Alex Routh, Professor of Colloid Science in the Department of Chemical Engineering and Biotechnology at the University of Cambridge was recently awarded the Thomas Graham Lecture.
The Graham Lecture is awarded, biennially, to a scientist working in the UK who is in the prime of their research career, has established an international reputation in colloid science, and has already made distinguished contributions to the field of colloid science.
Can you give us a few examples of the work you are doing in colloid science?
We work in the self-assembly of materials but from particles not molecules.
For example, a droplet of blood will dry to give a particular pattern or dried morphology that is dependent on the condition of the cells and surrounding fluid. The resulting pattern is indicative of those conditions. Another example is making shells around microcapsules by putting particles there and using that for controlled delivery, such as drugs or pesticides. We also examine the arrangement of long polymer molecules at interfaces and investigate the structures they take there and the impact on the friction between those surfaces.
The underlying physics of each of the examples is the same but covering diverse industries and that’s fascinating, similar science applied to very different areas. It can be very fruitful to sit at the interface between different disciplines and try to work to bring them together.
Why is colloid science important?
Colloid science is an underpinning physical chemistry discipline. It’s got applications across pretty much every industrial or practical example of material science that you can think of. They are all going to include colloidal forces or interface science and having that fundamental background enables you to apply that across the different industries.
How has the field of colloids evolved since you’ve been working in it?
You see some of the same problems coming around. Manufacturing of dispersions, such as paint, is a huge industry, and you often see similar problems reoccurring.
One area that is at the forefront of everyone’s minds is energy. Energy storage is problematic and if we can solve that and store large amounts of energy then the UK could be powered entirely from renewable energy sources. However, storing sufficient energy so that the UK can be powered for many months is difficult. It requires heat and mass transfer, fluid mechanics, it’s a surface science problem. It’s a highly complex problem, too big for one specific area but colloid science is front and centre. If we can use examples from different disciplines that we know work and apply it to these new areas that’s fantastic.
Is there still a lot of new science to work on?
Yes, there’s an enormous amount of work to do but I think it’s across disciplines. We’ve been doing a lot of work on the drying of blood droplets and can we apply that to medical uses. I come at it from the colloid literature; you look at the medical literature and it’s the same problem but with completely different language. We are saying the same thing and so it’s working at the boundaries. With energy there are some things that surface and colloid scientists can bring but there are also things that other disciplines such as process engineering can bring to it. It’s about sitting down figuring out what they know and what we know and how we can put that together.
Can you tell us a bit more about the work you are doing with blood?
If you take a droplet of anything and you dry it down, you’ll get a pattern. The classic example is if you dry coffee then you’ll get a ring. Mathematically what you are saying is that it’s an initial value problem. Whatever you put down you’re then not touching it, and it will go through its drying process, go through that physics, and give you a pattern. It’s set by the initial conditions. Now take a droplet of blood… and it’s the same problem; the shape and pattern it’s going to make is determined by its initial conditions.
Then you can you relate that back to whatever medical condition you might have. It’s not as simple as I’m making it sound because there are a million different conditions and only a few things you can look at in the droplet so how can you relate them. We are at very early stages. The question then is what is medically useful which I am collaborating with medics to answer.
How important is industry collaboration to you?
When you work in industry you are working on relevant problems so it’s interesting and exciting to do. I’ve been lucky with a few companies, to work with them for over 20 years. It gives us research ideas and relevant areas to work in it gives continuity to the group, it gives the students interesting areas to be working in that are having a real impact as well. I think it’s vital.
Are there still discoveries to be made?
I think there absolutely are. One area we are working on is called diffusiophoresis and this is movement of particles down gradients. The classic is a salt gradient, and you put a particle in there and it will move down the salt gradient. Trying to understand that is a hot topic in fluid dynamics.
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