A Novel Approach to Disentangle Carbon Nanotubes Using Viscous Sugar Syrup

The disentanglement of multi-walled carbon nanotube (MWNT) bundles by using a sticky sugar syrup was explored for the first time. The syrup was prepared by mixing sucrose, glucose, fructose, and distilled water in a 1:1:1:0.8 weight ratio. A disk-type mixer suitable for high-viscosity materials was built to mix this syrup with MWNTs. To find out the optimum mixing conditions for effective disentanglement of MWNTs, the content ratio of MWNTs to sugar syrup was varied at each mixing step. Digital image processing technique was used with optical micrographs to quantitatively estimate the dispersion of nanotubes in sugar syrups. This revealed that the most homogeneous dispersion of MWNTs in the sugar syrup was achieved by gradually adding the syrup at each mixing step rather than all at once at the initial mixing step. The dynamic viscosity (η') of the mixtures was measured to evaluate the overall dispersion state of MWNTs. The incorporation of MWNTs increased the η' of sugar syrup, exhibiting a decreased η' with an increase in the degree of dispersion. To validate this novel dispersion method for polymer composites, disentangled MWNTs were transferred into poly(vinyl alcohol) (PVA) and polyacrylonitrile (PAN); they exhibited uniform dispersion in each polymer matrix, without reagglomeration occurred.