Turning to Rheology to Understand Flowing Sticky, Gooey, Elastic Liquids 

Rheology is the study of the flow and deformation of matter—not simple matter, like water or air, but complex forms, like the sticky, gooey, elastic liquids that make up plastics. This complex matter is made of fluid molecules with long-chain structures. Modern rheological research is all about understanding and connecting chain structure with chain motions and alignments.

Rheologists uncover these connections by carefully jiggling the molecules found in plastics and resins, in expensive and sophisticated computerized instruments called rheometers. Dr. Jeffrey Giacomin, Canada Research Chair in Rheology, is deepening our understanding of the intricate inner workings of these complex fluids using new and unique rheometers. His research team is also exploring the role rheology plays in polymer processing and in plastics manufacturing.

Since flowing polymer molecules are too small to see, combining experimental rheology with detailed intricate theory about what the molecules might be doing can uncover stunningly beautiful mathematical structure to explain the curious, often counterintuitive, flow behaviours of complex liquids.  For instance, while water flows away from a rotating rod, elastic liquids will climb this same rod, because their molecular chains “remember” their past shapes. Rheologists study the mysterious physics underlying such phenomena.

The prosperity of Canada’s plastics processing industry relies on how deeply we can understand molecular motions in complex fluids, and on how well we can apply this understanding. This research is shedding new light on the intricate inner workings of these complex fluids.