Characterization of stochastic nanostructures on ethylene tetrafluoroethylene films

Application relevant properties such as optical transmittance and wetting behaviour of ethylene tetrafluoroethylene (ETFE) films may be improved by surface nanostructuring. Cast ETFE film and uniaxially stretched ETFE were nanostructured by a plasma etching process. The mechanical and optical properties as well as surface properties and structure formation changed for stretched ETFE. The mechanical behaviour, especially the elastic modulus, drastically increased from approx. 1000 MPa to up to 6000 MPa after uniaxial stretching. The maximum transmittance results in 95.7 % at 550 nm for stretched ETFE, whereas cast ETFE shows 95.0 % for the same process parameters.