Defining sulfonation limits of poly(ether-ether-ketone) for energy-efficient dehumidification

Dehumidification is a vital process in the cooling industry and has emerged as a promising tool for alleviating the effects of energy-intensive activities. Advanced engineering materials, which can be employed in dehumidification processes, have attracted considerable attention. However, the majority of commercial adsorbents suffer from low sorption performance in arid climates. In this work, sulfonated poly(ether-ether-ketones) (SPEEKs) were designed as desiccants for dehumidification processes. The in silico and experimental investigations at a molecular level enabled the development of desiccants exhibiting outstanding water uptake capacity of more than 300%, fast sorption uptake, and high transport rate. The sorption capacity of the prepared materials outperformed those of the previously reported desiccants. Membrane performance analyses demonstrated remarkably high water vapor permeability and selectivity; therefore, the desiccants developed herein showed potential for application in water vapor control and dehumidification processes in enclosed or confined spaces. Contrary to common assumptions, the correlation between the sulfonation degree and dehumidification performance showed a plateau after maximum curvature. The results of this study open new directions for tailoring energy-efficient materials for dehumidification processes.