Influence of CNT functionalization on the interphase region between CNT and polymer

• Simulating embedded functionalized CNT in polymer using semi-continuum approach.
• Modeling interphase between CNT and polymer using vdW and covalent interactions.
• Observing reduction in the micro-scale RVE modulus containing functionalized CNT.
• Studying influence of CNT length on the RVE modulus using continuum modeling.

The main goal of this research is to study the influence of interphase region on the Young’s modulus of the CNT-based nanocomposites at microscale. For this purpose, two different categories of interphase resembling normal CNT and functionalized CNT are studied. Normal CNT interacts through non-bonded van der Waals (vdW) interactions with resin; while the functionalized CNT interacts through a combination of non-bonded vdW and covalent interaction with surrounding polymer. Thanks to the induced structural defects into the nano-structure of the CNT after chemical functionalization, the influence of vacancy defects are firstly studied on isolated CNT. Then the Representative Volume Element (RVE) of the CNT-based nanocomposites as microscale consisting of CNT, interphase and surrounding polymer are simulated using semi-continuum mechanics approach. It is revealed that chemical functionalization will reduce the Young’s modulus of the RVE at microscale in comparison with the RVE containing non-defected CNT. The Young’s modulus of the interphase region for the continuum modeling as a very efficient alternative approach of semi-continuum modeling is obtained. Finally, the influence of CNT length on the Young’s modulus of the RVE is studied using continuum method.