Reversible control of single-walled carbon nanotube microstructure using poly(acrylic acid)

Poly(acrylic acid) is shown to control the level of SWNT dispersion in aqueous mixtures and the state of dispersion in a solid composite. At low pH, PAA-stabilized suspensions containing 0.1 wt % SWNT have a waterlike viscosity, but this mixture thickens as the pH is raised. This behavior is reversed when pH is again lowered. Changing pH varies the SWNT microstructure between aggregated and well-exfoliated states, as evidenced by electron microscopy and electrical conductivity measurements.

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Grunlan, JC; Liu, L; Kim, YS; Nano Lett., 20066 (5), 911-915 (featured as news item in Nature Materials).
Published in Nano Letters 2006