Stock #: DT115
Product name: CNTs/water dispersant
Components: 90 wt% aromatic modified polyethylene glycol ether, 10 wt% water
Application: to achieve a homogeneous CNTs/water dispersion
Suggested weight ratio of dispersant (DT115) to CNTs for
Regular-length carbon nanotubes (CNTs):
0.2:1 for CNTs with a diameter > 50 nm
1:1 for CNTs with a diameter between 2 and 8 nm
3.5:1 for CNTS with a diameter between 1 and 2 nm
Short-length or functionalized carbon nanotubes (SFCNTs):
0.1:1 for SFCNTs with a diameter > 50 nm
0.5:1 for SFCNTs with a diameter between 2 and 8 nm
1.5-1.8:1 for SFCNTS with a diameter between 1 and 2 nm
Procedures for dispersing CNTs in a solvent (water):
1). Dissolve dispersant in desired solvent [Heating (RT- 65 oC) may be used to help fully dissolve the dispersant in the solvent.
2). Add CNTs into the above solvent to fully wet the CNTs by the solvent, i.e., the CNTs do not float on the solvent. Write down the initial content of the CNTs in the solvent as Ci.
3). Use a sonicator to treat the CNTs/solvent dispersion for 5 minutes, stop the sonicating treatment, cool the dispersion in iced water to prevent the dispersion from over-heating and over- bubbling.
4). Check the status of dispersing by putting one drop of the above dispersion into a different fresh solvent. Uniformly dispersed CNTs can quickly/homogeneously diffuse in the solvent, similar to the case of putting one drop of black ink in water. In contrary, black particles appear when one drop of CNTs dispersions - that are NOT well dispersed - is putting into the solvent.
5). If the CNTs are not uniformly dispersed, repeat 3) an 4). The total sonicating time may reach 30 minutes.
6). If the CNTs are still not uniformly dispersed after 5), use more dispersant and repeat 1) to 5).
7) Centrifuge the dispersion at 2000 r/min for 30 minutes to remove non-dispersed CNTs from the solvent.
8) After the centrifuging treatment, filter the upper part of the dispersion by using 300-mesh filtering clothes to obtain the final uniformly dispersed CNTs dispersion. This final CNTs dispersion can be stable for more than 6 months.
9) Dry the lower part of the dispersion (till the subsides reach a constant weight Ws). Use TGA to heat and weigh the subsides. Assume the weight loss of the subsides at 450 oC is F, then the CNTs content in the final (uniform) CNTs dispersion (Cf) can be calculated as: Cf = Ci – (1 - F) x Ws.