Study of the contact electrification of polymers using contact and separation current

An instrument was developed that measures the current resulting from surface charge rearrangement during individual contact and separation events involving an insulating sample and a metal probe. It is shown that the values of peak current measured can be used to determine the position of the insulator in a triboelectric series. A modified field mill instrument was used to verify the accuracy of the triboelectric series determined using the contact-separation technique on a set of polymer films. Results agree with published triboelectric series in all cases for which there was agreement among the published series. All measurements were made in a controlled environment on samples which had been stored in a nitrogen atmosphere. The instrument offers the advantages of short measurement time and the ability to make nondestructive measurements on samples of arbitrary thickness including films which are <10 nm thick. Measurements can be made on either conducting or insulating samples