MSc Thesis Presentation: Rheology of Aqueous Dispersions of Phytoglycogen Nanoparticles

MSc Thesis Presentation

Candidate: Hurmiz Shamana

Abstract

Phytoglycogen nanoparticles are a promising, new nanomaterial with many applications in the personal care, food and pharmaceutical industries. These applications rely on exceptional properties that emerge from the highly-branched, dendrimeric structure of phytoglycogen, such as high water retention, low viscosity, and extraordinary stability in water. To better understand this unique interaction with water, we have used rheology to measure the mechanical response of aqueous dispersions of phytoglycogen particles as a function of volume fraction of the particles. Specifically, we measured the zero-shear viscosity η0and find only small increases in η0 up to volume fractions ~0.6 indicating that the particles interact weakly in dilute dispersions. At the largest volume fractions (~1), we observed very large increases in η0 (by up to six orders of magnitude) accompanied by significant deformation of the soft particles. These results demonstrate that phytoglycogen nanoparticles dispersed in water provide a very simple experimental realization of a soft sphere colloidal dispersion that can be used to validate theoretical models in detail. 

Examination Committee:

• Dr. Xiao-Rong Qin, Chair 
• Dr. John Dutcher, Advisor
• Dr. Robert Wickham