Percolation network dynamicity and sheet dynamics governed viscous   behavior of poly-dispersed Graphene nano-sheet suspensions
  The viscosity of Graphene nano-sheet suspensions (GNS)and its behavior with temperature and concentration have been experimentally determined. A physical mechanism for the enhanced viscosity over the base fluids has been proposed for the poly-dispersed GNSs. Experimental data reveals that enhancement of viscosity for GNSs lie in between that of Carbon Nanotube Suspensions (CNTSs) and nano Alumina suspensions (nAS) , indicating the hybrid mechanism of percolation (like CNTs) and Brownian motion assisted sheet dynamics (like Alumina particles). Sheet dynamics and percolation, along with a proposed percolation Network Dynamicity Factor; have been used to determine a dimensionally consistent analytical model to accurately determine and explain the viscosity of poly-dispersed GNSs. It has been hypothesized that the dynamic sheets behave qualitatively analogous to gas molecules. The model also provides insight into the mechanisms of viscous behavior of different dilute nanoparticle suspensions. The model has been found to be in agreement with the GNS experimental data, and even for CNT and nano Alumina suspensions. 
Purbarun Dhar, Mohammad Hasan Dad Ansari, Soujit Sengupta, V. Manoj   Siva, T. Pradeep, Arvind Pattamatta and Sarit K. Das
cond-mat.mtrl-sci cond-mat.soft