Fabrication of filter paper with tunable wettability and its application in oil–water separation

Abstract

Artificial materials with controllable wettability are of global interests in oil-water related applications. In the present report, a surface with superhydrophilicity/superoleophilicity and underwater superoleophobicity was constructed on filter paper via dip-coating ZnO colloids. However, the wettability of the filter paper was converted to be superhydrophobic and superoleophilic after being modified by octyltrimethoxysilane, and water contact angle on the surface is larger than 150°while oil contact angle is smaller than 5°. The filter paper can be employed to selectively adsorb oil floating on water or separate wateroil mixtures via filtration process because of its superhydrophobicity and superoleophilicity. Additionally, the filter paper has also the capacity to hold water, which is expected to be used as a material for manufacturing labwares. Graphical Abstract A filter paper with superhydrophobicity and superoleophilicity was fabricated by dip-coating and subsequent modification. Water contact angle and sliding angle on the filter paper are 157°and 6°, respectively. The filter paper with superhydrophobicity and superoleophilicity could be employed to separate oil-water mixture with high efficiency.

Expedited Transition in the Wettability Response of Metal Meshes Structured by Femtosecond Laser Pulses for Oil-Water Separation

“…Oil-water separation based on superhydrophobic-superoleophilic wetting behavior has been achieved with high separation efficiency by depositing SiO 2 nanoparticles on filter papers and foams (Khan et al, 2017 ). Similarly TiO 2 (Li J. et al, 2016 ; Bano et al, 2018 ) and ZnO (Feng et al, 2015 ) nanoparticles, with extreme wettability behavior, have been employed for oil-water separation. Moreover, techniques like sol-gel, electrodeposition, chemical etching, spray and dip coating of filter paper (Du et al, 2014 ), meshes (Zulfiqar et al, 2018 ), fabric (Sharma et al, 2019 ), and magnetic sponges (Wu et al, 2015 ; Beshkar et al, 2017 ) featuring super-wetting characteristics were employed to separate oil-water mixtures.…”

Functionalized Cellulose Networks for Efficient Oil Removal from Oil–Water Emulsions

“…Such materials present advantages due to the large surface-to-volume ratio, but also due to the synergistic effect of the properties of the individual components such as the mechanical properties of the polymeric support and the functionalities of the developed organic or inorganic layers. In particular, hydrophobic-oleophilic or hydrophilic-oleophobic functionalities are introduced on filter paper (FP), polymer films, foams, and textiles [ 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 ] upon the utilization of macromolecular layers, nano or micro-particles, nanofibers, etc. , making these materials able to separate floating oils on water or water–oil emulsions.…”

“…Numerous efforts have been made in order to turn these materials into water-resistant multifunctional systems, thus expanding their applicability in diverse technological fields [ 17 , 18 , 19 , 20 ]. To this end, studies have been conducted on the surface modification of cellulosic FP, which is commonly used for particle separation/filtration processes [ 9 ], in order to be utilized as an oil–water separator [ 5 , 6 , 7 , 8 , 9 , 10 , 11 ]. However, the majority of the proposed treatments demand complex preparation processes, some of the treatments have a high cost, the materials utilized limit the recyclability of the final system, and in some cases is difficult to scale up the fabrication process [ 6 , 7 ].…”

Design, Development, and Outlook of Superwettability Membranes in Oil/Water Emulsions Separation

“…[ 3,18,81 ] Meanwhile, as a main separation technology, the special wettability membranes are used for the separation of oil/water emulsions because of their high separation efficiency and speed, easiness to scale‐up, recyclability. [ 82,83 ] In this paper, the recent development and selective oil/water emulsion separation of filtration membranes with special wettability were analyzed. The research trends and future prospects of the special wettability membranes were briefly discussed.…”