Combination Of Fillers Research Articles

Electromagnetic Shielding of Composite Films Based on Graphite, Graphitized Carbon Black and Iron-Oxide

The present work regards the development of paint-like composites based on mixtures of carbon materials with magnetite in polyvinyl butyral matrix, and the investigation of the dependence on the electrical characteristics and the frequency of their electromagnetic shielding properties. It was found that high electromagnetic shielding effectiveness requires not only the presence of a high content of carbon components in the composite, but also the absence of an agglomeration of filler particles. Using these paint-like materials, a shielding effectiveness of up to −35 dB of UHF radiation can be obtained. A combination of fillers based on carbon-graphite materials of different morphology and magnetite was found to enhance shielding efficiency.

Comparison of Effectiveness and Safety of a Botulinum Toxin Monotherapy and a Combination Therapy with Hyaluronic Acid Filler for Improving Glabellar Frown.

Among numerous cosmetic procedures for face rejuvenation performed all over the world, botulinum toxin type A (BoNT-A) for wrinkles is one of the most widely practiced procedures. However, for severe frowns, the application of botulinum toxin is often insufficient. In this study, the effects of hyaluronic acid filler combination therapy and the BoNT-A alone were evaluated. Forty subjects with 2 or higher points (moderate to severe) of a facial wrinkle scale (FWS) when frowning in the glabellar area were assigned to 2 group: Botulinum toxin type A monotherapy group and a combination regimen of the toxin and hyaluronic acid filler group. Subjects visited outpatient department every 4 weeks until 28 weeks after the injection, and the assessment of the efficacy using FWS, subject satisfaction at both resting and maximum frowning and safety analysis were performed. Subjects of both group was administered 18U of BoNT-A and the subjects of the combination group received additional 0.45mL of hyaluronic acid filler regimen. Both at rest and maximum frown, the combination group scored lower FWS than the toxin and showed significance in the week-20 and week-28. And at final visit, subject satisfaction score of the combination was higher than that of toxin group. For patients with moderate to severe glabellar frown, the combined administration of BoNT-A and hyaluronic acid filler could be a considerable treatment for improving wrinkles. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Understanding the role of Ti addition on the corrosion and passive film characteristics of Nb stabilized AISI 347 weld

AbstractA multipass multilayer weld pad was fabricated on AISI 347 base metal with filler combinations of AISI 321 and AISI 347, to understand the role of Ti addition on metallurgical, corrosion, and passive film characteristics of the AISI 347 weld. Weld layers with Nb content of 0.53 wt.%, 0.47 wt.%, 0.23 wt.% and Ti of 0 wt.%, 0.21 wt.%, 0.33 wt.%, respectively, were extracted from fabricated weld pad. Selected weld metal compositions were subjected to thermal aging at 750°C for 24 h to investigate the influence of varying precipitation induced in these welds. Ti addition in AISI 347 weld showed lower enrichment of C and Cr at dendritic regions resulting in reduced Cr depletion, lower sensitization, enhanced pitting potential, and repassivation ability compared to conventional Nb stabilized AISI 347 weld. Passive film characteristics studied by electrochemical impedance spectroscopy and X‐ray photoelectron spectroscopy depicted formation of more protective, and dense passive film with higher Cr, Ni, and O concentrations for Ti added AISI 347 weld relative to conventional ones. Therefore, Ti addition via the use of Ti stabilized filler in the Nb stabilized AISI 347 weld proved to be efficient in enhancing its corrosion performance by forming a more protective passive oxide film.

Potential of biochar reinforced concrete as neutron shielding material

Biochar is a novel carbon based material derived from waste that shows promising properties for several applications. In this paper we investigate its potential use as a low cost, greener alternative to commonly used aggregates employed to enhance the neutron shielding performance of concrete. Monte Carlo simulations are performed with the PHITS code to estimate the neutron attenuation of blank and biochar-reinforced concrete exposed to high energy neutrons. We find that the shielding performance of concrete with 15% biochar is comparable with commonly used materials such as Boron Carbide at 20% and exceeds that of Basalt fibers with the same concentration, making these composites an interesting greener alternative to current solutions. A combination of biochar and heavier fillers also show extremely promising performance.

Evaluating cracking resistance of nano-hydrated lime treated asphalt mastic using work of fracture

ABSTRACT The present study aimed to understand the impact of inert-active filler combinations on cracking and resistance of asphalt mastic using work of fracture approach. A control grade asphalt binder (VG-30) and three fillers (inert: basalt (B); active: hydrated lime (HL) Nano hydrated lime (NHL)) were considered. The HL and NHL were added from 0% to 20% at 5% increment rate by weight of binder. The dosages of B were adjusted with respect to specific filler to binder ratios (0.6 to 1.2). The study focused on the influence of NHL on cracking resistance of mastic by means of ductile and fracture behaviour, evaluated using double edge notched tension test (DENT) at intermediate temperature condition. Findings indicated a beneficial impact in improving the cracking and fracture resistance of mastic due to reduction in the size of HL (NHL). The results signify that both HL and NHL can enhance the resistance to withstand ductile failure and fracture. Also, mastic prepared with B-NHL can be less susceptible to fracture over B-HL and hence, possessed improved ductile properties. Consequently, a lower dosage of NHL found to be superior over a higher dosage of HL in improving the cracking and fracture resistance of asphalt mastic.

Aeration Biofilter Filler Screening and Experimental Research on Nitrogen and Phosphorus Purification in Rural Black Water

In rural toilets, black water still remains polluted by nitrogen and phosphorus after being pre-treated by septic tanks. This study uses aerated biofilters to purify black water, screen the biofilter filler, and determine its effect on nitrogen and phosphorus purification in rural black water. This study introduced the concept of the “shape factor” into the Langmuir and Freundlich equations and optimized the isotherm adsorption model to better fit the actual dynamics of nitrogen and purification in black water. Combined with the first-order kinetic equation, the double constant equation, and the Elovich equation, the adsorption performance of seven kinds of biofilter fillers (i.e., zeolite, volcanic rock, sepiolite, ceramsite, anthracite, vermiculite, and peat) was studied. Then, the biofilter was constructed using a combination of fillers with better adsorption properties, and its ability to purify rural black water was studied. Results showed that vermiculite and zeolite had little effect on nitrogen and a high saturated adsorption of 654.50 and 300.89 mg·kg−1, respectively; peat and ceramsite had little effect on phosphorus and a high saturated adsorption of 282.41 mg·kg−1 and 233.89 mg·kg−1, respectively. The adsorption rate of nitrogen from fast to slow was vermiculite > peat > zeolite > volcanic rock > sepiolite > ceramsite > anthracite. The adsorption rate of phosphorus from fast to slow was peat > ceramsite > zeolite > sepiolite > vermiculite > volcanic rock > anthracite. Four combined biological filter fillers aided the removal of nitrogen and phosphorus from rural high-concentration black water. The combination of zeolite and ceramsite filler had a good nitrogen and phosphorus removal effect in high-concentration black water. After the system was stable, the nitrogen removal rate attained 71–73%, and the phosphorus removal rate attained 73–76% under the influent condition of total nitrogen and phosphorus concentrations of 150–162 and 10–14 mg·L−1, respectively. This study provides technical support and reference for the purification and treatment of rural black water.

Flexible magnetoelectric coupling nanocomposite films with multilayer network structure for dual-band EMI shielding

The rapid development of electronic information technology has brought huge challenges to high-performance electromagnetic interference (EMI) shielding films, especially for multi-band shielding. In this work, the core-shell structure of polydopamine coated silver nanowires (AgNWs) was formed by in situ polymerization of dopamine on the surface of AgNWs, the modified AgNWs were attached to the layered graphene surface through noncovalent bonds, magnetic Fe3O4 particles were then loaded on graphene/AgNWs to form magnetoelectric coupling fillers and cast with polyvinyl alcohol (PVA) to obtain nanocomposite films. The conductive fillers were uniformly dispersed in the PVA matrix with well compatibility, the resulting composite films not only displayed good flexibility, but also had been first time reported to show fine EMI shielding performance in both GPS band and X band thanks to the synergistic effect from the combination of conductive and magnetic fillers through an innovative structure. These nanocomposite films with good EMI shielding properties would show good application prospects in the fields of flexible electronics, electromagnetic countermeasure and stealth materials.

Mechanical, bonding and tribological performances of epoxy‐based nanocomposite coatings with multiple fillers

AbstractEpoxy nanocomposite coatings play an important role in the wear protection of steel exposed in harsh service environments. How to improve the mechanical and wear resistance of coatings through filler addition is necessary to meet the industry application requirements. In the present paper, an epoxy‐based nanocomposite coating was developed with addition of titanium dioxide (TiO2), graphite, short carbon fibers (SCFs), and zinc sulfide (ZnS) for enhancement in mechanical, bonding to steel, and tribological performances. The reciprocating friction and wear performances of the coatings were investigated at room temperature and 100°C. The addition of nanometer sized TiO2 and SCFs increased the tensile properties remarkably, while the addition of graphite and ZnS deteriorated the tensile properties. The fillers of graphite and ZnS had no obvious weakening effect on the interfacial shear strength between the coatings and steel, despite the solid lubrication of graphite and weak stiffness of ZnS. Compared with the epoxy sample, the wear rate of the coating filled with optimized filler combination (TTGCS5) was reduced by 19.5 times at room temperature and 25.9 times at 100°C. Addition of ZnS increased the wear resistance more pronounced compared to that of graphite at 100°C, which was attributed to formation of a compact, continuous and stable self‐lubricating transfer film on the coating surface. The optimized content of fillers was established for an epoxy coating to obtain the best friction rates of 0.51 and 0.56 (10−4 mm3/[N·m]) at 25 and 100°C, respectively.

Novel Conductive Polymer Composites for Asphalt Pavement Structure in Situ Strain Monitoring: Influence of CB/CNT and GNP/CNT Nano/Micro Hybrid Fillers on Strain Sensing Behavior

Sensing materials and devices with high sensitivity are necessary for engineering structure monitoring with the rapid development of intelligent infrastructure. This paper provides a novel approach to develop strain sensor with high sensitivity for pavement deformation monitoring by epoxying composites with hybrid nano/micro fillers. The effect of combined carbon black/carbon nanotubes (CB/CNT), graphene nanoplatelet/carbon nanotubes (CNT/GNP) fillers on the self-sensing behavior, morphology, dynamic mechanical performance and thermal properties of epoxy composites was discussed in detail. The incorporation of secondary CB results in significant improved self-sensing ability in micro-strain range. CB-CNT hybrid fillers show positive synergy effect on enhancement of piezoresistive response, while GNP show less positive effect on sensing behavior. The presence of CB forms the conductive core domain surrounded by CNT and constructs the multi scale conductive network of composites. The addition of two secondary fillers improves dynamic mechanical performance of composites. The self-sensing behavior of composites with combined filler was illustrated by SEM morphology and conductive pathway evolution during tensile deformation. Laboratory test showed that relative resistance changes have a linear relationship with the strain for developed sensor embedded in asphalt mixture. The polymer composite sensor shows strong sensing ability for asphalt concrete strain monitoring.

Electric-magnetic-dielectric synergism and Salisbury screen effect in laminated polymer composites with multiwall carbon nanotube, nickel, and antimony trioxide for enhancing electromagnetic interference shielding

Herein, polydimethylsiloxane (PDMS) was used as matrix, multi-walled carbon nanotubes (MWCNTs), nickel (Ni) and antimony trioxide (Sb2O3) particles were used as multiple fillers to explore the electric-magnetic-dielectric loss synergism in the composites. Generally, MWCNTs and Ni particles in the composites provided mainly electric and magnetic dissipation of microwaves, respectively. Sb2O3 particles were used to improve impedance matching and reduce surface reflection of microwaves. The synergistic effect of the Sb2O3-Ni-MWCNTs on electromagnetic interference (EMI) shielding effectiveness (SE) was discussed for combination of fillers with different ratio. Furthermore, the symmetrical structure (SS) and asymmetric structure (AS) composites were designed to obtain high EMI SE and absorption coefficient. For example, the SS composites and the AS composites could achieve the high EMI SET/absorption coefficient of ∼ 57.4 dB/ ∼ 0.75, and ∼ 55.7 dB/ ∼ 0.80, respectively, because of the electric-magnetic-dielectric synergism and Salisbury screen effect.

Investigation of physical, flexural, and dynamic mechanical properties of alumina and graphene nanoplatelets filled epoxy nanocomposites

AbstractIn this research, the different weight percentages of alumina and graphene nanoplatelets were homogeneously dispersed in the epoxy resin by a sonication and ball milling mixing process. The effect alumina and graphene nanoplatelets filled epoxy nanocomposites of physical, flexural, and dynamic mechanical properties were investigated. The epoxy nanocomposites showed a significant enhancement of 43.5% flexural strength and 29.5% flexural modulus for the combined filler loading of 2 wt% of alumina and 0.5 wt% of graphene nanoplatelets sample (EA2G0.5) than the neat epoxy. The EA2G0.5 epoxy nanocomposites sample showed an enhancement of 68.1% for the storage modulus. The loss modulus peak shifts toward the right side than the neat epoxy, which is showing better thermal stability of the composite. The differential scanning calorimetry technique was used to study the curing characteristics of the epoxy and epoxy nanocomposites. The scanning electron microscopy images of a fractured surface of the neat epoxy and alumina and graphene nanoplatelets filled epoxy nanocomposites showed the dispersion of the fillers, which is the sole cause of the enhancement of flexural properties. In general, these developed nanocomposites are suitable to be used as parent material in electrical and electronic packaging applications.

Ultrafine Grinded and Silane Grafted Iron Ore Tailings as Reinforcing Filler of Styrene Butadiene Rubber.

In order to realize the high value-added resource utilization of solid waste and reduce the cost of rubber manufacturing, iron ore tailings (IOTs) were used as raw material to prepare a reinforcing filler of rubber through ultrafine grinding and surface organic modification techniques. We studied the effects of ball mill grinding conditions on the particle size and distribution of grinded iron ore tailings (G-IOTs). The effects of bis-(triethoxy-silyl-propyl)-tetrasulfide (Si69)-modified G-IOT (Si69-G-IOT) loading levels on the cure characteristics, static mechanical and dynamic mechanical properties of the styrene butadiene rubber (SBR) composites were also explored in this paper. The grinding and modification mechanism of IOTs and the combination of filler and SBR matrix were explored by grinding simulation of population balance model, X-ray diffraction analysis, Fourier transform infrared spectroscopy and scanning electron microscopy. The results showed that when grinding IOTs at 2000 r/min for 150 min, the particle size distribution of the resulting G-IOTs was the narrowest, with a D90 value of 4.42 μm. The tensile strength and elongation at break of SBR filled with 120 phr Si69-G-IOT were 14.97 MPa and 596.36%, respectively.

Microwave absorbing materials based on hybrid filler

Composite elastomer microwave absorbers were developed based on two-phase hybrid filler. Nanosized magnetite was synthesized for the first time in the porous texture of activated carbon. Combination of fillers with high dielectric losses such as active carbon, and magnetite with high magnetic losses into hybrid filler is considered as a new Hightech for generation of microwave absorbers with specific technical characteristics. The influence of the obtained filler on the microwave shielding effectiveness of composite rubber absorbers was examined. The fillers were characterized by X-ray photoelectron spectroscopy (XPS), Scanning electron microscopy (SEM), Brunauer-Emmet-Teller (BET) method for the surface area analysis and texture parameters. The influence of the concentration of the synthesized filler on the microwave characteristics and shielding effectiveness was investigated.

Development and testing of hybrid green polymer composite (HGPC) filaments of PLA reinforced with waste bio fillers

Additive manufacturing is an emerging field for manufacturing complex geometry components. Ecological factors and need of eco-friendly materials leads to development of bio based materials and composites. The polymeric materials are major resource of pollution and many researchers are striving for development of green or ecological polymeric materials. On other side, the various by products form agriculture, food sector, etc generates abundant bio waste materials and it can be utilised to develop new hybrid polymeric bio composites. This work is the effort taken to develop bio composites using poly lactic acid (PLA) as a base (matrix) material and powder of waste wall nut shell, powder of waste egg shells and waste powder of white marble are used as fillers. There are six different types of 3 D printing filaments were prepared with various in combination of waste bio fillers. The filaments were tested for hardness, density, melting point, tensile strength and elongation.

Physical and mechanical behaviour of epoxy based hybrid composites with blast furnace slag and sisal fiber as reinforcement

The present work consists of designing and developing epoxy composite with blast furnace slag (BFS) along with sisal fiber (SF) as a hybrid filler material. The BFS is in the form of micro-particulates and sisal fibers are in the form of short fiber. The composites are fabricated keeping the content of BFS constant to 10 wt% and varying the content of sisal fiber from 0 wt% to 5 wt%. The epoxy/BFS/SF hybrid composites are tested for determining their physical behavior and mechanical properties. From the experimental analysis, it is observed that the density of the material rises with the BFS loading and decreases with the sisal fiber loading. Against that, void content and water intake rise with fillers loading. The mechanical properties of the epoxy-based hybrid composites under investigation improve with the inclusion of BFS and sisal fiber. From the analysis, it is recommended that a hybrid combination of fillers gainfully modifies the physical properties and enhances the mechanical properties so that the composites under investigation can find their potential application in light-duty structural applications.

Correction of nasolabial fold by combination of polydioxanone thread and hyaluronic acid filler: a case report

Correction of nasolabial fold by combination of polydioxanone thread and hyaluronic acid filler: a case report

Mechanical and Tribological Properties of Polytetrafluoroethylene Composites Modified by Carbon Fibers and Zeolite

Currently, lightweight and high-strength polymer composites can provide weight savings in the automotive and process equipment industries by replacing metal parts. Polytetrafluoroethylene and polymer composites based on it are used in various tribological applications due to their excellent antifriction properties and thermal stability. This article examines the effect of combined fillers (carbon fibers and zeolite) on the mechanical, tribological properties, and structure of polytetrafluoroethylene. It is shown that the introduction of combined fillers into polytetrafluoroethylene retains the tensile strength and elongation at break at a content of 1–5 wt.% of carbon fibers, the compressive stress increased by 53%, and the yield stress increased by 45% relative to the initial polymer. The wear resistance of polymer composites increased 810-fold compared to the initial polytetrafluoroethylene while maintaining a low coefficient of friction. The structural features of polymer composites are characterized by X-ray diffraction analysis, infrared spectroscopy, and scanning electron microscopy.

Combined effect of multiwalled carbon nanotubes, graphene nanoplatelets, and aluminum trihydride on the thermal stability of epoxy composites

AbstractGlass fiber reinforced epoxy matrix is modified with a hybrid combination of fillers, and composites were fabricated using the advanced pultrusion technique. The focus of the investigation was to comprehensively understand the synergy between the carbon nanofillers and the role of aluminum trihydride on the thermal characteristics. A ratio of 2 wt% of multiwalled carbon nanotubes and 3 wt% of graphene is established by prior optimization technique for improved thermal properties. Using X‐ray diffraction analysis, the presence of the two carbon fillers was confirmed. Aluminum trihydrate was incorporated in the epoxy matrix with the objective of improving the thermal properties. By thermogravimetric analysis and differential scanning calorimetry, assessment of the thermal properties of the composites has been undertaken. The use of the two carbon fillers leads to enhancement of the thermal properties and contrary to expectations, the composites with hybrid fillers undergo minimal degradation due to pyrolysis. Uniform dispersion of the nanoparticles and good interfacial bonding of fillers with the epoxy are observed to be critical for the enhancement of thermal properties. The ratio of the two carbon fillers used helps in their preferential alignment and hence significant improvements in thermal properties are observed. Glass transition temperature reveals a 13°C increase increases due to the inclusion of carbon nanofillers and aluminum trihydride.

Processing and Mechanical Behavior of Banana Fibre Reinforced Epoxy based Composite with Alumina and silicon Carbide

Polymer composites have outstanding qualities such as high strength, flexibility, stiffness, and lightweight. Currently, research is being performed to develop innovative polymer composites that may be used in many operational situations and contain a variety of fibre and filler combinations. Banana fibre has low density compared to glass fibre and it is a lingo-cellulosic fibre having relatively good mechanical properties compared to glass fibre. Because of their outstanding qualities, banana fibre reinforced polymer composites are now widely used in various industries. The primary goal of this study is to determine the effect of the wt.% of banana fibre, the wt.% of SiC, and the wt.% of Al2O3 in banana fibre reinforcement composites on the mechanical and physical properties of banana fibre reinforcement composites. Tensile strength and flexural strength of unfilled banana fibre epoxy composite increased with the increase in wt. of banana fibre from 0 wt.% to 12 wt.%. Further, an increase in wt.% banana fibre drop in mechanical property was observed. It has been concluded from the study that the variation in percentage weight of filler material with fixed amount (12 wt.%) of banana fibre affects the mechanical properties of filled banana reinforcement composites. Optimum mechanical properties were obtained for BHEC5 (72 wt.% Epoxy + Hardener, 12 wt.% banana fibre and 16 wt.% Al2O3).

Effect of Hybrid Fillers on the Bandgap Energy of Glass Epoxy Composites

Polymer composites are used increasingly in industrial applications due to their outstanding electrical, thermal, and mechanical properties. There is a vast literature on the advantages and limitations of nano and micro fillers and the effects of fillers on different properties of the polymers are reasonably understood. However, such information on the effects of a hybrid combination of nano and micron fillers is limited. In this investigation, the effect of hybrid fillers has been investigated in terms of the microstructure, optical absorption and electrical properties namely dielectric constant, AC conductivity and AC breakdown strength. Though different fillers are used, the bandgap energy varies over a narrow range of 2.5–3.2 eV. The hybrid fillers tend to influence the crystallinity and impart divergent optical absorbance spectra. The dielectric properties reveal dependence on the nature of the fillers and there are marked differences between the effects of conductive and insulating fillers, while the same is not observed in the case of the optical absorption spectra.