Inspired by nature, tunable wettability has attracted a lot of attention in both academia and industry. Various methods of polymer surface tailoring have been studied to control the changes in wetting behavior. Polymers with a precisely controlled wetting behavior in a specific environment are blessed with a wealth of opportunities and potential applications exploitable in biomaterial engineering. Controlled wetting behavior can be obtained by combining surface chemistry and morphology. Plasma assisted polymer surface modification technique has played a significant part to control surface chemistry and morphology, thus improving the surface wetting properties of polymers in many applications. This review focuses on plasma polymerization and investigations regarding surface chemistry, surface wettability and coating kinetics, as well as coating stability. We begin with a brief overview of plasma polymerization; this includes growth mechanisms of plasma polymerization and influence of plasma parameters. Next, surface wettability and theoretical background structures and chemistry of superhydrophobic and superhydrophilic surfaces are discussed. In this review, a summary is made of recent work on tunable wettability by tailoring surface chemistry with physical appearance (i.e. substrate texture). The formation of smart polymer coatings, which adjust their surface wettability according to outside environment, including, pH, light, electric field and temperature, is also discussed. Finally, the applications of tunable wettability and pH responsiveness of polymer coatings in real life are addressed. This review should be of interest to plasma surface science communality particularly focused controlled wettability of smart polymer surfaces.

Plasma technology is considered a sustainable and clean technology for the conversion of naturally abundant compounds (i.e., water (H2O) and nitrogen gas (N2)) into energy-abundant compounds (e.g., hydrogen gas (H2), ammonia (NH3)) or chemical feed molecules (e.g., nitric oxide (NO)). Here, we report a plasma catalyst-integrated system for sustainable ammonia production, which can facilitate massive, localized ammonia production. This study demonstrates the single-step cogeneration of H2 and nitric oxides (NO x ) from H2O in the nitrogen discharge used for ammonia production, which proceeded via the catalytic reduction of NO x by H2. The proposed plasma technique yields higher NO and H2 concentrations than conventional plasma methods, which were used to obtain an ammonia concentration of ∼0.84% with a selectivity of ∼95% and a production rate of 120 μmol/s. These promising results provide a breakthrough in the transition toward sustainable and environmentally friendly ammonia production.

In this study, a sustainable air plasma-based nitrogen fixation into reactive nitrogen species in water (e.g. nitrate and nitrite) is presented, which mimics the lightning-based nitrogen fixation that occurs in nature. We report a hybrid plasma system that combines a dielectric barrier discharge (DBD) reactor (as an efficient ozone source) and an arc plasma reactor (as an efficient NO x source). This hybrid plasma system completely converts gaseous NO x and O 3 into NO −x in water with almost zero emissions (NO x and O 3 ). Gaseous outlets, in-liquid species, and electrical parameters were investigated. The energy cost for nitrate production via a single-pass reaction was extremely reduced to 8 MJ mol −1 , which enhanced the applicability of the direct one-step nitrogen fixation into NO −x in water for distributed fertilizer production to decrease the dependence on the Haber-Bosh process toward sustainable agricultural development.

No abstract