Phase Behavior and Rheology of Attractive Rod Like Particles
-  Huang, F., Rotstein, R., Fraden, S., Kasza, K., & Flynn, N. Soft Matter. 5, 2766-2771 (2009).
- Keywords: Isotropic, Nematic, Viscoelastic, Sol-Gel Transition, Colloidal Rods, Phase Transition
Huang, Rotstein, Fraden, Kasza, and Flynn study an aqueous solution of rod-shaped particles to look for transitions between isotropic, nematic, liquid, and gel states. For this experiment, Huang et al. create particles consisting of bacteriofage fd coated with PNIPAM. The researchers use both rheological measurements and light scattering measurements to characterize the solutions which do not agree with previous theory.
The bacteriofage fd (a polymer with negative surface charge) is itself approximately rod-shaped. The researchers coat the bacteriofage fd with the polymer poly(N-isopropylacrylamide)(PNIPAN) to give the particle-particle interactions a temperature dependence. The temperature dependence of solubility of PNIPAM and bacteriofage fd are different.
-salt and temperature varied -20 degrees to 200 degrees C -debye length -sol-gel transition -comparison to predictions
Soft Matter Details
Dynamic Light Scattering
Open Questions/Ongoing Research: