Reversible viscosity change of nanotubular colloidal aqueous suspensions responding to an electric field

Imogolite (IG), a perfect rigid inorganic nanotubular polyelectrolyte, shows good water dispersibility, particularly at neutral or lower pH, and affords solutions containing monofilaments and thin bundles. In this letter, we present reversible viscosity change of IG aqueous suspension responding to an electric field. The shear stress of the IG aqueous suspension (with a volume fraction 0.001) reaches 0.14 Pa under an 8.0 V/mm electric field and 19 s−1 shear rate. Application of an electric field would disturb the electric double layer of the IGs that affords their assembling in thick bundles and increases the viscosity of the suspension.