This work investigates the application of novel sorption materials to heat-powered desalination systems. Two ionic liquids 1-ethyl-3-methylimidazolium acetate (Emim-Ac) and 1ethyl-3-methylimidazolium methanesulfonate (Emim-Oms) ionic liquids were impregnated in two silica supports, namely Syloid AL-1FP and Syloid 72FP. Emim-Ac and Emim-Oms composite sorbents have been compared on morphology, water vapor sorption equilibrium and heat of sorption. Fourier-transform infrared spectroscopy shows the ionic liquid partly organises on the silica surface. When used in a sorption desalination process powered by low grade heat at 60°C, these composites have exceptionally high theoretical working capacities ranging from 1 to 1.7 gwater gsorbent-1. Experimental tests on a lab scale desalinator show that Emim-Ac/Syloid 72FP in real operating conditions can produce 25 kgwater kgsorbent-1 day-1. To date, this yield is 2.5 times higher than the best achieved with silica gel.

The equipartition thickness provides a way to design advanced materials with task-specific surface properties and to predict their adsorption performance.

The arrangement of ionic liquids (ILs) within mesoporous ordered silica SBA-15 is revealed from nitrogen physisorption experiments combined with non-local density functional theory analysis of the pore structure and mean-field density functional theory (MFDFT). Using MFDFT on simple lattice models, we outline possible scenarios for IL distributions within the pores and conditions under which they originate. MFDFT predictions for nitrogen adsorption on these models of pore structures modified with ILs are in qualitative agreement with the experimental results. They demonstrate that the distribution of the ILs inside the pores of SBA-15 is sensitive to solid–fluid interactions, leading to different structures as a function of loading. This study also recommends the MFDFT and lattice models as a powerful framework for the interpretation of nitrogen sorption behavior, which complements the existing theoretical and experimental techniques to characterize the structure of supported ILs.