Superhydrophilic anti-fog polyester film by oxygen plasma treatment

Superhydorphilic polyester film has been obtained by oxygen plasma treatment to maintain optical clarity under high relative humidity. The original and treated films are simultaneously exposed to the vapor from hot water. The latter keeps its optical clarity because the condensed water formed a thin film on it instead of droplets for the former. Compared with the widely used coating method, plasma treatment to obtain anti-fog polymer film has the potential for mass production, lower cost, better compatibility with thermal extrusion process, and safer for food packaging. It can also be employed to improve the visualization of microfluidic reactors under high relative humidity.