Charge mosaics and electrostatic discharge
What generates the screeching sound heard during peeling the adhesive tape? This is due to the sequences of “sparks” created between delaminating materials. The recent research results presented by the PAS Institute of Organic Chemistry may help control the potentially harmful electrostatic discharges.
For centuries, scientists and engineers tried to understand the electrostatic phenomena. It has long been believed that two contacting/sliding materials should charge oppositely and uniformly. However, in the 1940s it was observed that each of the separated surfaces carries both (+) and (-) charges. This creates the so-called charge mosaics. Their formation was explained, among others, by irreproducibility of experiments and inherent inhomogeneities of materials that come into contact.
What have the scientists found?
This subject also interested the research group led by Prof. Bartosz Grzybowski from the Institute of Organic Chemistry of the Polish Academy of Sciences. Scientists have shown that these charge mosaics are a direct consequence of electrostatic discharges. Sequences of "sparks" are created between delaminating materials. They are responsible for forming (+/-) charge distributions symmetrically on both materials.
The theory explains why charge mosaics were seen on many different materials, including sheets of paper, rubbing balloons, steel balls rolling on Teflon surfaces, or polymers detached from the same or other polymers. It also hints at the origin of screeching sound when you peel off the adhesive tape – it might be a manifestation of the plasma discharges plucking the tape like a guitar string.
Increased control over electrostatic discharges
Presented research should help control the potentially harmful electrostatic discharges. In addition, these results will provide a better understanding of the nature of contact electrification.
The article "Charge mosaics on contact-electrified dielectrics result from polarity-inverting discharges" has been published in the Nature Physics journal.
Source of information: PAS Institute of Organic Chemistry
