Size-Dependent Same-Material Tribocharging in Insulating Grains
Abstract
Observations of flowing granular matter have suggested that same-material tribocharging depends on particle size, typically rendering large grains positive and small ones negative. Models assuming the transfer of trapped electrons can account for this trend, but have not been validated. Tracking individual grains in an electric field, we show quantitatively that charge is transferred based on size between materially identical grains. However, the surface density of trapped electrons, measured independently by thermoluminescence techniques, is orders of magnitude too small to account for the scale of charge transferred. This reveals that trapped electrons are not a necessary ingredient for same-material tribocharging.
- Publication:
-
Physical Review Letters
- Pub Date:
- May 2014
- DOI:
- 10.1103/PhysRevLett.112.218001
- arXiv:
- arXiv:1309.2578
- Bibcode:
- 2014PhRvL.112u8001W
- Keywords:
-
- 45.70.-n;
- 41.20.Cv;
- 73.25.+i;
- 78.60.Kn;
- Granular systems;
- Electrostatics;
- Poisson and Laplace equations boundary-value problems;
- Surface conductivity and carrier phenomena;
- Thermoluminescence;
- Condensed Matter - Soft Condensed Matter
- E-Print:
- 4.5 pages, 3 figures