Weak polyelectrolyte control of carbon nanotube dispersion in water

The dispersion of nanotubes by pH-responsive polymers (i.e., weak polyelectrolytes) enables the macroscopic properties of aqueous suspensions to be tuned. Microstructural changes were achieved as a function of pH in aqueous suspensions containing single-walled carbon nanotubes and imaged by cryogenic-TEM. Clear evidence of pH-sensitive nanotube dispersion is shown. We expect that many useful properties of these nanotube–polymer systems could be sensitive to microstructure, making this technique important for aqueous processing of carbon nanotubes and macroscopic tailoring of solid polymer nanocomposite behavior.

The dispersion state of carbon nanotubes can be reversibly switched between aggregated and exfoliated by altering pH in the presence of weak polyelectrolytes.Figure optionsDownload as PowerPoint slide