Application of DBD plasma treatment on surface modification of fuel cell stack at atmospheric pressure

Abstract

DBD plasma treatment for surface modification has been gradually finding attention in industrial application. Modifying surface property such as hydrophilicity on the stainless steel is growing popularity. For the fuel cell stack, stainless steel sheets are used, which were treated by an atmospheric pressure DBD plasma treatment source. The experimental set up was designed and developed in order to modify the surface properties of thin sheets to get optimum hydrophilic condition and higher surface energy with ageing effect. Five different surfaces were treated for different durations of time. DBD plasma discharge, parallel plate configuration was used with an air gap of four mm. A high voltage of 10kV was supplied for plasma discharge on to the surface of the sheets. Surface characteristics of the substrate were analyzed by using water contact angle and wetting energy analyzer; a goniometer, 3D nano surface profiler, field emission Scanning Electron microscopy (FE-SEM) and XRD. After plasma treatment, the surface's average water contact angle and surface wetting energy were found to be improved. This was investigated for 14 days by using a goniometer and ageing in an air. Different substrates treated in different times, showed different results. The shorter the discharge time, the longer the hydrophobic recovering of the surface. The plasma surface treatments for five second shows the optimum condition for surface treatment of stainless steel at atmospheric pressure DBD plasma.