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Improved Dispersion of Carbon Nanotubes in Polymers at High Concentrations

View Article: PubMed Central - PubMed

ABSTRACT

The polymer nanocomposite used in this work comprises elastomer poly(dimethylsiloxane) (PDMS) as a polymer matrix and multi-walled carbon nanotubes (MWCNTs) as a conductive nanofiller. To achieve uniform distribution of carbon nanotubes within the polymer, an optimized dispersion process was developed, featuring a strong organic solvent—chloroform, which dissolved PDMS base polymer easily and allowed high quality dispersion of MWCNTs. At concentrations as high as 9 wt.%, MWCNTs were dispersed uniformly through the polymer matrix, which presented a major improvement over prior techniques. The dispersion procedure was optimized via extended experimentation, which is discussed in detail.

No MeSH data available.


MWCNTs dispersed in different organic solvents via 30 min of sonication. Solutions from left to right: toluene (0.3 mg/mL MWCNTs), chloroform (0.3 mg/mL), dimethylformamide (DMF) (0.3 mg/mL), tetrahydrofuran (THF) (0.4 mg/mL). (a) Dispersion state directly after sonication, showing no visible MWCNT bundles; (b) Solutions at 70 h after sonication showing reaggregation effect of MWCNTs in order of toluene >> chloroform > THF > DMF; (c) Magnified view of visible MWCNTs bundles in chloroform solution; (d) one week after sonication. Volume of THF solution was slightly adjusted to match the others after 4 days with no further sonication; (e) eight months after sonication. Solutions have evaporated to different extents but three out of four dispersions remained stable; (f) Magnified view of visible MWCNTs bundles in chloroform dispersion, indicating that amount of bundles remained about the same with (c).
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nanomaterials-02-00329-f002: MWCNTs dispersed in different organic solvents via 30 min of sonication. Solutions from left to right: toluene (0.3 mg/mL MWCNTs), chloroform (0.3 mg/mL), dimethylformamide (DMF) (0.3 mg/mL), tetrahydrofuran (THF) (0.4 mg/mL). (a) Dispersion state directly after sonication, showing no visible MWCNT bundles; (b) Solutions at 70 h after sonication showing reaggregation effect of MWCNTs in order of toluene >> chloroform > THF > DMF; (c) Magnified view of visible MWCNTs bundles in chloroform solution; (d) one week after sonication. Volume of THF solution was slightly adjusted to match the others after 4 days with no further sonication; (e) eight months after sonication. Solutions have evaporated to different extents but three out of four dispersions remained stable; (f) Magnified view of visible MWCNTs bundles in chloroform dispersion, indicating that amount of bundles remained about the same with (c).

Mentions: After introducing MWCNTs into four solutions, each mixture was then sonicated using a mild sonication bath (FS20D Fisher Scientific, frequency 42 kHz, output power 70 W) for 30 min at nominal power. This process yielded semi-transparent dispersed MWCNT suspensions, as shown in Figure 2a, composed of individual nanotubes and micro-sized bundles which were invisible to the bare eye.


Improved Dispersion of Carbon Nanotubes in Polymers at High Concentrations
MWCNTs dispersed in different organic solvents via 30 min of sonication. Solutions from left to right: toluene (0.3 mg/mL MWCNTs), chloroform (0.3 mg/mL), dimethylformamide (DMF) (0.3 mg/mL), tetrahydrofuran (THF) (0.4 mg/mL). (a) Dispersion state directly after sonication, showing no visible MWCNT bundles; (b) Solutions at 70 h after sonication showing reaggregation effect of MWCNTs in order of toluene >> chloroform > THF > DMF; (c) Magnified view of visible MWCNTs bundles in chloroform solution; (d) one week after sonication. Volume of THF solution was slightly adjusted to match the others after 4 days with no further sonication; (e) eight months after sonication. Solutions have evaporated to different extents but three out of four dispersions remained stable; (f) Magnified view of visible MWCNTs bundles in chloroform dispersion, indicating that amount of bundles remained about the same with (c).
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Related In: Results  -  Collection

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getmorefigures.php?uid=PMC5304599&req=5

nanomaterials-02-00329-f002: MWCNTs dispersed in different organic solvents via 30 min of sonication. Solutions from left to right: toluene (0.3 mg/mL MWCNTs), chloroform (0.3 mg/mL), dimethylformamide (DMF) (0.3 mg/mL), tetrahydrofuran (THF) (0.4 mg/mL). (a) Dispersion state directly after sonication, showing no visible MWCNT bundles; (b) Solutions at 70 h after sonication showing reaggregation effect of MWCNTs in order of toluene >> chloroform > THF > DMF; (c) Magnified view of visible MWCNTs bundles in chloroform solution; (d) one week after sonication. Volume of THF solution was slightly adjusted to match the others after 4 days with no further sonication; (e) eight months after sonication. Solutions have evaporated to different extents but three out of four dispersions remained stable; (f) Magnified view of visible MWCNTs bundles in chloroform dispersion, indicating that amount of bundles remained about the same with (c).
Mentions: After introducing MWCNTs into four solutions, each mixture was then sonicated using a mild sonication bath (FS20D Fisher Scientific, frequency 42 kHz, output power 70 W) for 30 min at nominal power. This process yielded semi-transparent dispersed MWCNT suspensions, as shown in Figure 2a, composed of individual nanotubes and micro-sized bundles which were invisible to the bare eye.

View Article: PubMed Central - PubMed

ABSTRACT

The polymer nanocomposite used in this work comprises elastomer poly(dimethylsiloxane) (PDMS) as a polymer matrix and multi-walled carbon nanotubes (MWCNTs) as a conductive nanofiller. To achieve uniform distribution of carbon nanotubes within the polymer, an optimized dispersion process was developed, featuring a strong organic solvent—chloroform, which dissolved PDMS base polymer easily and allowed high quality dispersion of MWCNTs. At concentrations as high as 9 wt.%, MWCNTs were dispersed uniformly through the polymer matrix, which presented a major improvement over prior techniques. The dispersion procedure was optimized via extended experimentation, which is discussed in detail.

No MeSH data available.