DNA-assisted dispersion of multi-walled CNTs in epoxy polymer matrix

The main problem that is encountered in reinforcing a polymer matrix with CNTs is to obtain a homogeneous dispersion avoiding that the CNTs aggregate and turn into localized defects for the nano-reinforced composites. In order to overcome these problems, different approaches have been developed based on surface modification such as covalent and non-covalent functionalization methods. The covalent functionalization of CNTs reduces their exceptional properties because chemical treatment breaks the CNT structure introducing defects on its surface. Non-covalent functionalization mainly based on the use of dispersants, such as surfactants and polymers, are often not effective and the CNTs remain predominantly entangled. In this work, we present the effect of a recently designed dispersion approach, based on non-covalent functionalization of CNTs by DNA molecules, on the preparation of CNT/PRIME 20 LV composites. Multiwalled CNTs were first functionalized with DNA, and then used to fabricate nanocomposites at CNTs loading of 0.5 wt.%. Different techniques were used to test the dispersion homogeneity of the composites. In particular, a set-up for electrical measurements was developed to assess the stability of the CNT/PRIME 20 LV mixture in time.