Behind the PhD degree: Carlo Belloni

Small-scale changes make big differences. Understanding the smallest parts of life, can gain you a prestigious prize and a PhD. That’s what detail designer Carlo Belloni knows all too well.

The person behind the science, and the science behind the person.

Telescope to microscope

“I must have been one of the only two children who liked Disney’s Fantasia,” Carlo says jokingly. The spark that started the alchemical fire. Once Belloni learned that the unknown did not only lurk in the dark void of space but also in the open world of atoms, he was sold. Studying nano physics was as good of a bet. But it didn’t take long before Carlo’s curiosity slowly made him think more about the bigger picture, leeching into the different disciplines. And before he even knew it, he found a place in the phosphate theme at Wetsus – the perfect place to blend sciences even more.

Now, with a bit of a different challenge: how do you fish out less than microscopic phosphate molecules diluted in a large amount of different compounds and large surface water areas? Non-coincidentally the answer is in the details. Carlo tried to do so by modifying tiny crystals of iron and oxygen particles – or simply put – rust.

Excess of phosphate causes algal blooms and consequently chokes out the surface water ecosystems. Solutions now already involve rust particles sprinkled in to absorb the unwanted nutrient. “There are many kinds of iron oxides, but the ones mostly used have in common that they can hold a lot of phosphates. This sounds good at first until you realize that affinity is a more important property, when targeting ultra-low concentrations.”

Small contributions, big impacts

Essentially, Carlo and his supervisors were to be the inventors of a specific sponge. “Normally, people use iron oxides with a large surface area to absorb as much phosphate as possible. That means that with crystal is lined with bumps and ridges. Instead, we tried to alter the structure differently – by introducing impurities. Like how introducing carbon into iron makes stronger steel, we added different metal atoms to manipulate surface properties in the iron oxides.” In such a way, the rust becomes more of a “magnet” than a sponge. And the best thing is, you can recycle it too, and this is what makes the process economically viable.

The scientist had to zoom in to understand why and how to improve the absorber. “There is a rarely used but valuable technique called Mössbauer spectroscopy that allows you to look at the atomic core of crystals. It can tell exactly how an iron atom (or better, its nucleus) interacts with its neighbor atoms.” A valuable piece of fundamental understanding.

Carlo: “Changes at that level, even minor, can have big consequences.” So, precision tweaking is key. “When you look at gold at a human level, it is shiny and yellow. But if you see it at the nanoscale, it suddenly colors red. For our iron, it’s the same – changing from yellow to black and from magnetic to non-magnetic as you make little changes. Small contributions have big impacts.”

The understanding and move towards application made Belloni a true inventor as he filled a patent. Subsequently, a prize too. The prestigious Marcel Mulder award at the European Water Technology Week.

Another field to conquer

But if you ask Carlo what he’s most proud of, it’s not just the science. “I have not only learned to be a scientist, but the personal development courses have helped me too. I like learning from others, and the courses we had on communication have helped me a lot. I am proud of the connectedness here. And I value everyone’s point of view. The freedom to share and make mistakes here is also something I appreciate. As well as using fundamental knowledge to push applications.”

And because there is always room for scientific improvement, Carlo’s project will continue. And the scientist himself will help guiding the new PhD student. But once again, Belloni is already searching for his next challenge in the meantime, seeking another field to conquer.

(Carlo will defend his thesis on June 12)