Plasma technology has been investigated in the frame of new production processes for carbon blacks and graphite. Although proven feasible, work remains to be done on the development of high quality materials. It has been proven by some of the partners that fullerenes can be produced on this equipment and probably also nano-tubes. The present project covers the development of a plasma production technology for carbon nano-particules ranging from carbon black, over fullerenes to nano-tubes. In the frame of this project those new materials, especially fulleneres and nano-tubes will be made available in sufficient quantities to partners for evaluation and application development. The application fields covered are: electrochemistry, polymers, organic synthesis and hydrogen storage.
After evaluation of the percolation behaviour of the first plasma carbon black samples in LDPE it was concluded:
Some of the received carbon black samples could be used in the production of conductive plastic compounds and in the production of colored plastics:
-The commercial grade (Ensaco 250) had in LDPE clearly the lowest percolation threshold and the highest conductivity;
-In LDPE the plasma blacks Colza and C2H4 could also have some industrial applications in conductive compounds if their resistivities versus carbon black loadings are considered;
-The dispersion classes varied between 1-5. Dispersion class 1 (C8H8 and Ensaco 250), indicated that these samples had the best carbon black dispersion;
-The experimental percolation weight fractions for the new samples seemed to be fairly well in line with the calculated values.
Evaluation of five different carbon black/fullerene mixture samples in LDPE.
As stated in the previous section also some of the received carbon black/fullerene samples could be used in the production of conductive plastic compounds and in the production of colored plastics:
-If compared to the previous plasma black samples, the conductivities of these compounds were lower and needed significantly higher loadings (2-6 w-% higher) of carbon black/fullerene to reach the needed conductivities (<10+3 ohm cm);
-Plasma 325 and 314, if used more than ca. 26 w%, could be used in conductive compounds;
-Plasma black 330 had the highest percolation concentration (27 w-%) and the lowest conductivity;
-All of these samples had a low dispersion class (0.7 - 2.5) in LDPE indicating the filler is well dispersed in LDPE.
Oxygen indexes after the fullerene part in carbon black/fullerene mixtures was dissolved out with toluene The onset time of the oxidation peak at 200ºC was clearly the shortest with 25w;
- Ensaco 250 in LDPE. Second was the sample with 27 w-% Plasma 325 in LDPE. The longest onset time was detected with 31 w-% Plasma 325. Comparison of conductivities of carbon black and carbon black/nanotube mixture samples in elastomer;
-The nanotube part (ca. 10 w-%) did not give any improvement on the conductivity of the elastomer compound.
Funding SchemeCSC - Cost-sharing contracts
06904 Sophia Antipolis