Details
| Original language | English |
|---|---|
| Article number | 1355 |
| Journal | Polymers |
| Volume | 13 |
| Issue number | 9 |
| Publication status | Published - 21 Apr 2021 |
| Externally published | Yes |
Abstract
Incorporating nanofillers into elastomers leads to composites with an enormous potential regarding their properties. Unfortunately, nanofillers tend to form agglomerates inhibiting adequate filler dispersion. Therefore, different carbon nanotube (CNT) pretreatment methods were analyzed in this study to enhance the filler dispersion in polydimethylsiloxane (PDMS)/CNT-composites. By pre-dispersing CNTs in solvents an increase in electrical conductivity could be observed within the sequence of tetrahydrofuran (THF) > acetone > chloroform. Optimization of the pre-dispersion step results in an AC conductivity of 3.2 × 10−4 S/cm at 1 Hz and 0.5 wt.% of CNTs and the electrical percolation threshold is decreased to 0.1 wt.% of CNTs. Optimum parameters imply the use of an ultrasonic finger for 60 min in THF. However, solvent residues cause a softening effect deteriorating the mechanical performance of these composites. Concerning the pretreatment of CNTs by physical functionalization, the use of surfactants (sodium dodecylbenzenesulfonate (SDBS) and polyoxyethylene lauryl ether (“Brij35”)) leads to no improvement, neither in electrical conductivity nor in mechanical properties. Chemical functionalization enhances the compatibility of PDMS and CNT but damages the carbon nanotubes due to the oxidation process so that the improvement in conductivity and reinforcement is superimposed by the CNT damage even for mild oxidation conditions.
Keywords
- Carbon nan-otubes, Dispersion, Filler–filler interactions, Functionalization, Polydimethylsiloxane
ASJC Scopus subject areas
- Chemistry(all)
- General Chemistry
- Materials Science(all)
- Polymers and Plastics
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In: Polymers, Vol. 13, No. 9, 1355, 21.04.2021.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Influence of carbon nanotube-pretreatment on the properties of polydimethylsiloxane/carbon nanotube-nanocomposites
AU - Diekmann, Astrid
AU - Omelan, Marvin C.V.
AU - Giese, Ulrich
N1 - Funding Information: This research was funded by the Federal Ministry of Education and Research (BMBF), grant number 13GW0050C (KMU innovative—Flowtrode).We thank Niklas Burblies (Raman spectroscopy), Philipp Abendroth and Saskia Zailskas (X-ray photoelectron spectroscopy) for analytical support (Workgroup Behrens, Institute of Inorganic Chemistry, Leibniz University Hanover). We also owe thanks to Viktor Rose (DIK) for preparing the TEM images.
PY - 2021/4/21
Y1 - 2021/4/21
N2 - Incorporating nanofillers into elastomers leads to composites with an enormous potential regarding their properties. Unfortunately, nanofillers tend to form agglomerates inhibiting adequate filler dispersion. Therefore, different carbon nanotube (CNT) pretreatment methods were analyzed in this study to enhance the filler dispersion in polydimethylsiloxane (PDMS)/CNT-composites. By pre-dispersing CNTs in solvents an increase in electrical conductivity could be observed within the sequence of tetrahydrofuran (THF) > acetone > chloroform. Optimization of the pre-dispersion step results in an AC conductivity of 3.2 × 10−4 S/cm at 1 Hz and 0.5 wt.% of CNTs and the electrical percolation threshold is decreased to 0.1 wt.% of CNTs. Optimum parameters imply the use of an ultrasonic finger for 60 min in THF. However, solvent residues cause a softening effect deteriorating the mechanical performance of these composites. Concerning the pretreatment of CNTs by physical functionalization, the use of surfactants (sodium dodecylbenzenesulfonate (SDBS) and polyoxyethylene lauryl ether (“Brij35”)) leads to no improvement, neither in electrical conductivity nor in mechanical properties. Chemical functionalization enhances the compatibility of PDMS and CNT but damages the carbon nanotubes due to the oxidation process so that the improvement in conductivity and reinforcement is superimposed by the CNT damage even for mild oxidation conditions.
AB - Incorporating nanofillers into elastomers leads to composites with an enormous potential regarding their properties. Unfortunately, nanofillers tend to form agglomerates inhibiting adequate filler dispersion. Therefore, different carbon nanotube (CNT) pretreatment methods were analyzed in this study to enhance the filler dispersion in polydimethylsiloxane (PDMS)/CNT-composites. By pre-dispersing CNTs in solvents an increase in electrical conductivity could be observed within the sequence of tetrahydrofuran (THF) > acetone > chloroform. Optimization of the pre-dispersion step results in an AC conductivity of 3.2 × 10−4 S/cm at 1 Hz and 0.5 wt.% of CNTs and the electrical percolation threshold is decreased to 0.1 wt.% of CNTs. Optimum parameters imply the use of an ultrasonic finger for 60 min in THF. However, solvent residues cause a softening effect deteriorating the mechanical performance of these composites. Concerning the pretreatment of CNTs by physical functionalization, the use of surfactants (sodium dodecylbenzenesulfonate (SDBS) and polyoxyethylene lauryl ether (“Brij35”)) leads to no improvement, neither in electrical conductivity nor in mechanical properties. Chemical functionalization enhances the compatibility of PDMS and CNT but damages the carbon nanotubes due to the oxidation process so that the improvement in conductivity and reinforcement is superimposed by the CNT damage even for mild oxidation conditions.
KW - Carbon nan-otubes
KW - Dispersion
KW - Filler–filler interactions
KW - Functionalization
KW - Polydimethylsiloxane
UR - http://www.scopus.com/inward/record.url?scp=85106950061&partnerID=8YFLogxK
U2 - 10.3390/polym13091355
DO - 10.3390/polym13091355
M3 - Article
AN - SCOPUS:85106950061
VL - 13
JO - Polymers
JF - Polymers
SN - 2073-4360
IS - 9
M1 - 1355
ER -