Multi-walled Carbon Nanotube Fillers Research Articles

Statistical analysis to examine the influence of thermal aging on hybrid glass epoxy polymer composites with fillers of multi‐walled carbon nanotubes

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

Characterization and Evaluation of Mechanical Properties of Carbon Nanotube Filler Epoxy Composite

The outstanding mechanical properties of carbon nanotubes (CNT) have made them the focus of extensive investigation. To characterize and study the effects of the different volume fraction of multi walled carbon nanotubes (MWCNTs) on the mechanical properties of the nanocomposites attempted. The purpose of this work is to use experimental techniques to ascertain the mechanical characteristics of the nanocomposite. Tests on mechanical tensile strength were conducted to see how the MWCNT filler content affected the reinforced epoxy nanocomposite. The result of altered percentage of MWCNTs on the mechanical properties of the composites had been inspected. Results showed that 0.2 wt% MWCNT addition has the best effect on the mechanical properties of the matrix.

A computational Finite Element Study for Optimizing the Biomedical Strength of MWCNT Reinforced Polymer Nanocomposites

Multi-walled carbon nanotubes (MWCNTs) are highly regarded for reinforcing polymeric nano biocomposites, like polymethylmethacrylate (PMMA), owing to their versatility across various biological applications such as such as dental crowns, artificial teeth and dentures. In this study micromechanical models were meticulously developed to evaluate PMMA matrices fortified with MWCNTs at varying weight percentages (0.1%, 0.5%, and 1.0%). The assessment was conducted using Finite Element Analysis (FEA) facilitated by ANSYS 2022 (Ansys, Inc., USA). Notably, the investigation focused on validating the tensile strength against experimental data, revealing the peak tensile strength at 0.5 wt% MWCNT. Moreover, models featuring isotropic filler orientations demonstrated remarkable alignment with experimental outcomes. Furthermore, the study delved into exploring the influence of diverse MWCNT filler diameters (ranging from 10 to 35 nm) on the tensile strength, indicating a direct correlation with increasing diameter. However, it was observed that the larger diameters tended to correlate with decreased compressive and flexural strength. These comprehensive findings underscore the promising potential of MWCNT reinforced PMMA nanocomposites in advancing biomedical research, where enhanced mechanical properties play a pivotal role.

Multifunctionality of MWCNT and TiC hybrid filler silicone composite for energy harvesting and strain sensing

AbstractThe flexible silicone elastomer‐conductive composite was developed with enhanced energy harvesting and strain sensing. A hybrid nanofiller system with multi‐walled carbon nanotubes (MWCNTs) and titanium (IV) carbide (TiC) was used as reinforcing agents for the elastomer. The 4 MWCNT +5 TiC composite has 1.34 MPa tensile strength, 136.85% higher than unfilled silicone rubber (SR) matrix. The unfilled sample has a 1.558 MPa compressive modulus, while 4 MWCNT +5 TiC has 3.87 MPa. The machine and finger presses were utilized to test the energy harvesting of the composite. With greater cyclic stability, the 4 MWCNT +5 TiC sample performed exceptionally well in the machine press in the output voltage range of around 120 mV. Among the thumb presses, 2 MWCNT +5 TiC yielded the best results, with a voltage of about 100 mV. The 3 MWCNT +5 TiC sample produced 9044% more energy than the single filler 3 phr MWCNT sample from our previous work. Higher MWCNT content enhanced composite stiffness, making finger pressing harder and decreasing energy output. The strain sensing test on the 4 MWCNT +5 TiC composite showed high gauge factors (GF = 7.532 and 23.944) and good linearity (R2 = 0.909 and 0.939) over a strain range of Δε = 0%–14% and 14%–22%. Silicone composites' mechanical, energy harvesting, and strain sensing performance improved greatly with the MWCNT and TiC hybrid fillers. These composites could be used in self‐powered wearable electronics, machine or structural deformation monitoring, and human motion sensing.Highlights A stretchable device was developed with improved energy harvesting and strain sensing. Rubber composites were fabricated from MWCNTs, TiC hybrid fillers, and SR matrix. The energy harvesting was 9044% higher for hybrid filler compared to MWCNT as the only filler. Robust strain sensing properties with a gauge factor of 23.9, linearity of 0.91, and relaxation time of 0.1 s. The final composites are useful for self‐powered wearable electronics, health monitoring, and human motion sensing.

Kenaf Fiber and Hemp Fiber Multi-Walled Carbon Nanotube Filler-Reinforced Epoxy-Based Hybrid Composites for Biomedical Applications: Morphological and Mechanical Characterization

This study used a hybrid combination of kenaf and hemp fibers and the multi-walled carbon nanotube (MWCNT) reinforcements in the matrix phase to synthesize the composites. A kenaf/hemp fiber blend with MWCNTs in epoxy was used for the specific concentration. The procedure used three composite materials chosen from pilot trials. The ratio of MWCNT filler particles was altered up to the agglomeration limit based on initial trials. Two specimens (2 and 3) were supplemented with MWCNTs in a concentration range of 0.5 wt. % to 1 wt. %, with the fiber concentration being maintained in equilibrium with the epoxy resin, all of the materials were tested under the same conditions. The hybrid nanocomposite was characterized for its morphological and mechanical properties; the tensile properties were higher for 1% MWCNTs concentration (specimen 2), while the flexural properties were higher for 0.5% MWCNTs, with values of 43.24 MPa and 55.63 MPa, correspondingly. Once the MWCNT concentration was increased to 1 wt. %, the maximum impact strength was achieved (specimen 3). In the limits of the Shore-D scale, the kenaf fiber and hemp fiber matrix composite (specimen 1) gained a hardness index of 84. Scanning electron microscopy was carried out to analyze the morphological features of the fractured samples and to assess the adhesion between the fiber, matrix, and surface. Among the various fillers tested, the kenaf fiber/hemp/MWCNT composite (specimen 3) demonstrated superior binding and reduced the incidence of fiber pull-out, breakage, and voids. In addition to the comparative analysis, the addition of 0.5 wt. % MWCNTs resulted in better mechanical properties compared to the other two combinations.

Magnetic Polymer Actuators with Self-Sensing Resistive Bending Response Based on Ternary Polymer Composites.

A multifunctional polymer-based composite has been designed based on poly(vinylidene fluoride) (PVDF) as polymer matrix and cobalt ferrite (CoFe2O4, CFO) and multiwalled carbon nanotubes (MWCNTs) as fillers, allowing to combine magnetic and electrical responses. The composites were prepared by solvent casting with a fixed 20 wt % concentration of CFO and varying the MWCNTs content between 0 and 3 wt %, allowing to tailor the electrical behavior. The morphology, polymer phase, and thermal and magnetic properties are nearly independent of the MWCNT filler content within the polymer matrix. On the other hand, the mechanical and electrical properties strongly depend on the MWCNT content and a maximum d.c. electrical conductivity value of 4 × 10-4 S·cm-1 has been obtained for the 20 wt %CFO-3 wt %MWCNT/PVDF sample, which is accompanied by an 11.1 emu·g-1 magnetization. The suitability of this composite for magnetic actuators with self-sensing strain characteristics is demonstrated with excellent response and reproducibility.

Synergistically toughened silicone rubber nanocomposites using carbon nanotubes and molybdenum disulfide for stretchable strain sensors

Stretchable rubber nanocomposites have been investigated for detection in piezoresistive strain sensors. Tensile toughness must be improved while maintaining stretchability to realize high-performance, robust, stretchable nanocomposites. We investigate a stretchable and synergistically toughened silicone nanocomposite-based, piezoresistive strain sensor using multiwalled carbon nanotubes (MWCNTs) and molybdenum disulfide (MoS2). One-dimensional MWCNTs mechanically reinforce the silicone rubber matrix, improving tensile strength by 95% but decreasing fracture strain by 27% at 5 phr, providing an electrical percolation network. Adding two-dimensional nanolayers of MoS2 as a single filler increases fracture strain from 205% (unfilled) to 320% (5 phr MoS2), possibly due to cure retardation in the silicone rubber, preventing over-curing. Silicone nanocomposites exhibit improved tensile toughness at 8.46 kJ/m3 for 5-phr MWCNT-MoS2 hybrids due to the synergistic effects of the hybrid filler, a 125% improvement over unfilled rubber. Nanocomposites maintain a low elastic modulus (<0.45 MPa) suitable for stretchable sensors. The nanocomposite utility is demonstrated as body-attachable, piezoresistive strain sensing with a gauge factor of ∼25.95 (100%<Δε<155%), stretchability of up to 155%, and durability of over 5000 cycles. Toughened nanocomposites with MWCNT and MoS2 hybrid fillers could be useful for applications requiring robust stretchability and sensitivity.

MWCNT Filled Banana-Rice Husk Epoxy Hybrid Natural Fiber Polymer Composites

Natural fiber composites are prepared by combining two varying fiber/filler contents with a single matrix material. Hybrid polymer composite material made with synthetic agents (Thermosetting polymer) and natural fiber/filler contents. The current study focuses on hybrid polymer composite Multi Walled Carbon nanotubes (MWCNT)-filled Banana fiber/Rice husk filler-reinforced composites that have been assessed for mechanical responses. The banana fiber mat has been in the constant piling mode and altering the MWCNT and rice husk percentage in volume. Vacuum lay-up technique was used to construct the hybrid polymer composite and MWCNT was included with the help of ultrasonic probe sonicator instrument. Mechanical testing is performed accordance to the ASTM standards. The integration of MWCNT, as well as the constant piling order of banana fiber layers, has a stronger impact on mechanical properties. The three samples are prepared at the extremities 5% Banana fiber mat uniform loading and rice husk proportions are 10%, and 15% along with MWCNT filler (0.5% and 1%) for BRME2 and BRME3. The exhibited mechanical testing of the hybrid polymer composite to identify the conventional enhancement of hardness, tensile, impact, flexural, and compressive properties. Scanning Electron Microscope (SEM) is used to examine the fractograph of the tensile sample prepared with BRME3. BRME2 polymer composite with 1% weight of MWCNT was identified higher mechanical properties compare to BRME3 and BRME1 (Tensile, Flexural Strength, and Shore-D Hardness: 46.5 MPa, 59.7 MPa, and 88.5). Furthermore, the impact strength of BRME3 was significantly higher than BRME2 and BRME1.

Comparative Study on the Effect of Aluminium Trihydrate and Carbon Nanofillers on Thermal Properties of Glass Fiber Reinforced Epoxy Composites

High performance glass fiber reinforced epoxy composites are in greater demand in several industrial applications, from civil structures to aviation industry. The epoxy has highly cross-linked structure and is found to be high performance polymer. Further, carbon nanofillers such as multi-walled carbon nanotubes (MWCNT), graphene nanoplatelets (GNP) and thermally stable microfiller aluminium trihydrate (ATH) are being used to improve the thermal properties. GNP and MWCNT posses high aspect ratio and specific surface area contributing to improvement in thermal properties of composites. In spite of this, there are difficulties connected with nanofiller addition, such as dispersion and interaction. The fabricated nanocomposites are based on ECR glass fiber and epoxy resin by adding GNP, MWCNT and ATH fillers using pultrusion process assisted by ultrasonication. For the purpose of comparison, composites containing only MWCNT, GNP and ATH were also tested. The XRD and SEM were used to study the fillers dispersion and interaction. The thermogravemetric analysis(TGA) was carried out to determine the thermal stability of composites. From the thermal analysis result, it is found that the epoxy-MWCNT-GNP-ATH composite has enhanced thermal stability due to the addition of ATH micro filler.

Comparison of Carbon-Nanoparticle-Filled Poly(Butylene Succinate-co-Adipate) Nanocomposites for Electromagnetic Applications.

Electrostatic dissipative (ESD), anti-static (AS), and electromagnetic interference (EMI) shielding materials are commonly based on commodity fossil-fuel-based plastics. This, in turn, contributes to ever-growing non-biodegradable plastic pollution. Graphene nanoplatelets (GN), multi-walled carbon nanotubes (MWCNT), nanostructured carbon black (NCB), and amorphous carbon black (CB) were utilized as nanofillers to prepare bio-based and biodegradable poly(butylene succinate-co-adipate) (PBSA) nanocomposites. Solvent-cast composites were prepared with 1.1 to 30.0 vol.% nanoparticle loading. The literature mainly focuses on relatively low loadings; therefore, for this research, filler loadings were increased up to 30 vol.% but the maximum loading for NCB and CB loadings only reached 17.4 vol.% due to a lack of dimensional stability at higher loadings. The composites were characterized using tensile testing, volumetric and surface conductivity measurements, thermal conductivity measurements, dielectric spectroscopy in the microwave region, and transmittance in the terahertz range. Tensile tests showed excellent carbon filler compatibility and enhanced tensile strength for loadings up to 5 vol.% (up to 20 vol.% for MWCNT). The highest thermal conductivity values were reached for the MWCNT filler, with the 30.0 vol.% filled composite reaching 0.756 W/mK (262% increase over PBSA). All fillers were able to produce composites that yielded volume conductivities above 10−10 S/m. Composites with MWCNT, GN, and NCB inclusions above the percolation threshold are suitable for EMI applications in the microwave and THz frequency range.

Interface mechanics of liquid crystal polymer nanocomposites with high concentrations of MWCNTs

Compositing a liquid crystal polymer (LCP) with highly oriented multi-walled carbon nanotubes (MWCNTs) at non-dilute filler concentrations has attracted considerable attention due to its function as alignment layer as well as mechanical reinforcement. In this study, the structural and mechanical features of the LCP–MWCNT interface were investigated by all-atom molecular dynamics (MD) simulations. The results suggested that the MWCNT filler co-oriented with the liquid crystalline matrix enhances the crystallinity of the LCP molecules, especially in the interfacial area. The aromatic rings of the LCP components exhibited a repeating structural pattern because of the different equilibrium distances depending on the type of π-π stacking. The effect of the morphological change of LCPs in the interfacial region on the load transfer capability was also evaluated in terms of filler concentrations. In particular, tight coupling between the liquid crystal components and efficient load transfer to the outermost nanotube shell were first identified. These features account for the enhanced mechanical stiffness in the transverse loading direction with increasing volume fraction of the MWCNTs, as confirmed experimentally.

Preparation of poly(ionic liquid)/multi-walled carbon nanotube fillers using divinylbenzene as a linker to enhance the impact resistance of polyurethane elastomers.

The brittle fracture of polyurethane elastomer (PUE) under high-speed impact limits its application in high-speed impact protection. Here, based on the principle of free radical polymerization and π–π conjugation, composite nanoparticles (C-MWCNTs) are prepared by copolymerization of epoxy group ionic liquid (GVIMBr) and divinylbenzene (DVB) on MWCNTs using DVB as a linker. C-MWCNTs participate in the curing process of PUE through epoxy groups to form in situ crosslinked C-MWCNTs/PUE, which improves the energy absorption and high-speed impact properties of PUE. Compared with neat PUE, the maximum compressive strength and energy absorbed by C-MWCNTs/PUE are increased by 46.3% and 23.6%, respectively. By observing the microsurface and fracture morphology of C-MWCNTs/PUE, the relationship between macroscopic mechanical properties and microstructure is constructed. The improvement of the mechanical properties of the C-MWCNTs/PUE is attributed to the interfacial interaction and homogeneous dispersion of the C-MWCNTs in the PUE matrix. These microscopic effects are caused by the good compatibility between GVIMBr and PUE matrix and the synergistic enhancement between GVIMBr and MWCNTs.

Investigation of high temperature vulcanized and room temperature vulcanized silicone rubber based on flexible piezo‐electric energy harvesting applications with multi‐walled carbon nanotube reinforced composites

AbstractFlexible energy harvester can be able to produce continuous voltage output under the mechanical deformations. High temperature vulcanized (HTV) and room temperature vulcanized (RTV) silicone rubbers are used for making the flexible piezo‐electric energy harvester. A total of 1 and 2 phr of multi‐walled carbon nanotube (MWCNT) are used as the electrode material mixed with the rubber solution for the preparation of flexible electrode. Cyclic loading machine is used for the application of 2 Hz of bi‐axial load and uniaxial compression load in the specimen. One centimeter depth of displacement is applied during the bi‐axial cyclic loading and 4 mm amplitude of displacement is applied during the compression loading. Tensile and compression tests are performed to determine the engineering properties of the material. Tensile load withstanding value of the silicone rubber is increasing as increasing the MWCNT filler in the rubber. Tensile value of the pure HTV silicone rubber is 10.020 N and for 2 phr MWCNT reinforced rubber is 22.106 N. Compressive withstanding load of pure HTV rubber is 189.565 N and for 2 phr MWCNT reinforced rubber is 287.066 N. HTV silicone rubber is the highly stiffness material on compares with RTV rubber based on the tensile and the compressive value. Transmission electron microscopy, optical micrographs, and scanning electron microscope show the morphology of MWCNT and surface image of specimen. A total of 2 mm substrate based 2 phr MWCNT reinforced HTV flexible energy harvester undergo decrease in voltage during the cyclic loading due to breakage of electrode. A total of 2 phr MWCNT electrode‐based sample can be able to produce more output voltage than 1 phr MWCNT electrode‐based sample during bi‐axial and compression loading. More voltage is produced in the compression specimen than bi‐axial one.

The novel composite membranes containing chloride and acid functionalized multiwall carbon nanotube fillers for gas separation

The novel composite membranes containing chloride and acid functionalized multiwall carbon nanotube fillers for gas separation

Investigations on the preparation and properties of high-sensitive BaTiO3/MwCNTs/PDMS flexible capacitive pressure sensor

In this paper, a flexible capacitive pressure sensor with porous barium titanate (BaTiO3)/multi-walled carbon nanotubes (MwCNTs)/polydimethylsiloxane (PDMS) composite layer as the dielectric layer was fabricated. The sensitivity, stability, response time and human compatibility of the sensor were fully studied. The results showed that a controllable porous microstructure dielectric layer was built successfully where hybrid BaTiO3 and MwCNTs fillers with giant permittivity distributed homogeneously. The BaTiO3/MwCNTs/PDMS flexible capacitive pressure sensor possessed high sensitivity (~1.24 kPa−1) and good stability in the low pressure range (0 ~ 0.8 kPa). Moreover, a low detection limit (~7 Pa) and a fast response time (~200 ms) were obtained. Human compatibility test revealed that our flexible sensor could catch the response of human body swiftly so that it exhibited a bright application prospect in wearable electronics.

Hybrid Electrically Conductive Adhesive (HECA) Properties as a Function of Hybrid Filler Ratio with Increasing Total Filler Loading

This paper presents a study on Hybrid Electrically Conductive Adhesive (HECA) properties as an in-depth analysis regarding hybrid filler ratio at low filler range. It is well established that the hybridization approach exhibits excellent functional properties of HECA. Still, the highest potential ability of the proposed HECA concerning relative amounts of involving fillers is the least being discovered. In this work, silver micro-flake (AgMF) and multiwalled carbon nanotube (MWCNT) conductive fillers were incorporated from 3 to 15 wt.%, while AgMF: MWCNT filler ratio is varied between 0.006 up to 0.2 to choose the best combination. Here, a planetary centrifugal mixer with different mixing time and sequence were considered to identify the most effective mixing method. The functional properties of HECA were characterized in terms of a four-point probe electrical test and a lap shear test via tensile mode. The morphological study suggests that a shorter centrifugal mixing period allows an adequate dispersion of the micro-nano fillers in the HECA system and revealed superior interfacial bonding between the fillers at the optimum ratio. Interestingly, electrical resistivity at critical concentration showed an optimum ratio by incorporating only 2.5% AgMF in the hybrid fillers to yield a 42.62% reduction. However, the significant effects of hybridization are observed until the percolation threshold of HECA at 9 wt% only, followed by a 38.5% reduction beyond this limit. Moreover, the lap shear strength is most reliable at a total filler of 6 wt%, an indication of an excellent filler-binder load distribution.

Potentiality of MWCNT fillers on the lateral crashworthiness behaviour of polymer composite cylindrical tubes under quasi-static loading

In recent years, light-weight nano composite materials have been progressively employed in the aviation, defense, naval and automotive manufacturing applications owing to their outstanding mechanical and crashworthiness characteristics. In this regard, nano composite cylindrical tubes could be significantly utilized as energy absorbing elements for dissipating the impact energy during vehicle collisions. The present research study aimed to examine the lateral crashworthiness response of Multi-Walled Carbon Nano Tubes (MWCNT) filled epoxy composite (basalt fabric and glass fabric) tubes of three different inner diameters using quasi-static crushing experiments. Crushing profiles and crush force–deformation curves of all the recommended typical tube samples are computed and discussed elaborately. The results obtained revealed that better crashworthiness characteristics of MWCNT reinforced epoxy composite tubes with a larger diameter, were owing to more promising crushing modes occurring during lateral compression. It is also found that the lateral crashworthiness response of the MWCNT filled glass fabric epoxy composite tubes was marginally superior to that of the MWCNT filled basalt fabric epoxy composite tubes. However, both the recommended composite cylindrical tubes with nano-fillers might be employed as energy dissipating elements in modern vehicles.

An experimental analysis on the transverse crushing behaviour of Nano-filler reinforced composite cylindrical tubular elements

Thin-walled structures made of nanocomposite materials, could be employed as energy dissipating tubular elements in automobiles owing to its significant characteristics such as lightweight, fracture toughness, enhanced stiffness, and impact energy absorbing ability. The current research work aimed to investigate the transverse deformation behaviour of the hybrid aluminium-nano-filler reinforced glass/basalt fabric polymer composite cylindrical tubes under quasi-static experiments. The progressive crushing behaviour of these tubes were examined from photography. The experimental outcomes revealed that the aluminium-nano-filler reinforced composite tubes buckled displaying an ability of spreading the deformation under transverse compression. The use of multi-walled carbon nano tube fillers reduced the fibre fracturing and ultimately improved the energy absorbing ability of the tubes during crushing process. The nano filler induced tubes with more fabric plies revealed marginally better crashworthiness performance compared to the traditional aluminium-glass/basalt fabric polymer composite tubes.

Investigation of electrical properties of hybrid nanocomposites containing different fillers on pressure sensor applications under different loading

Conductive elastomeric nanocomposites (CEMs) were prepared in two stages to control the precision of pressure sensors. Carbon-based nanofillers such as multi-walled carbon nanotubes (MWCNT) or graphene (GR) were added to the rubber matrix. For Rubber/MWCNT composites, unfunctionalized (U-MWCNT) and –COOH functionalized MWCNT (F-MWCNT) fillers were synthesized. The properties of the CEMs and the synergistic improvements between the fillers and rubber matrix in composites were also investigated. SEM images show that F-MWCNT fillers were dispersed homogeneously in the composites and they interacted with rubber better than other carbon fillers. The piezoresistivity properties of the CEMs before and after compression were determined using the four-probe method by cyclic loading in 1 mm increments between 1.5 mm and 3.5 mm. F-MWCNT filled composites had higher strength than others when they were compressed by 2.5 mm. The F-MWCNT and GR filled nanocomposites possessed the best resistivity for pressure sensors when compressed at 2.5 mm (for F-MWCNT 1.1E + 08 Ω, GR 5.28E + 06 Ω). These nanocomposites are promising pressures sensors for air suspension systems.

Synergistic Effect of MWCNT and Carbon Fiber Hybrid Fillers on Electrical and Mechanical Properties of Alkali-Activated Slag Composites

Herein, we investigated the synergistic effect of multi-walled carbon nanotube (MWCNT) and carbon fiber (CF) hybrid fillers on electrical and mechanical characteristics of alkali-activated slag (AAS) composites. Many studies on AAS composites have been conducted in the past; however, not much progress has been made regarding characteristics of AAS composites with hybrid conductive fillers. The specimens with different mix proportions were fabricated in the present study, and numerous material characteristics, including flowability, electrical resistivity, and compressive strength of AAS composites were measured. In addition, the synergistic effects were investigated through scanning electron microscopy and thermogravimetric analysis. It was found that the 0.5 wt.% of MWCNTs and CFs lead the effects of the bridging and reducing crack propagation, thereby improving its electrical and mechanical performances. The filler exceeding a percolation point improved the electrical performance of the AAS composites; however, it interfered with the hydration process during the curing period, and caused a decrease in compressive strength of AAS composites.