Polydopamine as a Versatile Adhesive Layer for Robust Fabrication of Smart Surface with Switchable Wettability for Effective Oil/Water Separation

Abstract

A smart material with switchable surface wettability is highly desired for the practical application in removing oil from oily wastewater. In this work, we developed a robust and simple method to functionalize various substrate materials, such as a melamine sponge and nonwoven textile, with switchable surface oil wettability at varied media with different pHs. The modification method involves oxidative self-polymerization of dopamine on the material surface and subsequently functionalizing with a block copolymer, namely poly­(2-vinylpyridine-b-dimethylsiloxane) (P2VP-b-PDMS). The as-functionalized materials display stable and continuous switchable wettability. The materials switch their wettability by simply responding to aqueous pH, and the switch is achieved at room temperature and involves no organic solvent. The materials show excellent oil/water separation performance for different kinds of oils and exhibit durability in strong alkaline and corrosive solutions. This robust and simple chemical modification strategy reduces the production cost of smart materials with switchable wettability and thus would lead to their mass production and applications toward solving practical industrial problems.

A Review on Oil/Water Mixture Separation Material

“…Among all these stimuli-responsive materials, pH-responsive materials are more convenient to manipulate, and the wettability switch is achieved via protonation and deprotonation according to the pH change of the aqueous medium . In general, pH-responsive compounds were coated on the porous substrates, such as metallic mesh, fiber membrane, , filter paper, and sponge material. − …”

“…Other pH-controllable polymer poly­(2-vinylpyridine- b -dimethylsiloxane)­(P2VP- b -PDMS), smart reversible pH switching styrene-acrylonitrile (SAN) mesh, and poly­(dodeyl methacrylate- co -3-trimethoxysilylpropyl methacrylate- co -2-dimethylaminoethyl methacrylate)­(PDMA- co- PTMSPMA- co -PDMAEMA) deposited on the two-dimensional membranes or three-dimensional foam have also been reported in the literature.…”

The block copolymer shuffle in size exclusion chromatography: the intrinsic problem with using elugrams to determine chain extension success

“…It is particularly worthwhile reviewing such "inhomogeneous" BCPs since their internally cooperative-or multifunctionality is of strong interest for advanced applications, as smart coatings, [6][7][8][9] drug delivery, [10][11][12][13] bioimaging, [14][15][16] optoelectronics [17][18][19][20] and energy harvesting and storage. [21][22][23][24][25] We subdivide these non-classical BCPs into four "behavioural categories" and conclude with a brief survey of methods to improve the accuracy of molecular weight estimates.…”

Superhydrophobic paper with mussel-inspired polydimethylsiloxane–silica nanoparticle coatings for effective oil/water separation

“…[1][2][3] A variety of conventional methods such as gravity or density separation, burning, skimming, centrifugation, coagulation, adsorption, etc., have been invented to separate oil-water. [4][5][6][7][8][9][10][11] However, these methods are not completely satisfactory. For instance, the coagulation and gravity separation techniques are low efficiency and multistage ( Fig.…”