The classic methods for low volume fraction polymer nanocomposites based on CNTs involve melt blending, solution casting, solution mixing, direct mixing and in-situ polymerization. However, using these techniques has resulted in phase separation between polymer and CNTs, low polymer wetting of CNTs and low interfacial shear strength between polymer matrix and CNTs.
We have developed novel processing methods for the efficient fabrication of multifunctional CNT-epoxy composites. These technique involve the impregnation of a reinforcing modified CNT buckypaper so as to produce high volume fraction epoxy nanocomposites. The production procedure involves three stages:
- the modification of CNTs as described in the previous section
- the preparation of thin CNT sheets (buckypapers), which are porous membranes with porosity about 70%
- impregnation of these porous CNT preforms by epoxy monomer/curing agent mixtures within the autoclave chamber via the Resin Film Infusion (RFI) route or by simple soaking in solution phase
The RFI process was developed by aerospace manufacturers and involves the saturation of the porous structure with the use of a low viscosity resin film, under pressure. Processing takes place in an autoclave chamber using a full curing profile (applied pressure, vacuum, curing and post-curing). The applied vacuum removes the air and assists the resin infusion while the applied pressure contributes to the saturation of buckypaper and the consolidation of the nanocomposite.
- "Single-walled carbon nanotubes decorated with a pyrene–fluorenevinylene conjugate" by D. Tasis, J. Mikroyannidis, V. Karoutsos, C. Galiotis and K. Papagelis, Nanotechnology 20 (2009), 135606-135613 Download the paper (pdf)
- “Chemical Oxidation of Multi Walled Carbon Nanotubes” by V. Datsyuk, M. Kalyva, K. Papagelis, J. Parthenios, D. Tasis, A. Siokou, I. Kallitsis and C. Galiotis, Carbon, 46/6 (2008), 833-840 Download the paper (pdf)
- “Covalently functionalized carbon nanotubes as macroinitiators for radical polymerization” by Papagelis, K, Kalyva, M, Tasis, D, Parthenios, I, Siokou, A, Galiotis, C, Physica Status Solidi B-Basic Solid State Physics, 244/11(2007), 4046-4050 Download the paper (pdf)