Compositing polyetherimide with polyfluorene wrapped carbon nanotubes for enhanced interfacial interaction and...

Area of Science:

• Materials Science
• Polymer Chemistry
• Nanotechnology

Background:

• Polyetherimide (PEI) is a versatile polymer, but its properties can be further enhanced for advanced applications.
• Mutiwalled carbon nanotubes (MWCNTs) offer exceptional mechanical and electrical properties but require effective functionalization for optimal integration into polymer matrices.
• Achieving uniform dispersion and strong interfacial adhesion between MWCNTs and polymer matrices is crucial for realizing nanocomposite potential.

Purpose of the Study:

• To develop a novel non-covalent functionalization strategy for MWCNTs using polyfluorene polymer (PFO).
• To create superior polyetherimide (PEI) nanocomposites by incorporating PFO-functionalized MWCNTs.
• To investigate the impact of functionalized MWCNTs on the mechanical and electrical properties of PEI nanocomposites.

Main Methods:

• Non-covalent functionalization of MWCNTs with PFO via π-π stacking.
• Characterization of PFO-functionalized MWCNTs using UV-vis, fluorescence, and Raman spectroscopy.
• Morphological analysis using Atomic Force Microscopy (AFM), Scanning Electron Microscopy (SEM), and Transmission Electron Microscopy (TEM).
• Evaluation of mechanical properties (storage modulus) and electrical properties (volume resistivity) of PEI nanocomposites.

Main Results:

• PFO functionalization confirmed by spectroscopic techniques, leading to excellent dispersion of MWCNTs in solvent and PEI matrix.
• Strong interaction between PFO and PEI chains observed, indicating good interfacial adhesion.
• Significant improvement in mechanical properties: a 46% increase in storage modulus with 0.25 wt% modified MWCNTs and a 119% increase with 2.0 wt% modified MWCNTs.
• Dramatic reduction in volume resistivity of PEI composite by 12 orders of magnitude with 0.5 wt% PFO-modified MWCNT.

Conclusions:

• Non-covalent PFO functionalization is an effective method for preparing well-dispersed MWCNTs within a PEI matrix.
• The enhanced interfacial interactions lead to substantial improvements in the mechanical performance of PEI nanocomposites.
• The modified MWCNTs significantly enhance the electrical conductivity of PEI, opening possibilities for electromagnetic interference shielding and conductive applications.