Preparation of humidity-responsive antistatic carbon nanotube/PEI nanocomposites

A kind of polymer with antistatic property, poly(N,N-diethylacrylamide) (PDEAAm), was grafted onto the multi-walled carbon nanotubes (MWCNTs), and then such PDEAAm-g-MWCNTs was introduced into polyetherimide (PEI). The successful grafting was tested by FT-IR, XPS and TEM results, and the weight fraction of PDEAAm on the PDEAAm-g-MWCNTs was calculated according to the XPS and TGA. The PDEAAm-g-MWCNTs/PEI nanocomposites films were prepared by conventional solution processed method. The conductivity of nanocomposites increased by four orders of magnitude after absorbing moisture. The nanocomposites achieved the percolation threshold with the PDEAAm-g-MWCNTs loading of 0.25 wt.% and the volume conductivity reached 10−7 S/cm. Dynamic response and long-term stability test indicated good response sensitivity and stability property of this material. Thereby, such PDEAAm-g-MWCNTs/PEI nanocomposites had potential applications as passive humidity sensors.

► An antistatic poly(N,N-diethylacrylamide) (PDEAAm) is grafted to the CNTs.
► Percolation threshold of PEI matrix composite is at PDEAAm-CNTs loading 0.25 wt.%.
► The composite's conductivity raises 4 orders of magnitude after humidity absorption.
► The conductivity of the composite responds to the humidity.