Ion modeller has an eye on the prize

Kasimir Gregory has been named as a Finalist in the 7News Young Achiever Awards NSW & ACT – Western Sydney University Academic Achievement Award.

Kasimir is a post-doctoral fellow in the Materials Physics Department, working on the behaviour of salts in solutions.

“There are millions of salts out there – each one has a different behaviour, for example in our bodies. But we are still not really sure how they work,” Kasimir says.

“So I’m trying to quantify that.”

His quest could lead to not only better treatments for all kinds of diseases – most pharmaceuticals are salts – but also have much wider impact, for example in the development of better batteries, of which salts are a crucial component.

Kasimir joined RSPhys after a PhD at Newcastle University, during which he co-authored a paper with Dr Vince Craig from Materials Physics. Vince was so impressed with the work that he nominated Kasimir for the Academic Achievement award.

“Kasimir has made an outstanding contribution towards addressing a very significant problem in Physical Chemistry that is over 100 years old, and has resisted resolution despite the concerted efforts of scientists across the world,” Dr Craig said.

“It puts us within reach of being able to predict the properties of electrolyte solutions.

"The importance of this is hard to overstate, as this gap in our knowledge currently inhibits our understanding of a host of biochemical problems as well as technological problems such as crystallisation, reaction rates, battery electrolytes and CO2 capture technologies.”

Kasimir’s paper rocked the field of chemistry with a new explanation for the Hofmeister series – a classification of various salts made in the late 19th century by Czech chemist Franz Hofmeister.

Conventional thinking linked the Hofmeister series of ion properties with the polarizability of the atoms in the ion, but Kasimir’s modelling found that charge density was a much stronger predictor of ion behaviour. In the words of his award nomination, he “cracked a wicked and important scientific problem that has resisted explanation for over 130 years.”

Modestly, Kasimir attributes some of his success to luck, as the inspiration for his methodology, employing quantum chemistry, was based on work published only in 2016.

To test his model, he accumulated about 100 experimental and computational datasets to test the ion properties for 50 ions – an order of magnitude more than typical studies – and tried many parameters before finding the near-perfect correlation with charge density.

The work also confirms that the conventional wisdom wasn’t completely wrong – for halides, the ion behaviour correlates well with polarizability – and with charge density, as well.

Kasimir acknowledges there is still plenty to do.

“Capturing the perturbations – the deviations from the series – is the next trick,” he says.

“From a simplified perspective, this works really well, but the holy grail in the field is to develop a general predictive theory for these effects that encompasses not only the anions, but cations, solvents and co-solutes – it’s a whole matrix of properties!”

The awards ceremony is on Friday 13th of May – Best of luck Kasimir!

To hear more from Kasimir Gregory, check out his podcast, Anion the Future.

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Mr Kasimir Gregory

Updated:  6 July 2022/ Responsible Officer:  Director, RSPhys/ Page Contact:  Physics Webmaster