Interfacial reinforcement of epoxy nanocomposites via a COF-based silane coupling agent for one- and two-dimensional nanofillers

The efficacy of silane coupling agents in polymer nanocomposites is often restricted by limited reactive sites and insufficient physical engagement with the matrix. In this work, a multi-amino covalent organic framework-derived silane coupling agent (COF-SCA) was synthesized via a one-pot solvothermal method to engineer a stable filler–matrix interface. Unlike conventional small-molecule silanes, this macromolecular agent exhibits a porous, amino-rich framework. COF-SCA was applied to functionalize carbon nanotubes (CNTs) and hexagonal boron nitride (h-BN). Structural analysis indicates the formation of a continuous, rough coating on the nanofillers. Mechanical testing shows enhanced load-bearing capability, with tensile strength increases of 23% (CNTs) and 22% (h-BN) compared to APTES-treated systems. This enhancement is attributed to synergistic effects from abundant amino groups and the rigid porous framework.