Effect of Alignment on Enhancement of Thermal Conductivity of Polyethylene–Graphene Nanocomposites and Comparison with Effective Medium Theory
Thermal conductivity (<i>k</i>) of polymers is usually limited to low values of ~0.5 Wm<sup>−1</sup>K<sup>−1</sup> in comparison to metals (>20 Wm<sup>−1</sup>K<sup>−1</sup>). The goal of this work is to enhance thermal conductivity (<...
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MDPI AG
2020-06-01
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| Series: | Nanomaterials |
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| Online Access: | https://www.mdpi.com/2079-4991/10/7/1291 |
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| author | Fatema Tarannum Rajmohan Muthaiah Roshan Sameer Annam Tingting Gu Jivtesh Garg |
| author_facet | Fatema Tarannum Rajmohan Muthaiah Roshan Sameer Annam Tingting Gu Jivtesh Garg |
| author_sort | Fatema Tarannum |
| collection | DOAJ |
| description | Thermal conductivity (<i>k</i>) of polymers is usually limited to low values of ~0.5 Wm<sup>−1</sup>K<sup>−1</sup> in comparison to metals (>20 Wm<sup>−1</sup>K<sup>−1</sup>). The goal of this work is to enhance thermal conductivity (<i>k</i>) of polyethylene–graphene nanocomposites through simultaneous alignment of polyethylene (PE) lamellae and graphene nanoplatelets (GnP). Alignment is achieved through the application of strain. Measured values are compared with predictions from effective medium theory. A twin conical screw micro compounder is used to prepare polyethylene–graphene nanoplatelet (PE-GnP) composites. Enhancement in <i>k</i> value is studied for two different compositions with GnP content of 9 wt% and 13 wt% and for applied strains ranging from 0% to 300%. Aligned PE-GnP composites with 13 wt% GnP displays ~1000% enhancement in <i>k</i> at an applied strain of 300%, relative to <i>k</i> of pristine unstrained polymer. Laser Scanning Confocal Microscopy (LSCM) is used to quantitatively characterize the alignment of GnP flakes in strained composites; this measured orientation is used as an input for effective medium predictions. These results have important implications for thermal management applications. |
| first_indexed | 2024-03-10T18:46:57Z |
| format | Article |
| id | doaj.art-e7880a420cd74d8fb13ef7cab3dbf446 |
| institution | Directory Open Access Journal |
| issn | 2079-4991 |
| language | English |
| last_indexed | 2024-03-10T18:46:57Z |
| publishDate | 2020-06-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Nanomaterials |
| spelling | doaj.art-e7880a420cd74d8fb13ef7cab3dbf4462023-11-20T05:28:54ZengMDPI AGNanomaterials2079-49912020-06-01107129110.3390/nano10071291Effect of Alignment on Enhancement of Thermal Conductivity of Polyethylene–Graphene Nanocomposites and Comparison with Effective Medium TheoryFatema Tarannum0Rajmohan Muthaiah1Roshan Sameer Annam2Tingting Gu3Jivtesh Garg4School of Aerospace and Mechanical Engineering, University of Oklahoma, Norman, OK 73019, USASchool of Aerospace and Mechanical Engineering, University of Oklahoma, Norman, OK 73019, USASchool of Aerospace and Mechanical Engineering, University of Oklahoma, Norman, OK 73019, USASchool of Aerospace and Mechanical Engineering, University of Oklahoma, Norman, OK 73019, USASchool of Aerospace and Mechanical Engineering, University of Oklahoma, Norman, OK 73019, USAThermal conductivity (<i>k</i>) of polymers is usually limited to low values of ~0.5 Wm<sup>−1</sup>K<sup>−1</sup> in comparison to metals (>20 Wm<sup>−1</sup>K<sup>−1</sup>). The goal of this work is to enhance thermal conductivity (<i>k</i>) of polyethylene–graphene nanocomposites through simultaneous alignment of polyethylene (PE) lamellae and graphene nanoplatelets (GnP). Alignment is achieved through the application of strain. Measured values are compared with predictions from effective medium theory. A twin conical screw micro compounder is used to prepare polyethylene–graphene nanoplatelet (PE-GnP) composites. Enhancement in <i>k</i> value is studied for two different compositions with GnP content of 9 wt% and 13 wt% and for applied strains ranging from 0% to 300%. Aligned PE-GnP composites with 13 wt% GnP displays ~1000% enhancement in <i>k</i> at an applied strain of 300%, relative to <i>k</i> of pristine unstrained polymer. Laser Scanning Confocal Microscopy (LSCM) is used to quantitatively characterize the alignment of GnP flakes in strained composites; this measured orientation is used as an input for effective medium predictions. These results have important implications for thermal management applications.https://www.mdpi.com/2079-4991/10/7/1291thermal conductivitystrainalignment effectpolymersgraphenenanocomposites |
| spellingShingle | Fatema Tarannum Rajmohan Muthaiah Roshan Sameer Annam Tingting Gu Jivtesh Garg Effect of Alignment on Enhancement of Thermal Conductivity of Polyethylene–Graphene Nanocomposites and Comparison with Effective Medium Theory Nanomaterials thermal conductivity strain alignment effect polymers graphene nanocomposites |
| title | Effect of Alignment on Enhancement of Thermal Conductivity of Polyethylene–Graphene Nanocomposites and Comparison with Effective Medium Theory |
| title_full | Effect of Alignment on Enhancement of Thermal Conductivity of Polyethylene–Graphene Nanocomposites and Comparison with Effective Medium Theory |
| title_fullStr | Effect of Alignment on Enhancement of Thermal Conductivity of Polyethylene–Graphene Nanocomposites and Comparison with Effective Medium Theory |
| title_full_unstemmed | Effect of Alignment on Enhancement of Thermal Conductivity of Polyethylene–Graphene Nanocomposites and Comparison with Effective Medium Theory |
| title_short | Effect of Alignment on Enhancement of Thermal Conductivity of Polyethylene–Graphene Nanocomposites and Comparison with Effective Medium Theory |
| title_sort | effect of alignment on enhancement of thermal conductivity of polyethylene graphene nanocomposites and comparison with effective medium theory |
| topic | thermal conductivity strain alignment effect polymers graphene nanocomposites |
| url | https://www.mdpi.com/2079-4991/10/7/1291 |
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