Functionalisation plasma treatment

The evolution of XPS spectra, given in Fig. 21 shows that the contribution of pristine non-functionalised C atoms remains majoritary, whatever the duration of the plasma treatment. The most noticeable change is the increase of the component (4) corresponding to covalent C—F bonds which are formed by the interaction of F radicals with the reactive sites of the material, i.e. surface defects, hydrogenated/oxygenated C atom, borders of the graphitic domains. When all these surface sites are fluorinated, the surface is saturated, what is accounted for by the value of C/F ratio of 3.2 obtained for t > 120 min [99],... 

Paletta, J.R.J., et al., 2010. RGD-functionalisation of PLLA nanofibers by surface coupling using plasma treatment influence on stem cell differentiation. Journal of Materials Science Materials in Medicine 21 (4), 1363-1369. Available at http //link.springer.eom/10.1007/ S10856-009-3947-2. 

A completely different strategy for the surface functionalisation of CNTs with nitrogen-containing groups is the treatment of CNTs under atomic nitrogen flow obtained by molecular nitrogen dissociation in an Ar -t N2 microwave plasma. X-ray photoelectron spectroscopy of the nanotube surface demonstrated the presence of amides, oximes and mainly amine and nitrile groups. ... 

Functionalisation of VACNT. Nanotube functionalisation and exfoliation were performed in a much less powerful pulsed DC plasma reactor. The chamber walls form the anode, while the CNT samples were placed over the substrate holder cathode. The reactor chamber was first evacuated to 10 Torr by a diffusion pump to ensure low residual air. Then pure mygen (1 seem) was introduced and the ehamber pressure was controlled at 80 mTorr. The pulsed DC power supply was set at —700 V at 20 kHz and 45% duty cycle. Treatments were aeeom-plished within 2 minutes. 

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