Microencapsulated Vapor Taggants for Predetonation Detection of Explosives

摘要

SRI International prepared 28 samples of encapsulated fluorocarbon taggants for evaluation as explosives detectors. Several modifications of the REGEMA method of encapsulation were investigated. Five hydrophobic materials and several methods of incorporating these materials into the capsules were investigated as ways to minimize the effects of water vapor on the permeation rates. The characteristics of these capsules are summarized, and the permeation rates given are SRI's best estimate of equilibrium permeation rates. One of the major findings of this study is that a very long time period is needed for the permeation rate of the capsules to reach equilibrium. Also, changes in temperature and/or relative humidity increased permeation rates, which then returned to the previous rate in three to four weeks.