Recently, Cihui Liu, Yunsong Di and Zhixing Gan’s team from the research center for Future Optoelectronic Functional Materials in Nanjing Normal University has made progress on Bionic Janus Infiltrating Film. Inspired by lotus leaf and the shell of desert beetle, the team has developed a new structured color film made from candle soot and elastic PU/P (NiPAAm-bis-AA) Polymer, which has two different invasion and can respond to environment variable’s change by directional migration led by Marangoni effect on surface of complicated liquid, then giving quantitative feedback on external stimuli depended on change of film’s structured color. This research is expected to be used for visual water quality monitoring. The research finding was published on one of the top international journals “Advanced Functional Materials”.

In recent years, the research has been received more attention because of its good application prospect in oil-water separation, water mist steam sets and droplets transportation. However, the infiltrating film which has visible qualitative and quantitative reaction remains to be researched.

 

Inspired by the functions of lotus leaves and desert beetle backshells, the team prepared PU/P(NiPAAm-bis-AA) anti-opaline scaffolds, and then used the superhydrophobic properties of candle soot to construct Janus infiltrative films that can qualitatively and quantitatively respond to changes in water quality. The lower surface of the bionic Janus infiltrative film is a superhydrophilic surface with periodic anti-opal structure and large pores, which also has a bright structural color. The upper surface of the film has candle soot attached to it, making it superhydrophobic. The super-impregnating properties of the upper and lower surfaces are different, giving it excellent gas-liquid interface stability and the ability to float stably on the water surface. The unique stability and structural color sensing capability in complex liquid environments give the film the ability to respond to changes in environmental variables in response to external stimuli, not only through Marangoni effect-induced directional migration, but also through quantitative feedback of external stimulus signals through structural color changes in the film. These features demonstrate the potential of this Janus infiltrative film as a future open water intelligent water quality monitoring robot.

 

This paper was completed by the cooperation with the Research Center for Future Optoelectronic Functional Materials in NNU and Huai'an Tianda Medical Instrument Company. The graduate student Xinran Zhang from NNU is the first author of the paper. This work was supported by National Natural Science Foundation of China and the funding from Nanjing Normal University.