We selected COF-300 as the model system to investigate and evaluate the efficacy of our waterbased nanoreactor technology. In a typical synthetic process, we prepared a catanionic micellar media by mixing the cationic hexadecyltrimethylammonium bromide (CTAB) and anionic sodium dodecyl sulfate (SDS) surfactants in a 96:4 CTAB/SDS ratio (Figure ). The ratio was optimized to promote the formation of micellar assemblies with lower curvature, thereby facilitating the colloidal stabilization of the 3D COF precursors in water, namely of tetrakis(4aminophenyl)methane (TAM) and 1,4-benzenedicarboxaldehyde (BDA), Figure . The micellar media concentration was optimized to efficiently dissolve the otherwise insoluble COF-300 precursors in water and at room temperature. This approach yielded two colorless homogeneous solutions where the TAM and BDA were encapsulated within the hydrophobic core of the CTAB/SDS mixed micelles. Dynamic light scattering (DLS) measurements showed that both TAM and BDA loaded micellar aggregates had hydrodynamic diameter mean values of 2.4 nm and 3.3 nm, respectively (Figure ). Notably, these values were similar to those observed for the pure CTAB/SDS micelles. This observation confirms that the mixed micelles remained largely unaffected by the process of solubilizing the 3D COF precursors. Upon the mixing of both micellar solutions and with the addition of acetic acid as a catalyst (0.3 м), a color change was observed in the reaction mixture, which turned to yellow (see the Supporting Information (SI) for further details of the synthesis). This color change indicated the formation of imine bonds between the two COF precursors. Moreover, the formation of larger colloidal species was confirmed by the observation of a distinct Willis-Tyndall scattering behavior, when the reaction media was irradiated using a 630 nm red laser (Figure , left). Surprisingly, the resulting yellowish solution demonstrated remarkable colloidal stability, persisting without any observed precipitates even after a span of 10 days after its synthesis (Figure ).