Filler Fraction Research Articles

Taguchi and Regression Analysis of Abrasive Wear Behavior of Carbon Epoxy Composite

This study aimed to assess the abrasive wear performance of a composite material made of carbon epoxy and graphite particles. The experiments were conducted on Abrasion Test rig and examined the weight loss of the composite material, taking into account the sliding distance and normal load. Taguchi method is employed to study the effect of process parameters on composite wear. Multiple regressions were utilized to establish a correlation between wear and wear parameters. The findings indicated that weight loss increased with higher applied loads, sliding distances, and weight fractions of graphite filler. Finally, the experimental results were validated through confirmation tests.

Molecular dynamics simulation of thermal conductivity of diamond/epoxy resin composites

Improving the thermal conductivity (TC) of epoxy resin thermal interface material is of great significance in tackling the heat dissipation problem of high heat flux in microelectronic chips such as 5G. Using non-equilibrium molecular dynamics (MD) method, the effects of two different filling styles of nano-diamond fillers on the TC of EP based composites are investigated. The results show that the TC of the composite increases with the diamond size when single-particle filling is used, and that a larger diamond size leads to a more significant reduction of the free volume fraction and thus an improvement of the TC. In the multi-particle packing, the composite TC first increases and then decreases with increasing particle number. Increasing the number of particles reduces the free volume fraction, but also results in a larger specific surface area and interfacial thermal resistance, which has a more significant weakening effect on the TC. Moreover, within the same mass fraction of nano-diamond filler, increasing the filler size has a more significant TC improvement on the composite than increasing the number of particles. This study is instructive for the design and preparation of high thermal conductivity nanodiamond/epoxy resin composites.

A comparative study on surface roughness of a novel Snake grass fiber/Aluminium powder reinforced epoxy composite and Snake grass fiber epoxy composite

The main objective of this study is to evaluate the surface roughness of a novel Snake grass fiber/Aluminium powder reinforced epoxy composite and compare it with Snake grass fiber epoxy composite in drilling process. In this work, the Snake grass fiber epoxy composite was taken as a control group with (N = 20) sample specimens. Also, Snake grass fiber with 20 % filler reinforced epoxy composites was considered as an experimental group with (N = 20) sample specimens. Composites plates were prepared with the hand layup method by various volume fractions of 0 % (without filler), 20 % Aluminium powder novel synthetic-filler. Surface roughness of the Snake grass fiber 20 % filler reinforced epoxy composite is 3.72 µm. Snake grass fiber with 20 % filler epoxy composite is 4.20 µm. Snake grass fiber with 20 % filler has statistically significant p = 0.024 (p < 0.05) than Snake grass fiber epoxy composite. Within the limitations of this study, the surface roughness of Snake grass fiber with a 20 % volume fraction of aluminum powder filler reinforced epoxy composite exhibited better significance than the Snake grass fiber epoxy composite.

Identification of the Utilization of Jember Coffee Skin Biocomposite (Coffea Canephora) as a Sound Absorber Using the Tube Method

The development of technology and information is in line with the era of society 5.0 which occurs in various fields, especially in terms of infrastructure which of course will lead to high mobility. One of the negative impacts that arise is noise. For that we need a material that can be used as an acoustic material that functions to absorb sound. Coffee waste is one of the agricultural wastes that can be used as an acoustic material. The purpose of this study was to determine the effect of the sound damping coefficient on sound intensity and the mixture of filler and matrix mass fractions that can be used to muffle sound. The tube method with the Sound Level meter feature from Smartphone will be used to determine the value of the sound attenuation coefficient. In this study, the sound intensity used was 60-100 dB, with a mass ratio of filler and matrix used was 80%:20%, 70%:30%, 60%:40%, 50%:50% and the thickness used is 10mm. The results of the study show that an increase in intensity for each sample will show a decreasing coefficient for each sample. This is due to the higher the intensity of the sound, the higher the sound energy will also be greater so that it is more difficult for the sample to absorb

Ultralow‐k hollow glass microsphere filled perfluoroalkoxy composites

AbstractPerfluoroalkoxy (PFA) composites filled with different volume fractions of hollow glass microsphere (HGM) and HGM/PFA–HGM/HBO3–HGM/PFA sandwich layered composites were prepared by simple dry mixing and hot‐pressing process. The dielectric frequency and temperature response characteristics, thermal expansion coefficient, and mechanical strength were investigated as a function of the loading fraction of HGM fillers. The obtained .6VfHGM/.4VfPFA composite demonstrates ultralow‐k (εr ∼ 1,63@1 MHz; 1.57@10 GHz) with low‐dielectric loss (∼7.2 × 10−4@1 MHz; ∼1.73 × 10−3@10 GHz), water absorption of ∼1.21%, in‐plane thermal expansion coefficient of 42 ppm/°C, and temperature coefficient of dielectric permittivity (τεr) of ∼−92 ppm/°C. The temperature stabilities of dimension and dielectric permittivity for the .6VfHGB/.4VfPFA composite could be substantially improved by forming .6VfHGM/.4VfPFA–.6VfHGM/.4VfHBO3–.6VfHGM/.4VfPFA sandwich–layered composite, which still maintained reasonable dielectric properties and mechanical rigidity with flexural strength of ∼8.1 MPa.

Epoxy-Nanoceramic Composites for 5G Antennas

Epoxy–nanoceramic composites of BiVO4 (BVO), LaNbO4 (LNO), and Li6Mg7Ti3O16 (LMT) were prepared using the solvent mixing method. The ceramic nano-fillers volume fractions were (5, 8, 10, and 12%). X-ray diffraction (XRD) and Atomic Force Microscopy (AFM) were used to investigate the crystal structure and size distribution of nanoceramics, respectively. The dielectric constant and loss tangent were measured in the frequency range of (4-8) GHz. The measurement technique was the waveguide approach via a Vector Network analyzer (VNA). The effect of the volume fraction of ceramic fillers on the dielectric constant and loss tangent of the composites at 5.28 GHz (5G) was investigated. This work aims to design composite materials for 5G antennas of lower cost while maintaining the properties of 5G antennas. The results show that an optimum volume fraction of the ceramic filler brings the dielectric properties to their best value. However, epoxy composite with a 5% volume fraction of LMT shows good microwave dielectric properties (dielectric constant = 2.17 and loss tangent = 0.011) at 5.28 GHz. In addition, epoxy- LMT composite with an exceptionally low volume fraction of 5% provides a low-cost material for a 5G antenna. Another aspect of the cost reduction is the elimination of the costly and troublesome compaction and high-temperature sintering process. Furthermore, the epoxy composite overcomes the disadvantages of the high brittleness of the sintered all-ceramic products. As a result, epoxy composite with the 5% volume fraction of LMT is a potential candidate for 5G antenna materials.

Influence of Herbal Fillers Addition on Selected Properties of Silicone Subjected to Accelerated Aging.

This work aims to assess the impact of the type and percentage of powdered herbs on selected properties of silicone-based composites. The matrix was an addition cross-linked platinum-cured polydimethylsiloxane. The fillers were powdered thyme and sage, which were introduced at 5, 10, and 15 wt.%. The introduced fillers differed in composition, morphology, and grain size. The grain morphology showed differences in the size and shape of the introduced fillers. The qualitative and quantitative assessment resulting from the incorporation was conducted based on tests of selected properties: density, wettability, rebound resilience, hardness, and tensile strength. The incorporation slightly affected the density and wettability of the silicone. Rebound resilience and hardness results differed depending on the filler type and fraction. However, tensile strength decreased, which may be due to the matrix's distribution of fillers and their chemical composition. Antibacterial activity evaluation against S. aureus proved the bacteriostatic properties of the composites. Accelerated aging in PBS solution further deteriorated the mechanical properties. FTIR and DSC have demonstrated the progressive aging of the materials. In addition, the results showed an overall minimal effect of fillers on the silicone chemical backbone and melting temperature. The developed materials can be used in applications that do not require high mechanical properties.

High Dielectric Design of Polymer Composites by Using Artificial Neural Network

Polymer-based composites with a high dielectric property have shown great potential in electrical energy storage applications. It is important to predict the dielectric constant in designing polymer composites, but it is costly and time consuming. In this study, dielectric properties of various polymer composites have been predicted by using an artificial neural network (ANN) model trained with hundreds of experimentally measured data. Eight variables such as the dielectric constant of matrix, filler, and shell, the diameter of filler, the volume fraction of filler, the dimension of filler, the thickness of shell, and the frequency were considered. To improve the prediction accuracy, hyper parameters of the ANN model were optimized through the hyperband method. Using the ANN model, we demonstrated the correlation between the dielectric constant of polymer composites and the variables. The ANN model predicted the dielectric constant with a coefficient of determination (R2) of 0.97. Furthermore, the ANN model shows good performance to predict dielectric constant at various frequencies (spanning from 100 Hz to 100 kHz). Hence, we present that the AI-based prediction model using ANN method can be helpful in designing the polymer composites with desired properties.

Effect of alkaline treatment on physical, mechanical, and thermal characteristics of jute filler reinforced epoxy composites

AbstractWith burgeoning environmental concerns worldwide, using natural fibers/fillers to produce composites rather than conventional fibers is on the rise. The current work focuses on the physical and thermomechanical characteristics of alkaline‐treated jute filler‐based epoxy composites. The composites have been prepared with different weight fraction of jute fillers (0%, 2.5%, 5%, 7.5%, 10%, and 12.5%) using hand layup process. The X‐ray diffraction and Fourier transform infrared spectroscopy analysis observed that the alkali treatment of jute fillers improved the crystallinity and molecular structure, enhancing the interfacial and molecular bond between fillers and matrix. The mechanical characterizations of developed composites analyzed that the inclusion of treated jute fillers strengthened the tensile and flexural properties. The 5% filler‐based composites have demonstrated maximum tensile strength (54.06 MPa) and modulus (3.12 GPa) with maximum flexural strength (67.55 MPa) and modulus (3.90 GPa). The viscoelastic characteristics of composites revealed that the 7.5% filler‐based composite has the highest storage modulus (3.75 GPa), loss modulus (0.496 GPa), and glass transition temperature (91°C) due to greater interfacial interactions of molecules. The weight loss and degradation of composites analyzed with thermogravimetric analysis, and observed better thermal stability with treated jute fillers. The morphological analysis at fracture surfaces analyzed the brittle catastrophic failure of composites. Therefore, the finding produced better specific strength and stiffness with greater thermal stability for electronics equipment, packaging, and transportation.

Influence of Pumice Particles on the Mechanical and Morphology Properties of Polyester-Cornhusk Fiber Composites

The purpose of this study was to look into the performance of a cornhusk fiber (CHF) reinforced polyester composite with pumice powder (PP) as a filler. The influence of varied PP volume fractions on composite tensile, bending, impact, and fracture morphology was studied. Using the hot press process, polyester-CHF composites with varied volume fractions of PP filler, namely 5%, 10%, 15%, 20%, 25%, and 30% wt, were created. The results showed that increasing the PP volume fraction from 5% to 15% enhanced the tensile strength of the polyester-CHF composite. The modulus of elasticity and bending modulus tend to grow when filler Pp decreases from 5% to 30%, but elongation value decreases. Furthermore, the best bending strength and impact toughness of the polyester-CHF composite were produced at a volume fraction of PP filler of 20%. SEM images indicate the presence of CHF pull out in all composite variations as well as the number of voids dependent on the PP filler volume.

Effect of Core-Shell Rubber Nanoparticles on the Mechanical Properties of Epoxy and Epoxy-Based CFRP.

The aim of the research was to estimate the effect of core-shell rubber (CSR) nanoparticles on the tensile properties, fracture toughness, and glass transition temperature of the epoxy and epoxy-based carbon fiber reinforced polymer (CFRP). Three additives containing CSR nanoparticles were used for the research resulting in a filler fraction of 2-6 wt.% in the epoxy resin. It was experimentally confirmed that the effect of the CSR nanoparticles on the tensile properties of the epoxy resin was notable, leading to a reduction of 10-20% in the tensile strength and elastic modulus and an increase of 60-108% in the fracture toughness for the highest filler fraction. The interlaminar fracture toughness of CFRP was maximally improved by 53% for ACE MX 960 at CSR content 4 wt.%. The glass transition temperature of the epoxy was gradually improved by 10-20 °C with the increase of CSR nanoparticles for all of the additives. A combination of rigid and soft particles could simultaneously enhance both the tensile properties and the fracture toughness, which cannot be achieved by the single-phase particles independently.

Theoretical analysis of Soft Conductive Materials for Next Generation Wearable System

Purpose of the study: Recent advances in strategies for soft materials have transformed the wearable or bioelectronics from a rigid form into a soft, having advantages in terms of mechanical similarity with human tissue. Conductive nanocomposites are promising components as conductive interconnects in stretchable electronic system. This study is about optimizations of nanocomposite for enhancing its performances without degrading mechanical properties. &#x0D; Methodology: First, we summarize the recent advances in metallic nanocomposites. Next, we discuss the 3-dimensional percolation theory, which is basic theoretical basis to understand the random system of nanocomposite. From this, we also briefly search important parameters having potential to change percolative connections of nanoparticles.&#x0D; Main Findings: We investigated required parameters, which could affect the percolation network of conductive fillers in matrix. Dimension, shape and volume fraction of fillers are very important to realize the high conductivity of conductive composite. By calculating some parameters with theoretical formula, we analyzed the effect of shape and dimensions on performance of conductive composite.&#x0D; Implications: This study can help researchers to understand the potential parameters that could affect the performances of conductive nanocomposite and analyze them in qualitative and quantitative approaches.&#x0D; Novelty: The potential applications of optimized conductive nanocomposite, especially focused on wearable and bio-implantable system are discussed.

Polymer-bonded magnets produced by laser powder bed fusion: Influence of powder morphology, filler fraction and energy input on the magnetic and mechanical properties

Bonded permanent magnets are key components in many energy conversion, sensor and actuator devices. These applications require high magnetic performance and freedom of shape. With additive manufacturing processes, for example laser powder bed fusion (LPBF), it is possible to produce bonded magnets with customized stray field distribution. Up to now, most studies use spherical powders as magnetic fillers due to their good flowability. Here, the behavior of large SmFeN platelets with a high aspect ratio as filler material and its influence on the arrangement and the resulting magnetic properties are examined in comparison to a spherical magnetic filler. The 3D distribution and orientation of the magnetic filler was studied by computed tomography and digital image analysis. The platelet-shaped particles align themselves perpendicular to the buildup direction during the process, which offers a new and cost-effective way of producing composites by LPBF with anisotropic structural and functional properties. The influence of LPBF parameters on the properties of the composites is investigated. Highest filling fractions are required for high magnetic remanence, however the powder itself limits this maximum due to particle shape and required minimal polymer fraction to form mechanically stable magnets. The coercivity decreases for higher filling fractions, which is attributed to increased rotation of insufficiently embedded magnetic particles in the matrix. It is discussed how filler morphology influences the observed change in coercivity since the rotation of spherical particles in comparison to platelet-shaped particles requires less energy. Our work shows the challenges and opportunities of large platelet shaped fillers used in LPBF for the production of anisotropic functional and structural composites.

Passive Filler-Loaded Silicon Oxycarbide Coating on Nickle Alloy with High Thermal Shocking Behavior and Oxidation Resistance.

Polymer-derived ceramic (PDC) coatings of considerable thickness can offer promising protection for metallic and superalloy substrates against oxidation and corrosion, yet the preparation remains challenging. Here, a SiOC/Al2O3/YSZ coating was prepared on a nickel alloy with a spraying method using Al2O3 and yttria-stabilized zirconia (YSZ) as passive fillers. The thickness can reach up to 97 μm with the optimal mass fraction and particle sizes of the passive fillers. A small or isolated SiOC phase is formed in the coating, which can effectively alleviate the shrinkage and cracking during the pyrolysis. The SiOC/Al2O3/YSZ coating exhibits low thermal conductivity and high bonding strength with the substrate. Moreover, the coating shows good thermal shock resistance between 800 °C-room temperature cycles and oxidation resistance at 1000 °C for 36 h. This work provides an effective guide for the design of thick PDC coatings to further promote their application in the thermal protective field.

Flammability and mechanical properties of Timoho fiber-reinforced polyester composite combined with iron powder filler

Natural fiber reinforced composites are usually added with fillers to improve their performance. However, this often affects the other composite properties. This study describes the successful development of timoho fiber (TF)-reinforced polyester composites combined with iron powder (IP) filler. Composite fabrication used hot press method. Flame, thermal, mechanical, and morphological characteristics were analyzed to determine the effect of variations on the volume fraction of IP filler in polyester composites with 30% (wt) TF. The results showed that the PTF composite had the highest tensile strength of 119.26 MPa. The impact toughness and the highest compressive strength were obtained at 126.74 kJ/m2 and 155.72 MPa, respectively, for the TF10IP composite. The elongation of the polyester composite decreased with the addition of IP filler from 3.58% to 2.19%. In contrast to elongation, the modulus of elasticity of the polyester composite increased from 4.14 to 4.94 GPa with the addition of IP filler. However, the thermal stability (TGA) and flame resistance of the composite increased. Observation of composite fracture morphology revealed the appearance of voids and TF pullout which supported the analysis of composite tensile strength.

Thermal conductivity of several geopolymer composites and discussion of their formulation

AbstractWe fabricated 50.8‐mm cube‐shaped samples of metakaolin geopolymer (GP) composites with various additives chosen to increase or decrease the thermal conductivity of the composite. Sodium‐based GP (NaGP) and GP composites were more conductive than potassium‐based GP (KGP) composites for a given phase fraction of filler, but the maximum amount of filler phase was higher with KGP due to the lower viscosity of the KGP mixture. The highest thermal conductivity achieved was about 8 W/m K by KGP + 44‐vol% graphite flakes, whereas NaGP + 27 vol% graphite flakes reached 4.7 W/m K. The thermal conductivity was strongly affected by the moisture remaining in the composite, which appeared to have a greater effect at higher filler content. On the other hand, the size of alumina particles (6, 40, or 120 μm) did not have any apparent effect on thermal conductivity for the same filler content. Larger particles caused less change in mixture viscosity, though, thus permitting incorporation of higher filler phase fractions and therefore higher thermal conductivity.

Flexible and Robust Ti3C2Tx/(ANF@FeNi) Composite Films with Outstanding Electromagnetic Interference Shielding and Electrothermal Conversion Performances

Flexible and robust multifunctional electromagnetic interference (EMI) shielding materials are playing an increasingly important role in areas of aerospace, electronic communication, artificial intelligence, and wearable electronic devices. Herein, the magnetic and conductive Ti3C2T x /(ANF@FeNi) EMI shielding composite films are fabricated via in situ growth and vacuum‐assisted filtration methods. The introduction of magnetic FeNi nanoparticles can effectively enhance the electromagnetic recombination losses, leading to improved EMI shielding effectiveness (EMI SE) of the composite films. The obtained Ti3C2T x /(ANF@FeNi) composite films show excellent EMI shielding and electrothermal conversion performances. When the mass fraction of Ti3C2T x and FeNi fillers is 60 wt% and their mass ratio is 4:1, the EMI SE of the composite films (50 μm) reaches 60.7 dB in the X‐band (8.2–12.4 GHz). When a low voltage of 3 V is applied, the surface heating temperature of the composite films quickly reaches 111.2 °C. Moreover, the composite films possess satisfied long‐term heating stability under the constant applied voltage. In addition, the composite films exhibit excellent thermal conductivity and mechanical properties. The thermal conductivity (λ) and thermal diffusivity (α) reach 4.72 W m−1 K−1 and 4.36 mm2 s−1, respectively, and the tensile strength and tensile modulus reach 113.4 MPa and 3.1 GPa, respectively.

Dielectric response and molecular dynamics of nanocomposites based on TEMPO-oxidized cellulose nanofibrils and polyvinyl acetate

• Two series of nanocomposites based on Polyvinyl-acetate incorporated with two different TEMPO-oxidized cellulose nanofibrils were investigated. • The activation energy and the strength parameters were interpreted. • Electrical conductivity were evaluated using DC measurements. • The comparison between the two sets of CNF showed that PVAc/CNF-5 min films were able to build a denser CNF network and hence the highest potential of filling effect than those of PVAc/CNF-2 h films. A series of polyvinyl acetate polymer matrices (PVAc) incorporated with two different TEMPO-oxidized cellulose nanofibrils (CNF with 5 min and 2 h of oxidation) were studied. These composites have proven to be suitable for use as ion battery separators. For this purpose, dielectric properties and electrical conductivity have been investigated using impedance spectroscopy in the frequency range from 10 2 to 10 6 Hz and over the temperature range, 200–350 K. The effects of CNF loading on the molecular motion and the charge transport mobility in PVAc polymer chains were studied. Calculation of the strength parameter for the α-relaxation process revealed a threshold value of 8 % in the volume fraction of filler. A comparative study of the two nanocomposites films showed that PVAc/CNF-5 min nanocomposites were able to build a denser CNF network and hence the highest potential of filling effect than those of PVAc/CNF-2 h films. According to our results, the volume fraction of 8 % of CNF-5 min is recommended for achieving the highest performing nanocomposite with potential applications.

Dielectric properties of polyarylene ether nitrile composites based on modified boron nitride

Polyarylene ether nitrile (PEN) is a new type of super engineering polymer with excellent high-temperature resistance, radiation resistance, good electrical insulation, and mechanical properties. In this work, boron nitride (BN) and copper phthalocyanine (CuPc) hybrids were integrated as fillers, which were further dispersed into PEN matrix by solution casting method to obtain a series of PEN composite films. The successful preparation of hybrid fillers was proved by means of X-ray photoelectron spectroscopy and scanning electron microscopy. The test results of the dielectric properties of the composite films show that the CuPc-BN/PEN films exhibit good dielectric properties. When the mass fraction of filler reaches 10 wt%, the dielectric constant of the PEN composite film increases by 17%. This study shows that the composites composed of modified BN and PEN has excellent dielectric properties and has great application potential in heat-resistance thin-film capacitors.

Advancement of the Power-Law Model and Its Percolation Exponent for the Electrical Conductivity of a Graphene-Containing System as a Component in the Biosensing of Breast Cancer

The power-law model for composite conductivity is expanded for graphene-based samples using the effects of interphase, tunnels and net on the effective filler fraction, percolation start and “b” exponent. In fact, filler dimensions, interphase thickness, tunneling distance and net dimension/density express the effective filler fraction, percolation start and “b” exponent. The developed equations are assessed by experimented values from previous works. Additionally, the effects of all parameters on “b” exponent and conductivity are analyzed. The experimented quantities of percolation start and conductivity confirm the predictability of the expressed equations. Thick interphase, large tunneling distance, high aspect ratio and big nets as well as skinny and large graphene nano-sheets produce a low “b” and a high conductivity, because they improve the conduction efficiency of graphene nets in the system. Graphene-filled nanocomposites can be applied in the biosensing of breast cancer cells and thus the developed model can help optimize the performance of biosensors.