Physicist describes seeing chemical reactions as they happen

14 November 2014

Research that allows chemical reactions to be observed in real time with an electron microscope was described by pioneering scientist Prof. Pratibha Gai at the IOP’s London centre on 12 November.

Prof. Pratibha Gai

In a lecture entitled “Catch me if you can: atoms in action!” she described how her team have been working on understanding the catalysis of chemical reactions at an atomic level. Catalysis “impacts hugely on our daily lives”, she said, noting that through its importance in such fields as food, medicines, industrial chemicals and biofuels it contributes around £20 bn to the UK economy.

Atoms are too small to be observed with light in the visible spectrum, she said, so electrons had to be used instead, and for this the reactions had to be studied in an electron microscope. Normally, an electron microscope operates using a high vacuum, but her experiments have been conducted inside the microscope under realistic reaction conditions. The equipment also has to be aberration-corrected to enable atoms to be seen in focus, she said.

In studying a reaction of a metal with a substrate, for example, the team wanted to know where it was taking place, how it was happening and why the reaction stopped working. Understanding the underlying physics enabled scientists to produce new materials or improve existing ones, she said.

In a question and answer session, she was asked whether the electron beam itself affected the reaction by interacting with the substance being studied. This was allowed for by doing a calibration experiment, running the reaction with and without the electron beam, she explained.

Prof. Gai, who is a fellow of the IOP, is the JEOL Professor of Electron Microscopy and co-director of the York JEOL Nanocentre at the University of York. She was awarded the L’Oréal-UNESCO For Women in Science 2013 Laureate for Europe and chairs the L’Oréal-UNESCO UK Fellowships awards committee.

Following her talk, she said that more young women were being encouraged to come into science, partly as a result of the awards, and she would like to see more of them giving lectures at the IOP.

The IOP’s chief executive, Prof. Paul Hardaker, said her lecture was the last in a series that celebrated some leading science and emerging technologies as part of the IOP’s Opportunity Physics campaign. The series had also been about celebrating the contribution of leading physicists in these disciplines who were women.