Resistive Response of Carbon Nanotube-Based Composites Subjected to Water Aging
This work aimed to monitor, through the changes in electrical resistance, the evolution of the mechanical properties due to aging caused by water sorption in carbon nanotube-based epoxy composites. The epoxy/CNT nanocomposites were prepared by dispersing the filler in the precursor through the ultra...
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| Format: | Article |
| Language: | English |
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MDPI AG
2021-08-01
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| Series: | Nanomaterials |
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| Online Access: | https://www.mdpi.com/2079-4991/11/9/2183 |
| _version_ | 1797517952948371456 |
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| author | Liberata Guadagno Luigi Vertuccio |
| author_facet | Liberata Guadagno Luigi Vertuccio |
| author_sort | Liberata Guadagno |
| collection | DOAJ |
| description | This work aimed to monitor, through the changes in electrical resistance, the evolution of the mechanical properties due to aging caused by water sorption in carbon nanotube-based epoxy composites. The epoxy/CNT nanocomposites were prepared by dispersing the filler in the precursor through the ultra-sonication process and mixing the hardener by mechanical stirring. After an evaluation of the electrical properties, detected through a two-probe electrical measurement method, of nanocomposites at different percentages by weight of the filler (0.025, 0.05, 0.1, 0.3, 0.5, and 1.0), a concentration (0.1% by weight), close to that of the electrical percolation threshold, was chosen to evaluate the resistive response. This specific concentration was selected in order to obtain maximized values of the variation detected for the changes in the electrical resistance resulting from phenomena of structural relaxations/rearrangements due to water absorption. In particular, the electrical conductivity value switched from 8.2 × 10<sup>−14</sup> S/m for the unfilled epoxy resin to 6.3 × 10<sup>−2</sup> S/m for carbon nanotube-based epoxy composite at 0.1% by weight of the nanofiller. The water sorption caused a reduction in the mechanical properties (storage modulus and tan δ) due to swelling and plasticization phenomena, which caused the structural reorganization of the conductive interparticle contacts in the matrix with a consequent variation in the electrical resistance of the material. The found ‘non-Fickian’ water diffusion behavior was very similar to the variation in the electrical resistance with time. This last correlation allows the association of the measurement of the electrical resistance with the quantity of absorbed water and, therefore, with the aging of the material to water absorption, through the sensitivity factor (β). The resistive nature of the composite can be used to monitor the amount of water absorption and the changes in the structure of the material subject to water aging. |
| first_indexed | 2024-03-10T07:23:23Z |
| format | Article |
| id | doaj.art-9def6a771f0e4a2f88109cfef3f93f06 |
| institution | Directory Open Access Journal |
| issn | 2079-4991 |
| language | English |
| last_indexed | 2024-03-10T07:23:23Z |
| publishDate | 2021-08-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Nanomaterials |
| spelling | doaj.art-9def6a771f0e4a2f88109cfef3f93f062023-11-22T14:28:33ZengMDPI AGNanomaterials2079-49912021-08-01119218310.3390/nano11092183Resistive Response of Carbon Nanotube-Based Composites Subjected to Water AgingLiberata Guadagno0Luigi Vertuccio1Department of Industrial Engineering, University of Salerno, Via Giovanni Paolo II, 84084 Fisciano, ItalyDepartment of Industrial Engineering, University of Salerno, Via Giovanni Paolo II, 84084 Fisciano, ItalyThis work aimed to monitor, through the changes in electrical resistance, the evolution of the mechanical properties due to aging caused by water sorption in carbon nanotube-based epoxy composites. The epoxy/CNT nanocomposites were prepared by dispersing the filler in the precursor through the ultra-sonication process and mixing the hardener by mechanical stirring. After an evaluation of the electrical properties, detected through a two-probe electrical measurement method, of nanocomposites at different percentages by weight of the filler (0.025, 0.05, 0.1, 0.3, 0.5, and 1.0), a concentration (0.1% by weight), close to that of the electrical percolation threshold, was chosen to evaluate the resistive response. This specific concentration was selected in order to obtain maximized values of the variation detected for the changes in the electrical resistance resulting from phenomena of structural relaxations/rearrangements due to water absorption. In particular, the electrical conductivity value switched from 8.2 × 10<sup>−14</sup> S/m for the unfilled epoxy resin to 6.3 × 10<sup>−2</sup> S/m for carbon nanotube-based epoxy composite at 0.1% by weight of the nanofiller. The water sorption caused a reduction in the mechanical properties (storage modulus and tan δ) due to swelling and plasticization phenomena, which caused the structural reorganization of the conductive interparticle contacts in the matrix with a consequent variation in the electrical resistance of the material. The found ‘non-Fickian’ water diffusion behavior was very similar to the variation in the electrical resistance with time. This last correlation allows the association of the measurement of the electrical resistance with the quantity of absorbed water and, therefore, with the aging of the material to water absorption, through the sensitivity factor (β). The resistive nature of the composite can be used to monitor the amount of water absorption and the changes in the structure of the material subject to water aging.https://www.mdpi.com/2079-4991/11/9/2183resistive responsewater sorptionwater diffusion modelepoxy resincarbon nanotubes |
| spellingShingle | Liberata Guadagno Luigi Vertuccio Resistive Response of Carbon Nanotube-Based Composites Subjected to Water Aging Nanomaterials resistive response water sorption water diffusion model epoxy resin carbon nanotubes |
| title | Resistive Response of Carbon Nanotube-Based Composites Subjected to Water Aging |
| title_full | Resistive Response of Carbon Nanotube-Based Composites Subjected to Water Aging |
| title_fullStr | Resistive Response of Carbon Nanotube-Based Composites Subjected to Water Aging |
| title_full_unstemmed | Resistive Response of Carbon Nanotube-Based Composites Subjected to Water Aging |
| title_short | Resistive Response of Carbon Nanotube-Based Composites Subjected to Water Aging |
| title_sort | resistive response of carbon nanotube based composites subjected to water aging |
| topic | resistive response water sorption water diffusion model epoxy resin carbon nanotubes |
| url | https://www.mdpi.com/2079-4991/11/9/2183 |
| work_keys_str_mv | AT liberataguadagno resistiveresponseofcarbonnanotubebasedcompositessubjectedtowateraging AT luigivertuccio resistiveresponseofcarbonnanotubebasedcompositessubjectedtowateraging |