Fabrication of sustainable hydrophobic and oleophilic pseudo-ordered macroporous Fe–Cu films with tunable composition and pore size via electrodeposition through colloidal templates

Evangelia Dislaki,Juho Pokki,Salvador Pané,Jordi Sort,Eva Pellicer

doi:10.1016/j.apmt.2018.03.007

Abstract

In this work, sustainable hydrophobic and oleophilic macroporous Fe–Cu films are fabricated using a straightforward, inexpensive and environmentally friendly two-step procedure which combines electrodeposition with the colloidal lithography technique. Elemental, morphological and structural characterization of the resulting pseudo-ordered meshes is carried out and wettability is assessed using contact angle measurements with respect to two distinct film compositions (3at.% Fe vs 75–85at.% Fe) and three different pore diameters (namely, 200nm, 350nm and 500nm). Water contact angles are measured to be in the range of approximately 109.0–155.1° (without any post-surface functionalization) and a low contact angle hysteresis is observed in the superhydrophobic samples. The increase in the hydrophobic character of the films correlates well with an increase in surface roughness, whereas differences in composition play a minor role. For the superhydrophobic Fe-rich macroporous film, water–oil separation capability and recyclability are also demonstrated while the pore size is favorable for effective water–oil mixture and emulsion separation. The results shown here demonstrate that sustainable and affordable materials processed in a simple and cheap manner can be an asset for the removal of water-immiscible organic compounds from aqueous environments.

Highlights

Wetting phenomena observed in nature such as the water-repellent, non-adhesive surface of lotus leaves have attracted much attention due to the wide array of potential biomimetic technological applications in self-cleaning and anti-corrosion surfaces [1]
The results shown here demonstrate that sustainable and affordable materials processed in a simple and cheap pathway can be an asset for the removal of water-immiscible organic compounds from aqueous environments
Porous Fe–Cu coatings of Fe-rich (75-85 at.% Fe) and Cu-rich (3 at.% Fe) compositions and tunable pore size were prepared through a simple technique of combining electrodeposition and colloidal lithography

Summary

Introduction

Wetting phenomena observed in nature such as the water-repellent, non-adhesive surface of lotus leaves have attracted much attention due to the wide array of potential biomimetic technological applications in self-cleaning and anti-corrosion surfaces [1]. The development of inexpensive, sustainable and reusable materials that can separate the water and oil phases in an efficient way and even retrieve precious oil resources has garnered significant research attention in recent years These materials function either through filtration (e.g. metallic meshes, textiles and membranes) or absorption (e.g. particles, sponges and aerogels) [3,4,5]. Functionalization of metallic meshes and textiles generally involves dip- or spray coating with polymers and optionally incorporating nanoparticles, hydrothermal reaction, in situ growth of micro- and nanocrystals or thermal oxidation to increase roughness followed by further modification by chemical treatment [3,4,5] These materials are generally used in the separation of layered oil/water mixtures. The inherent difficulty of in-situ removal of oil from water in the filtration scheme, in addition to the issue of potential fouling or blockage with decreasing pore size which leads to a decline of permeation, has signalled towards absorption as a more promising strategy

Methods

Results

Conclusion