An Ice‐Dissolving‐Crosslinking Method for Efficient and Large‐Scale Preparation of Polyelectrolyte Monoliths with Ultra‐Stability in Aqueous Environments

Abstract Ice‐templating is a versatile method for constructing macro‐porous hydrophilic polymer materials. However, the ice‐templating method is generally limited by high energy cost and low efficiency for large‐scale fabrication. Further, due to its hydrophilic nature, the constructed materials are vulnerable to water swelling and have poor structural stability. Here, an Ice‐Dissolving‐Crosslinking (IDCr) method is developed for efficient and large‐scale preparation of polyelectrolyte monoliths with ultra‐stability in aqueous environment. Specifically, Ice‐Dissolving in water‐miscible organic solvent is responsible for pore creation, while subsequent Crosslinking ensures pore structures stabilization. The macro‐porous architecture of materials, taking sodium carboxymethyl cellulose (CMC) as a polyelectrolyte example and trimesoyl chloride (TMC) as the crosslinker, CMC‐TMC IDCr is made much stabler as compared with the case of conventional Lyophilization‐Crosslinking technique (CMC‐TMC LC ). The IDCr method is applicable to various hydrophilic polyelectrolytes and hybrids for long‐time use in water and brines, as exemplified by CMC‐TMC‐carbon nanotubes monolith, which exhibits high performance in solar thermal desalination process. This novel approach opens up new opportunities for the construction of porous monoliths with efficient preparation and excellent water stability.