Rheology is essentially the study of how things flow, and in practice it is mainly the study of things that have complex flow behaviour, things that are between solid and liquids. A classic example is toothpaste. In the tube it is more or less a solid, but a firm squeeze turns it into a liquid that flows out onto your toothbrush.
This week I attended the 2018 Annual European Rheology Conference, in Sorrento, Italy. As I found out at the meeting, the applications of rheology are many and diverse. They range from tarmacing roads, to chewing gum, to custard, to drugs, to cosmetics, to making infant formula, to fruit puree, to mayonnaise, to oil extraction, … the list goes on and on. It was a real eye opener to see all these examples where controlling flow was important.
One talk on fruit purees was fascinating. I will never look at purees the same way again, now I have seen detailed images of the partially destroyed fruit-cell walls that give purees their consistency.
I gave a talk on the Friday morning, on our attempts to model processes in drying paints. In the afternoon, I was surprised, but very pleased, to see our model applied to the process by which milk is dried to make baby-milk powder. When we developed the model, for paints, we never dreamt it could have applications to baby milk, but if it could help understand how to make better baby milk that would be great. Once you publish an idea in the scientific literature, as we did two years ago, anyone can take it and run with it, and is great to see fellow scientists do this.