Mechanical and Electrical Characterization of Entangled Networks of Carbon Nanofibers.
Ontology highlight
ABSTRACT:
SUBMITTER: Mousavi AK
PROVIDER: S-EPMC5455928 | biostudies-other | 2014 Jun
REPOSITORIES: biostudies-other
Similar Datasets
Project description:The present study compared the mechanical, electrical, morphological, and piezoresistive characteristics of epoxy-based sensing nanocomposites fabricated with inclusions of hybridized networks of four different carbon nanomaterials (CNMs), such as carbon nanotube (CNT), graphene, carbon nanofiber (CNF), and graphite nanoplatelet (GNP). Enhancements in elastic modulus and electrical conductivity were achieved by CNT-graphene composites and CNT-CNF composites, and these were explained by the morphological observations carried out in the present study and experimental studies found in the literature. The greatest gauge factor was accomplished by the CNT-GNP composite, followed by the CNT-CNF composite among composites where the CNM networks were sufficiently formed with a content ratio of 3%. The two types of the composites outperformed the composites incorporating solely CNT in terms of gauge factor, and this superiority was explained with the excluded volume theory.
| S-EPMC7180708 | biostudies-literature
Project description:Three-dimensional (3D) assemblies based on carbon nanomaterials still lag behind their individual one-dimensional building blocks in terms of mechanical and electrical properties. Here we demonstrate a simple strategy for the fabrication of an open porous 3D self-organized double-hierarchical carbon nanotube tube structure with properties advantageous to those existing so far. Even though no additional crosslinking exists between the individual nanotubes, a high reinforcement effect in compression and tensile characteristics is achieved by the formation of self-entangled carbon nanotube (CNT) networks in all three dimensions, employing the CNTs in their high tensile properties. Additionally, the tubular structure causes a self-enhancing effect in conductivity when employed in a 3D stretchable conductor, together with a high conductivity at low CNT concentrations. This strategy allows for an easy combination of different kinds of low-dimensional nanomaterials in a tube-shaped 3D structure, enabling the fabrication of multifunctional inorganic-carbon-polymer hybrid 3D materials.
| S-EPMC5662747 | biostudies-literature
Project description:Titanium oxynitride carbon composite nanofibers (TiON/C-CNFs) were synthesised with electrospinning and subsequent heat treatment in ammonia gas. In situ four-probe electrical conductivity measurements of individual TiON/C-CNFs were performed. Additionally, the TiON/C-CNFs were thoroughly analysed with various techniques, such as X-ray and electron diffractions, electron microscopies and spectroscopies, thermogravimetric analysis and chemical analysis to determine the crystal structure, morphology, chemical composition, and N/O at. ratio. It was found that nanofibers were composed of 2-5 nm sized titanium oxynitride (TiON) nanoparticles embedded in an amorphous carbon matrix with a small degree of porosity. The average electrical conductivity of a single TiON/C-CNF was 1.2 kS/m and the bulk electrical conductivity of the TiON/C-CNF fabric was 0.053 kS/m. From the available data, the mesh density of the TiON/C-CNF fabric was estimated to have a characteristic length of 1.0 µm and electrical conductivity of a single TiON/C-CNF was estimated to be from 0.45 kS/m to 19 kS/m. The electrical conductivity of the measured TiON/C-CNFs is better than that of amorphous carbon nanofibers and has ohmic behaviour, which indicates that it can effectively serve as a new type of support material for electrocatalysts, batteries, sensors or supercapacitors.
| S-EPMC9268360 | biostudies-literature
Project description:Geopolymers are inorganic crosslinked polymers with much less carbon footprint than ordinary Portland cement. Geopolymers and geopolymer-based materials have superior mechanical and durability properties with extreme thermal and chemical resistance. Carbon nano- or microfibers-reinforced geopolymers show potential properties such as electric conductivity, enhanced mechanical and thermal stability, and multi-functionality. This study evaluated the effect of incorporating carbon nanofibers in natural zeolite-based geopolymers and their impact on the mechanical, thermal, and electric conductivity of yielded geopolymer composites. Additionally, a life cycle assessment for 1 m3 geopolymer and its carbon fiber reinforced geopolymers' production has been conducted to evaluate the environmental impact of the processes.
| S-EPMC10957430 | biostudies-literature
Project description:This paper reports the effects of carbon nanofibers (CNFs) on nanoscaled mechanical properties of cement composites. CNFs were added to cement composites at the filler loading of 0.2 wt % (by wt. of cement). Micrographs based on scanning electron microscopy (SEM) show that CNFs are capable of forming strong interfacial bonding with cement matrices. Experimental results using nanoindentation reveal that the addition of CNFs in cement composites increases the proportions of high-density calcium-silicate-hydrate gel (HD-CSH) compared to low-density CSH gel. It was also found that the inclusion of CNFs increases the compressive strength of cement composites.
| S-EPMC5554043 | biostudies-other
Project description:Novel 2D Ti3C2Tx (MXene)-reinforced polyvinyl alcohol (PVA) nanofibers have been successfully fabricated by an electrospinning technique. The high aspect ratio, hydrophilic surfaces, and metallic conductivity of delaminated MXene nanosheet render it promising nanofiller for high performance nanocomposites. Cellulose nanocrystals (CNC) were used to improve the mechanical properties of the nanofibers. The obtained electrospun nanofibers had diameter from 174 to 194 nm depending on ratio between PVA, CNC and MXene. Dynamic mechanical analysis demonstrated an increase in the elastic modulus from 392 MPa for neat PVA fibers to 855 MPa for fibers containing CNC and MXene at 25°C. Moreover, PVA nanofibers containing 0.14 wt. % Ti3C2Tx exhibited dc conductivity of 0.8 mS/cm conductivity which is superior compared to similar composites prepared using methods other than electrospinning. Improved mechanical and electrical characteristics of the Ti3C2Tx /CNC/PVA composites make them viable materials for high performance energy applications.
| S-EPMC5576691 | biostudies-literature
Project description:The present study outlines a reliable approach to determining the electrical conductivity and elasticity of highly oriented electrospun conductive nanofibers of biopolymers. The highly oriented conductive fibers are fabricated by blending a high molar mass polyethylene oxide (PEO), polycaprolactone (PCL), and polylactic acid (PLA) with polyaniline (PANi) filler. The filler-matrix interaction and molar mass (M) of host polymer are among governing factors for variable fiber diameter. The conductivity as a function of filler fraction (φ) is shown and described using a McLachlan equation to reveal the electrical percolation thresholds (φc) of the nanofibers. The molar mass of biopolymer, storage time, and annealing temperature are significant factors for φc. The Young's modulus (E) of conductive fibers is dependent on filler fraction, molar mass, and post-annealing process. The combination of high orientation, tunable diameter, tunable conductivity, tunable elasticity, and biodegradability makes the presented nanofibers superior to the fibers described in previous literature and highly desirable for various biomedical and technical applications.
| S-EPMC8509057 | biostudies-literature
Project description:Recycling polymer/carbon nanotube (CNT) nanocomposites is not well common, despite a growing interest in using polymer/carbon nanotube (CNT) nanocomposites in industrial applications. In this study, the influence of mechanical recycling on the thermal, rheological, mechanical and electrical behavior of ethylene-vinyl acetate (EVA)/CNT nanocomposites is investigated. EVA/CNT nanocomposite with different amounts of CNTs (1, 3 and 5 wt.%) was subjected to mechanical grinding and reprocessing by injection molding in a close-loop up to three cycles, and the changes induced by mechanical recycling were monitored by Differential Scanning Calorimetry (DSC), capillary rheology, scanning electron microscopy (SEM), electrical resistance and tensile tests. It was found that the EVA/CNT nanocomposites did not exhibit significant changes in thermal and flow behavior due to mechanical recycling and reprocessing. The recycled EVA/CNT nanocomposites retain close to 75% of the original elastic modulus after three recycling cycles and about 80–90% in the tensile strength, depending on the CNT loading. The electrical conductivity of the recycled nanocomposites was about one order of magnitude lower as compared with the virgin nanocomposites, spanning the insulating to semi-conducting range (10−9 S/m–10−2 S/m) depending on the CNT loading. With proper control of the injection molding temperature and CNT loading, a balance between the mechanical and electrical properties of the recycled EVA nanocomposites can be reached, showing a potential to be used in practical applications.
| S-EPMC9919012 | biostudies-literature
Project description:In this paper, nanocomposites based on polypropylene (PP) filled with up to 5 wt.% of multi-walled carbon nanotubes (MWCNTs) were investigated for determining the material property data used in numerical simulation of manufacturing processes such as the injection molding and extrusion. PP/MWCNT nanocomposite pellets were characterized for rheological behavior, crystallinity, specific volume and thermal conductivity, while injection-molded samples were characterized for mechanical and electrical properties. The addition of MWCNTs does not significantly change the melting and crystallization behavior of the PP/MWCNT nanocomposites. The effect of MWCNTs on melt shear viscosity is more pronounced at low shear rates and MWCNT loadings of 1-5 wt.%. However, with the addition of up to 5 wt.% of MWCNTs, the PP/MWCNT nanocomposite still behaves like a non-Newtonian fluid. The specific volume of the PP/MWCNT nanocomposites decreases with increasing MWCNT loading, especially in the MWCNT range of 1-5 wt.%, indicating better dimensional stability. The thermal conductivity, depending on the pressure, MWCNT wt.% and temperature, did not exceed 0.35 W/m·K. The PP/MWCNT nanocomposite is electrical non-conductive up to 3 wt.%, whereas after the percolating path is created, the nanocomposite with 5 wt.% becomes semi-conductive with an electrical conductivity of 10-1 S/m. The tensile modulus, tensile strength and stress at break increase with increasing MWCNT loading, whereas the elongation at break significantly decreases with increasing MWCNT loading. The Cross and modified 2-domain Tait models are suitable for predicting the melt shear viscosity and specific volume as a function of MWCNTs, respectively. These results enable users to integrate the PP/MWCNT nanocomposites into computer aided engineering analysis.
| S-EPMC7825608 | biostudies-literature
Project description:In the present study, we discuss the electrospinning of medical grade polyurethane (Carbothane™ 3575A) nanofibers containing multi-walled-carbon-nanotubes (MWCNTs). A simple method that does not depend on additional foreign chemicals has been employed to disperse MWCNTs through high intensity sonication. Typically, a polymer solution consisting of polymer/MWCNTs has been electrospun to form nanofibers. Physiochemical aspects of prepared nanofibers were evaluated by SEM, TEM, FT-IR and Raman spectroscopy, confirming nanofibers containing MWCNTs. The biocompatibility and cell attachment of the produced nanofiber mats were investigated while culturing them in the presence of NIH 3T3 fibroblasts. The results from these tests indicated non-toxic behavior of the prepared nanofiber mats and had a significant attachment of cells towards nanofibers. The incorporation of MWCNTs into polymeric nanofibers led to an improvement in tensile stress from 11.40 ± 0.9 to 51.25 ± 5.5 MPa. Furthermore, complete alignment of the nanofibers resulted in an enhancement on tensile stress to 72.78 ± 5.5 MPa. Displaying these attributes of high mechanical properties and non-toxic nature of nanofibers are recommended for an ideal candidate for future tendon and ligament grafts.
| S-EPMC4312223 | biostudies-literature