Colloids made to order
Industries from food to pharmaceuticals rely on understanding the unique properties of colloidal materials. An EU-funded training network is equipping young researchers with the know-how needed to design new colloids for new purposes - with potential competitive benefits to industry.
© Mara Zemgaliete #126700773, 2018 fotolia.com
Why does ice cream go unpleasantly crunchy after a few days in the freezer? Can we make ice cream that stays creamy? These may seem trivial questions but they show that a basic understanding of colloids can have both scientific and commercial benefits.
A colloid is a mixture of two substances, where one is in the form of microscopic particles suspended in the other. Everyday examples include paint, cosmetics and, of course, ice cream.
Sofia Kantorovich of the University of Vienna, Austria is coordinator of the EU-funded COLLDENSE project, which is applying theoretical, experimental and computational approaches to design new types of colloidal materials. Early applications are likely to be in filtration technology and the food industry.
We want to use colloids that do not just work but work exactly the way we want them to work, she says.
Three types of colloid
One group of researchers is looking at deformable colloids, where the particles are made of liquid droplets. Such systems, Kantorovich says, can resist greater pressure than colloids containing solid particles.
This is very important for various microfluidics and rheological applications because they can sustain much higher pressures, she says.
In so-called hybrid colloids the surface of the particle is modified to give it some kind of functionality. It could be magnetised or given an electric charge so that it can be influenced by external magnetic or electric fields. It can also be implanted with rod-like molecules much like a hedgehogs spines to confer a wide range of physical or chemical properties.
So now we can tune not only the interactions between the droplets themselves but also between the molecules we add to cover the surface, she says.
A third group is looking at mixtures of colloids, opening up many possibilities for new types of exotic materials.
Once you know the behaviour of deformable colloids and of hybrid colloids you can mix them and get something new and interesting out of it, Kantorovich says.
The project received funding from the EUs Marie Skłodowska-Curie actions programme, supporting 15 PhD students in seven institutions in six countries.
The novelty of COLLDENSE lies not only in the development of new experimental techniques, Kantorovich says, but also in the interdisciplinary and intersectoral interactions between the early stage researchers.
Although the research is at a fundamental level, with no particular products in mind, early applications are most likely to be in filtration technology and the food industry. The researchers recently held a joint meeting with the EU-funded DISTRUC project, which is more oriented towards commercial colloid products.
All the students are spending up to six months on secondment to one of the other institutions in the COLLDENSE network. Two of the hosts are major manufacturing companies and the placements give students an insight into industry and the very different language of industrial activity.
Kantorovich detects a greater openness of young researchers towards a career in industry, and at least one third of the COLLDENSE students have decided that is where their future lies.
The main advantage of this European training network is that the EU provides a unique opportunity for mobility, intercultural, interdisciplinary and intersectoral exchange, she says. Its extremely good for students. Its really priceless.