A New Straightforward Protocol for the Fabrication of Smart Coatings
Interest in smart polymer coatings to control wetting properties has gained lots of interest over the last years due to their unique property in promising applications, such as drug delivery, biomaterial engineering, oil/water separation processes, sensors, and biofuel cells. The switchable wettability of stimuli-responsive surfaces is dramatically dependent on stimuli-responsive materials with the hydrophilic and hydrophobic building blocks capable of responses to external stimuli, such as pH, light irradiation, temperature, chiral and counter ion. The responsive copolymers are one of the most frequently-used stimuli-responsive materials to achieve switchable wettability due to the potential advantage of the ability to design chemical structures of responsive building blocks.
Recently the divers wetting responsiveness of the smart surfaces in different transition regions and ways to external stimuli shows growing demands in practical applications. However, most of the responsive surfaces normally show intrinsic responsive wettability due to the fixed functional building block of copolymers. It is difficult to tune the chemical structures of responsive copolymers with controlled wetting building blocks due to the complicated synthetic procedures and the dependence on chemical activation of modified surfaces in most of the wet grafting processes. Plasma copolymerization is an efficient one-step process to fabricate new surfaces with controlled amounts of specific chemical functionality at the outer surface of material.
In a newly published study in Plasma Processes and Polymers, Muzammil Iqbal and co-workers have shown the promising prospects for the plasma copolymerization technique of fabricating smart surfaces with tunable wettability and reversibly switchable pH-responsiveness. The polymer structures can be engineered to tune wetting states at extremes – from superhydrophobic state to superhydrophilic state. A simple plasma polymerization method was used for the preparation of smart copolymer coatings with tunable and reversibly-switchable wetting properties in various pH environments. The wide-range and tunable wetting properties by coordination of composition, functionality, and morphology using straightforward protocol open up a potential door for the fabrication of multifunctional smart coatings. Concluded: the possible wettability range is broad, and the protocol to tune wettability and chemical structure is straightforward, so this methodology opens up a potential door for the fabrication of smart surfaces. 
- Iqbal Muzammil; Yupeng Li; Mingkai Lei; Tunable wettability and pH-responsiveness of plasma copolymers of acrylic acid and octafluorocyclobutane. Plasma Processes and Polymers 2017, 14, 1700053, 10.1002/ppap.201700053.