Review on Polymer Materials for Solid Desiccant Cooling System

Abstract

As an alternative form of vapor compression air conditioning devices, solid desiccant cooling (SDC) techniques have increasingly been explored recently. The overall performances of SDC primarily rely on the capability of dehumidification and regeneration of desiccant. A desiccant with a great uptake capability and excellent regeneration potential is preferred in an SDC system. Although traditional desiccants like silica gels and zeolites are able to absorb moisture at moderate levels, hygroscopic polymers show a superior ability in moisture sorption and desorption. Significant research has been conducted to investigate the hygroscopic polymers in SDC for household and industrial applications. Here, first, an introduction to SDC systems is presented, and then hygroscopic polymers from natural and synthetic origins are discussed. Synthetic polymers discussed are metal–organic frameworks (MOFs), covalent organic frameworks (COFs), covalent triazine frameworks (CTFs), amorphous porous organic polymers (POPs), polyelectrolytes, and polymer‐based composites. Their dehumidification behaviors in SDC systems, primarily desiccant‐coated heat exchanger (DCHE) systems, are compared and summarized. Binders employed in SDC systems are also summarized, as a proper binder enhances the overall performance of the desiccant system. It can be anticipated that hygroscopic polymers and binder materials would witness extensive applications in the future.