Design of Superhydrophobic Porous Coordination Polymers through the Introduction of External Surface Corrugation by the Use of an Aromatic Hydrocarbon Building Unit

Abstract

We demonstrate a new approach to superhydrophobic porous coordination polymers by incorporating an anisotropic crystal morphology featuring a predominant surface that is highly corrugated and terminated by aromatic hydrocarbon moieties. The resulting low-energy surface provides particularly promising hydrophobic properties without the need for postsynthetic modifications or surface processing that would block the porosity of the framework. Consequently, hydrophobic organic molecules and water vapor are able to penetrate the surface and be densely accommodated within the pores, whereas bulk water is repelled as a result of the exterior surface corrugation derived from the aromatic surface groups. This study provides a new strategy for the design and development of superhydrophobic porous materials.

Self‐Generation of Surface Roughness by Low‐Surface‐Energy Alkyl Chains for Highly Stable Superhydrophobic/Superoleophilic MOFs with Multiple Functionalities

“…In contrast, the synthetic approach focused on the fabrication of a rough surface, which is popular for carbon‐ and metal‐based hydrophobic materials, remains in its infancy. Kitagawa and co‐workers reported an example, in which they synthesized superhydrophobic porous coordination polymers by incorporating an anisotropic crystal morphology with external surface corrugation …”

Shape Controlled Hierarchical Porous Hydrophobic/Oleophilic Metal‐Organic Nanofibrous Gel Composites for Oil Adsorption

“…[21][22][23][24][25][26][27][28] A great effort has been dedicated to fabricating porous materials with hierarchical porosity with a large specific surface area and being water resistant. Stable hydrophobic MOFs were prepared using hydrophobic functional (F and alkyl) organic linkers or through postsynthetic modification of MOF using hydrophobic groups; although, one cannot rely on many typical MOFs for the oil adsorption due to their microchannels.…”

An Ultrahydrophobic Fluorous Metal–Organic Framework Derived Recyclable Composite as a Promising Platform to Tackle Marine Oil Spills

“…Notably, the pristine linker (H 2 L) surface registered a moderately high WCA of about 136° (Figure S21 in the Supporting Information). To examine the influence of such distinct pore‐surface hydrophobicity on the actual surface properties of the bulk crystalline phase, contact angle (CA) measurements were performed on UHMOF‐100 (in pellet form), which reproducibly registered an unprecedentedly high WCA value of about 177° (Figure b and Figures S22 and S23 in the Supporting Information); even higher than the only few recent reports on superhydrophobic MOFs (Table S1 in the Supporting Information), with a small WCA hysteresis (difference between the advancing and receding CAs) of about 2–4°; therefore, marking it as the first ultrahydrophobic MOF. Furthermore, analogous CA measurements with an oil droplet carefully placed on UHMOF‐100 presented a CA of about 0° (Figure S22 in the Supporting Information); this indicated superoleophilicity, which is a property that coexists with ultrahydrophobicity.…”