Characterization of chargeability of biological particulates by triboelectrification

Triboelectric chargeability of pecan pollen and lycopodium spores, using commercial Teflon and nylon chargers, has been investigated as reported in this paper. The charge-to-mass ratio of lycopodium, measured at different powder feed rates, i.e., 50-500 mg/s, indicated that both Teflon and nylon chargers increased particle charge by approximately elevenfold over background with Teflon charging particles positively to +11.06 mC/kg and nylon negatively to -11.52 mC/kg. Pecan pollen charge increased by approximately 11 times for Teflon charging positively to +7.59 mC/kg, and five times for nylon charging negatively to a value of -3.72 mC/kg. Pollen charging was not affected by carrier-air humidity in the range of 18.1%-47.6% relative humidity (RH) and at a temperature of 22.5/spl deg/C. Pollen chargeability by Teflon measured as a function of the duration of air flow over the charger surface indicated that triboelectric charging was not degraded, even by 3.5 h continuous flow of humid air (44.2% RH at 19.2/spl deg/C). Results indicate that tribocharging is a feasible method for imparting charge to pollen in electrostatic pollination technology currently under development.