Rheology of nanoparticle suspensions in hydroxypropylcellulose (HPC) solutions

The effect of nanoparticle shape and concentration on the rheology of liquid crystalline solutions of hydroxypropyl cellulose (HPC) has been studied experimentally. Multiwalled carbon nanotubes (MWCNT) were dispersed by ultrasonification in HPC/M-cresol solutions, while commercial aqueous colloidal silica suspensions were mixed with HPC in water. The liquid crystalline phase behavior was identified by rheological measurements of the viscosity and optical microscopy of the solutions. Scaling arguments for the steady-state viscosity and the dynamic viscoelastic moduli will be presented. The effects of dispersion methods are also addressed.