Counterion‐Dictated Self‐Cleaning Behavior of Polycation Coating upon Water Action: Macroscopic Dissection of Hydration of Anions. (3rd July 2020) - Tao, Qi
Abstract: The counterions of polydiallyldimethylammonium (PDADMA) coatings were altered by incubation in aqueous solutions of different electrolytes. Oil de‐wetting on the resulting polycationic surfaces upon water action exhibited a straightforward connection with the Jones–Dole viscosity B‐coefficient ( Bη ) sign of surface counteranions. Upon water action, surface counteranions with negative Bη render PDADMA coatings oil‐adhering, but those with positive Bη furnish PDADMA coatings with excellent self‐cleaning. The oil‐adhering PDADMA surfaces can become self‐cleaning upon water action in response to the Bη of surface counteranions sign‐switching with increasing water temperature. Courtesy of surface counter‐anions with Bη >0, self‐cleaning PDADMA coatings enable not only conversion of conventional meshes into self‐cleaning membranes for oil/water separation, but also regioselective maneuver of oil flow on polycationic surfaces according to the Bη sign of surface counteranions patterned atop. Abstract : Polydiallyldimethylammonium surfaces with surface counterions with positive Jones–Dole viscosity coefficient ( Bη ) exhibit excellent self‐cleaning function upon water action. Those with surface counterions with negative Bη reasonably adhere to oil under water. This ion‐specific effect enables the guidance of oil flow on ionic surfaces upon water action according to the nature of surface (counter)ions.