Controlled Construction of High Mechanical Strength Pure COF Gels by Nonclassical Crystallization for AgCl‐Functionalized Efficient Removal of Iodide Ions

ABSTRACT

Macroscopic pure covalent organic framework (COF) gels are attractive due to their porosity and processability; however, their mechanical properties are limited by an unclear mechanism and difficulties in regulation. Here, alkylamines are introduced to provide noncovalent interactions, guiding COF gel crystallization from conventional pathways to controllable non‐classical pathways. Non‐classical crystallization significantly prolongs the kinetic assembly phase, promoting the gradual formation of a 3D network from 1D nanotube intermediates through non‐covalent entanglements, and completing the gelation transition at high temperatures. By regulating the variable non‐covalent interactions during the non‐classical crystallization process, we successfully synthesized a series of structurally controllable pure COF gels, named NCCOF‐Gel‐C _x , achieving control over morphology, multi‐scale porosity, and mechanical properties. The gel achieves a compressive modulus of up to 59.06 MPa, which is 2–3 orders of magnitude higher than most previously reported gels. Thanks to its interconnected, multi‐level pore structure, NCCOF‐Gel‐C ₄ exhibits outstanding iodine ion adsorption performance when used as a carrier for AgCl. This work not only provides visual insight into the non‐classical formation mechanism of COF gels but also establishes a generally applicable controllable synthesis route, offering a molecular‐level strategy for designing high‐strength, pure COF gel materials and advancing their development toward practical applications.