scholarly journals PLA/Graphene/MWCNT Composites with Improved Electrical and Thermal Properties Suitable for FDM 3D Printing Applications

2019 ◽  
Vol 9 (6) ◽  
pp. 1209 ◽  
Author(s):  
Evgeni Ivanov ◽  
Rumiana Kotsilkova ◽  
Hesheng Xia ◽  
Yinghong Chen ◽  
Ricardo Donato ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Electrical Conductivity ◽  
Thermal Properties ◽  
3D Printing ◽  
Filler Content ◽  
Hybrid Composites ◽  
Filler Concentration ◽  
Fused Deposition ◽  
Aspect Ratios ◽  
Uniform Dispersion

In this study, the structure, electrical and thermal properties of ten polymer compositions based on polylactic acid (PLA), low-cost industrial graphene nanoplates (GNP) and multi-walled carbon nanotubes (MWCNT) in mono-filler PLA/MWCNT and PLA/GNP systems with 0–6 wt.% filler content were investigated. Filler dispersion was further improved by combining these two carbon nanofillers with different geometric shapes and aspect ratios in hybrid bi-filler nanocomposites. Scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Raman spectroscopy exhibited uniform dispersion of nanoparticles in a polymer matrix. The obtained results have shown that for the mono-filler systems with MWCNT or GNP, the electrical conductivity increased with decades. Moreover, a small synergistic effect was observed in the GNP/MWCNT/PLA bi-filler hybrid composites when combining GNP and CNT at a ratio of 3% GNP/3% CNT and 1.5% GNP:4.5% CNT, showing higher electrical conductivity with respect to the systems incorporating individual CNTs and GNPs at the same overall filler concentration. This improvement was attributed to the interaction between CNTs and GNPs limiting GNP aggregation and bridging adjacent graphene platelets thus, forming a more efficient network. Thermal conductivity increases with higher filler content; this effect was more pronounced for the mono-filler composites based on PLA and GNP due to the ability of graphene to better transfer the heat. Morphological analysis carried out by electron microscopy (SEM, TEM) and Raman indicated that the nanocomposites present smaller and more homogeneous filler aggregates. The well-dispersed nanofillers also lead to a microstructure which is able to better enhance the electron and heat transfer and maximize the electrical and thermal properties. The obtained composites are suitable for the production of a multifunctional filament with improved electrical and thermal properties for different fused deposition modelling (FDM) 3D printing applications and also present a low production cost, which could potentially increase the competitiveness of this promising market niche.

scholarly journals The effect of additives metal on the D.C conductivity of epoxy resin

2011 ◽  
Vol 8 (1) ◽  
pp. 168-174
Author(s):  
Baghdad Science Journal
Keyword(s):  
Activation Energy ◽  
Electrical Conductivity ◽  
Epoxy Resin ◽  
Filler Content ◽  
Experimental Results ◽  
Filler Concentration ◽  
Effect Of Additives

The present studies are focused on the modification of the properties of epoxy resin with different additives namely aluminum, copper by preparing of composites systems with percentage (20%, 40% and 50%) of the above additives. The experimental results show that the D.C of conductivity on wt% filler content at ( 293-413 ) K electrical conductivity of all above composites increased with temperature for composites with filler contact and find the excellent electrical conductivity of copper and lie between (2.6*10-10 - 2.1*10-10)?.cm . The activation energy of the electrical conductivity is determined and found to decrease with increasing the filler concentration.

scholarly journals Three-Dimensional Printed Polylactic Acid (PLA) Surgical Retractors with Sonochemically Immobilized Silver Nanoparticles: The Next Generation of Low-Cost Antimicrobial Surgery Equipment

Nanomaterials ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 985 ◽  
Author(s):  
Lazaros Tzounis ◽  
Petros I. Bangeas ◽  
Aristomenis Exadaktylos ◽  
Markos Petousis ◽  
Nectarios Vidakis
Keyword(s):  
Electron Microscopy ◽  
3D Printing ◽  
Polylactic Acid ◽  
Low Cost ◽  
Three Dimensional ◽  
Film Deposition ◽  
Average Particle ◽  
Ag Nps ◽  
Fused Deposition ◽  
Vis Spectroscopy

A versatile method is reported for the manufacturing of antimicrobial (AM) surgery equipment utilising fused deposition modelling (FDM), three-dimensional (3D) printing and sonochemistry thin-film deposition technology. A surgical retractor was replicated from a commercial polylactic acid (PLA) thermoplastic filament, while a thin layer of silver (Ag) nanoparticles (NPs) was developed via a simple and scalable sonochemical deposition method. The PLA retractor covered with Ag NPs (PLA@Ag) exhibited vigorous AM properties examined by a reduction in Staphylococcus aureus (S. aureus), Pseudomonas aeruginosa (P. aeruginosa) and Escherichia coli (E. coli) bacteria viability (%) experiments at 30, 60 and 120 min duration of contact (p < 0.05). Scanning electron microscopy (SEM) showed the surface morphology of bare PLA and PLA@Ag retractor, revealing a homogeneous and full surface coverage of Ag NPs. X-Ray diffraction (XRD) analysis indicated the crystallinity of Ag nanocoating. Ultraviolent-visible (UV-vis) spectroscopy and transmission electron microscopy (TEM) highlighted the AgNP plasmonic optical responses and average particle size of 31.08 ± 6.68 nm. TEM images of the PLA@Ag crossection demonstrated the thickness of the deposited Ag nanolayer, as well as an observed tendency of AgNPs to penetrate though the outer surface of PLA. The combination of 3D printing and sonochemistry technology could open new avenues in the manufacturing of low-cost and on-demand antimicrobial surgery equipment.

scholarly journals Electrical and Thermal Conductivity of Epoxy-Carbon Filler Composites Processed by Calendaring

Materials ◽  
2019 ◽  
Vol 12 (9) ◽  
pp. 1522 ◽  
Author(s):  
Andrea Caradonna ◽  
Claudio Badini ◽  
Elisa Padovano ◽  
Mario Pietroluongo
Keyword(s):  
Thermal Conductivity ◽  
Electrical Conductivity ◽  
Hybrid Composites ◽  
Synergetic Effect ◽  
Multiwall Carbon Nanotubes ◽  
Carbon Filler ◽  
Aspect Ratios ◽  
Roll Mill ◽  
Mill Equipment ◽  
Noticeable Improvement

Electrical and thermal conductivity of composites which contain carbon-based fillers in an epoxy matrix were investigated. The fillers were dispersed in the liquid matrix by using three roll mill equipment. The filler/matrix mixture was cast in a mold and then cured, thus obtaining composite specimens. Multiwall carbon nanotubes, graphene-like nanoplatelets, and graphite were used as fillers and their effect on conductivity was investigated. Electrical and thermal conductivity were measured at different filler loads. It was found that the formation of percolation paths greatly enhanced electrical conductivity, although they were not so effective in improving thermal conductivity. The behavior of composites containing each single filler was compared with that of hybrid composites containing combinations of two different fillers. Results show that fillers with different aspect ratios displayed a synergetic effect resulting in a noticeable improvement of electrical conductivity. However, only a small effect on thermal conductivity was observed.

scholarly journals Effect of Kevlar Fiber and Nano Sio2 on Mechanical Andthermal Properties of Hybrid Composites

2021 ◽  
Vol 37 (3) ◽  
pp. 531-540
Author(s):  
P.S. Yadav ◽  
Rajesh Purohit ◽  
Anil Kothari ◽  
R. S. Rajput
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Thermal Properties ◽  
Hybrid Composite ◽  
Hybrid Composites ◽  
Mechanical And Thermal Properties ◽  
Nano Sio2 ◽  
Kevlar Fiber ◽  
Heat Deflection Temperature ◽  
Scanning Electron

The aim of the current investigation is an analysis of the mechanical and thermal properties of epoxy/ nano-silica/ Kevlar fiber hybrid composites. The ultrasonic vibration-assisted hand layup process was used for the preparation of composite with different weight percentages (1%, 2%, 3%, and 4%) of Nano SiO2 particles and 2 layers of the Kevlar fiber. For the evolution of mechanical properties tensile tests, hardness tests, impact tests, and flexural tests were done. For evaluation of morphological analysis Field Emission-Scanning Electron Microscopy, X-RD, and FT-IR tests were performed. A heat deflection temperature test was performed for the evaluation of the thermal characteristic of the hybrid composite. The results show the improvement of mechanical and thermal properties of the hybrid composite with increasing wt.% of nano SiO2 particles in the hybrid composites. As per the observation of experimental results, the Field Emission-Scanning Electron Microscopy,Fourier Transform Infrared Spectroscopy, and X-ray diffraction test also show the enhancement of surface morphology and chemical structure of hybrid composites. The heat diffraction test shows the improvement of thermal resistance and heat absorption capability.As per the observation of experimental results, the tensile strength, hardness, and impact strength increased up to 98%, 16%, and 42% respectively. The flexural test shows the improvement of flexural modulus and stresses 46% and 35% respectively. The heat deflection temperature of hybrid composite improves up to 30%.

scholarly journals 3D Printed Thermoelectric Polyurethane/Multiwalled Carbon Nanotube Nanocomposites: A Novel Approach towards the Fabrication of Flexible and Stretchable Organic Thermoelectrics

Materials ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 2879 ◽  
Author(s):  
Lazaros Tzounis ◽  
Markos Petousis ◽  
Sotirios Grammatikos ◽  
Nectarios Vidakis
Keyword(s):  
Electron Microscopy ◽  
Electrical Conductivity ◽  
Carbon Nanotube ◽  
Seebeck Coefficient ◽  
Morphological Characteristics ◽  
Multiwalled Carbon Nanotube ◽  
Melt Mixing ◽  
Multiwalled Carbon ◽  
Fused Deposition ◽  
3D Printed

Three-dimensional (3D) printing of thermoelectric polymer nanocomposites is reported for the first time employing flexible, stretchable and electrically conductive 3D printable thermoplastic polyurethane (TPU)/multiwalled carbon nanotube (MWCNT) filaments. TPU/MWCNT conductive polymer composites (CPC) have been initially developed employing melt-mixing and extrusion processes. TPU pellets and two different types of MWCNTs, namely the NC-7000 MWCNTs (NC-MWCNT) and Long MWCNTs (L-MWCNT) were used to manufacture TPU/MWCNT nanocomposite filaments with 1.0, 2.5 and 5.0 wt.%. 3D printed thermoelectric TPU/MWCNT nanocomposites were fabricated through a fused deposition modelling (FDM) process. Raman and scanning electron microscopy (SEM) revealed the graphitic nature and morphological characteristics of CNTs. SEM and transmission electron microscopy (TEM) exhibited an excellent CNT nanodispersion in the TPU matrix. Tensile tests showed no significant deterioration of the moduli and strengths for the 3D printed samples compared to the nanocomposites prepared by compression moulding, indicating an excellent interlayer adhesion and mechanical performance of the 3D printed nanocomposites. Electrical and thermoelectric investigations showed that L-MWCNT exhibits 19.8 ± 0.2 µV/K Seebeck coefficient (S) and 8.4 × 103 S/m electrical conductivity (σ), while TPU/L-MWCNT CPCs at 5.0 wt.% exhibited the highest thermoelectric performance (σ = 133.1 S/m, S = 19.8 ± 0.2 µV/K and PF = 0.04 μW/mK2) among TPU/CNT CPCs in the literature. All 3D printed samples exhibited an anisotropic electrical conductivity and the same Seebeck coefficient in the through- and cross-layer printing directions. TPU/MWCNT could act as excellent organic thermoelectric material towards 3D printed thermoelectric generators (TEGs) for potential large-scale energy harvesting applications.

scholarly journals Surfactant Incorporated Co Nanoparticles Polymer Composites with Uniform Dispersion and Double Percolation

2017 ◽  
Vol 2017 ◽  
pp. 1-6 ◽  
Author(s):  
Tajamal Hussain ◽  
Mirza Nadeem Ahmad ◽  
Aneela Nawaz ◽  
Adnan Mujahid ◽  
Farrukh Bashir ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Polymer Matrix ◽  
Threshold Value ◽  
Filler Concentration ◽  
Physical Interaction ◽  
Uniform Dispersion ◽  
Uv Visible ◽  
Filler Particles ◽  
Lcr Meter ◽  
Co Nanoparticles

Series of Cobalt nanoparticles incorporated polymethylmethacrylate composites in the presence and absence of dodecyl-benzene-sulphonic acid (DBSA-CoNPs/PMMA and CoNPs/PMMA, resp.) were synthesized by solution mixing methodology. UV-visible and FTIR techniques were used to confirm the formation of nanocomposite. UV-visible spectra of the composites showed the incorporation of filler particles in the polymer matrix. On the other hand, FTIR spectra indicated the physical interaction between the two phases of the composite. Moreover, the electrical nature of the composites was studied by plotting graphs between electrical conductivity (measured using LCR meter at 100 kHz) and contents of the filler particles as introduced in the polymer matrix. An increase in electrical conductivity was first observed with increasing filler concentration up to the critical percolation threshold value (0.5% for DBSA-CoNPs/PMMA and 1% for CoNPs/PMMA), which then dropped upon further increments in the filler content. However, at higher concentrations, a second jump in the conductivity was observed in case of DBSA-CoNPs/PMMA composites.

The Improvement in Mechanical and Thermal Properties of Biodegradable Poly(Butylene Succinate) (PBS) Nanocomposites with Low Loadings of Graphene Oxide (XGO)

2016 ◽  
Vol 872 ◽  
pp. 235-241
Author(s):  
Achanai Buasri ◽  
Udon Kampichit ◽  
Panupong Salacharoen ◽  
Pouvadon Sangsawee ◽  
Vorrada Loryuenyong
Keyword(s):  
Electron Microscopy ◽  
Graphene Oxide ◽  
Thermal Properties ◽  
Mechanical Test ◽  
Mechanical And Thermal Properties ◽  
Butylene Succinate ◽  
Degradation Temperature ◽  
Transmission Electron ◽  
Uniform Dispersion ◽  
Biodegradable Poly

This research aims to study the physical, mechanical and thermal properties of poly (butylene succinate)/graphene oxide (PBS/XGO) nanocomposites. The polymer nanocomposites were successfully prepared by solution processing in conjunction with compression molding at various contents of XGO from 0-1.0 wt%. The structure, tensile properties and thermal stability of materials have been investigated by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), mechanical test, and thermogravimetric analysis. The results revealed that PBS and XGO could mix with each other homogeneously, and uniform dispersion of XGO in the PBS matrix occurred when the filler content was less than 1.0 wt%. Young′s modulus and degradation temperature (Td) of biopolymer were greatly improved by the addition of a small amount of XGO (1.0 wt%). The nanocomposites have potential application as packing materials.

scholarly journals Direction Dependent Electrical Conductivity of Polymer/Carbon Filler Composites

Polymers ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 591 ◽  
Author(s):  
Karina Kunz ◽  
Beate Krause ◽  
Bernd Kretzschmar ◽  
Levente Juhasz ◽  
Oliver Kobsch ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Electrical Conductivity ◽  
Multiwalled Carbon Nanotubes ◽  
Vinylidene Fluoride ◽  
Extrusion Direction ◽  
Filler Concentration ◽  
Multiwalled Carbon ◽  
Carbon Filler ◽  
Aspect Ratios ◽  
Extruded Films

The method of measuring electrical volume resistivity in different directions was applied to characterize the filler orientation in melt mixed polymer composites containing different carbon fillers. For this purpose, various kinds of fillers with different geometries and aspect ratios were selected, namely carbon black (CB), graphite (G) and expanded graphite (EG), branched multiwalled carbon nanotubes (b-MWCNTs), non-branched multiwalled carbon nanotubes (MWCNTs), and single-walled carbon nanotubes (SWCNTs). As it is well known that the shaping process also plays an important role in the achieved electrical properties, this study compares results for compression molded plates with random filler orientations in the plane as well as extruded films, which have, moreover, conductivity differences between extrusion direction and perpendicular to the plane. Additionally, the polymer matrix type (poly (vinylidene fluoride) (PVDF), acrylonitrile butadiene styrene (ABS), polyamide 6 (PA6)) and filler concentration were varied. For the electrical measurements, a device able to measure the electrical conductivity in two directions was developed and constructed. The filler orientation was analyzed using the ratio σin/th calculated as in-plane conductivity σin-plane (σin) divided by through-plane conductivity σthrough-plane (σth). The ratio σin/th is expected to increase with more pronounced filler orientation in the processing direction. In the extruded films, alignment within the plane was assigned by dividing the in-plane conductivity in the extrusion direction (x) by the in-plane conductivity perpendicular to the extrusion direction (y). The conductivity ratios depend on filler type and concentration and are higher the higher the filler aspect ratio and the closer the filler content is to the percolation concentration.

scholarly journals Morphology, Barrier, Mechanical and Electrical Conductivity Properties of Oil-Extended EPDM/MWCNT Nanocomposites

2019 ◽  
Vol 8 (6) ◽  
pp. 4116-4121
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Electrical Conductivity ◽  
Mean Free Path ◽  
Filler Concentration ◽  
Multiwalled Carbon ◽  
Transmission Electron ◽  
Mwcnt Concentration ◽  
Bound Rubber ◽  
Frequency Independent

Oil- extended ethylene propylene diene monomer (EPDM) elastomer nanocomposites have been made by using multiwalled carbon nanotube (MWCNT) nanofiller as a reinforcing agent. The effect of MWCNT concentration on morphology, bound rubber, swelling, and mechanical properties have been studied. EPDM/MWCNT interactions have been studied by scanning electron microscopy (SEM) and highresolution transmission electron microscopy (HR-TEM) techniques. From the studies, it is observed that at lower MWCNT concentration (up to 4%), nanofillers are well separated and dispersed, but at higher loadings (6%) formation of agglomerates takes place. Hence it is expected that percolation limit of MWCNT in oil-extended EPDM occurs at around 4% concentration. The extent of reinforcement of MWCNT in EPDM matrix has been calculated in form of bound rubber (BdR) content and degree of swelling when exposed to solvents. BdR values of EPDM nanocomposites increase with MWCNT concentration hence confirmed the reinforcing nature of filler. Physico-mechanical properties like tensile strength, modulus and toughness of EPDM nanocomposites increases up to 4% MWCNT concentration, beyond which the effects are very marginal or decreases as filler-filler interactions exceed polymer-filler interactions. This confirmed the percolation threshold of MWCNT at 4% concentration. In addition to above, electrical conductivity of EPDM/MWCNT nanocomposites have been obtained as a function of frequency to measure the capability of a material to conduct electric current and it shows both frequency independent (DC) and dependent (AC) characteristic which increases exponentially in the applied field. AC conductivity of EPDM/MWCNT nanocomposites increases with filler concentration due to conductive nature of nanotube and a decrease in the mean free path of nanoparticles.

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