ambient temperature. Fluorescence spectroscopy analysis has shown increase in fluorophores intensity with filler dispersion in the ester fluid. Rheological properties of fluids mixed with nanoparticles are inspected with cone plane geometry configuration. Synthetic ester and its nanofluid exhibited Newtonian behavior of flow pattern and are independent of the applied shear rate. An exponential decay of viscosity of nanofluids was observed with temperature and it follows an Arrhenius law. The calculated activation energy has increased with the incorporation of filler concentrations. The complex modulus of AlN nanofluids was observed alongside exhibiting the viscous behavior where the loss modulus <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\text{G}''$ </tex-math></inline-formula> is much larger than the storage modulus <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\text{G}'$ </tex-math></inline-formula> , with the applied frequency.

Mechanical, morphological and water absorption properties of polyethylene/olive pomace flour bio-composites

The mechanical and physical properties of various weigh percent’s (% 0 - % 40) of the olive pomace flour (OPF) loaded linear low density polyethylene (LLDPE) in the presence of % 0, % 5 and % 10 coupling agent (C) were formulated and studied. Extrusion and hot press processing techniques were used to fabricate OPF/LLDPE composites. Tensile stress at yield increased by % 20 with the increasing of the filler loading up to % 20; and marginally increased in the presence of the C. Whereas, the decline in the tensile strain at yield of the polymer composite improved with the increase in the C content. The modulus increased from 631 MPa for the neat LLDPE to 680, 808, 700 MPa for the filled composite at % 5, % 10 and % 20 filler content’s, respectively. Whereas, a decrease in the given modulus (550 MPa) was observed at % 40 filler loading. The modulus has shown a successive improvement upon the addition of the C with values not less than 800 MPa. The impact strength decreased with the increase in filler loading from 119 kJ/m2 for the neat LLDPE to 81, 43, 27 and 16 kJ/m2 for the % 5, % 10, % 20 and % 40 OPF/LLDPE samples, respectively. On the contrary, % 10 C addition improved the impact strength of the composite by two folds in the case of 10 - 40 % filler inclusion. Scanning electron microscopic (SEM) illustrations proved the mechanical performance of various bio-composite formulations. Water absorption of the bio-composite increased with the OPF loading, from % 0.73 for the neat LLDPE to % 2.6 for % 40 OPF filled polymer composite, and decreased upon increasing the C content with an average of % 1.4 for all composites. Bio-composite formulated by mixing cellulosic based material OPF and LLDPE demonstrated compatible physical properties and can be used as an already available cellulosic filler for the bio-composite materials.