Biomimetic Synthesis of Sub-20 nm Covalent Organic Frameworks in Water

Abstract

Covalent organic frameworks (COFs) are commonly synthetized under harsh conditions yielding unprocessable powders. Control in their crystallization process and growth has been limited to studies conducted in hazardous organic solvents. Herein, we report a one-pot synthetic method that yields stable aqueous colloidal solutions of sub-20 nm crystalline imine-based COF particles at room temperature and ambient pressure. Additionally, through the combination of experimental and computational studies, we investigated the mechanisms and forces underlying the formation of such imine-based COF colloids in water. Further, we show that our method can be used to process the colloidal solution into 2D and 3D COF shapes, as well as to generate a COF ink that can be directly printed onto surfaces. These findings should open new vistas in COF chemistry enabling new application areas.

Fabrication of NanoCOF/Polyoxometallate Composites for Photocatalytic NADH Regeneration via Cascade Electron Relay

“…The Tp‐TTA nanoCOFs confined in CTAB/SDS micelles were prepared according to a literature method with slight modification using 1,3,5‐triformylphloroglucinol (Tp) and 4,4′,4″‐(1,3,5‐triazine‐2,4,6‐triyl)trianiline (TTA) as precursors (Scheme 1). [ 19 ] With surfactant concentration varying from 0.1 to 0.01 m , bright yellow solutions with Tyndall effect could be successfully obtained, suggesting the formation of nanoTp‐TTA colloids (Figure S1, Supporting Information). The particle size of nanoTp‐TTA colloids was measured to be, respectively, of 22, 26, and 44 nm with surfactant concentration of 0.1, 0.05, and 0.01 m on the basis of dynamic light scattering (DLS) measurement (Figure S2, Supporting Information).…”

Beyond Frameworks: Structuring Reticular Materials across Nano‐, Meso‐, and Bulk Regimes

“…External control over MOFs and COFs can be exerted by many different means, ranging from casting into template shapes [18a, 79] (Figure 4 i), direct ink writing into 2D [80] and 3D [81] architectures (Figure 4 f), whereby a reticular material is selectively added at a desired position, to dip pen lithography, where particles can be grown in confined volumes [82] . The growth of particles in microfluidic channels is similar, where either the extent of the channel limits the growth [18b] or particles are grown in droplets flowing in the microfluidic channel [83] . The growth of thin films exploit nucleation [16] and epitaxial growth on sacrificial substrates [84] .…”

“…[82] Thegrowth of particles in microfluidic channels is similar, where either the extent of the channel limits the growth [18b] or particles are grown in droplets flowing in the microfluidic channel. [83] Theg rowth of thin films exploit nucleation [16] and epitaxial growth on sacrificial substrates. [84] Additionally,t he growth of MOF films on self-assembled monolayer surfaces allows precise control over their thickness.…”

Towards the room-temperature synthesis of covalent organic frameworks: a mini-review

“…In other study, COF was fabricated using one-pot synthesis method at room temperature in water [59]. The applied method produced sub-20 nm crystalline imine-based COF particles.…”