Thermo-resistive and thermo-piezoresistive sensitivity of carbon nanostructure engineered thermoplastic composites processed via additive manufacturing
We experimentally examine the thermo-resistive and thermo-piezoresistive sensitivity of multiwall carbon nanotube (MWCNT)/polypropylene random copolymer (PPR) nanocomposites processed via fused filament fabrication (FFF) process. The filament feedstocks were fabricated by melt blending of neat PPR w...
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| Format: | Article |
| Language: | English |
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Elsevier
2021-01-01
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| Series: | Polymer Testing |
| Subjects: | |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S0142941820321905 |
| _version_ | 1818823964673179648 |
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| author | Pawan Verma Andreas Schiffer S. Kumar |
| author_facet | Pawan Verma Andreas Schiffer S. Kumar |
| author_sort | Pawan Verma |
| collection | DOAJ |
| description | We experimentally examine the thermo-resistive and thermo-piezoresistive sensitivity of multiwall carbon nanotube (MWCNT)/polypropylene random copolymer (PPR) nanocomposites processed via fused filament fabrication (FFF) process. The filament feedstocks were fabricated by melt blending of neat PPR with a predetermined amount of MWCNTs (either 4, 6 or 8 wt%) using a twin-screw extruder. Thermo-resistive characteristics of MWCNT/PPR composites were measured under both constrained and unconstrained heating from approximately 30-100 °C. For all MWCNT concentrations considered here, negative temperature coefficients of resistivity (TCR) were observed for both constrained and unconstrained heating, as a consequence of thermal fluctuation-induced tunneling at MWCNT junctions. The highest thermo-resistive sensitivity was measured for the composite with the lowest MWCNT concentration (4 wt%) under unconstrained conditions, reporting a TCR of −12,800 × 10−6/°C, which is higher in magnitude than that of other polymer nanocomposites reported in the literature. Moreover, the MWCNT/PPR composites exhibit strong thermo-piezoresistive response under tensile loading. For 4 wt% MWCNT loading, the gauge factor (measured over 0–20% strain range) of the composite increased from 27.8 to 52.3 when the temperature was raised from 30 °C to 60 °C. Our results further evince higher thermo-piezoresistive sensitivity i.e., a gauge factor as high as 395 at 60 °C. The electron tunneling and hopping, both thermally-assisted and activated by mechanical deformation of the PPR matrix, significantly increase the thermo-piezoresistance with the increase in temperature in this range. The excellent thermo-resistive and thermo-piezoresistive characteristics of MWCNT/PPR composites reported in this study would enable the development of smart nanocomposites for self-sensing both temperature and strain/damage state. |
| first_indexed | 2024-12-18T23:48:21Z |
| format | Article |
| id | doaj.art-919ccfa69d7e4706b4ca01b61fbd098f |
| institution | Directory Open Access Journal |
| issn | 0142-9418 |
| language | English |
| last_indexed | 2024-12-18T23:48:21Z |
| publishDate | 2021-01-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Polymer Testing |
| spelling | doaj.art-919ccfa69d7e4706b4ca01b61fbd098f2022-12-21T20:47:08ZengElsevierPolymer Testing0142-94182021-01-0193106961Thermo-resistive and thermo-piezoresistive sensitivity of carbon nanostructure engineered thermoplastic composites processed via additive manufacturingPawan Verma0Andreas Schiffer1S. Kumar2Artie McFerrin Department of Chemical Engineering, Texas A&M University, College Station, TX, 77840, USADepartment of Mechanical Engineering, Khalifa University of Science and Technology, 127788, Abu Dhabi, United Arab EmiratesJames Watt School of Engineering, University of Glasgow, Glasgow, G12 8LT, UK; Corresponding author.We experimentally examine the thermo-resistive and thermo-piezoresistive sensitivity of multiwall carbon nanotube (MWCNT)/polypropylene random copolymer (PPR) nanocomposites processed via fused filament fabrication (FFF) process. The filament feedstocks were fabricated by melt blending of neat PPR with a predetermined amount of MWCNTs (either 4, 6 or 8 wt%) using a twin-screw extruder. Thermo-resistive characteristics of MWCNT/PPR composites were measured under both constrained and unconstrained heating from approximately 30-100 °C. For all MWCNT concentrations considered here, negative temperature coefficients of resistivity (TCR) were observed for both constrained and unconstrained heating, as a consequence of thermal fluctuation-induced tunneling at MWCNT junctions. The highest thermo-resistive sensitivity was measured for the composite with the lowest MWCNT concentration (4 wt%) under unconstrained conditions, reporting a TCR of −12,800 × 10−6/°C, which is higher in magnitude than that of other polymer nanocomposites reported in the literature. Moreover, the MWCNT/PPR composites exhibit strong thermo-piezoresistive response under tensile loading. For 4 wt% MWCNT loading, the gauge factor (measured over 0–20% strain range) of the composite increased from 27.8 to 52.3 when the temperature was raised from 30 °C to 60 °C. Our results further evince higher thermo-piezoresistive sensitivity i.e., a gauge factor as high as 395 at 60 °C. The electron tunneling and hopping, both thermally-assisted and activated by mechanical deformation of the PPR matrix, significantly increase the thermo-piezoresistance with the increase in temperature in this range. The excellent thermo-resistive and thermo-piezoresistive characteristics of MWCNT/PPR composites reported in this study would enable the development of smart nanocomposites for self-sensing both temperature and strain/damage state.http://www.sciencedirect.com/science/article/pii/S0142941820321905Temperature sensingStrain sensing3D printingMultifunctional compositesFused filament fabrication |
| spellingShingle | Pawan Verma Andreas Schiffer S. Kumar Thermo-resistive and thermo-piezoresistive sensitivity of carbon nanostructure engineered thermoplastic composites processed via additive manufacturing Polymer Testing Temperature sensing Strain sensing 3D printing Multifunctional composites Fused filament fabrication |
| title | Thermo-resistive and thermo-piezoresistive sensitivity of carbon nanostructure engineered thermoplastic composites processed via additive manufacturing |
| title_full | Thermo-resistive and thermo-piezoresistive sensitivity of carbon nanostructure engineered thermoplastic composites processed via additive manufacturing |
| title_fullStr | Thermo-resistive and thermo-piezoresistive sensitivity of carbon nanostructure engineered thermoplastic composites processed via additive manufacturing |
| title_full_unstemmed | Thermo-resistive and thermo-piezoresistive sensitivity of carbon nanostructure engineered thermoplastic composites processed via additive manufacturing |
| title_short | Thermo-resistive and thermo-piezoresistive sensitivity of carbon nanostructure engineered thermoplastic composites processed via additive manufacturing |
| title_sort | thermo resistive and thermo piezoresistive sensitivity of carbon nanostructure engineered thermoplastic composites processed via additive manufacturing |
| topic | Temperature sensing Strain sensing 3D printing Multifunctional composites Fused filament fabrication |
| url | http://www.sciencedirect.com/science/article/pii/S0142941820321905 |
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