Electric potential decay on polyethylene: Role of atmospheric water on electric charge build-up and dissipation

Electrostatic potential decay on corona-charged low-density polyethylene (LDPE) was recorded as a function of position and time, using a macroscopic scanning electrode and also Kelvin force microscopy. Potential decays independently in adjacent sample areas until reaching equilibrium at negative values (4.6 +/- 0.7 V), irrespective of the initial potential signal. Other observations already described in literature were confirmed: negative potential decays slower than positive potential and the relative humidity has a large effect on the dissipation rates. These results are discussed considering ion exchange associated to adsorption and desorption of water clusters at the solid-gas interface. (C) 2011 Elsevier B.V. All rights reserved.