Non-Linear Mobility of Nanoparticle In Semidilute Polymeric Solutions and Gels

The mobility of particle in fluid is illustrated by Stokes – Einstein equation where the diffusivity of particle is inversely proportional to the fluid viscosity. However, Stoke – Einstein equation cannot be applied to describe the particle mobility in polymer solution and gel because the diffusivity of particle is not inversely proportional to the bulk viscosity. Therefore, the modified Stokes – Einstein equation, in which the microviscosity of polymer solution is used instead of the bulk viscosity, is applied for the mobility of particle in polymer solution and gel. The mobility of latex particle at different size in hydroxypropyl methyl cellulose solution is investigated. Our results show that the Stoke – Einstein equation is still applicable for small particle when the polymer solution is dilute. The mobility of particle in polymer solution and gel is revealed by Dynamic light scattering (DLS) technique. Latex particle from 50 nm to 400 nm is investigated.