Metal–Organic Framework (MOF) Derived Recyclable, Superhydrophobic Composite of Cotton Fabrics for the Facile Removal of Oil Spills

Abstract

Marine oil spill cleanup is one of the major challenges in recent years due to its detrimental effect on our ecosystem. Hence, the development of new superhydrophobic oil absorbent materials is in high demand. The third-generation porous materials, namely metal−organic frameworks (MOFs), have drawn great attention due to their fascinating properties. In this work, a superhydrophobic MOF with UiO-66 (SH-UiO-66) topology was synthesized strategically with a new fluorinated dicarboxylate linker to absorb oil selectively from water. The fully characterized superhydrophobic MOF showed extreme water repellency with an advancing water contact angle (WCA) of 160°with a contact angle hysteresis (CAH) of 8°. The newly synthesized porous MOF (S BET = 873 m 2 g −1 ) material with high WCA found its promising application in oil/ water separation. The superhydrophobic SH-UiO-66 MOF was further used for the in-situ coating on naturally abundant cotton fiber to make a superhydrophobic MOF@cotton composite material. The MOF-coated cotton fiber composite (SH-UiO-66@CFs) showed water repellency with a WCA of 163°and a low CAH of 4°. The flexible superhydrophobic SH-UiO-66@CFs showed an oil absorption capacity more than 2500 wt % for both heavy and light oils at room temperature. The superoleophilicity of SH-UiO-66@CFs was further exploited to separate light floating oil as well as sedimentary heavy oil from water. SH-UiO-66@CFs material can also separate oil from the oil/water mixture by gravity-directed active filtration. Hence, the newly developed MOF-based composite material has high potential as an oil absorbent material for marine oil spill cleanup.

Hierarchical porous metal–organic framework materials for efficient oil–water separation

“…38,39,49 Superhydrophobic MOFs exhibiting superoleophilicity with OCA ¼ 0 are called superhydrophobic-superoleophilic MOFs. 50,51 The hydrophobicity of MOFs is an important property which can be achieved by four different strategies: (1) uorinated/ alkylated ligand-based MOF synthesis, (2) post-synthetic modi-cation of MOFs, (3) introduction of surface corrugations on MOFs, and (4) synthesis of composite hydrophobic MOFs. 19 The main motive behind these strategies is to minimize the SFE of MOFs and enhance their surface roughness, which ultimately increase their hydrophobicity.…”

“…129 Thus, superhydrophobicity is oen induced in MOF-based cotton fabrics (CFs) either by post-synthetic modication of the MOF@cotton fabric or by preparing uorinated linker-based MOFs followed by their coating onto the cotton fabric. 51,129,130 Recently, the micro/nano-structure of MOFs has also been deposited on the fabric surface for the synthesis of hydrophobic MOF-based fabrics. 131 Moreover, to overcome the poor resistance of MOF@cotton fabrics toward UV radiation, some UV resistant MOF@cotton fabrics have also been reported.…”

“…11b). 51 The uorinated linker (2-triuoroacetamido-1,4-benzenedicarboxylic acid H 2 TF-BDC) based SH-UiO-66 (Zr 6 O 4 (OH) 4 (TF-BDC) 6 ) MOF imparted superhydrophobicity (WCA ¼ 163 ) to the resultant composite fabric. SH-UiO-66@CFs also possessed superoleophilicity.…”

Efficient and Fast Removal of Oils from Water Surfaces via Highly Oleophilic Polyurethane Composites

“…The latter can be further divided into organic and inorganic [ 25 , 26 ]. Synthesis of composite materials employing both synthetic and natural substances is a developing technique and the amount of published research is fast growing [ 27 , 28 , 29 ]. This methodology allows to exploit both the potential of synthetic materials and the cost-effectiveness of natural ones with the aim of improving chemical-physical characteristics [ 30 , 31 , 32 , 33 ].…”

Fluorine‐Free Bio‐Based Multifunctional Superhydrophobic Hyperbranched Self‐Cleaning Coating for Oil‐Water Separation

“…Superhydrophobic surface with a water contact angle (CA) larger than 150 and a water sliding angle (SA) lower than 10 has aroused great concern [1][2][3][4] in recent years owing to its properties of easyto-clean, [5] highly efficient oil/water separation, [6,7] good antifogging, [8] anti-icing, [9] anti-smudge, [10] anti-corrosion, [11] and anti-bacterial. [12] Inspired by natural phenomena such as lotus leaves.…”