pH and electro-responsive release behavior of MWCNT/PVA/PAAc composite microcapsules

The pH and electro-responsive composite microcapsules were prepared by using multi-walled carbon nanotubes (MWCNTs), poly(vinyl alcohol), and poly(acrylic acid). MWCNTs were employed to improve the electro-responsive properties of microcapsules. The surface modification of MWCNTs was carried out by oxyfluorination for the improved dispersion in the microcapsule shell. The morphology of microcapsules and the location of MWCNTs in the microcapsule shell were investigated by SEM and TEM. The dispersion of MWCNTs in the microcapsule shell and the formation of composite microcapsules were improved by using the oxyfluorinated MWCNTs having the hydrophilic functional groups on the surface. The dual pH and electro-responsive release behavior of the composite microcapsules had a close relation with the uniform distribution of MWCNTs in the microcapsule shell.