Hydroxyl radicals may be used as disinfection agent in the advanced oxidation processes or tertiary treatment of waste and occasionally drinking water. We very recently oxidised a gram negative bacterial cell wall proxy at the liquid-solid interface with aqueous hydroxyl radical, the experiment (RB1820244) was a complete success and is being written up as a letter for publication. Our previous exploratory work, demonstrated the polysaccharides are an effective layer to resist oxidative attack, but did not characterise the structure of the film during oxidation – we propose to study the oxidised film with multiple contrasts and angles to determine if the oxidised film ‘holes’ or ‘thins’ and can be completely removed or not. The proposal is a collaboration between two teams with expertise in bacterial cell wall proxies and oxidation kinetics. It supports a joint ISIS/DLS funded student.