Covalent
organic frameworks (COFs) have been widely used
in catalysis,
energy storage, environmental protection, and separation. However,
they require a long assembly period (∼3 days) and complex synthesis
conditions; differences in water resistance have restricted their
overall versatility. In this paper, the preparation of COF-DhaTab
was optimized, and this process can be easily performed in air. Thus,
it is feasible for the scale-up of COF-DhaTab in the near future.
The superhydrophobic properties of COF-DhaTab (water contact angle,
>150°) can be created by regulating the wettability of COF-DhaTab
by grafting fluoride. When the grafting degree of fluoride increased
to 4.32%, the water contact angle of COFs increased from 0° to
more than 150°. The grafted COFs are termed COF-DhaTab fluoride
(COF-DTF). The chemically modified COF-DhaTab maintains its original
porosity and crystallinity. The superhydrophobic COF-DTF can be applied
to various substrates, for example, foam, fabric, and glass. These
all exhibit outstanding water repellency, self-healing, and excellent
self-cleaning. Importantly, the coating maintains its original superhydrophobicity
even under extremely acidic/basic conditions (pH = 1–14) and
toward boiling water (100 °C). Furthermore, COF-DTF displays
long-term stability and is easily scaled. It is a promising and practical
candidate for hydrophobic modifications to various substrates.