How is the nanoscale structure of Amorphous Solid Water (ASW) impacted by the presence of adsorbates?

This experiment will determine how the structure and porosity of Amorphous Solid Water (ASW) changes when the “ice” is “contaminated” by adsorbate molecules. ASW is a porous material formed by vapour-depositing water onto a cold plate, an analogue of the ice found in star- and planet-forming regions of our galaxy. Our previous work has shown that the ASW has very small-scale porosity, but NIMROD data of the pure water ice alone are unable to elucidate pore accessibility; open pores can trap volatile molecules well beyond their desorption temperature and therefore act as a reservoir for coolant molecules in star-forming regions. This experiment tests ASW porosity evolution as a function of ice-adsorbate morphology and measures ASW structural changes as the ice is grown and heated, exploiting the broad Q-range of NIMROD to probe the molecular level and meso-scale of the ice concurrently.