Journal of Rheology, Vol.54, No.1, 117-131, 2010
Analysis of the linear viscoelasticity of polyelectrolytes by magnetic microrheometry-Pulsed creep experiments and the one particle response
We report experimental measurements on polyacrylamide (flexible polyelectrolytes), actin (semi-flexible polyelectrolytes), and self-assembled peptide (gelled semi-flexible polyelectrolytes) solutions. The measurements were obtained using a two-pole piece magnetic microrheometer based on an upright Olympus microscope with an oil immersion (x100) lens. Pulsed creep experiments produced high quality data over a wide time range with good agreement between passive particle tracking and magnetic microrheology results. This implies a commonality of the one probe particle response to its viscoelastic environment in both passive and active microrheology experiments.